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HomeMy WebLinkAboutWWP273062 (11)o ° � ,� �. �° �° �o o , � �� o �. � �.. o .. � � .. � ..oq � � � ° ° ° .08� - o ° �` �.. .� � �° � � � � ° �" .. o a� ° . �� o ��o a o o�, ° ° - o � o . - o � �o 0 0� a � 0 oa o, o e o Q eo o Q `o e o� � c o O o O a0 6 `, ., 8 p, a `o � �.,- � Q c o 0 0� °� ' o� ° � � o�° ° �� � �o � o � � � �o a ° o ` n 8. ^� o o � � � , � � �� p , � �o� 0 0 � , o �� � � o ; � �a �o o ° o a ° March 2001 �� � Q � °° ° � � � � � ' _` �, oo° ° o e �a °000 o` ° oRevised January 2002° o°'� °, : e� o � �o 0 0 � , ,� o 0 0 � , ,o o � o °���o 00 � .�° o o � � � � � o �0 a � ° o " � °� ° o 00 0 �, o ' � p �_ o oe, � � . � � d �0 � e ^ e. �' � � � � �° � ° � � � o � � �. � � , � o 0 0� ^° � � o � . � � � � � Q ° ° �� � 0 0 0 0 � p �' p � ��o 0 0°9 0 � w� ,� ' o � � e �° � ��� � ° . o KENNY�DALE LAK�EFRONT° ° a ` � ° e � o °�; � � � o �� �� o � p o o ` o o ° o`�o ° , o � a� �e ° o° 0 8'� , � o o �� a.. o �� °� � e� �� �SAN�ITARY SE�WER � � ��� oa � � p � a � . ao 0 o a, � �a o 0 0 � oa o o , � 40 � � �� ��� ° o �. ° � °� ��o °O � �°�� � �o � °o = �°' a. e . � � o . � � � _ � �� �� �o�BIOLOGI'CAL EUALUATIONo � ° � ° � � � ��� � �� � �� �a ���� a� � am� ���� o o� o� 0 6, � o o ��o 00 �o a o0 0 0_ e �o e o � � �a, � � o 0 0 ° � , ° °o ° o a ° o a o . e �-� ° `oo "" ` � n o�° � o,o a a� -o� a • o a � r� o '°�� � ` � � � � � £' o � ° For Coordination witfi� � -�� °° � b�.� ° � � ° � � � �� e $_ . o a� a a � ,o a °. o` ,r o, 04� � oa° < o�,� � � °� o iVational lVlarine �Fis`heries Service` and ° e� 0. �. . 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' V _ p° o, o o.� . o 0 0o a. o o�° A ti o � Prepared by: ° R a o °o° a a o .�. °� �° o e�� oQo o°. �° ° oE ° J°� � 1 � -� o ° �`� ° Qdolfson Associates; Inc. °, A o0 o i F s o� N �e � . � � ° .- a � �- 5309°�Shilshole��Avenue.NW,oSuite �200 ° ��� � ° � ��� � o � � �� �° c o, � � � � � � � � � � � � � � � S'e�attle, VUashington 98�1'07� � � o a ° � � ° v "� � ' Q , a e o ., o � O 9 � e e� o 0 00 � o � o 0 0 � _ ° �° eo � ° � � � � � � o ��a��aln C=ooperation�with: ��� �°� o �� ° ° `�°o`� ° ° � e o ��0 8 oa , �o � ��o.�,d� ° e�� °� °o . � ��� �� ° � �o�° � oo� o. o. �, � . ° p � - ° � �ity��of�Renton UtilityoSystems � o � � ' � `� ° o _� � o �� � �� - ���°o ° o � � o � �,1055 Grady�Vi�lay� South, 5th�Floo� ° o � �o �°� �� �`��o �° �°� � : . � � : � � �° � � � ° � ° °� �RentQn, ��Washington�98055 , �° o � ��o ° � � ° � �� a = � � � � � � � ���� � � ��` � �e� , �_� � � , _ � �o�° � �� m o�o � � o �, , �� . �o 0 0� o ,, �� �� � �� o� o�And` o� ° a o o°o 0 0 0 0 � � o a� � 8° ��° o � � ,e � r o ` o a� e.�� � � � p�o Qo , � � � g ° .� o , ��o� � oo � �� � ° � ° o o � � e °� o � � o �� Tetra �Tech%KCM� o o �� a ° � � �� � � � � o 0 0 ° ° ° � ° � ° °1917 �First;Averiue ° ° - � � �� ° � � � °�° ° � � � �° o° o� � o � ° a � � �Seatt�le, VUas�lii�ngton° 981010 ° � � � �. �` � �� °° �� o � � � �� a� � ��`. � � ,. `. ° ..O � . . � � o,. ° � ` fl � � ��o �� �� p o ` � o ° � , , ' o .. ` � A �� o � ` � � � � . � � o � o �,o p �_ , � �, � � vo o � � � �o ,. o „ o ° - ° �p ��o o � � 01 �e ' �, '.o oB.� o° o .o � J p o,ao , o � ,��a° ° o� e � a o d' o� y o � �� �o 0 � ., o o� 9'/� ° � . D 0 40 0 - � � o ° ' o; ` o � o a c g � 0 0 , `p � ° o� o �^ a � ° o � ° . � . " � � � � o . � o ° � ` � ��> o'� � � �`o . � o � � ,� ° � ` �� �� � � � .. � � �, ° �� � e , �. o �oo o°.. . _ � ° o " p ` . ' � , o b � a. � a � � _ ro., o � o n o .�° ��8� e � � �_�, a ' o e �.,2 � �o . �o p� � �.o� ��0� ^ � �, ° , ��1° o � � . - 'Q ,,. ` o _ °� ° °o _ o o ' o _ „ -, � � � � o .. � o LETTER OF TRANSMITTAL DATE: January 24, 2002 TO: Jonathan Smith U.S. Army Corps of Engineers Seattie District Regulatory Branch ����'V�,Q 4735 East Marginal Way Seattle, Washington 98124-2255 �A[� 2$ 2Q02 CC: Jeff Lykken, Tetra Tech/KCM ,ITY OF RENTON .,TI� ��i.t �v.`TCrAs FROM: Dave Wortman PROJECT NAME/NUMBER: COE# 2000-2-01573 �,, .� � ♦ O O l F i O M .�rwirorirnerita� So�"ions URGENT FOR REVIEW AND COMMENT PLEASE REPLY FOR YOUR INFORMATION PLEASE FIND ENCLOSED: A Cover Letter B 4 Copies of the Revised Biological Evaluation for COE 2000-2-01573 NOTES/COMMENTS: Ptease, see cover letter. ADOLFSON ASSOCIATES, INC. 5309 Shilshole Avenue NW, Suite 200 Seattle, WA 98107 Tel 206 789 9658 Fax 206 789 9684 \� / / % � A D O L F 5 O N �nvironmen.ra.� ,So�uL"ions January 24, 2002 Jonathan Smith, Project Manager U.S. Army Corps of Engineers Regulatory Branch CENPS-OP-RG Federal Center South 4735 E. Marginal Way South Seattle, Washington 98134-2385 Subject: Revisions for the Biological Evaluation for Kennydale Sanitary Sewer Repairs COE 2000-2-01573 Dear Mr. Smith: Please find enclosed four copies of the Revised Biological Evaluation (BE) prepared for the Kennydale Lakefront Sanitary Sewer Pipeline project. We have addressed the comments as requested in your December 28, 20021etter. Specifically we have added an evaluation of EFH and included a detailed description of the maintenance requirements and methods for the sewer. Please do not hesitate tc contact me or Benn Burke, our Senior Fisheries Biologist, with any questions about the BE or the project in general. We both can be reached at (206) 789-9658. Additional Contact information, including contact information for the City of Renton and Tetratech/KCM is included on Page 2 of the enclosed BE. We would also be pleased to meet with you at your convenience to discuss the project and any additional permit issues that remain. Sincerely, fson sso iates, Inc. � � Dave Wortman ' ` Plannin� Program Manager ADOLFSON ASSOCIATES, INC. 5309 Shilshole Avenue NW, Suite 200 Seatt�e, WA 98107 7� 206 789 9658 �aX 206 789 9684 a�oijsor.�iada�on{om Kenrrydale Lakefront Sanitary Sewer Biologica! Evaluation TABLE OF CONTENTS 1.0 INTRODUCTION ............................................................................................................................................. 1 I.1 PROJECT NEED ................................................................................................................................................ 1 1.2 PURPOSE OF THE PROPOSED ACTION ............................................................................................................... 1 1.3 PROIECT INFORMAT[ON ................................................................................................................................... 2 2.0 STUDY PURPOSE ............................................................................................................................................ 2 3.0 STUDY OBJECTIVES ..................................................................................................................................... 3 4.0 4.1 4. 4.3 4. 4. 4. 4. 5.0 5. �. 5. 5. 6.0 DESCRIPTION OF THE ACTIOIY AREA AND THE PROPOSED ACTION .......................................... 3 ACTIONAREA ................................................................................................................................................. 3 2 BASELINE CONDITIONS .......................................................................................:.......:.::::.............................. 4 PROJECTDESCRIPTION ................................................................................................... •............................... 8 4 DESCRIPTION OF CONSTRUCTION ACTIVITIES ................................................................................................. 8 SMONITORING PLAN ....................................................................................................................................... 1 O 6 T[MING/CHRONOLOGY OF SPECIFIC CONSTRUCTION ACTIONS ..................................................................... 1 O 7 CURRENT AND FUTURE MAINTENANCE ACTIVITIES ...................................................................................... 10 STATUS OF THE SPECIES AND CRITICAL HABITAT ........................................................................ 11 1 PUGET SOUND ESU CHINOOK SALMON ........................................................................................................ 1 1 2 BALD EAGLE ................................................................................................................................................. 12 3 COASTAL BULL TROUT ................................................................................................................................. 13 4 PUGET SOUND/STRAIGHT OF GEORG[A ESU COHO SALMON ........................................................................ 15 EFFECTSOF THE ACTION ........................................................................................................................ 16 6.1 DIRECT EFFECTS ........................................................................................................................................... 16 6.2 INDIRECT EFFECTS ........................................................................................................................................ 21 ' 6..i CUMULATIVE EFFECTS .................................................................................................................................. 22 6.4 BENEFICIAL EFFECTS .................................................................................................................................... 2.i 6.5 CONSERVATION MEASURES .......................................................................................................................... 2.i 7.0 SUMMARY ..................................................................................................................................................... 24 7.1 Cf-I[NOOK SALMON ........................................................................................................................................ 24 72 BULL TROUT ................................................................................................................................................. 25 ' 7.� BALD EAGLE ................................................................................................................................................. 25 7.4 COHO SALMON .............................................................................................................................................. 26 1 , �� 8.0 DETERMINATIONS OF EFFECT .............................................................................................................. 26 8.1 THREATENED SPECIES ................................................................................................................................... 26 8ZPUGET SOIND/COASTAL BULL TROUT .......................................................................................................... 27 8.� CRITICAL HAB[TAT ....................................................................................................................................... 28 8.4 CANDIDATE SPECIES ..................................................................................................................................... 28 9.0 ESSENTIAL FISH HABITAT ASSESSMENT ............................................................................................ 29 9.1 POTENTIAL ADVERSE EFFECTS OF PROPOSED ACTfON .................................................................................. 3O 9.2 EFH CONSERVAT[ON MEASURES .................................................................................................................. �O 9.3 EFH CoNC1.USloN .................................................................'...................................................................... 30 10.0 REFERENCES AND BIBLIOGRAPHY ................................................................................................. 31 APPENDIX A: TABLES / FIGURES APPENDI�C B: AGENCY CORRESPONDENCE APPENDIX C: FISH AND WILDLIFE SURVEY RESULTS 20109 March 2001 Revised January 2002 Page i ' ' ' 1.0 INTRODUCTION ' , ' , Kennydale Lakefront Sanitary Sewer Biological Evaluation The City of Renton Utility Systems currently operates, owns, and maintains the 4,700-foot long Kennydale Lakefront Sanitary Sewer (Lakeline). The Kennydale Lakeline is an 8-inch diameter cast iron sewer pipeline that serves 52 lakefront homes in the City's Kennydale neighborhood along Lake Washington (Figure 1; Photos 1 and 2). The existing sewer pipeline was constructed in 1972 below the ordinary high water mark of Lake Washington and generally extends between Gene Coulon Park and North 40�h Street (Figure 2). Much of the Lakeline was constructed within 40 feet of the shoreline in less than 6 feet of water. The Lakeline passes beneath many of the residential docks of the lakefront residences. 1.1 Project Need Since its construction in 1972, the existing Kennydale Lakefront Sanitary Sewer Lakeline has ' been difficult to maintain due to sags in the pipeline and limited access for maintenance. The Lakeline was constructed generally following the profile of the lake bottom along its entire alignment. Initial plans called for the entire pipeline to be buried below the lake bottom, but as a ' result of difficult construction, the Lakeline was installed in many places at, ar above, the lake bottom (Tetra Tech/KCM, 2000). A flushing station at Station 0+00 (Figure 2) near Gene Coulon Park drives wastewater through the Lakeline to a lift station at Station 47+35 (Figure 2) ' near 40t�' Street. The Lift Station pumps flows to a King County Metro sewer where it is eventually conveyed to Metro's Renton Wastewater Treatment Plant. ' 1 ' ' ' ' ' ' 1 Low flushing velocities in the system result in sediment accumulating in the pipeline sags. Flushing velocities of about three feet per second (fps) are required to resuspend solids that have settled in the pipe. However, because of the elevation of many of the waterfront homes served by the Lakeline, the system must be operated at a flow velocity significantly below 2 fps to prevent sewage backups into the homes. The City is only able to conduct partial cleaning of the Lakeline using water jets at clean-outs located at some of the side sewers from the lakefront properties (Figure 2). While this method does allow cleaning of about half of the pipeline, this has not been successful at eliminating the collection of waste material at the sag locations. The accumulation of waste material in the Lakeline has blocked the Lakeline and resulted in overflows of sewage into Lake Washington in the past (Tetra Tech/KCM, 2000). The sags in the pipeline occur at the following locations: Station 3+60; Station 21+50, Station 28+30, and Station 40+20 (Tetra Tech/KCM, 2000)(Figure 2). A condition assessment of the Lakeline was performed in 1999 as part of the project development process. During the condition assessment, an approximately 2-inch hole was found in the eYisting lakeline at approximately Station 44+00 (Tetra Tech/KCM, 2000). 1.2 Purpose of the Proposed Action The proposed action includes the installation of four precast concrete manholes at the sag locations to allow access to the eYisting 8-inch Lakeline for maintenance cleaning and repair of 20109 March 200 / Revised January 2002 page 1 ' , ' , 1 Kennydale Lakefront Sanitary Sewer Biologica[ Evaluation the hole found in the existing pipe. Precast manholes would be installed at the following locations: Station 9+70; Station 21+70, Station 28+30; Station 40+00 (Figure 2). The methods of construction and discussions of maintenance activities are discussed in detail in Section 4.7 of this report. In addition to this work, the City proposes to repair the approximately 2-inch hole near station 44+00 concurrently with manhole installation. 1.3 Project Information Project Name: Kennydale Lakefront Sanitary Sewer Project ' Location: NW '/4 Section 5, Township 23, North Range 5 East WM. SW'/4 Section 31, Township 24 North, Range 5 East WM. 122°, 12' 29.5" West 47°, 31' 24.3" North , 1 Project Proponent City of Renton Utility Systems 1055 Grady Way South, Sth Floor Renton, Washington 98055 ' 1 1 , 1 Contact: David Christensen Phone: (425) 430-7212 Preparer: Adolfson Associates, Inc. 5309 Shilshole Avenue NW, Suite 200 Seattle, Washington 98107 Contact: Dave Wortman Phone: (206) 789-9658 2.0 STUDY PURPOSE In cooperation with the City of Renton, the project proponent, and Tetra Tech/KCM, the project ' engineers, Adolfson Associates, Inc. (Adolfson) has prepared this Biological Evaluation (BE) to facilitate review of the proposed action as required by section 7(c) of the Endangered Species Act (ESA). This BE has been prepared to facilitate coordination between the US Army Corps of ' Engineers, the federal action agency, and the National Marine Fisheries Service (NMFS) and the United States Fish and Wildlife Service (LTSFWS), jointly referred to as the Services. Information ' provided by NMFS (2000) and USFWS (2000) (Appendix B) indicates that the project will occur within the general range of the following species: ' ' ' 20109 March 200/ Revised January 2002 page Z ' ' �� ' , Kennydale Lakefront Sanitary Sewer eiolagica! Evaluation Common Name Scientific Name Regulatory Agency/Status Chinook salmon Oncorhynchus tshawytscha NMFS/Threatened Bald eagle Haliaeetus leucocephalus USFWS/Threatened (Proposed Delisted) Bull trout Salvelinus confluentus USFWS/Threatened Coho salmon Oncorhynchus kisutch NMFS/Candidate ' 3.0 STUDY OBJECTIVES , 1 ' ' This study has the following objectives: • To review information on species within the action area. In addition, Adolfson contacted regional experts with�specific knowledge of habitat conditions and fish use within Lake Washington. A listing of pertinent references and contacts is provided at the end of this report. • To conduct a review of the project area to observe species habitat site specific conditions. • To discuss impacts of the proposed action and effects to the species and habitats. • To discuss permit conditions and additional conservation measures. ' • To provide a recommendation with regard to effect determinations. The final determination of effect can only be made by the federal action agency. If the action agency determines that a project "is likely to adversely affect" listed species or Critical Habitat, then formal ' consultation is required unless an exception applies. If the action agency determines that a project is "not likely to adversely affect" listed species or habitat, and the Services provide written concurrence, formal consultation is not required. ' 1 ' 4.0 DESCRIPTION OF THE ACTION AREA AND THE PROPOSED ACTION 4.1 Action Area ' Work will occur within Lake Washington adjacent to the Kennydale neighborhood within the City of Renton, Washington. Although work will only occur at four limited locations along the existing pipeline (Figure 2), the action area for the proposed project may extend to other areas ' that may be affected by the proposed action (NMFS and USFWS, 1998). For the purpose of this assessment, the action area includes all of Lake Washington (Figure 3). Since the lists of species for this project (NMFS, 2001; USFWS, 2001) include fish species which may occur within Lake ' ' 20109 March 2001 Revised January 2002 Page 3 ' ' ' Kennydale Lakefront Sanitary Sewer Biological Evaluation Washington and since construction projects may have the potential to impact the surrounding aquatic system beyond the immediate construction area, the action area extends beyond the immediate vicinity of construction. (Specific effects and their impact on the action area are discussed in detail in Section 6 of this report). ' The species list for this project also includes bald eagle. The action area for bald eagle includes the topographic section where the project is located and all of the adjacent topographic sections. This area is considered to be the disturbance zone for bald eagles for construction activities , causing noise but excluding blasting, pile driving, or smoke. Therefore, the action area for bald eagles includes up to a one-mile radius around the four new manhole locations. , The action area for a federal project encompasses all areas that will be affected directly or indirectly by the federal action and not merely the immediate area involved in the action (50 C.F.R. §402.02). Therefore, before the action area can be determined, the federal agency must ' consider the effects of the federal action. Direct effects are the direct or immediate effects of the project on the species or its habitat. Indirect effects are those that are caused by the proposed action and are later in time, but still are reasonably certain to occur (50 C.F.R. §402.02). ' ' 1 Commonly, sewer improvements, roads, and other infrastructure projects can result in indirect impacts beyond the areas that may be directly modified or influenced by construction activities. For projects that may result in secondary impacts, the action area must be extended to include all areas affected by the project. The existing Lakeline serves 52 developed lots. No new properties will be connected to sewers as a result of this project. No additional capacity will be added to the existing Lakeline and no new development is anticipated to occur as a result of the project. ' 4.2 Baseline Conditions Baseline conditions within the action area are discussed below in relation to the condition of ' indicators critical for the success of healthy fish and wildlife populations. For aquatic systems, these indicators include: water quality parameters such as temperature, sediment, nutrients, and chemical contaminants; habitat access and characteristics; channel condition and dynamics; flow , and hydrology; and overall watershed conditions (NMFS, 1996; USFWS 1998). The services have described thresholds for properly functioning conditions for these indicators based on flowing systems in montane forested ecosystems. Although environmental conditions in Lake ' Washington are, by nature, different from those found in flowing water systems, most elements necessary to maintain functioning stream and river systems are also important in the lake environment. Water quality, habitat access, habitat condition, and watershed condition are all ' relevant to the discussion of baseline conditions in relation to the lake environment. These indicators of properly function conditions are summarized in Table 1 and discussed in detail below. 1 4.2.1 Water Quality ' ' ' No site specific water quality sampling was undertaken for this analysis; however, water quality data are abundant for Lake Washington in the vicinity of the project. King County maintains a 20109 March 2001 Revised January 2002 Page 4 1 ' ' 1 1 ' 1 ' 1 , ' ' ' t ' ' ' ' Kennydale Lakefront Sanitary Sewer Biological Evaluation water quality monitoring buoy approximately 0.25 mile northwest of the Kennydale Lakeline alignment. In addition, water quality data related to temperature and bacterial counts are regularly collected at Gene Coulon Park at the southern end of the sewer alignment. Water quality data for the sampling buoy nearest to the project can be accessed electronically at http://dnr.metrokc.gov/wlr/waterres/lakes/site0840.htm. Water quality information is summarized below. Three main factors contribute to Lake Washington's high water quality: 1) inflow from the Cedar River, 2) low residence time, and 3) lake depth and turnover cycles. The mouth of the Cedar River is located one mile to the south of the alignment of the Kennydale Lakeline. The Cedar River serves as the primary water supply for the City of Seattle and its upper watershed is managed to maintain high water quality. This is evident by the fact that the Cedar River contributes approximately 57 percent of Lake Washington's annual hydraulic flow but only 25 percent of the lake's annual phosphorus load (KCDNR, 2000). High flushing rates and the lake's natural turnover cycle reduce the tendency of nutrients and other constituents affecting water quality to accumulate within the basin. The average residence time for the lake is approximately 2.3 years (KCDNR, 2000) and the depth of Lake Washington and the local climate causes the lake to turnover annually. Turnover allows miYing that aerates the lake's depths with oxygen. Dissolved oxygen on the lake bottom prevent phosphorus from releasing from the lake floor (KCDNR, 2000). Aerobic dissolved oxygen levels in the lake are relatively high. KCDNR data collected at a sampling buoy in proximity to the Kennydale Lakeline alignment show dissolved oxygen levels generally fluctuate between a high of approximately 13 parts per million (ppm) in the winter and spring to a low of about 8.9 ppm in the summer and fall. Dissolved oxygen levels are highly dependent on water temperature and the two are inversely related. The lake's temperature is lowest in the late winter and early spring and is highest in the late summer and early fall. Surface temperatures in Lake Washington commonly range between a low of about 45 degrees in March to a high of about 73 degrees in September. Despite these conditions, there are several water quality issues that remain in Lake Washington. Some sections of the lake are listed as Clean Water Act 303(d) Impaired and Threatened Surface Waters (DOE, 2000). These include 1) �ower trending pH; 2) annual algal blooms; and 3) high levels of fecal coliform bacteria. Data analysis shows an upward long-term trend in alkalinity (KCDNR, 2000). The causes and effects of this trend are not fully understood; however, changes in alkalinity can change the toxicity of often commonly occurring chemical contaminants such as aluminum and copper. Although toxic blue green algae blooms have decreased in frequency since most of the Lake Washington Basin was sewered, spring algal blooms can result in increases in turbidity and decreases in dissolved oxygen. Natural algae blooms in 1995 and 1996 were the highest in more than a decade (KCDNR, 2000) and may be an indicator of increasing nutrient levels within the basin. Fecal coliform bacteria counts have been high in some localized areas. Fecal coliform counts are highest during the late fall and early winter as a result of CSO discharges. 20109 March 2001 Revised January 2002 Page .i ' ' ' 4.2.2 Habitat Access Kennydale Lakefront Sanitary Sewer Biologica! Evaluation ' The outlet of Lake Washington is controlled at the Hiram Chittenden Locks operated by the U.S. Army Corps of Engineers. The locks are a control structure to maintain the level of Lake Washington and facilitate the passage of vessels between the freshwater environment of Lake ' Washington and the Lake Washington Ship Canal and the estuarine environment of Salmon Bay (Puget Sound). The locks were constructed in the early 20`h century and in 1917 a fishway (or fish ladder) began operation. That original fishway was underutilized as a result of poor ' attraction flows and a new fishway was constructed and put into service in 1976. The new fishway significantly improved upstream fish passage by allowing returning adult salmon and trout to pass the locks. 1 , ' ' ' ' ' u ' ' ' ' 1 Although upstream fish passage was enhanced by the new fish ladder, downstream fish passage has remained an important issue. The Corps has recently undertaken a program to improve downstream fish passage through the locks. In 1999, the Corps started construction of four flumes that bypass the locks and fishway and provide a less hazardous route for outmigrating juvenile salmon and trout (Corps, 2000). In addition to the flumes, the Corps is testing other methods to exclude fish from hazardous areas of the locks. 4.2.3 Habitat Elements The south end of the eYisting Kennydale Lakefront Sewer Line enters Lake Washington at approximately 2807 Mountain View Avenue North (Station 0+00). From this point north, the eight-inch pipe lies close to the shore, passing under docks and along bulkheads (Figure 2; Photo 2). As discussed above, most of the Lakeline is covered by lake-bottom sediments. Approximately 1,000 feet of the 4,700-foot Lakeline are exposed according to a survey conducted by the City of Renton in 1987 (Tetra Tech/KCM, 2000). Adolfson surveyed habitat elements and fish use along the existing Lakeline during the spring of 2000. Adolfson biologists conducted snorkel surveys of the project alignment weekly for eight weeks during daylight hours. In a separate study conducted concurrently with, but separately from, the Adolfson study, USFWS biologists conducted night snorkel surveys in the same general area. Results of the Adolfson habitat survey and fish use evaluation are included as Appendix C. Results from the USFWS study have not been published, but were publicly presented at a November 2000 conference. Results of these studies are summarized below. 4.2.3.1 General Habitat Conditions Since the construction of the Lake Washington Ship Canal lowered the level of Lake Washington to its current limits, development has significantly altered the natural configuration of the lake shore. Much of the shoreline adjacent to the alignment of the Kennydale Lakeline has been developed with houses, condominiums, bulkheads, docks, boat launches, and landscaped lawns (Photos 1 and 2). Natural shoreline conditions are generally lacking. 20109 March 2001 Revised January 2002 Page 6 ' ' ' � ' Kennydale Lakefront Sanitary Sewer eiologica! Evaluation The Lakeline lies between four to 12 feet of water below the lake surface in most areas. The lake bottom along the project alignment is generally silty, with occasional cobble, rubble and gravel (Adolfson, 2000). The southern end of the alignment was generally lacking rooted aquatic vegetation whereas the bottom of the lake in the northern portion of the alignment is largely covered by vegetation (mainly milfoil). Some areas of the lake bottom along the alignment were littered with debris including sunken trees, truck tires, and lumber scraps. The lake share contours along the alignment range from gradual natural banks to vertical bulkheads. ' 4.2.3.2 Site Specific Habitat Descriptions ' The proposed action is to install four access manholes at approximately Station 9+70, Station 21+70, Station 28+30, and Station 40+00 along the existing Lakeline. ' Station 9+70. The southernmost location is approximately 30 feet from shore. During the spring time survey, this location was approximately five feet under water. The dominant substrate is silt and sand. Bottom habitat structures in this area are dominated by lumber and man-made ' debris. Station 21+70. The proposed manhole location near station 21+70 is approximately 15 feet from ' shore. This section of the pipeline is in approximately eight feet of water. The bottom is relatively steep in this area, with sand substrates. Habitat cover in the area is mainly limited to docks and pilings. ' ' 1 ' ' ' ' ' ' ' Station 28+30. This location is in approximately 10 feet of water and is approximately 20 feet offshore. The shoreline adjacent to this location generally consists of bulkheads. As a result, slopes are vertical at the shoreline, and gradual from the shoreline to the pipeline. The bottom is sand with some branches and man-made debris. Station 40+00. This location is approximately 60 feet from shore and is in approximately ten feet of water. Slopes are gradual and the bottom is dominated by silt and sand with some debris. The surface is largely covered by docks and moored boats. The Lakeline alianment is located along the outer perimeter of the docks in this area. � 4.2.4 Watershed Conditions The Lake Washington basin has undergone a number of significant changes in the past 60 years. Currently, over 60 percent of the land around the lake is fully developed. Prior to 1963, sewage from surrounding areas was discharged directly to Lake Washinaton. This resulted in eutrophication and water quality degradation in the lake. Between 1963 and 1967, sewage system upgrades diverted sewage discharges from lake, leaving Combined Sewer Overflows (CSO) the only remaining source of untreated effluent discharge to the lake after 1968. Water quality improvements rapidly followed. 20109 iLlarch 2001 Revised Janua�y 2002 Page 7 Y• , , 4.3 ' ' , Ll ' , ' ' 1 ' ' ' ' ' � ' ' Project Description Kennydale Lakefront Sanitary Sewer Biological Evalz�ation 4.3.1 Primary Features of Proposed Action The proposed action includes the installation of four approximately six-foot round by four-foot high pre-cast concrete manholes to allow periodic cleaning and maintenance of the Lakeline. The use of pre-cast manholes will prevent any uncured concrete from coming in contact with the lake. A typical view of the proposed manhole is included as Figure 3. Manholes will be installed at approximately Station 9+70, Station 21+70, Station 28+30, and Station 40+00 (Figure 2). The proposed action also includes the repair of the approximately 2-inch hole discovered in the Lakeline near Station 44+00 during the 1999 condition assessment. 4.3.2 Secondary Features of the Proposed Action Each manhole will be installed by divers operating-from a floating barge. Barge access will be via existing facilities. No temporary access points ar staging areas, or access roads are expected to be necessary. No other improvements or modifications to the existing Kennydale Lakefront Sanitary Sewer are associated with this project. 4.3.3 Construction Duration and Site Preparation It is anticipated that each pre-cast manhole will require beriveen 8 and 12 hours to install. Repair of the hole near Station 44+00 is anticipated to take approximately 4 hours. During installation of each manhole and during repair of the hole, the homes that are served by the sewer will be prohibited from discharging waste to the Lakeline. Prior to the work, the existing flushing station at the southern eYtent of the project alignment will be operated for several hours to flush all wastewater out of the pipe to the downstream pump station. 4.4 Description of Construction Activities The final construction sequence for this project will be developed by the contractor prior to the initiation of work; however, based on previous experience with this type of project it is anticipated that, from a construction standpoint, the implementation of the proposed action will be simple and straight-forward. First the contractor will locate a barge adjacent to each proposed manhole location. The barge will act as the platform from which all work will occur. A sedimentation curtain will be placed around the barge and the manhole installation area to contain sediments that may be stirred from the lake bottom during the installation of the pre-cast manholes. A diver will remove an approximately 10 foot length of the existing pipe using an underwater saw. The pipeline will be removed by a crane or similar device mounted on the barge. Following removal of the pipe segment, both ends of the pipe will be plugged to prevent discharge of material from the pipe. The contractor will lower the pre-cast manhole into the area where the old pipe was removed. The manhole will have short pipe stubs at the inlet and outlet to allow it to be connected to the 20109 March 2001 Revised January 2002 Page 8 ' , ' ' ' ' , , , ' ' ' LJ 1 � ' ' ' , � Kennydale Lakefront Sanitary Sewer Biologica! Evaluation existing pipe. The connection will be made using pressure rated couplings. Depending on site conditions at each manhole location, it may be necessary to remove up to 10 cubic yards of lake bottom sediments or add up to 3 cubic yards of gravel bedding material per manhole to properly align the stubs with the existing pipeline. If it is necessary to remove lake bottom material, the material will be removed by a barge-mounted backhoe. Lake bottom materials will be disposed of at an upland site to be determined by the construction contractor. If it is necessary to add gravel bedding material, the bedding material will be similarly added using a backhoe or other equipment mounted on the barge. The sediment curtain will remain in place while work is in progress. This procedure will be repeated at each of the four manhole locations. The hole in the Lakeline will be repaired by removing an approximately 5-foot length of the existing pipe and replacing it with a new 5-foot section. The remaining pipe and new section will be connected with pressure-rated couplings on each end. A sediment curtain will be place around the pipe repair area and will remain in place while construction is in progress. 4.4.1 Clearing and Grading No shoreline disturbance or other clearing or grading will be necessary to install any of the four manholes. 4.4.2 Temporary Erosion and Sedimentation Control No work is anticipated to occur on land as a result of the proposed action. Erosion from upland areas and sedimentation from upland sources is not anticipated as a result of this project. As discussed above, the construction contractor will install a hanging silt curtain entirely around the construction barge and the manhole location. The silt curtain will be installed to contain any lake bottom sediments that may be disturbed and re-suspended during construction. The silt curtain will remain in place when in-water work is in progress to install the pre-cast manholes or repair the hole in the pipe. 4.4.3 Impervious Surface No net change in the overall quantity of impervious surface area will occur as a result of this project corridor. 4.4.4 Blasting No blasting will be required. 4.4.5 Pile Driving No pile driving will be required. 20109 March 200/ Revised Jant�ary 2002 Page 9 , , , � ' ' ' ' ' ' , ' 1 4.4.6 Wetiand Impacts Kennydale Lakefront Sanitary Sewer Biological Evaluarion No wetlands will be affected. Approximately 112 square feet (ftZ) of lake bottom will be covered by the pre-cast structures (four manholes with a foot print of approximately 28 ft2 each). 4.5 Monitoring Plan A representative of the City of Renton will be on-site during all in-lake construction. This representative will be responsible for construction observation and project monitoring. The on- site representative will be present to observe the placement of the silt curtain and all construction. The installation of each manhole is likely to result in the temporary suspension of lake sediments. Although plugs will be installed at both cut ends after each section of pipe is cut, a small amount of flushing water may be discharged to the lake when the existing iron pipe is cut and removed. The City of Renton will monitor water quality before, during, and following construction on a daily basis. Monitoring will include both visual observations of site conditions and sampling. Sampling will be conducted from the work barge prior to the initiation of work, periodically during installation of each manhole, and after installation is complete. Dissolved oxygen, turbidity, and temperature will be recorded during each sampling event. 4.6 Timing/Chronology of Specific Construction Actions It is anticipated that between 8 and 12 working hours will be required to install each one of the four pre-cast manhole. Repair of the hole in the line is anticipated to take approximately 4 working hours. Initial setup time will be required at each manhole location and the pipe repair location to position the barge, deploy the sediment curtain, etc. It is expected that the construction work in the lake will be completed within a two week time frame between July and October 2002. 4.7 Current and Future Maintenance Activities The City of Renton currently performs maintenance on the Lakeline each summer to minimize ' sediment accumulation in the pipeline. The pipeline is accessed through five onshore cleanouts and jetted using a City vactor truck. The City is currently able to jet approximately 2,500 feet of the 4,700-foot line. Sediment that has accumulated in the line can only be removed at one of the , five cleanout locations. The City plans to continue with this summer cleaning activity in the future. ' ' ' ' Installation of the new manholes will allow those portions of the line not accessible from the shore to be jetted, and provide a means to remove accumulated sediment from the line during cleaning operations. Cleaning operations at the manhole locations will be accomplished with a barge-mounted vactor truck, since shore-side access to the manhole locations will not be possible. The manholes will be accessed from a portable shaft that is temporarily installed and eYtends above the lake level (Figure 3). A diver will set the shaft. The lakeline will then be 20109 March 2001 Revised January 2002 Page 10 �: , ' ' Kennydale Lakefront Sanitary Sewer Biologica! Evalt�ation jetted upstream and downstream of the manhole, and the vactor truck will remove sediment that is drawn back towards the manhole. This procedure will be repeated at each of the four manhole locations, and will be conducted by an outside cleaning company with marine expertise. It is expected that future cleaning activities at the manhole locations will be completed within a ' two-week time frame between July and October. The City anticipates cleaning the line from these locations once every two to five years; however, the required cleaning frequency will ultimately depend on the rate at which sediment accumulates in the line. Future cleaning ' activities will adhere to the procedural and permit requirements that have been adopted at the time of the cleaning. ' 5.0 STATUS OF THE SPECIES AND CRITICAL HABITAT 1 ' , , 5.1 Puget Sound ESU Chinook Salmon Chinook salmon have a historic range from the Ventura River in California to Point Hope, Alaska in North America; and from Hokkaido, Japan to Anadyr River in Russia (Myers, et al., 1998). Chinook salmon in Lake Washington are included in the Puget Sound Chinook ESU, a population currently listed as threatened under the ESA. 5.1.1 Critical Habitat Critical Habitat has been designated for Puget Sound ESU chinook salmon and includes all ' waterways historically accessible to chinook. Lake Washington and all shoreline areas are included within this designation. C� , ' ' ' 1 ' , 5.1.2 Life History The life history of Puget Sound chinook salmon is described in detail in NOAA Technical Memorandum NMFS-NWFSC-35 Status Review of Chinook Salmon from Washington, Idaho, Oregon, and California (Myers et al., 1998) and is included herein by reference. A summary follows to assist in the discussion of effects related to the proposed action. Chinook require varied habitats during different phases of their life. Spawnin� habitat typically consists of riffles and the tailouts of pools with clean substrates dominated by cobbles. These habitats are located in the mainstem of rivers and large tributaries. Juvenile chinook rear in the lower mainstem of rivers and tributaries before entering the estuary and salt marshes (Myers et al., 1998). Adult chinook salmon spawn in freshwater streams in the late summer and fall. Fry emerge in the late winter and early spring. Juvenile chinook may rear in freshwater from three months to two years (Myers et al., 1998). Most Lake Washington chinook migrate to salt water the following spring and summer (Myers et al., 1998; Wydoski and Whitney, 1979); however, a small portion of the population is expected to rear within the lake and tributary river and streams from one to three years. The exact percentage of chinook juveniles that remain in the Lake 20109 March 2001 Revised January 2002 Page 1/ C� 1 ' 1 ' ' , ' , ' ' , ' ' ' ' ' , , Kennydale Lakefront Sanitary Sewer Biological Evaluation Washington basin beyond the first summer is not clear, although recent evidence indicates it may be higher than previous estimates of one percent. After outmigrating through the Hiram Chittenden Locks, most Lake Washington chinook spend from two to four years feeding in the Puget Sound and North Pacific before returning to spawn. Chinook salmon die after spawning. 5.1.3 Environmental Baseline Chinook spawning occurs in the larger tributaries of Lake Washington. The highest level of wild chinook spawning in the basin occurs in the Cedar River and Bear Creek (Williams et al., 1975; WDFW, 1994; Carrasco, et al., 1999). The mouth of the Cedar River is located approximately one mile to the southwest of the project area. Bear Creek drains to the Sammamish River that enters the north end of Lake Washington. In the Cedar River, chinook return in the late summer and early fall to spawn from mid-September through October. Chinook salmon spawn as far upstream as the Landburg Dam (RM 21.4) (Williams et al., 1975). Escapement data show a range of returns to the Cedar River in the late summer and early fall ranging from approximately 400 to 1,800 adults. Stock origin in the Cedar River is native, and reproduction is wild (WDFW, 1994). Night snorkel surveys of juvenile fish use in southern Lake Washington were conducted by USFWS biologists in the spring of 2000 (WDFW, unpublished) and observations of daytime fish use were noted during Adolfson's weekly snorkel surveys also conducted in the spring of 2000 (Adolfson, 2000). No other publications were identified that discussed chinook use specifically in the vicinity of the Kennydale Lakeline. No juvenile chinook salmon were identified utilizing habitats along the Lakeline alignment during the day. Chinook juveniles were observed in the project vicinity at night congregating along shoreline areas with gradually sloping bottoms and sandy substrates (Piaskowski, personal communication, 2000). Although the results of the USFWS dive survey have not been published, preliminary analysis indicates that most juvenile salmonids were most often associated with the shallow water zones immediately along the lakeshore in areas lacking complex bottom substrates and with limited overhead cover. It is unclear if juvenile chinook prefer these habitats or if they are merely avoiding deeper habitats with mare complex cover because these areas may also provide cover for potential predators. Smallmouth bass, in particular, were commonly observed within the project area in association with overhead cover or large substrates (riprap) (Adolfson, 2000; Piaskowski, personal communication, 2000). 5.2 Bald Eagle The bald eagle is federally listed as threatened in Washington State. Bald eagle populations in Washington have recently been proposed for delisting by USFWS; however, the publication of a final delisting rule, if determined by USFWS to be warranted, is not anticipated prior to project implementation. 10109 �U/arch 2001 Revised January 2002 Page 12 ' 1 ' ' ' ' ' ' , ' , , ' LJ ' ' , 5.2.1 Critical Habitat Kennydale Lakefront Sanitary Sewer Biologica! Evaluation No Critical Habitat has been designated or proposed for bald eagles. 5.2.2 Life History The life history of bald eagles is described in detail in the Pacific Bald Eagle Recovery Plan (USFWS, 1986) and is included herein by reference. A summary follows to assist in the discussion of effects related to the proposed action. Bald eagles are both residents in, and migrants through, King County. Eagle populations are usually highest in the Puget Sound region in January, when birds that had moved north in late summer to feed on coho salmon runs in British Columbia and Alaska return to winter in the region (Matthews, 1988). In western Washington, bald eagles breed during mid- to late winter. Bald eagles typically return to one of several nests located within an established nesting territory (Matthews, 1988; Stalmaster, 1978). Eggs laid in March and April hatch within one and a half months. Young eagles hatched in June will generally fledge in mid-summer (September). As bald eagles are primarily fish eaters, they usually nest within one mile of open water. Their home range generally extends up to eight miles from the nest (Muller, personal communication, 1994). Bald eagles generally perch, roost, and build nests in mature trees near water bodies and available prey. Bald eagles usually spot prey while perching or soaring (Ehrlich et al., 1988). Stalmaster (1987) reports that typically over 50 percent of an eagle's diet comes from fish, 25 percent from other birds, and 15 .percent from mammals, although they will also feed on carrion (Stokes and Stokes, 1989; Matthews, 1988). 5.2.3 Environmental Baseline The occunence of bald eagles in central Puget Sound has been documented since pre-settlement times. Eagle populations have decreased within the region as a result of hunting (legal until the 1940's) and the widespread use of DDT. Since DDT was banned in 1972, bald eagle numbers have been increasing in the region. The rivers and numerous lakes in the Puget Sound lowlands provide habitat for both nesting and wintering bald eagles. 5.3 Coastal Bull Trout The historical distribution of bull trout eYtends from northern California to Alaska. In Washington, bull trout are found throughout coastal and inland streams and lakes (WDW, 1991). Bull trout in the Lake Washington basin are considered coastal bull trout. This population has been listed by USFWS as threatened. ' 20/09 March 2001 Revised January 2002 Page 13 , , , ' ' ' LJ ' , ' , ' , , ' ' ' ' ' Kennydale Lakefront Sanitary Sewer Biologica! Evaluation 5.3.1 Critical Habitat No Critical Habitat has been established or identified for coastal bull trout. 5.3.2 Life History The life history of coastal bull trout is described in detail in the Determination of Threatened Status for Bull Trout in the Coterminous United States; Final Rule (Federal Register, 1999 (USFWS, 1986) and is included herein by reference. A summary follows to assist in the discussion of effects related to the proposed action. Bull trout have a complex life history that includes a resident form and a migratory form. The individuals of the migratory form may be stream dwelling (fluvial), lake-dwelling (adfluvial), or ocean- or estuarine-dwelling (anadromous) (USFWS, 1998). Individuals of each form may be represented in a single population; however, migratory populations may dominate where migration corridors and sub-adult rearing habitats are in good condition (USFWS, 1998). Most inland populations of bull trout are either fluvial or adfluvial, migrating from larger rivers and lakes to spawn in smaller tributary streams in September through October (Wydoski and Whitney, 1979). Bull trout spawn in streams with clean gravel substrates and cold (less than 9 degrees Celsius/48 degrees Fahrenheit) water temperatures (USFWS, 1998). Spawn timing is relatively short, spanning from late October through early November. Redds are dug by females in water eight to 24 inches deep, in substrate gravels 0.2 to 2 inches in diameter (Wydoski and Whitney, 1979). Emergence generally occurs in the spring. Bull trout are opportunistic feeders, consuming fish in the water column and insects on the bottom (WDFW, 1991). 5.3.3 Environmental Baseline Low stream temperatures and clean substrates are key features of bull trout habitat. This species is most commonly associated with pristine or only slightly disturbed basins (USFWS, 1998). Bull trout and Dolly Varden occurrence in the Lake Washington drainage basin is rare. The Bull Trout and Dolly Varden Appendix to the 1998 Salmonid Stock Inventory (WDFW, 1998) states that reproducing populations of native char (potentially including both bull trout and Dolly Varden) within the Lake Washington basin are limited to the upper Cedar River basin in Chester Morse Lake (WDFW, 1998). The adfluvial population of native char in Chester Morse Lake is a glacial relic separated from stocks in the Snohomish River system when the outlet of Chester Morse Lake was diverted south during the last glacial period (WDFW, 1998). The waterfall that resulted at the outlet of the lake, known as Cedar Falls, is a blockage to anadromous populations. Even though reproducing bull trout populations have not been documented in the Lake Washington Basin below Chester Morse Lake (WDFW, 1998), adult fluvial bull trout may enter Lake Washington from other basins to forage. The extent of use by bull trout in Lake Washington is unknown, but expected to be rare. The shoreline of Lake Washington is considered an"intermittent use zone" for foraging bull trout (USFWS, 2000). Only 10 bull trout/Dolly Varden individuals have been observed and documented in Lake Washington drainage in the last 20 years (WDFW, 1998). Three of these observations were made in the 20109 March 2001 Revised Janz�ary 2002 Page l4 ' J ' ' ' 1 ' ' � ' , Kenrrydale Lakefront Sanitary Sewer Biological Evaluation Cedar River delta (near the Lake Washington confluence) in the mid-1980s and are thought to represent anadromous bull trout straying from other basins (KCDNR, 2000). No bull trout were observed during the snorkel surveys conducted in 2000. The presence of bull trout in the project area is estimated to be low due to the rarity of the species in the watershed. 5.4 Puget Sound/Straight of Georgia ESU Coho Salmon Coho salmon are currently a candidate fish stock. No protection for candidate stocks is afforded under the ESA, and section 7 consultation or conference with NMFS is not required for anticipated impacts to these species. Summary information for this candidate species is included herein in the event these candidate species become listed or proposed prior to project completion. 5.4.1 Critical Habitat No Critical Habitat has been identified or proposed for coho salmon. 5.4.2 Life History The life history of Puget Sound coho salmon is described in detail in NOAA Technical MemoYandum NMFS-NWFSC-2=� Status Review of Coho Salmon from Washington, Oregon, and California (Weitkamp et al., 1995) and is included herein by reference. A summary follows to assist in the discussion of effects related to the proposed action. Coho salmon are anadromous, and occur in most major river basins around the Pacific Rim from ' central California to Karea and northern Hokkaido, Japan (Weitkamp et al., 1995). Adult coho salmon spawn in freshwater streams in the late fall and early winter. Coho typically spawn in low gradient riffles with clean substrates ranging from pea-sized gravels to orange-sized cobbles ' (Henry, 1995). Rearing juveniles prefer off-channel pools with complex cover including both large and small woody debris (Henry, 1995). Juvenile coho rear in freshwater for a year to 18 months. Smolts migrate to the ocean in the spring of their second year. Most male coho, and all ' female coho, spend from 16 to 20 months rearing in the ocean and return to spawn in fresh water as three-year old adults. 1 ' ' u ' 5.4.3 Environmental Baseline Coho are known to occur in the Lake Washington Basin including two tributary basins in proximity to the Kennydale area, the Cedar River and May Creek systems. Juvenile coho are known to rear in the nearshore environments of Lake Washington during the late spring, and may be present, at least in smaller numbers, throughout the year. Schools of coho fry (estimated at between one and two inches long) were observed along the project alignment during several of the spring 2000 snorkel surveys (Adolfson, 2000). These fry were commonly found among schools of three-spine stickleback and were generally situated in shallow, protected areas along the shore. Occasionally schools of coho and stickleback were observed positioned in the water column. The four manhole locations are all in deeper water than coho were commonly observed. 20109 March 2001 Revised Janz�ary 2002 Page 1� 1 � 1 , 1 ' ' ' �� � ' 1 Kennydale Lakefront Sanitary Sewer Biologicnl Evaluation 6.0 EFFECTS OF THE ACTION Potential impacts related to the proposed action are discussed below. Close coordination with the project design engineers has occurred to determine anticipated construction techniques and potential impacts. Discussed below are the potential effects that could occur unless adequately avoided or mitigated. Conservation measures that have been implemented during project design or that will be implemented during project construction are discussed in Section 6.5 of this document. The eYpected potential of the project to affect listed species considering the conservation and mitigation measures is summarized in Section 7.0 of this report. Statements of determination of effects are included for each species in Section 8.0 of this report. 6.1 Direct Effects 6.1.1 Fish Species The proposed project has three primary actions that could result in direct effects to fish species or critical habitat unless adequately avoided, minimized, or otherwise mitigated. The first effect is related to temporary impacts that may occur during the installation of the four pre-cast manholes. The second effect is related to the effects on the habitat of listed or candidate species related to the four pre-cast manholes. The third effect is related to the potential for increased predation of juvenile salmonid fish as a result of changes to habitat conditions at the location of the four pre- cast manholes. As described in Section 4.7 above, future cleaning activities at the manhole locations are ' expected to be completed within a two-week time frame between July and October. This work will be accomplished by an outside cleaning company with marine expertise. 1 ' � 6.1.1.1 Construction-Related Effects Construction-related effects to chinook salmon, coho salmon, and bull trout are anticipated to be related to three actions: 1) increased turbidity within the work areas during construction; 2) temporary habitat exclusion during construction; and 3) the potential for the release of hazardous material into the lake environment during construction. Turbiditv. As discussed in Section 4.4 of this study, the project is anticipated to cause increased � turbidity in the proximity of each manhole and the hole repair during construction as a result of the temporary disturbance of lake-bottom sediments. It is anticipated that turbidity will be limited to the area around the work area by a silt curtain that will remain in place during the ' installation of each pre-cast manhole and the hole repair; however, elevated turbidity levels are anticipated within the work area delineated by the silt curtain. � Work to install the manholes will require a diver to remove a section of the existing pipeline and, with the assistance of a barge-mounted crane or similar device, position the new pre-cast manholes on the lake bottom such that the stubs on the manhole are aligned with the cut ends of ' , 20109 March 2001 Revrsed January 2002 Page 16 � ' ' ' , ' � ' , ' ' 1 , ' , ' ' , ' , Kennydale Lakefront Sanitary Sewer Biological Evaluation the pipeline. The habitat surveys conducted by Adolfson during the spring of 2000 identified that the bottom substrates along the existing pipeline included silty sediments. It is likely that the necessary activity to install the pre-cast manholes will disturb the bottom sediments and result in a temporary increase in turbidity within the work area. The level of suspended sediments that can affect salmonids depends on many factors including the level of background turbidity, the amount of increase in turbidity, and duration of increased turbidity (NMFS, 2000). A study by Servizi and Martens (1992 in NMFS, 2000) indicated that turbidity alone is not likely to result in direct mortality unless extremely high levels occur; however, other studies have shown that juvenile salmon avoid turbid water when turbidity exceeded a threshold level. Bisson and Bilby (1982 in NMFS, 2000) found that the avoidance threshold for coho was 70 nephelometric turbidity units (NTU). Berg and Northcote (1985 in NMFS, 2000) demonstrated habitat displacement, disruption of feeding and social behavior, and gill flaring of juvenile coho because of increased turbidity as a result of upland sediment. The silt curtain installed around the work area at each manhole is anticipated to preclude fish from moving into the work area during installation of the pre-cast manholes (see discussion below). This will generally limit the potential exposure of fish to increased levels of turbidity within the silt curtain. The potential exposure of chinook salmon, coho salmon, and bull trout to increased turbidity is also limited by the timing of the project in the late summer and early fall, after the period that juvenile salmonids are commonly found in nearshore habitats in Lake Washington. Habitat Exclusion. The silt curtain installed to limit the potential effects of increased turbidity. will temporarily eYclude chinook salmon, coho salmon, and bull trout from the work area. Generally, this is a positive effect, as this will lower the potential exposure of these species to conditions within the silt curtain; however, fish that would normally use these areas will be displaced to other habitats. Overall, potential harm as a result of this displacement is anticipated to be discountable. The silt curtain is expected to remain in place at each manhole for only one work-day and will be removed following construction as discussed above. Similarly, the work is scheduled in the late summer and early fall, following the period that juvenile salmonids are commonly found in nearshore habitats in Lake Washington. Dischar�e of Hazardous Materials. There are two potential pathways for hazardous materials to enter Lake Washington during construction: 1) as a result of spills of potentially toxic materials (e.g., hydraulic fluid, gasoline, and oil) used during construction, or 2) from the existing sewer line after the line has been cut to allow installation of each manhole. All life stages of chinook, coho, or bull trout present in the affected area of Lake Washington could be harmed by the discharge of hazardous materials. Several conditions will exist that are anticipated to limit the potential for harm to chinook, coho, or bull trout as a result of the potential discharge of hazardous materials. A spill prevention and contingency plan will be required to be developed and implemented by the construction contractor. This requirement will be included in the construction specifications for this project. The silt curtain will be suspended from a floating boom that will be installed around the work area and will help contain any floating materials from exiting the work area. The discharge of hazardous materials from the cut sewer pipeline is not anticipated during construction. The 20/09 March 2001 Revised January 2002 Page l7 ' ' ' Kennydale Lakefront Sanitary Sewer Biological Evaluation pipeline will be flushed for several hours prior to work. Cut ends of the pipe will be plugged to avoid discharge of material while construction is underway. Also, the pipeline serves only residential homes. No industrial properties that may handle hazardous materials are served by the Kennydale Lakeline. ' 6.1.1.2 Habitat Modifications ' The degree that habitat modifications could affect chinook salmon, coho salmon, and bull trout is largely dependent on the extent of habitat alterations and the level of use of those habitats by these species. A relatively small quantity of lake bottom will be impacted by the proposed ' project. The proposed action includes installing four pre-cast manholes. Each of the pre-cast manholes measure approximately 6 feet in diameter by four feet high. Each manhole will cover approximately 28 ftZ of lake bottom. A total of 112 ft2 of lake bottom (28 ft2 x 4 manholes) will ' be covered by the four newly installed manholes. Up to 3 feet of the manhole may extend above the lake bottom depending on the depth required to bury the bottom of the manhole to align the manhole with the existing Lakeline. Manholes will be installed at approximately Station 9+70, ' Station 21+70, Station 28+30, and Station 40+00 along the existing Lakeline (Figure 2). Habitat conditions at each location are summarized in Section 4.2.�.2 of this report. , The installation of the four manholes will not occur within habitats used as migratory conidors or for spawning by adult chinook salmon, coho salmon, or bull trout. None of the four proposed manhole locations are situated at the mouths of streams or rivers that may be used by adult ' salmonids for spawning. Lake Washington is known to contain a non-native population of lake- spawning sockeye salmon originally planted from Baker Lake stocks (Skagit River drainage); however, lake-spawning populations of chinook or coho are not known to occur in Lake ' Washington. Reproducing populations of migratory bull trout are not known to occur in Lake Washington; therefore, it is unlikely that bull trout spawning or juvenile bull trout rearing would be present in the vicinity of the project alignment. ' ' , ' ' � ' , Juvenile chinook and coho are known to use Lake Washington as rearing habitat and utilize habitats in the vicinity of the Kennydale Lakeline during some periods of their early life history. Extensive use of habitats at the four proposed manhole locations is not anticipated, however, because of existing habitat conditions at each of the four proposed manhole locations. Surveys of the project corridor during the spring of 2000 found that most habitat use by juvenile salmonids along the project corridor occurs in shallow nearshore areas (less than 3 feet in depth) (Adolfson, 2000; WDFW, unpublished). Although coho salmon were occasionally observed in the water column in the vicinity of the sewer line alignment during day surveys, juvenile coho were never observed in close association with the lake bottom at depths of greater than 3 feet. WDFW biologists conducting surveys in 2000 for chinook salmon abundance found that juvenile salmonids, particularly juvenile chinook salmon, were most frequently found in less than 3 feet of water over gently sloping bottoms free from debris, with substrates of sand or small gravel. The bottom of the lake at each of the four proposed manhole locations is irregular and littered with debris. The avoidance of this type of the lake bottom may be a response to reduce potential predation. Deeper water with irregular bottoms may provide increased opportunities for predators on juvenile salmonids. Predation is discussed in more detail in the following section. 20109 Nlarch 2001 Revised January 2002 Page 18 , ' 6.1.1.3 Predation Kennydale Lakefront Sanitary Sewer eiologica! Evaluation ' Predator-prey relationships are complex and impacts associated with predation are difficult to quantify with certainty. The following discussion is provided to identify potential contributing and mitigating factors related to predation on listed and candidate species. u , ' ' ' ' 1 , ' , , ' , ' , � Although juvenile chinook and coho are not expected to extensively utilize habitats along the lake bottom at the four manhole locations, they may occasionally occur in the water column above each manhole and juvenile coho and chinook are known to utilize the shoreline parallel to the project alignment (WDFW, unpublished). If the project were to provide increased habitat opportunities for predators of juvenile chinook or coho, it may be expected that predation on these juvenile fish could increase. The potential for predators to impact salmonid populations is a primary concern to fisheries managers. Predation effects are usually associated with impacts from other fish stocks on rearing and outmigrating juveniles, although predation by birds on juveniles and predation by marine mammals on returning adults may be significant concerns in other areas (Myers et al., 1998). _ There are many predators to juvenile salmonids in Lake Washington. Smallmouth bass, largemouth bass, northern pikeminnow, rainbow trout, cutthroat trout, and sculpin are found in the lake and all are known predators on juvenile salmonids. Predator-prey relationships related to chinook salmon and coho salmon in Lake Washington have only recently begun to be investigated in detail; however, there is a growing body of information on predation of juvenile salmonids in other drainages and there are studies that address effects of predation on other juvenile salmonids in Lake Washington. Specifically, three studies were identified in the course of this assessment that specifically address predation of juvenile salmonids by these species. Fayram (1996) observed predation rates of largemouth bass and smallmouth bass in Lake Washington. Swartzman and Beauchamp (1990) and Beauchamp et al. (1992) studied predation rates on juvenile salmon by rainbow trout cutthroat and found that the most predation by rainbow trout and cutthroat trout on juvenile salmonids occuned in pelagic (deep water) areas of the lalce. These studies also identified that juvenile sockeye salmon, which are relatively abundant in Lake Washington, were the most common salmonid prey of piscivorous rainbow and cutthroat trout (longfin smelt and juvenile sockeye salmon accounted for the majority of these trout's diet as observed during the study period). In addition to these published works, the USFWS initiated an investigation of predation by northern pikeminnow and bass in Lake Union and the Lake Washington Ship Canal in 2000 (USFWS, unpublished). Initial results indicate that predation rates of bass and northern pike minnow on juvenile salmonids were high in Lake Union and the ship canal during periods of juvenile salmon outmigration. Fayram (1996) also found the highest predation rates observed in their study at one of the study sample sites at the mouth of the Lake Washington Ship Canal; however, this study found little salmonid predation by bass in less confined areas. These results are consistent with information from other drainages that show that juvenile salmonids are not commonly a large component of the diets of predators such as pikeminnow and bass under natural conditions. The potential for increased rates of predation is highest at dams and in areas that attract both rearing juvenile salmonids and predators (Tabor et al., 1993). 20109 March 2001 Revised January 2002 Page 19 � ' ' ' ' ' Kenrrydale Lakefront Sanitary Sewer Biologica! Evaluation Predation is of greatest concern in areas where habitats that attract rearing salmonids, such as backwaters, and habitats that attract predators, such as developed shorelines, are closely associated (Tabor et al., 1993; Farr and Ward, 1993). In other areas piscivorous predators appear to key in on the most abundant prey, and may exclude less abundant prey items from their diet when their preferred prey are available (Swartzman and Beauchamp, 1990). Where predatory fish and juvenile salmonids occur together under more natural shoreline conditions (compared to conditions at dams or confined channels), predators tend to key in on other prey unless juvenile salmonids are particularly abundant and/or other prey species were in short supply (Swartzman and Beauchamp, 1990; Tabor et al., 1993; Beauchamp et al., 1992; Beauchamp, 1995; Fayram, 1996). ' The proposed action could result in increased rates of predation if it were to result in increased habitat for predators and provided increased opportunities for these predators to prey on juvenile chinook or coho. Adolfson biologists conducted snorkel surveys of the project alignment weekly ' for eight weeks from mid April through mid June. Adolfson (2000) observed relatively few predators during their spring 2000 habitat surveys. - Although the concentrations of predators were relatively sparse, individual smallmouth bass were regularly observed along the project ' alignment. In every instance where smallmouth bass were observed, they were closely associated with overhanging structures such as sunken logs and, in least one instance, under the sewer pipeline where the pipeline was raised from the lake bottom. In all instances where bass ' were observed during the habitat surveys, they were found stationed along the bottom of the lake under overhanging cover suspended approximately one foot above the lake bottom. , , ' ' ' ' ' , ' , In summary, because the project will result in modifications to habitat, and these general types of modifications have been associated with increased abundance of predatory fish, particularly smallmouth bass (Tabor et al., 1993; Farr and Ward, 1993), the possibility of increased predation cannot be completely discounted. But although not completely discountable, the installation of the four pre-cast manholes is not anticipated to result in significant increased predation rates along the project alignment. The four manhole locations are not associated with backwater areas, confined channels, stream mouths, or other areas that may concentrate juvenile salmonids (prey) and trigger predators associated with habitats near the Lakeline to display an increased preference for juvenile salmonids. Because the manholes will be partially buried, no overhanging cover will be created and there will be no opportunity for bass or other predatory fish to hide under the manhole and ambush juvenile chinook or coho. These factors are expected to result in minimal increases to the risk of predation as a result of the proposed action. 6.1.2 Critical Habitat for Chinook Salmon Modifications to habitat within the project corridor are discussed in detail in section 6.1.12. Roughly 5 acres of similar lake bottom habitat occurs along the alignment of the 4,700-foot Lakeline. The project will result in the loss of approximately 112 square feet of lake bottom habitats within the Kennydale area of Lake Washington. This represents a loss of approximately 0.0� percent of the available lake bottom habitat along the project alignment. While this impact is not discountable, it has a relatively low level of significance when compared to the potential long term water quality impacts that could continue to occur as a result of continued overflows 20109 March 2001 Revised Janz�ary 2002 Page 20 � ��J ' ' Kennydale Lakefront Sanitary Sewer Bio[ogical Evaluation from the pipeline. This relatively small impact to critical habitat is not expected to be limiting within the system nor result in significant long-term adverse impacts to habitat. 6.1.3 Potential Direct Effects on Bald Eagle ' Eagles have been found to be sensitive to both noise and human activity within specific distances of their nests (Stalmaster, 1987; Watson, 1994). Recommended buffer zones around nest sites range from 600 to 800 feet (Watson and Cunningham, 1994). Less is known about eagle ' tolerance of human activity near feeding or perching sites. The WDFW recommends a buffer of 1,500 feet between feeding areas and both human activity and permanent structures. In perching areas, where little screening is present, buffers of 800 to 1,000 feet are recommended ' (Stalmaster, 1987). The closest known bald eagle territaries are more than 1 mile north of the project area on Mercer Island. No known nesting, roosting, or perching habitat will be impacted by the project. ' ' 1 ' ' ' ' , , , ' ' ' Bald eagles may forage along Lake Washington in the vicinity of the project. The highest level of foraging activity is eYpected during the spring and early summer when nest sites along Lake Washington may be occupied (May through mid-August). The proposed construction window is anticipated to occur within this period; therefore, some foraging activity may occur within the project area during the construction window for this project since eagles are not precluded from the project area and the bald eagle has an extensive prey base. The project area currently experiences noise and activity associated with Interstate 405, industrial activity and a seaplane facility along the southern shore of Lake Washington. In addition, high levels of recreational boating and other human activity associated with nearby Gene Coulon Park and Kennydale Beach Park occur in the area. Eagles that may forage in the project area are likely to be acclimated to activities associated with urban development. Impacts to foraging eagles are not anticipated to be significant. 6.2 Indirect Effects 6.2.1 Potential Indirect Effects On Fish Species The most common indirect effects resulting from construction projects are usually related to habitat modifications that result in impacts to listed species or habitat that may occur later in time beyond the period of construction. For this project, the modification of habitats and increased potential for predation are two impacts that could continue beyond the period of initial construction. These potential direct effects are discussed in detail in Section 6.1 of this assessment. In addition to actions that specifically alter habitat elements, projects related to infrastructure often have indirect impacts related to secondary actions that are either interrelated and/or dependent on the infrastructure modifications. 20/09 March 200! Revised January 2002 Page 21 -r � , ' ' ' ' ' ' ' Kennydale Lakefront Sanitary Sewer Biologica! Evnluation 6.2.1.1 Interrelated and Interdependent Actions The purpose of the proposed action is to construct four access locations so that the City of Renton can perform routine and scheduled maintenance on the existing sewer pipeline. The project has been initiated because the existing Lakeline has sags that tend to collect material and have resulted in occasional overflows of raw sewage into Lake Washington. As discussed in Section 1, the Kennydale Lakeline is an 8-inch diameter cast iron sewer pipeline that serves 52 lakefront homes in the City's Kennydale neighborhood along Lake Washington. Currently all of the lots served by the Lakeline have been developed. No additional sewer hookups will be facilitated by the proposed construction and the proposed action will not add capacity for the purpose of expanding development within the City of Renton. 6.2.2 Critical Habitat for Chinook Salmon The primary indirect effect on Critical Habitat for chinook salmon would be as a result of habitat modifications associated with the installation of each of the four pre-cast manholes. The implications of these alterations are discussed in Sections 6.1.1.2 and 6.1.2. 6.2.3 Potential Indirect Effects on Bald Eagles Indirect effects to bald eagles could occur if the proposed action were to reduce or eliminate ' habitat for eagles or their prey. No perching, nesting, or roosting habitat will be altered by the proposed action. No trees will be removed. , ' � ' , ' Waterfowl prey are abundant in Lake Washington. Seasonal concentrations of these prey species may provide good foraging opporlunities for eagles. Other birds in the project vicinity are likely to be affected to differing degrees by the noise and human activity associated with the sewer line project. Most of the species that currently utilize this habitat are acclimated to a wide range of human activities. Individual birds may be temporarily displaced by the project activities. Most of the displaced birds are anticipated to be waterfowl; however, these impacts are anticipated to be relatively short term and are anticipated to be limited to the period when work is actively occurring to install each manhole. Impacts to the eagle's avian prey base are not expected to be consequential. 6.3 Cumulative Effects The NMFS and USFWS (1998) identify cumulative effects as actions that are reasonably certain to occur, and not involving a federal action. Projects involving a federal action would be evaluated through a separate section 7 review. Most actions directly affecting the lake would require at least one federal permit neYus and therefore would be reviewed separately. ' This project is not eYpected to significantly increase the cumulative effect of development; however, cumulative effects are expected to continue regardless of the proposed action. This study did not include a comprehensive study of land use in the Lake Washington basin; however, , ' 20109 March 2001 Revised January 2002 Page 22 � , ' � ' ' ' Kenrrydale Lakefront Sanitary Sewer Biologrcal Evaluation some level of potential cumulative effects are evident. The shoreline of Lake Washington both in the Kennydale area and elsewhere is largely developed (Photos 1 and 2). Shoreline uses range from high intensity industry to single family homes, to parks and open space. Developinent in the entire Lake Washington Basin including shoreline areas has resulted in an overall degradation of aquatic habitats in the action area as discussed in Section 4 of this assessment. A patchwork of existing zoning codes, sensitive areas regulations, and comprehensive plans regulate land use in the Lake Washington Basin. Some portion of the lake shore is located within 12 local jurisdictions (Renton, Newcastle, Bellevue, Mercer Island, Beaux Arts Village, Medina, Hunts Point, Kirkland, Kenmore, Lake Forest Park, Seattle, and King County) all with differing land-use regulations. However, Lake Washington has been designated a Shoreline of the State and any development within 200 feet of the ordinary high water mark of the lake is subject to review under the Washington State Shoreline Management Act. 6.4 Beneficial Effects The USFWS and NMFS (1998) identify beneficial effects as actions which "are ' contemporaneous positive effects without any adverse effects." While the conservation measures presented below are expected to result in some benefits, these are not considered "beneficial effects" since they are intended to avoid or minimize anticipated adverse effects. The primary , beneficial effect of the project will result from increased reliability in the area's sanitary sewer system that will reduce the risk of untreated sewage being discharged into Lake Washington as a result of overflows from the Kennydale Lakeline. ' 6.5 Conservation Measures , ' ' ' 1 ' A number of conservation measures will be undertaken to minimize potential impacts to listed and candidate species during construction: To avoid potential direct and indirect effects, all permitting agencies, the contractor, and the City of Renton will designate a primary and secondary contact representative. Project goals, methods, schedule, and target milestones will be discussed during a pre-construction meeting attended by all representatives. All coordination will occur through these individuals. The designated representatives will be responsible for distributing pertinent project information to other parties within their organizations. 2. To help avoid unanticipated direct impacts and to minimize identified direct impacts during construction, a qualified fisheries/wildlife biologist will be available on an on-call basis throughout the construction period to advise the City of Renton regarding site specific conservation measures and to provide general spot checks of the implementation of turbidity control measures. The on-call biologist will report directly to the City of Renton representative or agent on-site. 3. To minimize the potential for unanticipated impacts and to insure compliance with permit ' conditions, the City of Renton will designate a responsible party_who is to remain on-site during construction to install each manhole. City representatives are expected to include the , ' 20109 tLtarch 2001 Revised January 2002 Page 23 LJ ' , ' f� � ' ' ' � , ' Kenrrydale Lakefront Sanitary Sewer Biological Eval:�ation on-site construction inspectors and/or engineers who will be present whenever work is occuning on the project. , 4. To minimize the potential for unanticipated impacts and to insure compliance with permit conditions, lake water will be periodically tested for compliance with State of Washington water quality standards. Testing will occur each day prior to the start of construction and will occur throughout the work day. The silt curtain installed along the work area will not be removed until work is completed for each manhole and the pipe repair. 5. To avoid potential direct impacts to rearing juvenile salmonids, in-water construction will only occur from July 15 to October 15 or as otherwise specified by the WDFW HPA permit (currently pending). 6. To minimize the potential for accidents resulting in direct effects to listed and candidate fish, construction equipment will be fitted with emergency spill kits and construction crews will be trained in their proper use. 7. To minimize the potential for accidents which may result in direct effects to listed fish and wildlife, the City of Renton or their agent will be responsible for informing and educating all crew members and all onsite personnel, including the personnel of subcontractors, independent operators, and vendors. Personnel will be informed of environmental precautions and permit conditions. 7.0 SUMMARY 7.1 Chinook Salmon Chinook salmon are present in the Lake Washington basin and are known to utilize the lake as a ' migratory corridor and as rearing habitat. Over their entire range, juvenile chinook may rear in fresh water systems for up to three years. Most juvenile chinook salmon in the Lake Washington drainage rear in fresh water for between one and six months before migrating to Puget Sound via ' the Lake Washington Ship Canal. Some component of this population is thought to hold over within the lake for longer periods. ' ' ' ' ' ' Juvenile chinook salmon in Lake Washington are closely associated with nearshore lake environments and appear to prefer shallow-water habitats with gradually sloping bottoms having uniform, small-grained substrates. Juvenile chinook use is common in Lake Washington through mid July when it is thought that the majority of chinook outmigrate. Juvenile chinook salmon have been observed during night snorkel surveys along the lakeshore in the vicinity of the Kennydale Lakeline alignment; however, no juvenile chinook were observed along the alignment of the sewer pipeline during daylight surveys in the spring of 2000. Juvenile chinook are not eYpected to occur in close association with the habitats located in the vicinity of the proposed locations of the four new manholes. 20109 March 2001 Revised Janz�ary 2002 Page 24 � ' ' 1 ' I � ' Kennydale Lakefront Sanitary Sewer Biological Evaluation Installation of the manholes will result in temporary and permanent alterations of Lake Washington. Installation of the pre-cast manholes may result in temporary increases in turbidity within the immediate work area and juvenile chinook will be temporarily excluded from habitats in the immediate work area during construction. Water quality in the lake could also be affected by spills of hazardous materials should they occur during construction. The level of adverse effect of each of these potential impacts is anticipated to be low. Construction will employ best management practices including the installation of a silt curtain to limit turbidity. Water quality will be monitored during construction. Habitat exclusion is not anticipated to result in a limiting condition for chinook. Work will occur during a relatively short period of time after most juvenile chinook salmon are expected to have outmigrated from the lake, and each manhole location is not consistent ��ith habitats commonly preferred by rearing chinook (deeper habitats with irregular bottoms). Each manhole will occupy approximately 28 ft2 and will extend up to three feet above the lake ' ' bottom. While this modification is not anticipated to result in limitations to chinook salmon by significantly reducing habitat opportunities (the four manholes will cover only about 0.05 percent of the lake bottom within the project corridor), the manholes may provide increased ' habitat opportunities for predator species. The potential for increased predation cannot be discounted; however, the design of the manholes and their location in open portions of the lake �vill likely reduce the potential for increased predation to negligible levels. In the long term, the ' proposed action is not anticipated to result in adverse indirect, interrelated, or interdependent actions that would result in harm to chinook salmon. , ' ' ' ' ' 1 ' ' ' 7.2 Bull Trout Bull trout use within Lake Washington in the project corridor is not expected but is not specifically excluded. Bull trout are known to occasionally occur within the Lake Washington basin and there are no blockages between the project corridor and the rest of the Lake Washington. The most likely scenario for bull trout use within the basin is that adult bull trout may enter Lake Washington to farage. The potential for adult bull trout occurrence within the work areas at each manhole location is expected to be unlikely, but cannot be discounted. Impacts to bull trout, if any are present, are expected to be similar to those discussed above for chinook. The primary exception being that no rearing or spawning activity is expected in the Lake Washington system and, thus, the potential for predation on juvenile bull trout is eYpected to be discountable. 7.3 Bald Eagle The most likely scenario of potential effects on bald eagle is that construction activity and increased human presence in the Kennydale area could result in the temporary limitations on bald eagle foraging. This effect is expected to be minimal since eagles within the action area are likely conditioned to human presence and the project is not anticipated to result in excessive disruptions as a result of construction methods (i.e., no blasting, pile driving, or smoke). 20109 March 2001 Revised January 2002 Puge Z.i � , � 7.4 Coho Salmon Kennydale Lakefront Sanitary Sewer Biological Evaluation , The mechanisms to impact coho salmon are similar to those that may impact chinook except tliat coho salmon are more likely to be present within the project vicinity during construction. Coho use is more abundant in the Lake Washington system and coho are known to regularly rear in ' fresh water streams for up to three years. The level of affect for coho as a result of these elements is not expected to result in long-term reductions to coho populations within the Lake Washington drainage. ' � 8.0 DETERMINATIONS OF EFFECT Provided that the construction techniques and conservation measures summarized herein and � discussed in the Predesign report prepared for the project (Tetra Tech/KCM, 2000) are properly implemented, this project is anticipated to have the_ following effects on ESA regulated species and candidate species: ' 8.1 Threatened Species ' , 1 ' ' 8.1.1 Puget Sound ESU chinook salmon The Kennydale Lakefront Sanitary Sewer project may affect, and is likely to adversely affect, Puget Sound ESU chinook salmon. A"may affect" determination is warranted based on the following rationale: l. Multiple sources document historic chinook usage in Lake Washington and juvenile chinook use of habitats in the vicinity of the Kennydale Lakeline is known to occur. 2. The proposed action will include the temporary modification of water quality in Lake Washington to complete installation of each manhole. The project will involve eYcavation of the lake bottom at each of the proposed manhole locations, which is e;cpected to increase turbidity within the work areas. � 3. The project will require the use of machinery requiring fuel and other fluids. The project will require the contractor to cut a section from the existing Lakeline. While not anticipated, accidents may occur which could discharge toxic materials into the lake and the proposed ' flushing may not be sufficient to remove all materials from the pipeline that could affect water quality. ' , ' ' A"may affect, likely to adversely affect" determination is warranted for this proposed action for chinook because: 1. No in-water work will occur during peak rearing or outmigration periods; however, chinook juveniles, if present, may be harassed by habitat displacement or temporary increases in turbidity during construction. 20109 i�/arch 2001 Revised Janz�ary 2002 Page 26 �,. ' , ' Kennydale Lakefront Sanitary Sewer eiological Evaluation 2. The project will result in habitat modifications that could increase the opportunity for increased predation rates on juvenile chinook salmon. Although predation rates are not anticipated to increase substantially as a result of construction of the four manholes, predation rates are difficult to quantify, particularly over the long-term. , 8.2 Puget Sound/Coastal bull trout 1 LJ �� ll 1 , ' ' 1 ' ' ' ' , � The Kennydale Lakefront Sanitary Sewer project may affect, and is not likely to adversely affect, Puget Sound/Coastal bull trout. A"may affect" determination is warranted based on the following rationale: 1. Reproducing populations of bull trout in the Lake Washington Basin are limited to drainages in the upper Cedar River watershed, but adult bull trout straying from other basins are not specifically precluded from Lake Washington. 2. The proposed action will include the temporar}r modification of water quality and may result in temporary exclusion of habitat by adult bull trout, if present. The project will require the use of machinery requiring fuel and other fluids. While not anticipated, accidents may occur which could discharge toxic materials into Lake Washington. A"may affect, not likely to adversely affect" determination is warranted for this proposed action for bull trout because: 1. The rationale for effects resulting from sedimentation, habitat degradation, and potential toYic spills for bull trout are the same as discussed for chinook. However, the potentially adverse effects related to displacement from rearing habitat and potentially increased predation rates on juveniles, discussed above for chinook, are not anticipated for bull trout because bull trout use in the action area is likely to be by foraging adults. 8.2.1 Bald Eagle This project "may affect," but is "not likely to adversely affect" bald eagles. A"may affect" determination is warranted based on the following rationale: 1. Bald eagles have been identified in the general project vicinity of the proposed action. 2. Bald eagles may forage along Lake Washington in the general vicinity of the Kennydale Lakeline. A"may affect, not likely to adversely affect" determination is warranted for this proposed action for bald eagles because: No impacts to bald eagle nesting activity are anticipated as a result of this project. The closest known bald eagle territory is located on the southern portion of Mercer Island. 2. No potential nesting, roosting, or perching habitat trees will be impacted by the project. 20109 March 2001 Revised Janzrary 2002 Page 27 1 ' ' Kenrrydale Lakejront Sanitary Sewer eiologica! Evale�ation 3. The highest level of foraging activity is expected during the spring and early summer when nest sites along the lake may be occupied. The project will generally occur after the peak nesting season for bald eagles. However, some foraging activity may occur within the project area during the construction window for this project. , 4. Eagles that currently utilize this area are likely to be acclimated to disturbance and activity associated with Interstate 405, surrounding urban developments, and recreational boat use from Gene Coulon Park. ' S. Impacts to the eagles' prey base are expected to be negligible. ' 8.3 Critical Habitat ' 1 ' , ' ' ' 8.3.1 Critical Habitat for Puget Sound ESU Chinook Salmon The Kennydale Lakefront Sanitary Sewer will not result in significant modification of Critical Habitat. The alterations to the lake bottom as a result of the installation of the four pre-cast manholes will affect approximately 0.05 percent of the lalce bottom habitat in the vicinity of the sewer pipeline alignment. This is not expected to result in "adverse modification" to designated chinook Critical Habitat. 8.4 Candidate Species 8.4.1 Coho salmon Coho salmon are currently a candidate fish stock. No protection for candidate stocks is afforded under the ESA, and section 7 consultation or conference with NMFS is not required for anticipated impacts to these species. Summary information for this candidate species is inclltded herein in the event these candidate species become listed ar proposed prior to project completion and to assist with NMFS coordination under the Magnuson-Stevens Fishery Conservation and Management Act. This assessment has identified that the project has the potential to impact coho salmon; however ' the project is not eYpected to result in significant adverse impacts to coho salmon or coho salmon habitat over the long term. Should coho salmon become proposed for listing or listed under the ESA prior to completion of the project, the action agency will confer with NMFS to determine if ' additional coordination or consultation is warranted. In the event that coho become listed prior to project completion, it is expected that further consultation would result in a"may affect, and is likely to adversely affect" determination for coho salmon as defined by section 7 of the ESA. t ' , , A"may affect" determination would be warranted based on the following rationale: 1. Multiple sources document coho usage in Lake Washington. 2. The project area is known to contain habitat suitable to support rearing by coho salmon. 20109 March 2001 Revised Jantrary 2002 Page 28 �.. , ' 1 1 1 1 , ' ' , , 1 ' , 1 ' ' ' ' Kenrrydale Lakefront Sanitary Sewer Biological Evaluarion 3. The proposed action will include the modification of in-water habitats as discussed above for chinook and bull trout. A"may affect, and is likely to adversely affect" determination would be warranted for this proposed action following the same rationale discussed above for chinook salmon. 9.0 ESSENTIAL FISH HABITAT ASSESSMENT The Magnuson-Stevens Fishery Conservation and Management Act (MSA), as amended by the Sustainable Fisheries Act of 1996 (Public Law 104-267), requires Federal agencies to consult with NMFS on activities that may adversely affect Essential Fish Habitat (EFH). The objective of this EFH assessment is to determine whether or not the proposed action "may adversely affect" designated EFH for relevant commercially, federally-managed fisheries species within the proposed action area. It also describes conservation measures proposed to avoid, minimize, or otherwise offset potential adverse effects to designated EFH resulting from the proposed action. For the purpose of this assessment, the proposed action for the EFH assessment and BA incorporate the same project elements. A detailed description of the proposed action is included in Section 4.3 of the BE. As discussed above, the proposed action occurs within Lake Washington, which provides habitat for species of Pacific salmon, specifically chinook salmon, coho salmon, and chum salmon. EFH for the Pacific salmon fishery includes those waters and substrate necessary for salmon production needed to support a long-term sustainable salmon fishery and salmon contributions to a healthy ecosystem. EFH includes all those streams, lakes, ponds, wetlands, and other currently viable water bodies and most of the habitat historically accessible to salmon in Lake Washington. In addition to Pacific salmon, EFH has been designated for groundfish and coastal pelagic species. EFH for Pacific coast groundfish is generally defined as the aquatic habitat from the mean higher high water line, and the upriver extent of saltwater intrusion in river mouths seaward. The Coastal Pelagic Species Fishery Management Plan describes the habitat requirements of five pelagic species: Northern anchovy, Pacific sardine, Pacific (chub) mackerel, jack mackerel and market squid. These four finfish and market squid are treated as a single species complex because of similarities in their life histories and habitat requirements. EFH for coastal pelagic species is generally defined all marine and estuarine waters from the shoreline offshore above the thermocline. 20�09 March 2001 Revised January 2002 Page 29 ' 1 1 ll ' ' ' ' Kennydale Lakefront Sanitary Sewer Biological Evaluation 9.1 Potential Adverse Effects of Proposed Action 9.1.1 Adverse Effects to Salmon EFH Potential effects to Pacific salmon EFH including chinook salmon and coho salmon are discussed in Section 6.0 of this Biological Evaluation. 9.1.2 Adverse Effects to Ground Fish EFH No areas of EFH for Pacific coast groundfish occur within the action area. 9.1.3 Adverse Effects to Coastal Pelagics EFH No areas of EFH for coastal pelagic species occur within the action area. 9.2 EFH Conservation Measures ' The measures implemented for the proposed action in relation to the conservation of ESA- regulated species described in Section 6.5 of the BE will also avoid or minimize the potential adverse effects to designated EFH described above. 1 � , 1 ' ' 1 ' ' ' 9.3 EFH Conclusion The proposed action is anticipated to effect Pacific salmon EFH and Critical Habitat for chinook salmon similarly. The proposed action will require in-water work in water bodies that provide EFH for Pacific salmon species as discussed in Section 6.1.1 of the BE. The proposed action has been identified as having the potential to effect Pacific salmon and their habitat in Lake Washington as a result of construction activities. 20109 March 200/ Revised January 2002 Page 30 � ' ' 1 1 1 1 , ' ' 1 1 ' t , Kennydale Lakefront Sanitary Sewer Biological Evaluation 10.0 REFERENCES AND BIBLIOGRAPHY Adolfson Associates, Inc. 2000. Memorandum describing results of early 2000 habitat surveys in Lake Washington for the Kennydale Lakeline. Beauchamp, D. A., S. A. Vecht and G. L. Thomas. 1992. Temporal, Spatial, and Size- Related Foraging of Wild Cutthroat Trout in Lake Washington. Northwest Sci., Vol. 66 No. 3 p. 149-159. Carrasco, K., S. Foley, and M. Leslie. 1999. Draft Summary of the 1998 Lake Washington Chinook Spawner Survey. Ehrlich, Paul R., and David S. Dobkin, and Darryl Wheye. 1988. The Birder's Handbook. Simon and Schuster Inc. New York. 785 pages. Farr, R. A. and D. L. Ward. 1993. Fishes of the Lower Willamette River•, Near Portland, Oregon. Northwest Sci. Vol. 67 No. 1 p. 16-22. Fayram, Andrew H. 1996. Impacts of Largemouth Bass (Micropterus salmoides) and Smallmouth Bass (Micropterus dolomieui) Predation on Populations of Juvenile Salmonids in Lake Washington. Masters Thesis, University of Washington. Seattle, Washington. Federal Register Volume 64, Number 210, November 1, 1999, Determination of Threatened Status for Bull Trout in the Coterminous United States; Final Rule. Fuerstenberg, R. R. 1998. Needs of Salmon in the Ciry: Habitat in the Urban Landscape. King County Department of Natural Resources. Seattle, WA. Henry, R. 199�. Backgrounder: Coho Salmon and the State Endangered Species Act Special Publication. Oregon Department of Fish and Wildlife. Portland, Oregon. King County Department of Natural Resources (KCDNR), 2000. Lake Washington water quality website http://dnr.metrokc.gov/wlr/waterres/lakes/site0840.htm. Matthews, Daniel. 1988. Cascades, Olympic Natural History. Raven Editions, Portland Oregon. Muller, Martin. Seattle Audubon Society. Telephone Conversation of April 7, 1994. Seattle, Washington. Myers, J. M, R. G. Kope, G. J. Bryant, D. Teel, L. J. Lierheimer, T. C. Wainwright, W. S. ' Grant, F. W. Waknitz, K. Neely, S. T. 1998. NOAA Technical Memorandum NMFS- NWFSC-35 Status Review of Chinook Salmon From Washington, Idaho, Oregon, and California. NOAA. Seattle, WA. ' National Marine Fisheries Service (NMFS) 2000. Biological Opinion: Kennedy Memorial Bridge Replacement Project (Draft), NMFS. Lacey, Washington. ' National Marine Fisheries Service (NMFS). 1996. Making Endangered Species Act Determinations of Effect for Individual or Grouped Actions at the Watershed Scale. NMFS Environmental and Technical Services Division. ' t 20109 March 2001 Revised Jam�ury 2002 Page 3/ r ' ' LJ , II C ' ' ' ' ' 1 ' ' ' ' , ' ' Kennydale Lakefront Sanitary Sewer Biologica! Evalt�arion Piaskowski, 2000. Personal Communication. Telephone Conversation with Webster Peirce. Stalmaster, M. V. and J. R. Newman. 1978. Behavior Response of Wintering Bald Eagles to Human Activity. Journal of Wildlife Management 42: 506 - S 13. Stokes, Donald and Lillian Stokes. 1989. A Guide to Bird Behavior, Volume III. Little, Brown, and Company, Boston, Massachusetts. 397 pages. Swartzman, G. L. and D. A. Beauchamp. 1990. Simulation of the Effect of Rainbow Trout Introduction in Lake Washington. Trans. Am. Fish. Soc. Vol. 119 No. 1 p. 122-li4. Tabor, R. A., R. S. Shively and T. P. Poe. 1993. Predation on Juvenile Salmonids by Smallmouth Bass and Northern Squawfish in the Columbia River near Richland, Washington. N. Am. J. Fish. Manage. Vol. 13 No. 4 p. 831-838. Tetra Tech/KCM. 2000. Kennydale Lakefront Sewer Predesign Report prepared for the City of Renton Utility Systems, Renton, Washington. United States Department of the Interior Fish and Wildlife Service (USFWS). 1986. Recovery Plan for the Pacific Bald Eagle. U.S. Fish and Wildlife Service. Portland Oregon. United States Department of the Interior Fish and Wildlife Service (USFWS). 1998. A Framework to Assist in the Making of Endangered Species Act Determinations of Effect for Individual or Grouped Actions at the Bull Trout Subpopulations Watershed Scale (Draft). U.S. Fish and Wildlife Service. United States Department of the Interior Fish and Wildlife Service (LTSFWS) and National Marine Fisheries Services (NMFS). 1998. Endangered Species Act Consultation Handbook. United States Department of the Interior, Fish and Wildlife Service. 2001. Written Response to Request for Information on Sensitive Species. Washington Department of Ecology (DOE). 2000. Water Quality Website. http://www.ecv.wa.�ov/programs/wq/wQhome.html. December 19, 2000. Washington Department of Fish and Wildlife (WDFW) and Western Washington Treaty Indian Tribes (WWTIT). 1994. 1992 Washington State Salmon and Steelhead Stock Inventory Appendix One Puget Sound Stocks North Puget Sound Volume. Washington Department of Fish and Wildlife. 2000. Habitats and Species Database. Olympia, Washington. Washington Department of Wildlife. 1991. Management Recommendations for Washington's Priority Habitats and Species. Wildlife Management, Fish Management, and Habitat Management Divisions. Olympia, Washington. Watson, James W. and Brenda Cunningham. 1994. Relationships of Human Activity and Habitat Characteristics to Bald Eagle Productivity and Nesting Behavior in Western Washington. Progress Report 1. Washington Department of Wildlife. Olympia, Washington. 11 pages. 20109 March 200J Revised January 2002 Page 32 ' ' , , ' ' ' ' 1 1 ' , ' ' ' ' ' ' ' Kenrrydale Lakefront Sanitary Sewer eiologica! Evaluation Weitkamp, L. A., T. C. Wainwright, G. J. Bryant, G. B. Milner, D. J. Teel, R. G. Kope, and R. S. Waples. 1995. NOAA Technical Memorandum NMFS-NWFSG24; Status Review of Coho Salmon from Washington, Oregon, and California. National Marine Fisheries Service, Northwest Fisheries Science Center, Coastal Zone and Estuarine Studies Division. Seattle Washington. Williams, R. W., R.M. Laramie, and J. J. James. 1975. A Catalog of Washington Streams and Salmon Utilization: Volume l, Puget Sound Region. Washington State Department of Fisheries. Olympia, Washington. Wydoski, R.S., and R.R. Whitney. 1979. Inland Fishes of Washington. University of Washington Press. Seattle, Washington. 20109 March 2001 Revised January 2002 Page 33 ; ' , ' ' ' ' , 1 1 1 1 1 1 1 1 1 1 1 , �' 20109 March 200 / Revised January 2002 Kennydale Lakefront Sanitary Sewer Biological Evaluation APPENDIX A: TABLES / FIGURES .r 1 ' ' ' ' 1 ' ' ' ' ' , ' ' I,� �� ' ' , , Kennyda[e Lakefront Sanitary Sewer Biological Evaluation Table 1. Summary of Baseline Conditions within Lake Washington, Washington. Pathways: Environmental Baseline Effects of the Action(s) Proper(y At risk Not Properly Restore Maintain Degrade Indicators functioning Functioning Water Quality Temperature x x Sediment x x Chemical (contaminants x x and nutrients) (improvement expected) Habitat Access Physical barriers x x Habitat Elements Substrate N/A N/A LWD N/A N/A Pool frequency N/A N/A Pool quality N/A N/A � Refugia N/A N/A Off-channet habitat N/A N/A Channel Condition and Dynamics N/A N/A W idth/Depth Ratio Streambank condition N/A N/A Floodplain Connectivity N/A N/A Flow/Hydrology Peak/Base Flows N/A N/A Drainage Network x x Increase Watershed Conditions Road density and location X X Disturbance History Y % Riparian reserves x s 20109 rLlarch Z001 Revised January 2002 � � � � � � � � � � � � � � � � � � � � � • `` � ', . � �: ; 1;: � �� ,, ; ; � ,' �� ''�� � � „ � a , � � �it i . � , �. , . j'..I�� ry �� t`, �� _ il,. I �I p ' . T �I � �� i� t � I �it . . . . / % i � ' k ��. . , � �� � �� � , �rr � � f � : i � '. �. J ;�/ _ 7 �l � j f . � " w'r O �� �+, � �� � ��� � `2ti. `.. � ,j y , � , ; �` ' � � , . u� 'L � � � ,��., `. �' � �j� �``o. � ;i m �� . -� 'I . �-� ;� �`' .,\',�\ � ` '. '; � �� ` `��. �� '`eu � i� � � � � ��-��- � �� � �:� � � � `��,� . ��, C o � � �:,:�� ,� �� � �. 4} • � 1' � �� `� r �: � if � � ��� � -\ �' ��.. � � ,� � � ��t �� `1�i � ,�'1 � I � � ,`; cn „ ' �n ,, � ;, .`` � `, � .�/ , . , � �`�k , K �l ,�G 1 � �. ; � (, `c � \.,:. �, , � i � " `1 h',+� '. ,� \ \ i ' U YJ O Tetra Tech/ City of Renton KCNI, Inc. KENNYDALE LAKEFRONT SEWER 1917 Fir:st Aven�ie Seattle, Washington 98101 REPLACEMENT PROJECT l ake Wa shington ���. L Mercer lsland � �r��.�Ec r I 5/�� i ^; � �� .: � i, �� 4_. � Q' I . 4' i� 7, I !' � � N � �: �� y'I 1 1 � �°�Y `: Figure 1 Vicinity Map � , _ � �I ' �, I� i sca t� � ' +o•oa �'� ' � /- : � / I � /:� � �_.. 1 � ���� .,\ -1,., � �� ` ��� � _� � �- , s'��I1 -�ril �-�.w. � ,� • _.:.�n��e`NA�B N , I I FLUSH S-AT�ON I, ���-ISIa 0•00) �'� ' \ „ � i 1, � , � � 'y ' � . ,� ' ' ' � � 1 , ' , ' 1 , a, c A 21 > ��� � a: 3 '. 0 .��,:,-. . L � � ' \� �� fl0 _ � : ar:e N;:sti,1;_^,c,r � � � ��' - - -- ---- - — --- - -- - -- LEGEND ---�-- Existing 8" Sewer Line - � --�- -- - - Existing Side Sewer Existing Cleanouts -- — — Approximate Inner Harbor Line _ Proposed Maintenance Manhole Install Nlaintenance Manholes in Four , Locations _ z 1 . ��u„�_. �� � � u . . �_ \ S� ' N i Z \\ � _ � � �-UO a - �ti j � �•��r�.. �� . 1 1 ��. �-. �� � VI t"s ' � —. " � `�`— —� � �,) '�'. �'� . _ \ _ ��w�, �.,� r.,��` Sta �sh, �-� . � F���� `�s` 30-00 ngro��_- • � �'' � ` i�a'�"s: � � . �-� -� Sta � �`� ^ 35�OU � 3�r^no`5... ` —�' '! �� Kern,da;a �i_ "'� f.:� � ` —n � t -� � 5��nir, Beacn aa�i, -' .__-�_ - ' \ - 9tp� :� »e ' — I � _ �G n� p�_ � ~' � � � `- _ \ \ � � � � Four new manholes are installed in the � � existing lakeline to provide access for i ' maintenance. Three of the manholes are � I installed at existing sag locations and the � fourth is south of Coleman Point. I Maintenance of the line would be � ! performed from the water by an outside � � contractor with barge-mounted equipment. � O Telra Tech/ � KCM, lnc. i 1917 First Avenue Seattle, Washington 98101 • • ��� ESTIMATED RANGE OF PERMITTING COST: •, � ��� •� ��� ESTIMATED MAINTENANCE COST: '..• 1�1 •- • �• Maintenance access can be r���e from the lake rather than across ; I residential properties. ; �• Installing manholes at sag locatiuns ; , would facilitate removal �f i accumulated sediment from the li�e. � City of Renton KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT � '. � ~ � i �`� .,, �� is o0 �� ��:����r. �` �:'' '� - ;, . .,� . ,� r� � � �' - ��, \ zc-oo , �"� ��:''1� � .\ �r `Ij .c":;��':�}j�a��.aG;+s��ai=<rr �`'� - � �� �""- =-- � i I :n ' .. � � � '- _ �..� Sta Metro Sewer �p z��. --„` _�,. �� � aa�00 LIF? �,:�.-. �., �-�. :\.t STATION _.. � � �� � � ��. is�a. y>•a;, BurnnttAve Z ' -- ¢,. � - , \ � �+ . � ---'� �' � T ' - ...-, �.,� C c � �`,--� � �� � � �n °` ,� '� <a,}e "j,'=��tf�,�S -:``�:: � ~ � \�wssh� � _'E�� �,,. � � �9ro *.- �'`�rs ��,n e , \a �... �\ 'V��`���� �� � Sta `� SS•00 �ay� `�� I� h � \ � �-� �~`��`\ `� '•,`�" � ���:,t � .,:'� ��` 4, . � �` T`r ? � N = ti .f. + �_ / �• C�88f11(l� th2 �Ill� 'v, ;�. Ga a�-f"�'�G_if1:8� c:���:?"1B,i: fz':�_ ��c: "16 v'��"�r, i:; b� performed by an outside contractor. �• Divers are required to instal� temporary access shafts at manholes each i time the line is cleaned. • Pipeline sag at Station 3+60 is not accessible for sediment removal. ;• Sediment removal will be difficult if existing lakeline an�� side sewers leak i significantly. i• Cleaning services will be expensive. �• Regulatory approvals may be difficult to attain. NOTE: 1. Homes and docks on map based on 1984 survey by Horton Dennis Associates. Figure 2 Kennydale Lake!ine Cxisting ,�lignment and Proposed Manhole Locations � � � � � � � � � � � ! � i � � � � � `� Lake Washington iY,lt `,tidf� ♦ i ii, i� � V �v � E 0 a, a m 0 L N u � I i � Tetra Tech/ City of Renton KCM, Inc KENNYDALE LAKEFRQNT SEWER 1917FirstAven�ie REPLACEMENT PROJECT Seattle, Wasf�inqton 98101 8' ( )uc,ltl�- LxYsting ti � IfUI� `ittd, c:ast hu�i `;r.�:,t,� I- • � New 48" Gi�ni�_ter Precast Manhole I ,�V�e f;u�lulii M Figure 3 Maintenance Manhole Section , or ie�ra iecn�n�m ��uw , ' ' , ' ' 1 � � �_ i!}��. � ,� � ��+�ti ft �.� ; �__- � �—� ��,: ��s��5 �� r� ,�. ��� l 9a�����,`1 ���'"�'� '�t`r�u' ';=�+wi�!'fiL.��lfl.�',::.",li,:':�1l6�,� �...�:1�` ��r- �.���""-'-"����ifi:i_� . ;• � :a _. ' �, �.',—� -_, �; r �.�+� ::,a� s�'..��i . - � � � ! � .,.��~�� . ,��:. ' _ .-4 -. - ;�.t4d` S � `.x'R y�.��":� � s Photo 1: Common shoreline development in the Kennydale area of Renton, Washington. Phoiograpn courtesy of TetreTech/KCM i2G00i ' ' ' ' ' ' �� . ' � � ' s o o: F�� v � � � 4aa� ,3E � �,. . ..._._ �'� ,«. ,.. . .r �j;.� �a ��t �� .a._ MI� ��a� A �: ��� _ ��:�' • �,.,`� '{ ' h . �� �k . .�._ `?k :�y�t.�. ,..�. _ � ' ��(��•';, "ti �} �� i^ .� � �• - 7S__. �. -- -._ '�:�f ' ��:_. :. .. �..� ��,�.�„,�, :� .k ' . . .:ra :.�' � � • - " � �- . � -' '- ���-:. . .;�� -. _ • • _e.:-- . �'""`." �.�-P���_- . _ .. ' ". Photo 2: Common shoreline development in the Kennydale area of Renton, Washington. Note existing lakeline is located under existing docks and boat houses. F�lename 20�09phorol&2a� NoSCale Onginalgraph�cby BCB PHOTOS 1& 2. Edits by Date� 3l12J01 Kennydale Lakeline Sanitary Sewer Renton, Washington ' l� J ' 1 ' Kennydale Lakefront Sanitary Sewer Biological Evaluation APPENDIX B: AGENCY CORRESPONDENCE 1 �l 1 1 0 1 1 1 1 � 1 1 1 20109 March 2001 ' Revised Janz�ary 2002 � ' S�ENr oF Tti ' Q�PP w.: i . �`�ym A y O 7 � , _ . 9. �4ACH 3 �ap ' ' ' Dear Species List Requester: DEC 2 2 2000 You have requested a list of listed and proposed threatened and endangered species, candidate ' species and species of concern (Attachment A) that may be present within the area of your proposed project. This response fulfills the requirements of the U.S. Fish and Wildlife Service (Service) under section 7(c) of the Endangered Species Act of 1973, as amended (Act). We have also enclosed a ' copy of the requirements for Federal agency compliance under the Act (Attachment B). ' Should the Federal agency determine that a listed species is likely to be affected (adversely or beneficially) by the project, you should request section 7 consultation through this office. If the Federal agency determines that the proposed action is "not likely to adversely affect" a listed species, ' you should request Service concurrence with that determination through the informal consultation process. Even if there is a"no effect" situation, we would appreciate receiving a copy for our information. , , ' ' � Species of concern are those species whose conservation standing is of concern to the Service, but for which further status information is still needed. Conservation measures for species of concern are voluntary, but recommended. Protection provided to these species now may preclude possible listing in the future. There may be other federally listed species that may occur in the vicinity of your project which are under the jurisdiction of the National Marine Fisheries Service (NMFS). Please contact NMFS at (360) 753-9�30 to request a species list. In addition, please be advised that federal and state regulations may require permits in areas where wetlands are identified. You should contact the Seattle District of the U. S. Army Corps of Engineers for Federal permit requirements and the Washington State Department of Ecology for State permit requirements. ' , ' ' United States Department of the Interior FISH AND WILDLIFE SERVICE Western Washington Office 510 Desmond Drive SE, Suite 102 Lacey, Washington 98503 Phone: (360) 753-9440 Fax: (360) 534-9331 ' ' ' ' ' , ' ' ' ' ' ' ' ' , ' ' ' ' Your interest in endangered species is appreciated. If you have additional questions regarding your responsibilities under the Act, please contact Yvonne Dettlaff (360) 753-9582 or Bobbi Barrera (360) 753-6048. Sincerely, \ �� / � Gerry A. Ja'ckson, Manager Western Washington Office Enclosure(s) cc: WDFW R4 ' ' ' , ' 1 1 ' , 1 ' , ' ' , ' ' ' ' ATTACHMENT A December 18, 2000 LISTED AND PROPOSED ENDANGERED AND THREATENED SPECIES, CANDIDATE SPECIES AND SPECIES OF CONCERN WHICH MAY OCCUR WITHIN THE VICII�IITY OF THE PROPOSED LAKE WASHINGTON SEWER LINE ADJUSTMENT PROJECT IN KING COUNTY, WASHIi�1GTON (T24N ROSE 531-32; T23N ROSE SS-6) FWS REF: 1-3-01-SP-0275 LISTED Bald eagle (Haliaeetus leucocephalus) - There is one bald eagle nesting territory located in the vicinity of the project at T24NROSES30. Nesting activities occur from January 1 through August 15. Wintering bald eagles may occur in the vicinity of the project. Wintering activities occur from October 31 through March 31. Bull trout (Salvelinus confluentus) - occur in the vicinity of the project. Major concerns that should be addressed in your biological assessment of the project impacts to listed species are: 1. Level of use of the project area by listed species. 2. Effect of the project on listed species' primary food stocks, prey species, and foraging areas in all areas influenced by the project. 3. Impacts from project construction (i.e., habitat loss, increased noise levels, increased human activity) which may result in disturbance to listed species and/or their avoidance of the project area. PROPOSED None. CANDIDATE None. ' ' ' ' ' ' , 1 ' , , ' ' ' ' ' ' ' ' T' SPECIES OF CONCERN The following species of concern may occur in the vicinity of the project: Long-eared myotis (Myotis evotis) Long-legged myotis (Myotis volans) Olive-sided flycatcher (Contopus cooperi) Pacific lamprey (Lampetra tridentata) Peregrine falcon (Falco peregrinus) River lamprey (Lampetra ayresi) Western toad (Bufo boreas) TY 1 Endangered Species Act Status of West Coast Saimon & Steelhead Updated: Februa 22, 200( ,... , . . ,. S ecies/ESU'. St2tU5 ' .:(E = Endangered; T Threatenedt mo./yr.) ' '. ' - ' ': ` NeXt.Ste s >< .. - Pink Sa[mon Listed: __None--M_�--�-_----•_•_•--_.___.�.�----_�----- Not Warranted: 1) Even-year ESU (10/95) 2 Odd- ear ESU 10/95 Listed: 1) Central CA ESU (T - 10/96) 2) Southern OR/Northern CA Coasts ESU (T - 5/97) Coho Salmon 3�_oR Coast Esu.(T.:aisal._...___..______ _. _________ > Complete listing assessments for candidate ESUs. Candidates: ^ 1) Puget Sound/Strait of Georgia ESU (7l95) _2j.Lower Columbia River/Southwest WA ESU_(7/95�_.____._ Not Warranted: 1) Olympic Peninsula ESU (7/95) Listed: 1) Sacramento River Winter-run ESU (E - 1194) 2) Snake River Fall-rvn ESU (T -4/92) 3) Snake River Spring/Summer-run ESU (T-4/92) 4) Puget Sound ESU (T - 3/99) C/ttnOOk 5) Lower Columbia River ESU (T - 3/99) Salmon 6) Upper Willamette River ESU (T - 3/99) 7) Upper Columbia River Spring-run ESU (E - 3/99) 8) Central Valley Spring-run ESU (T - 9/99) > Develop 4(d) rules for Central Valley Spring-run 8 _9) CA_Coastal ESU.iT_9/99) .___..___�_ ,___.�____ CA Coastal ESUs. Candidates: 1�.Central Valley Fall and Late Fall_run ESU�9l99� __^_ Not Warranted: 1) Upper Klamath-Trinity Rivers ESU (3/98) _ 2) OR Coast ESU (3/98) 3) WA Coast ESU (3/98) 4) Mid-Columbia River Spring-run ESU (3/98) 5) Upper Columbia River Summer/Fall-run ESU (3/98) 6) Southern OR and Northem CA Coastal ESU (9/99) 7) Deschutes River Summer/Fall-run ESU (9/99) Listed: 1) Hood Canal Summer-run ESU (T - 3/99) Chum Sa[mon 2) Columbia River ESU (T - 3/99) �---•----•-••----....._.._.---•-------•----•-••••----------•---•----•--_...._... Not Warranted: 1) Puget Sound/Strait of Georgia ESU (3/98) 2) Pacific Coast ESU (3/98) Listed: 1) Snake River ESU (E - 11/91) 2 Ozette Lake ESU T- 3/99 .SOC%iCy¢ ----�._---•--------•--__.---- --------- •----..._--- ................_.._----....... Not Warranted: 1) Baker River ESU (3/99) 2) Okanogan River ESU (3198) 3) Lake Wenatchee ESU (3/98) 4) Quinault Lake ESU (3/98) 5 Lake P�easant ESU 3/98 Listed: 1) Southern CA ESU (E - 8/97) 2) South-Central CA Coast ESU (T - 8/97) 3) Central CA Coast ESU (T - 8/97) 4) Upper Columbia River ESU (E - 8197) 5) Snake River Basin ESU (T - 8/97) Stee[head 6) Lower Columbia River ESU (T - 3/98) > Develop 4(d) rule for Northern CA ESU. 7) CA Central Valiey ESU (T - 3/98) > Complete listing assessments for proposed & , 8) Upper Wiliamette ESU (T - 3/99) candidate ESUs. 9) Middle Columbfa River ESU (T - 3/99) 10 _Northern CA ESU T- 6/00 - � --...-------•••--•...--- --------.. .__...-------------•--._...._-----••-•_ Proposed Listings: _11_Klamath Mountains Province ESU �2/01�_ , Candidates: 2 OR Coast ESU 3l98 -----...--------- __._..._-------•_--------- --- _ ).---••-----------•-••-•--•L------�--•---•-•--------•-- Not Warranted: 1) Southwest WA ESU (8/96) 2) Olympic Peninsula ESU (8/96) 3 Pu et Sound ESU (8/96 ' Proposed Listings: __1)_Southwestern WA/Columbia_Riyer_ESU_jT.;4/991_____________ COaStal Candidates: _1�.Ore�on Coast ESU (4/99)_ ___ .__� ._..___�___�_________ Cutthroat Not Warranted: 1) Puget Sound ESU (4/99) NOTE: This species is now under the jurisdiction of Trout 2) Olympic Peninsula ESU (4/99) the U.S. Fish and Wildlife Service. ' 3) Upper Wiilamette River ESU (4/99) 4) Southern OR/CA Coasts ESU 4/99) '' An Evolutionarily Significant Unit or "ESU" is a distinctive group of Pacific salmon or steelhead. ' 5� ' ' ' , Kenrrydale Lakefront Sanitary Sewer Brological Evaluation I APPENDIX C: FISH AND WILDLIFE HABITAT ASSESSMENT 1 � 1 1 1 1 1 1 , 20109 March 2001 , Revised January 2002 3- , ' MEMORANDUM � DATE: , TO: FROM: ' CC: ' RE: ' ' , ' ' ' ' ' ' ' ' ' , J u ly 25, 2000 City of Renton Webster Peirce, Project Fisheries Scientist �, .�= � nao�FsoM .�Ycvironrnentc�l ,So�ons Jeff Lykken, KCM; Molly Adolfson and Benn Burke, Adolfson Scientist Results of the Spring, 2000 Snorkel Survey, Kennydale Sewer Manhole Installation Project: Renton, Washington Introduction and Purpose The city of Renton is examining the potential environmental impacts that may result from the installation of four subsurface manhole junctions along an existing underwater sewerline in Lake Washington. The existing 8-inch pipeline serves the Kennydale lakefront community, and measures approximately 5,000 in length. The four proposed in-line manhole junctions would be concrete cylinders approximately two feet high and four feet in diameter. Existing conditions along the Kennydale shoreline were assessed by Adolfson fisheries biologist Webster Peirce in the Spring of 2000. The focus of the survey was to observe the use of different cover types along the shoreline by salmonid juveniles and predators of salmonid juveniles, including any use of the existing sewerline. Methods Eight free-dives were conducted during daylight hours over a seven-week period. The time of day, number of days between dives, and direction of approach were varied over the seven-week period, and dives were scheduled during a variety of weather conditions. Total dive time spent in observation was 7.25 hours. In addition to the above parameters, the following qualities of the project area were observed: 1) 2) condition of existing cover for salmonids juveniles and salmonid predators, use of existing cover features by predators and/or juvenile salmonids, and 3) number and species of observed fish. Results The following is a discussion of baseline conditions in the proposed project area. Data sheets for the six dives are included in Appendix A. Route of Existing Pipeline The south end of the existing Kennydale Lakefront Sewerline begins on land at station 0+00 at a flush station. The pipeline then enters Lake Washington at approximately station 2+00, which is located near 2807 Mountain View Avenue North. From this point, the eight-inch pipe runs north along the shoreline, passing under docks and along bulkheads, connecting to approximately 35 smaller residential sewer lines along the way. The north end of the pipeline enters a lift station on shore at station 47+35 where it connects to the Eastside Interceptor sewerline. ADOLFSON ASSOCIATES, INC. 5309 Shilshole Avenue NW, Suite 200 Seattle, WA 98107 Tel 206 789 9658 Fax 206 789 9684 a� , ' For the most part, lake-bottom sediments cover the pipe. Some sections, however, have ' remained uncovered or have been uncovered since the placement of the pipe. Exposure is likely caused by natural movement of the lake bottom or human disturbance of the lake bottom (e.g. prop scour near docks). Approximately 1,000 feet of the 5,000-foot pipeline was observed ' exposed during surveys conducted by the City of Renton in 1987. Although some of the locations of the exposure have changed since 1987, the overall percentage of exposure during the 2000 surveys appeared to be close to the 1987 percentage. 1 ' ' The lake bottom is generally silt and sand, with occasional cobble, rubble and gravel. Little macrophytic vegetation is evident towards the south end of the pipeline, whereas the bottom from station 20+00 to 45+00 is dominated by water milfoil (Myriophyllum spp.). Some areas have large amounts of debris on the lake bottom, including fallen trees, truck tires, lumber, and in one location on the west side of Coleman Point, plywood scraps. Lake-bottom slopes range from nearly flat in some sections to relatively steep in others, dropping several inches in depth per foot. As a result, the pipeline crosses shoreline habitats of varying depth and lies between four and 20 feet below the surface of the lake. Shoreline Conditions ' Much of the shoreline has been densely developed with houses, condominiums, docks, boat launches, and lawns. Shoreside vegetative cover, however, exists in some areas along the survey stretch. Overhanging vegetation along the shoreline that could provide cover for either ' salmonid juveniles or for predators generally consists of deciduous and coniferous trees. Although some of the Kennydale shoreline had been armored with bulkheads and rockery, shallow areas remain that provide suitable rearing habitat for juvenile salmonids. ' , ' ' � � ' ' ' ' Salmonid Observations Approximately 1,000 Coho fry (Oncorhynchus kisutch) measuring approximately 1.4 to 2 inches were observed from April 27 through May 18, with rare sightings on the May 24 dive. These fry were generally found in shallow protected areas along the shore (less than six feet deep), and generally positioned in mid-water (see attached dive notes for specific locations). The only observed cover preference appeared to be schools of three-spine stickleback (Gasterosteus aculeatus). These large schools, numbering in the hundreds, were ubiquitous along the shoreline from April 27 through May 18, and coho were only observed amongst these schools. Coho fry appeared to be fewer in number than the stickleback (approximately 50 to 100 coho fry per school of 100 to 400 stickieback), and stickleback appeared to be slightly larger than the coho fry, ranging from two inches to four inches in length. Shade characteristics did not appear to influence the location of stickleback/coho congregation areas, as some schools were found in shaded areas between docks and some in sunny uncovered locations. Similarly, no bottom features appeared to attract more salmonid fry or stickleback that others. Schools were found above water milfoil, cobble, rubble, fallen trees, and silt. Salmonid Predator Observations Smalimouth and largemouth bass (Micropterus dolomieui and M. salmonides) are common predators of salmonid juveniles in the nearshore habitats of Lake Washington, and these species are known to utilize shade as cover during fry predation. Six smallmouth bass, varying in length from approximately eight inches to 14 inches, were observed during the seven-week survey—some individuals repeatedly observed in the same location over consecutive dives. All bass were initially seen under overhanging cover, although all observed bass left their shaded cover to examine and—with the larger individuals—approach the diver. Two bass, measuring approximately 10 to 12 inches in length, were observed under a ADOLFSON ASSOGIATES, INC. 5309 Shilshole Avenue NW, Suite 200 Seattle, WA 98107 Tel 206 789 9658 Fax 206 789 9684 � � 1 ' , ' 1 prop-scoured section of the sewer pipeline near a dock at station 26+50 on the April 13 and 19 dives. One 8 to 10-inch bass was also observed under this dock on the April 10 and April 19 dives. Two 14-inch and one four-inch smallmouth bass were also observed under a dock located at station 19+10 on May 18. Cylinders of similar dimensions to those proposed for installation were found along the survey route (truck tires), and no fish of any kind were observed utilizing these features as cover or habitat. Details of the observations are listed in the attached field notes for each dive. Water Quality Temperatures during the main period of salmonid presence (Aprii 27 to May 18) started at approximately 60 degrees Fahrenheit (F), dropped to approximately 55 degrees F, and then . reheated to 59 degrees F. High surface turbidity was observed in the upper two feet of the water column during the May-9 dive, dense in some locations and absent in others (see attached dive notes for May 9). Overall, visibility ranged from five to 15 feet with no consistent improvePnent or degradation observed over the seven-week period except that suspended algae reduced visibility during the first two dives in April. Conclusion Suitable cover for coho fry appeared to be schools of similar-sized individuals, while suitable ' cover for smallmouth bass appeared to be overhanging shade. Conversely, vertical cylinders on the bottom unassociated with an overhang or a school of stickieback (e.g. truck tires, lone pilings) did not appear to attract bass or salmonids. ' 1 1 , 1 t J ' ' 1 Overall, cover availability appears to be adequate for both salmonid juveniles and for salmonid juvenile predators. In fact, many suitable cover features were not in use during the field observations: not all schools of stickleback were observed with coho fry, and an estimated 90 percent of the docks observed were unoccupied by bass or other species. ADOLFSON ASSOCIATES, INC. 5309 Shilshole Avenue NW, Suite 200 Seattle, WA 98107 Tel 206 789 9658 Fax 206 789 9684 � Memo ' ' , ' t 1 , , , ' , � , , 1 ' ' , Tetra Tech/KCM, Inc. Date: July 28, 1999 To: Dave Christensen City of Renton Utility Systems 1055 Grady Way South, 5th Floor Renton, WA 98005 c.' Workshop Participants Leslie Betlach, City ofRenton Parks Department LarryFisher, Department ofFish and Wildlife Cen tral Files (2-2) From: Project No.: Jeff Lykken 2830120-003 Subject: City of Renton Kennydale Lakefront Sewer Replacement Project Workshop 3—Alternative Evaluation Workshop This memorandum presents the results of the Kennydale Lakefront Sewer Replacement Project Workshop 3, which was conducted by KCM for the City of Renton on May 19, 1999. Workshop 3 was the third of three workshops conducted during project predesign. Goals for the. workshops were as follows: Workshop 1—Establish goals and constraints for the project Workshop 2—Identify and rank alternatives for repair, rehabilitation and replacement of the sewer system Workshop 3—Refine the alternatives developed in Workshop 2 and narrow the potential solutions for final design. Reduce the list of options to as many as three alternatives, perform additional preliminary engineering, and choose a final design solution. Workshop 1 was a project initiation workshop, conducted on February 16, 1999. Objectives completed at Workshop 1 included bringing the consultant team and City staff to a common understanding of the problems and issues associated with the e�dsting facilities, conceptualizing initial alternatives, confirming project goals and constraints, and establishing criteria for ranking the alternatives. Workshop 2 was conducted on March 9, 1999. Objectives completed at the workshop included brainstorming alternative solutions for the sewer replacement, conducting an initial screening of available alternatives, and selecting the top-ranking alternatives for further evaluation. Following the workshop, KCM performed additional preliminary engineering and cost estimating for the top-ranking alternatives. Tetra Tech/KCM, Inc. � 1917 Firat Avenue • Seattle, WA 98101-1027 • Te1206 443-5300 • Fax 206 443-5372 ' , ' � Goals for Workshop 3 were to present the results of the preliminary engineering and cost estimating and narrow the potential solutions for final design. PROJECT BACKGROUND ' The Kennydale lakefront sanitary sewer is an 8-inch line in Lake Washington that serves appro�mately 51 homes and the Kennydale Beach Park along the lake in Renton. The 4,700-foot-long cast-iron line begins at the north end of Gene Coulon Park and ends at ' North 40th Street. Except for the southern 300 feet of pipe, the sewer was installed in the lake. A flush station (Lake Washington Flush) at the south end of the facility flushes lake water north through the pipe to a City of Renton lift station (Lake Washington #2) in the ' 3900 block of Lake Washington Boulevard North. From there, sewage is pumped up to Metro's Eastside Interceptor sewer in Lake Washington Boulevard. J �II L_� � ' ' � ' , ' ' , ' ' The facility has been difficult to maintain due to sags in the pipe and limited access for maintenance. Sediment accumulates in the sags, causing backups in the line and overflows into Lake Washington. City workers are able to access only about one-third of the line to rod and flush it with their existing equipment. The top of the pipe is exposed above the lake bottom along much of the alignment. Where the pipe is buried, the depth of cover does not exceed 2 feet. The pipe has been snagged and damaged by boaters and contractors more than a half-dozen times. Because of the past problems with the line and continued uncertainty about the pipe's condition, the City wishes to assess upgrading or replacing the facility. KCM, Inc. has been selected by the City of Renton to provide predesign and final design services on the project. Because of this project's many permitting, constructability and community issues, KCM is conducting workshops to identify alternatives and select a preferred alternative for implementation. WORKSHOP PROCESS Workshop 3 was conducted as a facilitator-led working group. It was facilitated by Don Stafford of Robinson, Stafford & Rude, Inc. (RSR). The five-hour workshop consisted of the following steps: Present the results of the preliminary engineering and cost estimating completed for the top-ranking alternatives developed in Workshop 2. Discuss technical issues associated with the alternatives and refine the alternatives as appropriate. Narrow the list of available alternatives for further evaluation. Workshop participants included the following City staff and design team members: • Dave Christensen, City of Renton Wastewater Utility Supervisor • John Thompson, City of Renton Wastewater Maintenance Division • Jennifer Henning, City of Renton Planning • Barry Scott, KCM, Inc. Page 2 , ' ' � ' ' � LJ � � • Jeff Lykken, KCM, Inc. • Molly Adolfson, Adolfson Associates • Jennifer Kauffman, EnviroIssues • Dave Cotton, Golder Associates, Inc. SUMMARY OF ALTERNATIVES Using brainstorming techniques, participants at Workshop 2 identified a list of alternatives to accomplish the following project objective, which was developed in Workshop 1: Provide a cost-effective, reliable and maintainable sewage disposal system with a minimum 20-year life that can be implemented in the current regulatory and community setting. The north and south ends of the lakeline have different physical constraints affecting the feasibility of solutions, so the project was divided into two parts, but without precisely defining the dividing point between the two. Table 1 summarizes the 11 north and south end alternatives that were screened and ranked at Workshop 2 for further evaluation. Two additional alternatives that were not originally screened at Workshop 2 were also ' developed. They were identified as Alternative N15-a and Alternative S15 and are shown in Table 2. Both alternatives involve installing individual grinder pumps stations at the e�usting side sewer locations and pumping to a new low-pressure sewer located onshore. ' These additional alternatives were developed because of feasibility issues related to constructing onshore gravity sewers. � ' � i 1 1 � ' Page 3 � � U � � ' ' ' � LJ � r � � ' � L__1 i I� 1 � TABLE l. ALTERNATIVES DEVELOPED AT WORKSHOP 2 FOR FURTHER EVALUATION No. Descri tion N1 Replace the existing lakeline with a new minimum 6-inch diameter gravity sewer in the lake. N3 Leave the existing lakeline in place, restrain pipe joints, add access points for maintenance, and re-lay portion of the line to remove sags in the profile. N6 Construct a new gravity sewer between the homes and the railroad using trenchless pipeline installation methods. Re-route side sewers to the new gravity sewer using trenchless installation methods. N8 Microtunnel a new gravity sewer in Lake Washington Boulevard and install new side sewers using directional drilling from the lake side. N13 Replace the existing lakeline with a new 6-inch or 8-inch diameter sewer in the lake with flushing capacity. N15 Slipline the existing lakeline to Station 22+50 with 3-inch diameter plastic pipe, install grinder pumps at homes and new pressure side sewers. S3 Leave the existing lakeline in place, restrain pipe joints, add access points for maintenance, and re-lay a portion of the line to remove sags in the profile. S6 Construct a new gravity sewer between the homes and the railroad using open cut pipeline installation methods. Construct a new lift station to convey flows to Lake Washington Boulevard S8 Microtunnel a new gravity sewer in Lake Washington Boulevard and install new side sewers using directional drilling from the lake side. The flush station would remain in service to intermittently flush the new gravity sewer for cleaning purposes. S13 Replace the existing lakeline with a new 6-inch or 8-inch diameter sewer in the lake with flushing capacity. S21 Construct a new gravity sewer between the homes and the railroad north to Station 28+00. Direct flow in the existing lakeline from Station 36+00 south and construct a new lift station at Station 28+00. ' Page 4 � ' 1 ' � , ' ' ' , � � ' ' ' � ' , , � TABLE 2. ADDITIONAL ALTERNATIVES EVALUATED FOR WORKSHOP 3 No. Descri tion N15-a Install grinder pumps at each of the existing side sewer connections between Kennydale Beach Park and the existing lift station. New pressure side sewers would discharge to a new 3-inch force main installed by open-cut construction in the frontage road. S15 Install grinder pumps at each of�the existing side sewer connections between Station 3+00 and Station 25+00. New pressure side sewers would discharge to a new 3-inch force main installed by open cut construction in Mountain View Avenue North. The four southerly homes would drain by gravity to a new gravity sewer. The existing flush station would be replaced with a lift station, and flows from the new main would be pumped up to the existing gravity sewer in Lake Washington Boulevard. PRELIMINARY ENGINEERING AND COST ESTIMATING After Workshop 2, additional preliminary engineering and cost estimating were performed for each of the alternatives listed above. Refinement of the alternatives included the following: • Additional field information was gathered to address construction issues regarding work on individual residential properties and construction within the lake. • Si}c contractors were contacted to discuss the feasibility of employing various construction methods to install new side sewers, a new lakeline, and new onshore gravity and pressure sewers. Construction methods investigated included directional drilling, microtunneling, pipe ramming, marine construction and shore side construction. • City mapping and as-built drawings were assembled for the project area. • A preliminary layout was developed for each alternative. The layouts included an appro�umate profile for gravity sewers and new lakelines. • Planning level cost estimates were prepared for each alternative. • A plan drawing was prepared for each alternative, showing the primary features of the alternative, advantages and disadvantages, and a preliminary project capital cost. The drawings are included in Appendix A. Cost estimates for each alternative are included in Appendix B. Each evaluated alternative presents technical challenges that affect its feasibility. For alternatives that involve construction of a new pipe in the lake, space constraints present the greatest challenge. The existing pipeline is generally constructed close to the shoreline, running beneath most of the existing docks. Lake depth along the alignment is often shallow, in the 4- to 6-foot range, and there is little space between the docks. Page 5 ' ' ' il � �I' � � �J ' ' ' ' � � ' �� General Construction Company, a marine contractor, was contacted about building a new pipeline along the same general alignment. The company said that it would be very complicated and costly to construct a new line along this same alignment. The new line would have to be laid with equipment mounted on a barge. Unless the existing docks were removed during construction and subsequently rebuilt, a custom barge and equipment would be necessary because of the space constraints and shallow water depth. Because of these restrictions, it was assumed that a new pipe will need to be aligned immediately beyond the existing docks for alternatives that include a new lakeline. For alternatives that include construction of a new on-shore sewer, the greatest technical challenge would be rerouting the existing side sewers to the new line. A connection to the e�usting side sewers would have to be made on the west (lake-side) side of the homes, and new side sewers would be routed inland to the new line. On most of the properties, there is very little room between the existing homes, sometimes as little as 8 feet, making it difficult to install a new side sewer. In most cases, the little space available includes improvements such as patios, stairways, decks and rockeries that would have to be removed and replaced if the side sewers were installed using open-cut construction. For this reason, it was assumed that most new gravity side sewers would need to be installed using trenchless methods. It may be possible to install small-diameter pressure side sewers by open-cut construction since the line could be installed at a shallow depth. Findings of the preliminary engineering and cost estimating for each alternative were presented at Workshop 3. The findings are described below, along with technical, permitting and regulatory issues identified for each alternative at the workshop. Alternative Nl A new 6-inch diameter gravity sewer would be installed in Lake Washington beyond the existing docks. The new gravity sewer would have a minimum burial depth of 2 feet below the lake bottom and would have a minimum slope of 0.004 feet per foot. Connection to existing side sewers would be made near the lakeshore, and new side sewers would be extended out to the new lakeline. To attain the minimum burial depth and pipe slope, the existing lift station at the north end of the project would need to be lowered approximately 12 feet. The estimated project cost for Alternative N1 is $1.62 million. Advantages of this alternative are that flushing of the new line would no longer be ' required, gravity flow in the line would reduce maintenance requirements for the sewer, and side sewer connections would cause little disruption to residential properties. , � ' ' � The line would remain vulnerable to damage from homeowners doing work on their docks, and lowering the lift station an additional 12 feet would be difficult and expensive. Adolfson Associates believes this alternative will be the most difficult to permit because of the extent of in-lake work and habitat disturbance, and that the permitting costs during project design could be in the $100,000 to $200,000 range. This level of permitting costs was not accounted for in the cost estimate. Page 6 C� 1 ' , ' Alternative N3 The existing lakeline would remain in service. 1�vo sagging sections of the line would be rerouted closer to the shoreline to improve hydraulic characteristics of the line. Additional access to the pipeline would be added to simplify maintenance, and pipe joints would be restrained where the line is in jeopardy of pulling apart. The exact number of joints needing restraint is not known; for cost estimating purposes, it was assumed that 25 pipe joints would be restrained. This represents approximately 25 percent of the pipe joints between Station 27+50 and the lift station. The estimated project cost for Alternative N3 is $0.68 million. � Of the in-lake alternatives, this alternative would involve the least amount of work in the lake. It has the least cost of the north-end alternatives and requires little work on the residential properties. ' ' ' Disadvantages of this alternative are that pumping rates and flushing velocities of the existing system would remain low, the line would remain vulnerable to damage, and maintenance access to the system would remain difficult. The group agreed that since the structural integrity of the existing 8-inch cast iron lakeline remains questionable, this alternative does not meet the required project objective. Alternative N6 ' A new 24-inch diameter casing pipe and 8-inch diameter carrier pipe would be installed by microtunneling in the frontage road next to the homes. The frontage road is too narrow to install the sewer using open cut construction. Side sewers would be re-routed to the new , sewer by installing new pipe from the west side of the homes using pipe ramming or directional drilling. The estimated project cost for Alternative N6 is $1.52 million. ' Advantages of this alternative are that the sewer line is removed from the lake, the line can be more easily maintained, and the sewer is no longer vulnerable to damage. � Feasibility issues regarding installation of the side sewers and connections to the new sewer main in the frontage road are the major drawbacks of this alternative. Loy Clark Construction, a pipeline contractor, made a visit to the site to assess the feasibility of , installing gravity side sewers using directional drilling. The company's opinion was that the space constraints of the sites would present serious problems in setting up the equipment and installing the side sewer pipe. The risk of failure to install the pipe to grade ' would be high should a contractor attempt directional drilling or pipe ramming. It would also be very difficult to provide access for homeowners during construction of the gravity sewer along the frontage road and connection of the new side sewers. ' ' � The group agreed that this alternative would not receive further consideration because of the feasibility issue of installing the new side sewers. ' Page 7 ' 1 L__. ' , , , ' , ' , � Alternative N8 A new 24-inch diameter casing pipe and 8-inch diameter carrier pipe would be installed by microtunneling in Lake Washington Boulevard. Side sewers would be rerouted to the new sewer by installing new pipe from the west side of the homes using pipe ramming or directional drilling. Each of the new side sewers would need to cross under the Burlington Northern Railroad tracks. The estimated project cost for Alternative N8 is $3.24 million. Advantages of this alternative are that the sewer line would be removed from the lake, the line could be more easily maintained, and the sewer would no longer be vulnerable to damage. As with Alternative N6, the questionable feasibility of installing the side sewers is the major drawback of this alternative. The risk of failure to install the side sewers to grade is much higher with Alternative N8 because of increased side sewer length. Given these drawbacks and the high cost of this alternative, the group concurred that cost and risk are too high to consider this alternative further. The City also believed that it would be impossible to get permits from Burlington Northern Railroad for the number of side sewer crossings required. Alternative N13 A new 8-inch diameter flush line would be installed in Lake Washington beyond the existing docks. The new flush line would have a minimum burial depth of 2 feet below the lake bottom. Connection to the existing side sewers would be made near the lakeshore, and new side sewers would be extended out to the new line. To attain the minimum burial depth, the existing lift station at the north end of the project would need to be lowered approximately 8 feet. The estimated project cost for Alternative N13 is $1.92 million. Advantages of this alternative are that lowering the lift station would increase the amount � of flow that can be flushed through the line without backing up into homes, and that side sewer connections would require little disruption to residential properties. ' ' ' ' 1 ' ' The line would remain vulnerable to damage from homeowners doing work on their docks, and lowering the lift station an additional 8 feet would be difficult and expensive. As with Alternative N1, Adolfson Associates believes this alternative may be expensive to permit. The required level of permitting costs was not accounted for in the cost estimate. Alternative N15 Grinder pump stations would be installed at each of the 18 e�usting side sewer connections between Station 25+00 and the lift station. The existing 8-inch lakeline would be sliplined with a new 3-inch diameter plastic force main pipe. Existing side sewers would be sliplined with new 1.5-inch pressure sewer pipe and connected to the 3-inch main. The new force main would discharge to the existing lift station. The estimated project cost for this alternative is $1.11 million. Page 8 ' ' ' !I ,J �II � Advantages of Alternative N15 are that flushing of the lakeline would no longer be required and the sliplined installation of the 3-inch force main inside the existing 8-inch pipe would be easier and less expensive than installation of a new lakeline. Drawbacks of this alternative are that the City would have 18 additional pump stations to maintain, the sewer line would remain vulnerable to damage in the lake, and repairs to the lakeline would be difficult with the configuration of one pipe inside another. Installation of the grinder pump stations and connection to the existing side sewers would be difficult because of the improvements in place at existing side sewer locations. City staff said they would require installation of a commercial grade duplex pump station , for this alternative rather than the residential grinder pump station typically installed for single-family homes. This requirement was not accounted for in preliminary engineering and cost estimating, and would increase the cost of this alternative. II � ' ' ' � ' The City is also concerned about sewage spills into the lake during power outages or in the event of a mechanical failure, since most of the pump stations would be located near the lake shore. Alternative N15-a Grinder pump stations would be installed at each of the 14 existing side sewer connections between Kennydale Beach Park and the lift station. New 1-1/2-inch pressure side sewers would discharge to a new 3-inch diameter force main installed by open cut construction in the frontage road. It was not known whether the grinder pump stations would have enough head to pump sewage along the alignment and then lift it Lake Washington Boulevard, so it was assumed that the new force main would discharge to the existing lift station. If the individual pump stations have the capacity to lift sewage to Lake Washington Boulevard, the existing lift station would no longer be required, reducing future City operations and maintenance costs. The estimated project cost calculated for this alternative is $0.88 million. Advantages of this alternative are that the sewer line is removed from the lake, the line ' can be more easily maintained, and the sewer is no longer vulnerable to damage. Since the side sewers would only need to be 1-1/2-inch diameter with minimal burial depth, the new lines could likely be installed using trenchless construction techniques. The new 3-inch , force main could be installed by open-cut methods in the frontage road since it will require a minimal burial depth and would not need to be laid to grade. 1 ' ' ' , Drawbacks of this alternative are that the City would have 14. additional pump stations to maintain, and installation of the grinder pump stations and connection to the existing side sewers will be difficult because of the improvements present at the existing side sewer locations. As with Alternative N15, the cost of this alternative would increase with the requirement to install commercial grade duplex pump stations. Page 9 ' 1 ' , , LJ ' ' ' ' ' ' ' ' ' ' ' � , � Alternative S3 The existing lakeline would remain in service. One sagging section of the line would be rerouted overland to improve the line's hydraulic characteristics. Additional access to the pipeline would be added to simplify maintenance of the system, and pipe joints would be restrained where the line is in jeopardy of pulling apart. The exact number of joints needing restraint is not known; for cost estimating purposes, it was assumed that 30 pipe joints would be restrained. This represents appro�umately 25 percent of the pipe joints between Station 4+00 and the Station 27+50. The estimated project cost for Alternative S3 is $0.45 million. The group agreed that since the structural integrity of the existing 8-inch cast iron lakeline remains questionable, this alternative does not meet the required project objective. Alternative S6 A new S-inch gravity sewer would be installed by open-cut construction in Mountain View Avenue North. This road is less constricted than the frontage road on the north end of the project, making open-cut construction possible. While still very difficult, gravity side sewer construction is more feasible on the south end of the project because of fewer space constrictions. Side sewers in constricted areas would be rerouted to the new sewer by installing new pipe from the west side of the homes using directional drilling. In less constricted areas, side sewers could be installed by open-cut construction. Two homes at the far north end of the alternative project limits are too low to be served by the new gravity sewer. These homes would be served by grinder pump stations that pump up to the new gravity sewer. The estimated project cost for Alternative S6 is $1.89 million. Advantages of this alternative are that the sewer line would be removed from the lake, the line could be more easily maintained, and the sewer would no longer be vulnerable to damage. Mountain View Avenue North is as much as 14 feet higher than the elevation of the lowest floor elevation of the homes. This would require the new sewer to be installed 14 to 18 feet deep to serve the homes with low floor elevations. Dave Cotton noted that construction dewatering would be a big concern for this alternative because of the burial depth and groundwater conditions near the lake. Providing access for homeowners during construction would be difficult because of the large equipment required to construct a deep sewer line. The group agreed that this alternative would not receive further consideration because of the required burial depth and the feasibility issue of installing the new side sewers. Alternative S8 A new 24-inch diameter casing pipe and 8-inch diameter carrier pipe would be installed by microtunneling in Lake Washington Boulevard. Side sewers would be rerouted to the new sewer by installing new pipe from the west side of the homes using pipe ramming or directional drilling. Each of the new side sewers would have to cross under the Burlington Northern Railroad tracks. This alternative proved to be unfeasible because of the excessive Page 10 , , ' � ��� � i � I� � burial depth required. The elevation of Lake Washington Boulevard varies from 39 feet to 74 feet within the alternative project limits. The new sewer line would need to be at elevations between 10 and 15 feet to serve the homes. This would require microtunneling pits and side sewer connection excavations in excess of 60 feet. The group agreed that this alternative would not receive further consideration. A project cost was not estimated for Alternative S 13 this alternative. A new 8-inch diameter flush line would be installed in Lake Washington beyond most of the existing docks. The new flush line would have a minimum burial depth of 2 feet below the lake bottom. Connection to the e�.sting side sewers would be made near the lakeshore, and new side sewers would be extended out to the new flush line. The existing flush station would be upgraded to increase flushing capacity. To attain the minimum burial depth, the ea�isting lift station at the north end of the project would need to be lowered approximately 8 feet. The estimated project cost for Alternative S13 is $1.92 million. ' Advantages of this alternative are that lowering the lift station increases the amount of flow that can be flushed through the line without backing up into the existing homes and the side sewer connections would require little disruption to residential properties. ' ' , The line would remain vulnerable to damage from homeowners doing work on their docks, and lowering the lift station an additional 8 feet would be difficult and expensive. Adolfson Associates believes that, like the other lakeline alternatives, this alternative may be expensive to permit. The required level of permitting costs was not accounted for in the cost estimate. Alternative S 15 , Grinder pump stations would be installed at each of the 15 existing side sewer connections between Station 3+00 and Station 25+00. New 1.5-inch pressure side sewers would discharge to a new 3-inch diameter force main installed by open cut construction in , Mountain View Avenue North. It is not known whether the existing grinder pump stations would have enough head to pump sewage along the alignment and then lift it to Lake Washington Boulevard, so it was assumed that the new force main would discharge to a ' new lift station at the location of the existing flush station. If the individual pump stations have the capacity to lift sewage to Lake Washington Boulevard, the new lift station would not be required. The estimated project cost calculated for this alternative is $1.56 million. ' , , ' ' Advantages of this alternative are that the sewer line would be removed from the lake, the line could be more easily maintained, and the sewer would no longer be vulnerable to damage. Since the side sewers would need to be only 1.5-inch diameter, with minimal burial depth, the new lines could likely be installed using trenchless construction in constricted areas. The new 3-inch force main could be installed by open-cut methods in Mountain View Avenue North since it to would require a minimal burial depth and would not need to be laid to grade. Page 11 , � r �I U' ' ' ' , , ' Drawbacks of this alternative are that the City would have 15 additional pump stations to maintain, and installation of the grinder pump stations and connection to the existing side sewers would be difficult at many of the side sewer locations. The new lift station included in the alternative accounts for approximately $530,000 of the overall project cost. The project cost could be reduced by this amount if the individual pump stations have the capacity to lift sewage to Lake the individual grinder pumps would increase with the grade duplex pump systems. Alternative S21 Washington Boulevard. The cost of requirement to install commercial A new 8-inch gravity sewer would be installed in Mountain View Avenue North from the flush station to a new lift station at Station 28+00. The direction of flow in the new line would be from south to north. The existing lakeline would remain in service as gravity sewer between Station 28+00 and Station 31+00 to serve the Kennydale Beach Park. Flows from the new gravity main and remaining lakeline would be pumped up to the existing gravity sewer in Lake Washington Boulevard. Side sewers in constricted areas would be re- routed to the new sewer in Mountain View Avenue North by installing new pipe from the west side of the homes by directional drilling. In less constricted areas, side sewers could be installed using open-cut construction. A project cost of $2.34 million was estimated for Alternative 521. Advantages of this alternative are that most of the sewer ' lake and would no longer be vulnerable to damage, an maintained. line would be removed from the d the line could be more easily , Since Mountain View Avenue North is as much as 14 feet higher than the elevation of the lowest floor elevation of the homes and the new sewer would be laid opposite to the existing road grade, the new sewer would have to be installed 16 to 22 feet deep to serve , the homes with low floor elevations. Because of the excessive burial depth, it was assumed that roughly 1,100 feet of the new gravity main would need to be installed by microtunneling. Providing access for homeowners during construction would be difficult ' because of the size of jacking pits required to microtunnel the new sewer line and casing pipe. ' LJ The group agreed that this alternative would not receive further consideration because of the project cost, required burial depth for the new sewer and the feasibility issue of installing the new side sewers. ALTERNATIVES SCREEIVING RESULTS ' Table 3 lists the alternatives that workshop participants, after review and discussion of all alternatives, concluded do meet project objectives. Of these, the north and south end alternatives were paired to form a list of options for an overall project solution. Order-of- ' magnitude operations and maintenance costs were estimated for each overall solution and added to the project costs previously developed. Table 4 shows the paired alternatives and costs. ' ' Page 12 ' � ' TABLE 3. ALTERNATIVES THAT MEET PROJECT OBJECTIVES North End Alternatives , N1 N13 ' N15 N15-a , South End Alternatives S13 S15 ' TABLE 4. COMBINATIONS OF NORTH AND SOUTH ALTERNATIVES THAT MEET PROJECT OBJECTIVES ' Estimated Cost ($million) Paired Alternatives Canital Cost O& M Cost Total Proiect Cost , N1 & S13a N1 & S15 N13 & S13 N13 & S15a N15 & S13a N15 & S15 N15-a & S13a N15-a & S15 $3.7 $3.2 $4.0 $3.5 $3.5 $2.7 $3.3 $2.4 $0.3 $0.6 $02 $0.6 $0.7 $1.0 $0.7 $1.0 $4.0 $3.8 $4.2 $4.1 $4.2 $3.7 $4.0 $3.4 , � , ' 1 ' , , 1 ' a. A new flush station would be required for this combination of alternatives. Capital and O&M costs for a new flush station are not included above. ALTERNATIVES FOR FURTHER EVALUATION A meeting was held at City Hall in Renton on June 1, 1999 to further narrow the list of paired alternatives. Meeting attendees included the following City staff and design team members: • Dave Christensen, City of Renton Wastewater Utility Supervisor • Jennifer Henning, City of Renton Planning • Leslie Betlach, City of Renton Parks Page 13 , , ' � ' � , , ' , � ' , ' 1 ' ' ' ' � • Barry Scott, KCM, Inc. • Jeff Lykken, KCM, Inc. It was decided at the meeting that the alternative pairs shown in Table 5 best meet the project objective. These two project solutions will be evaluated further. TABLE 5. REMAINING ALTERNATIVES Alternative Pair N13 & S13 N15-a & S15 Replace the existing lakeline with a new 6-inch or 8-inch diameter sewer in the lake with flushing capacity. Install a 3-inch diameter force main in the frontage roads adjacent to the homes, install grinder pump stations at existing side sewer locations and new pressure side sewers. Page 14 ' ' ' , APPENDIX A. PREDESIGN ALTERNATIVES , ' i� � � � ' ' ' ' , J ' ' ' ' 1 ' ' ' , , ' 1 ' a : � � � ' c 1 � Sta ��s+oo _..�� � ��— 6�ry�n9ton � 6 ��he� �'�RR \ � \ � .\ � � -� ?�� sta ` s o� � y_ 30+00 ' ---_ ; � Eathho�se � B��a Maintenance Manhole at Kennvdale Beach Burnelt Ave. A new 6-inch-diameter gravity sewer is installed in Lake Washington beyond the existing private docks. Connection to the existing side sewers wouid be made near the lakeshore and extended out to the new sewer. A new, deeper pump station would be required. The existing lakeline would be abandoned in place. LEGEND --}-- Existing 8" Sewer Line -----------------------��--�-- Existing Side Sewer � Existing Cieanouts -----D—�-- New Sewer Line ----------• New Side Sewer —� - ------ Approximate Inner Harbor Line 100' 0 100' 200' 300' 400' Approximate Scale: 1" = 200' � Park x� 0 � N � se„'� S1.62 miilion • Flushing of line no longer required � • Less maintenance of line required • Connection to existing side sewers requires little disruption to residenYs property N Abandon Existing Lakeline in Place Extend Existing Side Sewers to �� _ New Gravity Line � (14 Total) ��� - _� . � � � � � Lake Washington .` A �., ` � Sta �� _ ! ' �'�`• i� 40+00 � `� � �..�� � � � � � '� � � � � '-� i ' �� Ex�sting Lif'F Station ' - � r �.�. 45S �0 47+35) � �� New �ift Station Invert Elevation of New 6" Sewer Aonrox. -6.0' • Lift station must be lowered approximately 12 feet to accommodate gravity flow • Sewer line remains vulnerable to damage • Disproportionate costs required to continue line to serve the two homes south of Kennydale Beach NOTES: 1. Homes and docks on map based on 1984 survey by Horton Dennis Associates. 2. New 6-inch gravity sewer has a minimum of 2 feet of cover. Tetra Tech/ KCM, Inc. 1917 First Avenue Seattle, Washington 98101 City of Renton KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT New 6" Gravity Sewer Installed Beyond Existing Docks at 0.4% Slope `� � �� .�. Sta �._ 35+00 ALTERN,�TIVE N1 ��� 1 1 1 � ' 1 1 � ' t 1 ' ' ' ' ' ' a d � a ' ' � S� � �„ Z�+00 ��� \ �_'1 F/ 6��y�n81on �o .. . _ r� rthe� RR �°�'e �._ , �., Re-Route —400' of Line Next to Shoreline to Remove Saq � Maintenance Manhole at Kennydale Beach Sta �`� 30+00 �' � - �/'�?'' _ �. Sta y 55+00 �- �h.,. __� `�-�� r'"1 _ 1 � 0 @��p Burnett Ave. The existing lakeline would remain in seivice. Sections of the line that have sags in the profile would be re-routed to improve hydraulics. Access to the line would be provided to simplify maintenance of the system and pipe joints would be restrained where the line is in jeopardy of pulling apart. LEGEND ---►-- Existing 8" Sewer Line �----------------�---------�-- Existing Side Sewer � Existing Cleanouts -----�--�— New Sewer Line ----------- New Side Sewer — -- --- Approximate Inner Harbor Line 100' 0 100' 200' 300' 400' Approximate Scale: 1" = 200' ES TI MATED PROJECT COST: '1.: • Kennydale Beach Park Z1 `d'+ � N 381�i4 Existing Lakeline to Remain in Service; Provide Joint Restraint at Pipe Joints in Jeopardv of Separati Dock Cleanouts at Two Locations Accessible to Citv Jettinq Equipment ` _ \ _ � ,_. \\ sta � ,� , \ }.�_18 � 4�+00 � �, Re-Route —20' of Line to Remove Sa • The least amount of in-water work of all the alternatives that involve a lakeline • Least cost of all the north-end afternatives • Little work required on the residential properties r • Ability of alternative to achieve requireG 20-year design life is questionable because of uncertainty regarding structural integrry of existing lakeline • Pumping rates and flushing velocities of existing system would remain low • Line remains vulnerable to damage • Maintenance access to the line remains difficult • Repositioning pipe joints for sUengthening could cause leaks in the line NOTES: 1. Homes and docks on map based on 1984 survey by HoRon Dennis Associates. 2. Cost estimate based on restraining a total of 25 pipe joints, approximately 2596 of the totai number of joints between 5tation 27+50 and the lift station. Tetra Tech/ KCM, Inc. 1917 First Avenue Seatffe, Washington 98101 City of Renton KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT � � Lake Washington \ _` \ '\ �' ��. �� Existing �tft ._\ Station ISta.47+35) �' � st� � as+oo � �� ,� ALTERNATIVE N3 �� ' ' ' ' 1 ' CI ' ' ' , 1 ' ' ' ' ' � < : � ' � ' �e , �4 , � � � Sta �a8h�he._ eathh�,.�Q•��� �'` ��_ ;'.l 36i QO _\ -. �, � � Sta \ � � 25+00 � ���\ � _ �f � � � Side Sewers Re-Routed to �� _, New Gravity Main by e�r/i � Sta - Directional Drilling or �9to,�No� �� o �� 30+00 ��,` Pipe Ramming From Lake he,n � � RR " �_ y'�� �` �- . @��a -�_` � Kennyda/e Beach Park Open Cut 8" Gravity Sewer in Kennydale Beach Park Burnett Ave. x w � 3 � A new 24-inch-diameter casing pipe and 8-inch-diameter carrier pipe is installed by microtunneling in the frontage road next to the homes. Side sewers would be re- routed to the new sewer by installing new pipe from the lake between the existing houses by pipe ramming or directional drilling. The existing lakeline would be abandoned in place. LEGEND ---�-- Existing 8" Sewer Line --�---�---------------------- Existing Side Sewer � Existing Cleanouts — a New Sewer Line ----------- New Side Sewer — -- � — Approximate Inner Harbor Line 100' 0 100' 200' 300' 400' Approximate Scale: 1" = 200' ESTIMATED PROJECT COST: . , � . � '• Sewer line is removed `rorn the lake • New line can be accessed for � maintenance from Lake Washington Boulevard rather than from private properties • Sewer line no longer vulnerable to damage . Existing Lif� Station ' - � � (Sta. 47+35) y Sta �� ` 45+00� v� �_/ ���1 �� Connection to the existing side sewers and installation of new side sewers to the frontage road will damage yards and bulkheads of residential properties Very difficult to accurately install side sewers to grade to match elevation of new line in frontage road Connection of new side sewers to new main would be difficult because ofwidth constraint of frontage road Access to homes during construction will be very difficult to coordinate NOTES: 1. Homes and docks on map based on 1984 survey by Horton Dennis Associates. 2. Cost of new sewer main would be reduced if installed by directional drilling, however, flat slope of the Ime may make this option unfeasible. Tetra Tech/ KCM, lnc. 1917 Firsf Avenue Seatt/e, Washington 98101 City of Renton KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT Abandon Existing Lakeline in Place � � �, �� _\ ��_ \ � � � � Lake Washington \ � - i 1, \ Sta f:' �`, =_ ` � , � �,�� �►. � 40+00 - , � � �1 '. � New 8" Gravity Main in Microtunneled 24" Casing Pipe at 0.4% Slope �' � ALTERNATIVE N6 ' 1 ' ' , 1 � 1 ' ' ' ' ' ' 1 ' ' m � _ a N O ' � ' � Sta �� 25+00 ��� \ , ,.� � B4ry�n91�� Np� e�� �'R �ake u. .� .,� ,` `�`- , \ �\ e� v New 8" Gravity Main in Microtunneled 24" Casing Pipe in Lake Washington Boulevard at D.4% Slope � A new 24-inch-diameter casing pipe and 8-inch-diameter carrier pipe are installed by microtunneling in Lake Washington Boulevard. Side sewers would be re-routed to the new sewer by installing new pipe from the lake, between the existing houses and under the railroad tracks, by pipe ramming or directional drilling. The exiting lakeline would be abandoned in place. Side Sewers Re-Routed to Microtunneled Gravity Main by Directional Orilling Abandon Existing or Pipe Ramming From the Lake Lakeline in Place . �. ` _ `1 ( ` .� Sta y � 35+00 -_, � ser,� r ! � Kennydale � � Beach Park � ; � � � ^ � + �'� II Burnett Ave. x! � N LEGEND -->-- Existing 8" Sewer Line -------�------��---��-�--- Existing Side Sewer � Existing Cleanouts ---�----- New Sewer Line ----------- New Side Sewer — - - — - - — - Approximate Inner Harbor Line 100' 0 100' 200' 300' 400' Approximate Scale: 1" = 200' ESTIMATED PROJECT COST: • • Sewer line is removed from the lake • New line can be accessed for maintenance from Lake Washington Boulevard rather than from private properties • Sewer line no longer vulnerable to damage \ ��. � � Lake Washington Sta D+00 ( � � �i Existing Lif�' � 1 :,itdtl0ll � (Sta.47+35) ` � ' � sta � i �� ! \4� o/% r • Connection to the existing side sewers and installation of new side sewers to Lake Washington Boulevard will damage yards and bulkheads of residentiat properties • Very difficult to accurately install side sewers to grade to match elevation of new line in Lake Washington Boulevard • Connections of new side sewers to new main would require 30-foot deep excavations in Lake Washington Boulevard • Casing of side sewers may be required under railroad crossing NOTES: 1. Homes and docks on map based on 1984 survey by Horton DennisAssociates. 2. New side sewers would need to be installed at approximately t% slope or less to match grade of new sewer line in Lake Washington Boulevard. Tetra Tech/ KCM, Inc. 1917 Firsf Avenue Seatt/e, Washinqton 98101 City of Renton KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT ALTERN�TIVE N8 ' , ' ' , , ' t ' , ' ' ' ' ' ' m ' � Z < a N O ' � N 1 __ � -���`� \ �� � e4n� _ i � �g�o� No � o, �he� 'QR �� .� '� .\ � sta Lake Washington �� � _` � 25+00 '� ej � � ��/� Sta� �`f j�. 30+00� �.� thhoUSe Extend Existing Side Sewers to New Gravity Line (17 Total) '- Maintenance Manhole at Kennydale Beach ,` -.\ Burnett Ave. A new 8-inch-diameter flush line is installed in Lake Washington beyond the existing private docks. Connection to the existing side sewers would be made nearthe lakeshore and extended out to the new lakeline. A new, deeper pump station would be required. The existing lakeline would be abandoned in place. LEGEND --�-- Existing 8" Sewer Line --�------------------------� Existing Side Sewer ° Existing Cleanouts �— New Sewer Line ----------- New Side Sewer — -- — Approximate Inner Harbor Line 100' 0 t 00' 200' 300' 400' Approximate 5cale: 1" = 200' ESTIMATED PROJECT COST: . � New 8" Flush Line Installed Beyond Existing Abandon Existing Docks w/Minimum Lakeline in Place 2 Feet of Cover Dock Cleanouts at Two Locations Accessible to City Jetting Equipment • Lowering the lift station increases the amount of fiow that can be flushed through the line • Connection to existing side sewers requires little disruption to resident's property � � _` ` -. � ��� �- . M Existing Lif�' S�tlOfl ` � � �%j� � � 5S a 47+35) � �..1' New Lift Station Invert Elevation of New 8" Flush Line ADDfOX. -Z.O • The new alignment would need to be outside the existing docks for constn�ctability. This requires lowering the line to an approximate elevation of -2.0' to provide 2 feet of cover • Lift station must be lowered approximately 8 feet to accommodate lowered flush line • Sewer line remains vulnerable to damage NOTES: 1. Homes and docks on map based on 1984 survey by HoRon DennisAssociates. 2. New 8-inch flush line has a minimum of 2 feet of cover. 3. Cost of new flush station is included in Alternative S13. Tetra Tech/ KCM, lnc. 1917 Firsf Avenue Seattle, Washington 98101 City of Renton KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT Z� � N / Sta � ' �y _ , 35+00 � � � da/e �r, -� � �__ Park � �. � � �?�.� ' � � �• `i ,1 .. � n\� Sta r��i�lk ��.` _li � �i 40+00 ALTERNATIVE N13 ���\ , ' ' ' ' , 1 ' ' ' ' ' ' ' � 1^ Q a N O ' � N ' _� � sta � �, 25+00 ` � _ \ \ � \ � _," � '�Ur/��91 ,.� \ � St8 \� ' eo� , � 30+00 No� � � he�� �� ��> x.� RR �''�� '� 11 �� v� v � Bathho�Se � ej�a Bumett� Grinder pump staticns are installed at each of the existing side sewer connections between Station 25+00 and the lift station. The existing 8" lakeline is sliplined with a new 3-inch-diameter p�astic force main pipe. The existing side sewers are sliplined with a 1-1/2-inch pressure sewerand connected to the 3-inch main. The new force main discharges to the existing lift station LEGEND --� — — Existing 8" Sewer Line -------�-------�---------- Existing Side Sewer Existing Cleanouts ----�-- New Sewer Line ----------- New Side Sewer — — --- Approximate Inner Harbor Line • New Grinder Pump Station � oo� o i oo� 200� 3ao� aoo� Approximate Scale: 1" = 200' ESTIMATED PROJECT COST: • Lake Washington Maintenance Manhole at Kennydale Beach for MaintenanceAccess � \\ � � \ Kennydale Beach Park z, 0 s w � Slipline Existing Lakeline With 3" Plastic Force Main Pipe � � `� Install New 1-1/2" Pressure � Sewer Inside Existing � Side Sewers and Connect � to 3" Pressure Main \\ 5ta Install Grinder 40+00 � � � Pump Sta:ion at � � Each Side y � Sewer Lo�ation � �_i� ���� (18 Total) � � ��.�.➢ 11,� � �-- Dock Cleanout at One Location Accessible to City Jetting Equipment • Flushing of line no longer required • Sliplined installation of pressure main much easier than installation of a new lakeline r � � � ��. ��j`0f�o, _ , � � • City has 18 additional pump stations to maintain and spare pumps to stock • Connection to the existing side sewers and installation of new grinder pump stations will damage yards and bulkheads of residential properties • Sewer line remains wlnerable to damage • Repairs to "pipe inside a pipe" will be difficult in the event of a break �' ���� �� �' _ V Existing Lift Station (5ta. 47+35) Sta � 45+00 � � :� NOTES: 1. Homes and docks on map based on 1984 survey by Horton Dennis Associates. 2. Telemetry for monitoring by City included in cost. � Tetra Tech/ KCM, Inc. 1917 First Avenue Seattle, Washington 98101 City of Renton KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT Std � - � 35+00 � � ALTERNA7IVE N15 \ � \ � Sta ' � v 25+00 �y� � � � � , � e4��4gjo� '� o� � y 30+00 �'��rn R i� ��+:` y� ' �` � \ (a�e i.. `,"� _ e/Vp Burnett Ave. LEGEND --� -- Existing 8" Sewer Line ---------------�-�----��-- Existing Side Sewer � Existing Cleanouts ----n— New Pressure Sewer Main ----------- New Pressure Side Sewer — --- — Approximate Inner Harbor Line • New Grinder Pump Station 100' 0 100' 200' 300' 400' Approximate Scale: 1" = 200' Grinder pump stations are installed at each of the existing side sewer connection between Kennydale Beach Park and the lift station. New pressure side sewers would discharge to a new 3" pressure main installed by open cut in the frontage road. The existing lakeline would be abandoned in place. ESTIMATED I PROJECT COST: .� :: • K Z+ w � S K Abandon Existing Lakeline in Place � � New 1 1/2" Pressure Side Sewers to � New Force Main �-� By Directional Drilling Sta y 35+00 \ � �,�I _ 1 � Park • Sewer line is rerrioved from the lake • New line can be accessed for maintenance from frontage road rather than from private properties • Sewer line no longer vulnerable to damage • Pressure side sewers can be drilled from frontage road � �' � \ _ ` � ��� � � � �� Lake Washingion \ \' �� ', /'-;�. � Sta � � �, ' � 40+00 - \ , - �� Install Grinder Pump Station ! i ; at Each Side Sewer Location �__� (14 total) ;t � Existing Liff � �'� i Station - � ��� � (5ta.47+35) � � Sta � � as+oo � � � Install new i . 3" Open Cut �'�, Pressure Sewer ` � 1 � \.� z� `�, � � �hef''o • Connection to the existing side sewers and installation of the grinder pump stations will damage yards and bulkheads of residential properties • Ciry has 14 additional pump stations to maintain and spare pumps to stock NOTES: 1 Homes and docks on map based on 1984 survey by Horton �ennis Associates. 2. Telemetry for monitoring by City include cost. Tetra Tech/ City of Renton KCM, Inc. ALTERNATIVE N15-a 1997FirstAvenue KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT Seaftle, Washington 98101 ' ' ' / /,. /,. / % i / /,. /� � i ��'� / � / �� �" � '`, / / �� �5 / Sta �._ � 5+00 � � X, / �/ �.._�� � ' ' ' ' ' ' ' ' ' ' ' ' ' , ' FLUSH ,� STATION (sta. o+oo� � / \ 1 � \ / ? N � ? r 100' 0 100' 200' 300' 4Q0' Approximate 5cale: 1" = 200' The existing lakeline remains in service. One section of the line that has a sag in the profile would be re-routed to improve hydraulics. Access to the line would be provided to simplify maintenance of the system and pipe joints would be restrained where the line is in jeopardy of separating. ESTIMATED PROJECT COST: ,� • Z w � r� �, �_ �� Existing Lakeline to � Remain in Service; Provide Joint Restraint at —"�` � � Pipe Joints in Jeopardy �'` � ? �� of Separating ,�,,,� - � I ',.�o,a��� � � � .�� � \ Sta - --_� � � � e+oo �, \ � � -- . , Sta � � (' � ��� y0+00 azo, s � � .�,� � � - � �_ -� 11�� Maintenance Manhole � `�� at Kennydale Beach ' for Maintenance Access � � � � (3 Total) � 1� . �, � t f.,. � � � j i _�� '�`: r ��'`� i i �� �_ z w � f'� � • The least amount of in-water work of any ofthe aftematives that involve a lakeline • Least cost of all the south-end alternatives • Little work required on residential properties z w N 7 a rN' Lake Washington Z w w a M I f� �� \ � Sta � \ � '�,�t�0 � � � \ .`\ _\ `�� � ---��� � � � �a�re � ` //��� � � Sta �ash�' 4'.__ sao, �'� � 30+00 � 9tp' � � /' � � � e� ?�� 1.Q, % � / _�'s` Bathhou e _ � Kennyda/e .. . 8each Park No�her R R • Ability of atternative to achieve required 20-year design life is questionable because of uncertainty regarding structural integrity of existing lakeline • Pumping rates and flushing velocities of existing system would remain low • Line remains vulnerable to damage • Maintenance access to the tine remains difficult • Repositioning pipe joints for strengthening may cause leaks in the line • Negotiating easements for locating maintenance manholes or dock cleanouts on private property may be difficult Metro Sewer Burnett Ave. Z "e+ i N � NOTES: 1. Homes and docks on map based on 1984 survey by Horton Dennis Associates. 2. Cost estimate based on restraining a total of 30 pipe joints, which is approximately 25°�6 of the total number of pipe joints between Station 4+00 and Station 27+50. Tetra Tech/ KCM, lnc. '1917 Firsf Avenue Seattle. Washington 98101 City of Renton KENNYDALE LP,KEFRONT SEWER REPLACEMENT PROJECT Sta 10+00 �/ // e � i .' Re-Route Approximately 250' of Line to Remove Sag ALTERNATIVE S3 LEGEND ---�-- Existing 8" Sewer Line --�--��--------------�----- Existing Side Sewer - Existing Cleanouts --�— New Sewer Line ----------- New Side Sewer -------- Approximate Inner Harbor Line _\ �� ��� / /,. � � / 5ta 10+00 � � .�; /� , ji . / / i �' � r. / � � � '' �y`'\ � i� ��. �! ; t � � �� / i / `�� \ t / / Sta � ••.__ i �� �t .St�� � / X. j' � %" ��i � ��,. , --,..V\e`N P� Replace Existing Flush Station With New Lift Station A new 8-inch-diameter gravity sewer is installed by open cut in Mountain View Avenue North. Side sewers wouid be re-routed to the new sewer by directional drilling or open cutting. The existing flush station would be replaced with a lift station, and flows from the new main would be pumped to the gravity sewer in Lake Washington Boulevard. Grinder pump stations would service the residences at 3233 and 3307 Mountain View Avenue North. The pressure sewer from these two homes would discharge to the new gravity sewer. The existina lakeline would be abandoned in place. Z Bore & Jack Crossing N of Burlington Northern 3 Railroad �, .. ` ��� � Sta ��� 20+00 � `� \ ��� � � � Z w w 1 a � Install New 1-1/2" Open Cut Pressure Sewer to New Gravitv Sewe ' Connect New Force Main to Existing Gravity Sewer in N Lake Washington Boulevard 100' 0 100' 200' 300' 400' Approximate Scale: 1" = 200' ' L' � �� a _ 0 � �� ESTIMATED PROJECT COST: :• • 2 w � s � � � � Abandon Existing � Lakeline in Place �� � �,' "�•� l �\ - � ,��`! � 1 �0,91, � I_.� ` sta ; ` � �5+�� _\ ` � �. ;� � ►�, � � � , l'� ��'� ►, ., 1 ` -=�. �,' l�� ; �. � � ��. ��� Install New 8" Open Cut Gravity Sewer z w � r� 3205 J; � ., . Re-Route Side Sewers to New Gravity Main by Directional Drilling or Ooen Cuttina \ \ \ `� Install Grinder �_ � Pump Stations �� at Two Homes I 2 w u 3 a � • Sewer line is removed from the lake • Flushing of line no longer required • New line can be accessed for maintenance from Mountain View Avenue North • Sewer line is no longer vulnerable to damage � �� � � Sta � 25+00 k �_ -,� ,\ �''d T \ � �, �a � _�'�` � Sta e h'a �� � � 30+00 _ Sh� �.... �� � �� � � f t� hh�O' \ ` � v e/`a � ��` r �� � 8��hh0�se �; '� � Kennyda/e „_.. Beach Park RR • The new gravity main must be installed from 14 to 18 feet deep to serve the homes with lower floor elevations • Access to homes during construction will be very difficuit to coordinate • Re-routing side sewers to Mountain View Avenue North will damage yards of residential properties Metro Sewer Burnett A� Z w � z N r NOTES: 1 Homes and docks on map based on 1984 survey by Horton Dennis Associates. Tetra Tech/ KCM, Inc. '� - 1917 First Avenue ', Seattle. Washington 98101 City of Renton KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT ALTERNATIVE S6 LEGEND --�--- Existing 8" Sewer Line - �---- --��-�---�-�--------- Existing Side Sewer = Existing Cleanouts —�— New Gravity Sewer Line --� New Force Main ----------- New Side Sewer -------- Approximate Inner Harbor Line • New Grinder Pump Station Lake Washington � .� _� ��� / New 8" Flush Line � � Installed Beyond � Existing Docks With /� ' Minimum 2' of Cover /-� .* � �Sta — , 1d�+;00 �I � � / /. /. / Existing Flush Station � -�Sta. 0+00) � � � � Extend Side / Sewers to New Flush Line / (15 Total) f � i. i' Sta / 5+00 . /' � � Rebuild Existing Flush Station � �: Z N �► 3 N T N 100' 0 100' 200' 300' 400' Approximate Scale: 1" = 200' A new 8-inch-diameter flush line is installed in Lake Washington beyond the existing private docks. Connection to the existing side sewers would be made near the lakeshore and extended out to the new lakeline. The existing flush station would be upgraded to increase flushing capacity. The existing lakeline would be abandoned in place. ESTIMATED PROJECT COST: � • / / / . V�a'� z w O � !N' � � � Abandon Existing � -� Lakel�ne in Place � ' �.� ,.,.� \ 'I-r��+��, \ I�, � ��E_. � � . � � Z w � f Sta � 15+00 i �! � yf�� �� � • A new, deeper lift station is required because of the lower profile of the new flush line. Lowering the lift station increases the amount of flow that can be flushed through the line • Connection to existing side sewers requires little disruption to residents' property Lake Washington v;`�� � �� \ � 5�- .� 20+ 0- � �"'� � 3POS� �'. �� "\ �I (r , : �� � � - � � ;i \ . Maintenance Manhole � � on Private Property � �- _ (3 Total) 2 w N 7 G. y � Z w w o. M 1 I � I; �� \\ Sta � 25+00 \ \ � LEGEND — —> — — Existing 8" Sewer Line - -- - - -----�----- ----� Existing Side Sewer Existing Cleanouts --D— New Sewer Line ----------- New Side Sewer -- — — Approximate Inner Harbor Line -�� ��� \ \ '•� \ `_� �r " �r � � Sta � ` , a e�ash� '�� 3ao, ` r�\ 30+00 f^ 'gfOo � � '\ ', � ` e�c.a % � � `\ �� �Se � gathh� V� � '� Kenn�_ ur�f�9ton Beach Park Nonhern R R Metro Sewer Bumett Ave. Z .w m z N ;• • The new lakeline alignment would need to be outside the existing docks for constructability. This requires lowering the line to an approximate elevation of -2.0' to provide 2 feet of cover. • Lift station must be lowered about 10 feet to accomodate lowered flush line • Sewer line remains vulnerable to damage • Maintenance access to the line remains difficult • Negotiating easements for locating maintenance manholes or dock cleanouts on private property may be difficult NOTES: 1 Homes and docks on map based on 1984 survey by Horton Dennis Associates. 2. Maintenance manholes could be located at end of private docks if easements could be negotiated and if they are accessibie by City maintenance equipment. 3. New 8-inch flush line has a minimum of 2 feet of cover. 4. Cost of new lift station is included in Alternative N-13. � , Tetra Tech/ City of Renton ALTERNATIVE S13 , KCM, Inc. -- -- — — 1917FirstAvenue KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT Seattle, Washington 98101 / /,. Sta 10+00 �/ i� �� / /� �;�� / � .� . '1 / i. . /•" � �"� � �n � Sta ,,/ 5+00 J' ; � ,' i Replace Existing Flush Station With New Lift Station Install new 8" open cut iravitv sewer Z w O S f'� Z Bore & Jack Crossing N of Burlington Northern S Railroad N .. ' Connect New Force Main to Existing Gravity Sewer in N Lake Washington Boulevard 100' 0 100' 200' 300' 400' Approximate Scale: 1" = 200' Grinderpump ��_�t.c;�7s a:e .i:stalied at each ofthe existing side sewer connection between Station 3+00 and Station 25+00. New pressure side sewers would discharge to a new 3" pressure main in Mountain View Avenue North. The four southerly homes would drain by gravity to a new gravity sewer. The existing flush station would be replaced with a lift station, and flows from the new main would be pumped up to the gravity sewer in Lake Washington Boulevard. ESTIMATED PROJECT COST: . • _\ '�� � Abandon Existing � Lakeline in Place � t � �� � ,� .I�_`, \ 1 i �oas'. � ''�_. � 1 _ ���\ \ Sta .� ` 15+00 � 'i, � ��\����P _ � ,�, ,fi-� Install New 3" Open Cut Pressure Sewer z w w .. t'� � � , Install Grinder Pump Station at each Side Sewer Location (14 total) � �'� � � � A� � � 3205 i — z w N 7 a T'� Sewer line is removed from the lake Flushing of line no longer required New line can be accessed for maintenance from Mountain View Avenue North Sewer line is no longer vulnerable to damage More flexibility in routing pressure side sewers. New pressure sewer main can be easily installed in Mountain View Avenue North. 0 C ----�-- Existing 8" Sewer Line �------------- �-------------- Existing Side Sewer � Existing Cleanouts ---+�- New Gravity Sewer Line --D- New Force Main ----------- New Side Sewer ------- Approximate Inner Harbor Line • New Grinder Pump Station .�� .\ � Lake Washington ��� I � ��� I '� { �� � � ' �� � � � Sta ` \\�.r1t0� l� � ta�e � ��5���9f �°6 �''a, \\ �� �` � //`�� � �. \. � \ Sta � 30+00 �� �� l�� � gathh '�r� ��''� , , � o�s� �� �� Kennydale � Beach Park No��RR Connection to the existing side sewers and installation of new grinder pump stations will damage yards City has 15 additional pump staiions to maintain and spare pumps to stock Re-routing side sewers to Mountain View Avenue North will be difficult Metro Sewer Burnett Ave. x .w a� s N A NOTES: 1 Homes and docks on map based on 1984 survey by Horton Dennis Associates. 2. Telemetry for monitoring by City included in cost. � Tetra Tech/ KCM, lnc. 1917 Frrst Avenue Seaffle, Washington 98101 City of Renton KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT i � �f�.. V �g:N � LEGEND Re-Route New 1 1/2" Pressure Side Sewers to New Force Main by Directionai Drilling or Open Cutting � S� � �� zo+oo '`'�s+. -i �'�� ��I �\\ � z W W a � ALTERNATIVE S15 / �' � �� / /. /. /,. % /,. � � ��f��� i � � �..._ . < /f � ti / � t' ;sta / �._. � 5+00 /' : � � / / Abandon Existing Flush Station � � \ / �� � �� �� �� •�� � �� i �� �� Z N � S M Sta +. �o+oo � � '� i �� .�f i,:.� �/ . �rJ � � Abandon Existing � Laketine in Place From Station �7 ,, 0+00 to Station 28+00 ���� 1 .� � � sta j � 15+00 � � � '�� ii � L� i� �11 , � _ _ � . . ". � � i � i---� � 11 � i 3115 ,� . � . �� , i; szus , � � �' J � :� i � ' I - I � � • -• • , A new 8-inch-diameter gravity sewer is installed in I$2.34 million ' Mountain View Avenue North from the flush station to � a new lift station at Station 28+00. 5ide sewers would be re-routed to the new sewer by directional drilling , or open cutting. The existing lakeline would remain in service as a gravity line to serve the Kennydale Beach �, �w� Park. The existing flush station would be abandoned. Q� Flows from the new gravity main would be pumped ` II up to the gravity sewer in Lake Washington Boulevard. ` The existing lakeline would be abandoned in place M from Sta 0+00 to Sta 28+00. � �� � Install New 8" Gravity Sewer Between Station 0+00 and Station 28+00 z w � s r� cn Sewer line is removed from the lake Flushing of line no longer required New line can be accessed for maintenance from Mountain View Avenue North Sewer line in Mountain ViewAvenue North not vulnerable to damage z w N � a � � ��� •� � $�a � a`\Ij 2U+U� � ..�, , _ z w w a � LEGEND — --> — — Existing 8" Sewer Line -------------------------��-� Existing Side Sewer Existing Cleanouts —�-- New Open Cut Gravity Sewer Line --�-- New Trenchless Gravity Sewer Line ----------- New Side Sewer -- — -- Approximate Inner Harbor Line — � New Force Main � � ��� � ' - � Lake Washington � .�� � � ��� � � ��� I ��� l �� �-� �d ��� � � \�� 25+00 New Lift Station \ � Invert Elevation � of New 8" �' � Sewer -8.0' ��� �e� dsh�4 ��p�? e/L q 0 Direct Flow in the Existing �akeline From Station 34+00 South to New Lift Station � �� � Sta �o� �- � ` 30+00 i � �ti ��� �_.� .,\ /, ��` hn � ��� eat r � � ��se� ``Kennydale Beach Park Bore 8 Jack Crossing of Connect New Buriington Force Main to Northern Railroad Existing Gravity Sewer in Lake shington Boulevard � . � � ' The new gravity main must be installed from 14 to 24 feet ' deep to serve the homes with lower floor elevations Access to homes during construction will be very difficult. to coordinate • Re-routing side sewers to Mountain View Avenue NoRh will damage yards of residential properties Routing gravity sewer from south to north increases depth of cover, requiring trenchless installation of pipe along majority of route. Remaining lakeline vulnerable to damage. ,,,� RR Metro Sewer Burnett Ave. � w °.+ � N .. NOTES: 1. Homes and docks on map based on 1984 survey by Horton Dennis Associates. Tetra Tech/ I KCM, lnc. 1917 First Avenue ' Seattle, Washington 98101 City of Renton KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT ALTERNATIVE S21 ' ' 1 � ' ' t 1 1 t ' ' � 1 ' ' 1 ' APPENDIX B. ALTERNATIVE COST ESTIMATE 1 � � � � � � � � � � � � � � � � � � � PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Pro'ect Alternative N 1 PROJ. NO: 2830120 CLIENT : Ci of Renton BY: JWL DATE: 2-Au -99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Northend Alternative N1 New Gravity Sewer in the Lake 1 MOBILIZATION (8%) LS 8% $67,800 2 6" SEWER PIPE - 2 TO 4 FEET OF COVER 880 LF $175 $154,000 3 6" SEWER PIPE - 4 TO 8 FEET OF COVER 400 LF $225 $90,000 4 6" SIDE SEWER PIPE 420 LF $150 $63,000 5 CONNECT SIDE SEWER TO MAIN 14 EA $4,000 $56,000 6 NEW LIFT STATION (Incoming IE=-6.0) 1 EA $450,000 $450,000 7 MAINTENANCE MANHOLE 1 EA $35,000 $35,000 SUBTOTAL $916,000 CONTINGENCY 25.0% $229,000 SUBTOTAL $1,145,000 SALES TAX 8.6% $98,000 CONSTRUCTION COST $1,243,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0% $373,000 TOTAL ESTIMATED PROJECT COST $1,616,000 � � � � � � � � � � � � � � � � � � � PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Pro ect Alternative N3 PROJ. NO: 2830120 CLIENT : Cit of Renton BY: JWL DATE: 2-Au -99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Northend Alternative N3 Existing Lakeline to Remain; Restrain Joints; Remove Sags; Add Access 1 MOBILIZATION (8%) LS 8% $28,600 2 8" SEWER PIPE - 2 TO 4 FEET OF COVER 600 LF $300 $180,000 3 PIPE JOINT RESTRAINTS 25 EA $3,000 $75,000 4 6" SIDE SEWER PIPE 180 LF $150 $27,000 5 CONNECT SIDE SEWER TO MAIN 6 EA $4,000 $24,000 6 DOCK CLEANOUT 2 EA $8,000 $16,000 7 MAINTENANCE MANHOLE 1 EA $35,000 $35,000 SUBTOTAL $386,000 CONTINGENCY 25.0% $97,000 SUBTOTAL $483,000 SALES TAX 8.6% $42,000 CONSTRUCTION COST $525,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0% $158,000 TOTAL ESTIMATED PROJECT COST $683,000 � � � � � � � � � � � � � � � � � � � PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Pro'ect Alternative N6 PROJ. NO: 2830120 CLIENT : Ci of Renton BY: JWL DATE: 2-Au -99 ITEM DESCRIPTION (�UANTITY UNIT UNIT AMOUNT NO. PRICE Northend Alternative N6 New Onshore Gravity Sewer 1 MOBILIZATION (8%) LS 8% $63,600 2 8" MICROTUNNELED SEWER PIPE W/ 24" CASING 1240 LF $350 $434,000 3 8" SEWER PIPE - 5 TO 10 FEET DEEP 340 LF $80 $27,200 4 MANHOLES 6 EA $3,800 $22,800 5 6" TRENCHLESS SIDE SEWER PIPE 900 LF $150 $135,000 6 CONNECT TO EXISTING SIDE SEWER 14 EA $2,000 $28,000 7 CONNECT SIDE SEWER TO MAIN 14 EA $4,000 $56,000 8 RESTORE LANDSCAPING / PATIO / BULKHEAD 14 EA $6,000 $84,000 9 ASPHALT OVERLAY, CLASS B 1,400 SY $6.00 $8,400 SUBTOTAL $859,000 CONTINGENCY 25.0% $215,000 SUBTOTAL $1,074,000 SALES TAX 8.6% $92,000 CONSTRUCTION COST $1,166,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0% $350,000 TOTAL ESTIMATED PROJECT COST $1,516,000 � � � � � � � � � � � � � � � � � � � PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Pro'ect Alternative N8 PROJ. NO: 2830120 CLIENT : Ci of Renton BY: JWL DATE: 2-Au -99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Northend Alternative N8 New Microtunneled Gravity Sewer in Lake Washington Boulevard 1 MOBILIZATION (8%) LS 8% $135,900 2 8" MICROTUNNELED SEWER PIPE W/ 24" CASING 2000 LF $500 $1,000,000 3 MANHOLES 5 EA $3,800 $19,000 4 6" TRENCHLESS SIDE SEWER PIPE 2,800 LF $150 $420,000 5 CONNECT TO EXISTING SIDE SEWER 17 EA $2,000 $34,000 6 CONNECT SIDE SEWER TO MAIN 17 EA $7,000 $119,000 7 RESTORE LANDSCAPING / PATIO / BULKHEAD 17 EA $6,000 $102,000 S ASPHALT PAVEMENT PATCH 700 SY $7.50 $5,250 SUBTOTAL $1,835,000 SALES TAX 8.6% $158,000 SUBTOTAL $1,993,000 CONTINGENCY 25.0% $498,000 CONSTRUCTION COST $2,491,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0°/a $747,000 TOTAL ESTIMATED PROJECT COST $3,238,000 � � � � � � � � � � � � � � � � � � � PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Pro'ect Alternative N13 PROJ. NO: 2830120 CLIENT : Ci of Renton BY: JWL DATE: 2-Au -99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Northend Alternative N13 New Gravity Flush Line in the Lake 1 MOBILIZATION (8%) LS 8% $80,500 2 8" SEWER PIPE - 2 TO 4 FEET OF COVER 880 LF $200 $176,000 3 8" SEWER PIPE - 4 TO 8 FEET OF COVER 1,020 LF $250 $255,000 4 6" SIDE SEWER PIPE 540 LF $150 $81,000 5 CONNECT SIDE SEWER TO MAIN 17 EA $4,000 $68,000 6 NEW LIFT STATION (Incoming IE=-2.0) 1 EA $375,000 $375,000 7 DOCK CLEANOUT 2 EA $8,000 $16,000 8 MAINTENANCE MANHOLE 1 EA $35,000 $35,000 SUBTOTAL $1,087,000 CONTINGENCY 25.0% $272,000 SUBTOTAL $1,359,000 SALES TAX 8.6% $117,000 CONSTRUCTION COST $1,476,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0% $443,000 TOTAL ESTIMATED PROJECT COST $1,919,000 � � � � � � � � � � � � � � � � � � � PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Pro'ect Alternative N15 PROJ. NO: 2830120 CLIENT : Ci of Renton BY: JWL DATE: 2-Au -99 ITEM DESCRIPTION 4UANTITY UNIT UNIT AMOUNT NO. PRICE Northend Alternative N15 New Grinder Pump Stations 1 MOBILIZATION (8%) LS 8% $46,600 2 SLIPLINED 3" PRESSURE SEWER 2235 LF $55 $122,925 3 SLIPLINED 1-1/2"" PRESSURE SEWER 600 LF $35 $21,000 4 GRINDER PUMP STATION 18 EA $10,000 $180,000 5 CONNECT SIDE SEWER TO MAIN 18 EA $4,000 $72,000 6 TELEMETRY 18 EA $2,000 $36,000 7 RESTORE LANDSCAPING / PATIO / BULKHEAD 18 EA $6,000 $108,000 8 DOCK CLEANOUT 1 EA $8,000 $8,000 9 MAINTENANCE MANHOLE 1 EA $35,000 $35,000 SUBTOTAL $630,000 CONTINGENCY 25.0% $158,000 SUBTOTAL $788,000 SALES TAX 8.6% $68,000 CONSTRUCTION COST $856,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0% $257,000 TOTAL ESTIMATED PROJECT COST $1,113,000 � � � � � � w ■� +■� � � � � � � � � � � PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Pro'ect Alternative N 15-a PROJ. NO: 2830120 CLIENT : Ci of Renton BY: JWL DATE: 2-Au -99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Northend Alternative N15-a New Onshore Pressure Sewer System 1 MOBILIZATION (8%) LS 8% $37,000 2 3" PRESSURE SEWER 1,580 LF $30 $47,400 3 1-1/2" TRENCHLESS PRESSURE SIDE SEWER 900 LF $50 $45,000 4 CONNECT SIDE SEWER TO MAIN 14 EA $2,500 $35,000 5 CONNECT TO EXISTING SIDE SEWER 14 EA $2,500 $35,000 6 GRINDER PUMP STATION 14 EA $10,000 $140,000 7 TELEMETRY 14 EA $2,000 $28,000 8 RESTORE LANDSCAPING / PATIO / BULKHEAD 22 EA $6,000 $132,000 SUBTOTAL $499,000 CONTINGENCY 25.0% $125,000 SUBTOTAL $624,000 SALES TAX 8.6% $54,000 CONSTRUCTION COST � $678,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0% $203,000 TOTAL ESTIMATED PROJECT COST $881,000 � � � � � � � � � � � � � � � � � � � PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Pro'ect Alternative S3 PROJ. NO: 2830120 CLIENT : Ci of Renton BY: JWL DATE: 2-Au -99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Southend Alternative S3 Existing Lakeline to Remain; Restrain Joints; Remove Sags; Add Access 1 MOBILIZATION (8%) LS 8% $18,700 2 8" SEWER PIPE - 5 TO 10 FEET DEEP 250 LF $80 $20,000 3 PIPE JOINT RESTRAINTS 30 EA $3,000 $90,000 4 6" SIDE SEWER 50 LF $45 $2,250 5 CONNECT SIDE SEWER TO MAIN 1 EA $4,000 $4,000 6 MAINTENANCE MANHOLE 3 EA $35,000 $105,000 7 RESTORE LANDSCAPING / PATIO / BULKHEAD 2 EA $6,000 $12,000 SUBTOTAL $252,000 CONTINGENCY 25.0% $63,000 SUBTOTAL $315,000 SALES TAX 8.6% $27,000 CONSTRUCTION COST � $342,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0% $103,000 TOTAL ESTIMATED PROJECT COST $445,000 � � � � � � � � r � � � �■ � � � � � � PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Pro'ect Alternative S6 PROJ. NO: 2830120 CLIENT : Ci of Renton BY: J W L DATE: 2-Au -99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Southend Alternative S6 New Onshore Gravity Sewer 1 MOBILIZATION (8%) LS 8% $79,200 2 8" SEWER PIPE - 10 TO 15 FEET DEEP 200 LF $96 $19,200 3 8" SEWER PIPE - 15 TO 20 FEET DEEP 1,445 LF $128 $184,960 4 6" SIDE SEWER 2,060 LF $75 $154,500 5 CONNECT SIDE SEWER TO MAIN 16 EA $4,000 $64,000 6 CONNECT TO EXISTING SIDE SEWER 17 EA $2,500 $42,500 7 3" PRESSURE SEWER 420 LF $30 $12,600 8 GRINDER PUMP STATION 2 EA $10,000 $20,000 9 NEW LIFT STATION (Incoming IE=8.0) 1 EA $300,000 $300,000 10 6" FORCE MAIN 100 LF $75 $7,500 11 BORED AND JACKED RAILROAD CROSSING 100 LF $225 $22,500 12 RESTORE LANDSCAPING / PATIO / BULKHEAD 27 EA $6,000 $162,000 SUBTOTAL $1,069,000 CONTINGENCY 25.0% $267,000 SUBTOTAL $1,336,000 SALES TAX 8.6% $115,000 CONSTRUCTION COST $1,451,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0% $435,000 TOTAL ESTIMATED PROJECT COST $1,886,000 � � � � � � � � � � � � � � � � � � � PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Pro'ect Alternative S13 PROJ. NO: 2830120 CLIENT : Ci of Renton BY: JWL DATE: 2-Au -99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Southend Alternative S13 New Gravity Flush Line in the Lake 1 MOBILIZATION (8%) LS 8% $86,900 2 8" SEWER PIPE - 2 TO 4 FEET OF COVER 300 LF $200 $60,000 3 8" SEWER PIPE - 4 TO 8 FEET OF COVER 2,100 LF $250 $525,000 4 6" SIDE SEWER PIPE 1,240 LF $150 $186,000 5 CONNECT SIDE SEWER TO MAIN 15 EA $4,000 $60,000 6 NEW FLUSH STATION - SUBMERSIBLE PUMP 1 EA $150,000 $150,000 7 MAINTENANCE MANHOLE 3 EA $35,000 $105,000 SUBTOTAL $1,173,000 CONTINGENCY 25.0% $293,000 SUBTOTAL $1,466,000 SALES TAX 8.6% $126,000 CONSTRUCTION COST � $1,592,000 ENG., ADMIN. 8� CONSTRUCTION MGMT 30.0% $478,000 TOTAL ESTIMATED PROJECT COST $2,070,000 � � � � � � � � � � � � � � � � � � � PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Pro'ect Alternative S15 PROJ. NO: 2830120 CLIENT : Ci of Renton BY: JWL DATE: 2-Au -99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Southend Alternative S15 New Onshore Pressure Sewer System 1 MOBILIZATION (8%) LS 8% $65,600 2 8" SEWER PIPE - 5 TO 10 FEET DEEP 370 LF $80 $29,600 3 3" PRESSURE SEWER 1,700 LF $30 $51,000 4 1-1/2" TRENCHLESS PRESSURE SIDE SEWER 2,060 LF $50 $103,000 5 CONNECT SIDE SEWER TO MAIN 15 EA $2,500 $37,500 6 CONNECT TO EXISTING SIDE SEWER 15 EA $2,500 $37,500 7 GRINDER PUMP STATION 15 EA $10,000 $150,000 8 NEW LIFT STATION (Incoming IE=8.0) 1 EA $300,000 $300,000 9 6" FORCE MAIN 100 LF $75 $7,500 10 BORED AND JACKED RAILROAD CROSSING 100 LF $225 $22,500 11 RESTORE LANDSCAPING / PATIO / BULKHEAD 27 EA $3,000 $81,000 SUBTOTAL $885,000 CONTINGENCY 25.0% $221,000 SUBTOTAL $1,106,000 SALES TAX 8.6% $95,000 CONSTRUCTION COST $1,201,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0% $360,000 TOTAL ESTIMATED PROJECT COST $1,561,000 PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Pro�ect Alternative S21 PROJ. NO: 2830120 CLIENT : Ci of Renton BY: JWL DATE: 2-Au -99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Southend Alternative S21 New Onshore Gravity Sewer Sta 0+00 to Sta 28+00 1 MOBILIZATION (8%) LS 8% $98,200 2 8" SEWER PIPE - 10 TO 15 FEET DEEP 800 LF $96 $76,800 3 8" MICROTUNNELED SEWER PIPE W/ 24" CASING 1,135 LF $350 $397,250 4 6" SIDE SEWER 2,060 LF $75 $154,500 ' 5 CONNECT SIDE SEWER TO MAIN 16 EA $4,000 $64,000 6 CONNECT TO EXISTING SIDE SEWER 17 EA $2,500 $42,500 7 NEW LIFT STATION (Incoming IE=8.0) 1 EA $300,000 $300,000 8 6" FORCE MAIN 100 LF $75 $7,500 9 BORED AND JACKED RAILROAD CROSSING 100 LF $225 $22,500 10 RESTORE LANDSCAPING / PATIO / BULKHEAD 27 EA $6,000 $162,000 SUBTOTAL $1,325,000 CONTINGENCY 25.0% $331,000 SUBTOTAL $1,656,000 SALES TAX 8.6% $142,000 CONSTRUCTION COST $1,798,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0% $539,000 TOTAL ESTIMATED PROJECT COST $2,337,000 r"� �- CITY UF RENTON � Planning / Building / Pablic Works WORKSHOP NUMBER 3 Kennydale Lakefront Sanitary Sewer Replacement ,� 3 L ' �-�=� i ��:,?"` - _ :�. ^ ""' : '�-.�-��:y^. _ �s -�',�"; _ �Cr- ' v �,,;*� �.� `=�� �-rr. � - - _ -. 7.� - '�-��s��.��"4.��"�,,,;;,.�''' - �� �-� ^S� � `-- - , . ..� '��"" �+fi '.-...s�... � `�.. , _ _ ' _. � ~�C'�.�. _s May 19, 1999 � � and Associated Firms PURPOSE AND SCOPE Workshop 3 is the final workshop in the predesign phase of the Kennydale Lakefront Sewer Replacement Project. �vo previous workshops were conducted on February 16 and March 9, 1999. Goals for the previous workshops are as follows: Workshop 1—Establish goals and constraints for the project Workshop 2—Identify and rank alternatives for repair, rehabilitation and replacement of the sewer system The goal for Workshop 3 will be to refine the alternatives developed in the previous workshop and narrow the potential solutions for final design. The list of options will be reduced to up to three alternatives, and the City of Renton will choose a final design solution. ` 1\� IU : i � �_ _ I� • • Using brainstorming techniques, participants at Workshop 2 identified a list of alternatives that accomplish the following project objective, which was developed in Workshop 1: Provide a cost-effective, reliable and maintainable sewage disposal system with a minimum 20-year life that can be implemented in the current regulatory and community setting. The north and south ends of the lakeline have different physical constraints affecting the feasibility of solutions, so the project was divided into two parts, but without precisely defining the dividing point between the two. Table 1 summarizes the eleven north and south end alternatives that were screened and ranked at Workshop 2 for further evaluation. Additional preliminary engineering and cost estimating was performed for each of these alternatives. Refnement of the alternatives included the following effort: • Additional field information was gathered to address construction issues regarding work on individual residential properties and construction within the lake. • Six contractors were contacted to discuss the feasibility of utilizing different construction methods to install new side sewers, a new lakeline and new onshore gravity and pressure sewers. Construction methods investigated included directional drilling, microtunneling, and shore side construction. • City mapping and as-built drawings were assembled within the project area. • A preliminary layout was developed for each alternative. The layouts included an approximate profile for gravity sewers and new lakelines. • Planning level cost estimates were prepared for each of the alternatives. • An 11"x17" plan drawing was prepared for the alternatives that includes the primary features of the alternative, advantages and disadvantages, and a preliminary project cost. TABLE 1. ALTERNATIVES FOR FURTHER EVALUATION No. Descri tion N1 Replace the existing lakeline with a new minimum 6-inch diameter gravity sewer in the lake. N3 Leave the existing lakeline in place, restrain pipe joints, add access points for maintenance, and re-lay portion of the line to remove sags in the profile. N6 Construct a new b avity sewer between the homes and the railroad using trenchless pipeline installation methods. Re-route side sewers to the new gravity sewer using trenchless installation methods. N8 Microtunnel a new gravity sewer in Lake Washington Boulevard and install new side sewers using directional drilling from the lake side. N13 Replace the existing lakeline with a new 6-inch or 8-inch diameter sewer in the lake with flushing capacity. N15 Slipline the existing lakeline to Station 22+50 with 3-inch diameter plastic pipe, install grinder pumps at homes and new pressure side sewers. Eliminate the existing pump station and add access to the lakeline at 1000-foot intervals. S3 Leave the existing lakeline in place, restrain pipe joints, add access points for maintenance, and re-lay a portion of the line to remove sags in the profile. S6 Construct a new gravity sewer between the homes and the railroad using open cut pipeline installation methods. Construct a new pump station to convey flows to Lake Washington Boulevard S8 Microtunnel a new gravity sewer in Lake Washington Boulevard and install new side sewers using directional drilling from the lake side. The flush station would remain in service to intermittently flush the new gravity sewer for cleaning purposes. S13 Replace the existing lakeline with a new 6-inch or 8-inch diameter sewer in the lake with flushing capacity. S21 Construct a new gravity sewer between the homes and the railroad north to Station 28+00. Direct flow in the existing lakeline from Station 36+00 south and construct a new pump station at Station 28+00. In developing the alternatives, it was found that Alternative S8 was not feasible. A new microtunnel installed in Lake Washington Boulevard along the southern half of the project would have to be up to 60 feet deep, and connection to each side sewer would be prohibitively expensive, therefore a preliminary plan and cost estimate for this alternative was not developed. �vo additional alternatives that were not originally screened at Workshop 2 have been developed and are included in this document. They are identiiied as Alternative N15-a and Alternative 515. Both the alternatives involve installing individual grinder pumps stations at the residences and pumping to a new low- pressure sewer located onshore. These additional alternatives were developed because of feasibility issues related to constructing onshore gravity sewers. The preliminary plans and planning level cost estimates for the developed alternatives are included in the following pages. � \` � sta �25+00 7 � ---� \ �� � . BU� 9to� � w\ 1 No�rh �� ; y ��' RR ���� � �, Sta 30+p0 /� ��� � � � , �a Bath _ Q !�` hO�s � ,,� .. ej�y Kennydafe Beach Park Maintenance Manhole at Kennvdale Beach Burnett Ave. � � � A ne 6'nch-diameter gravity sewer is installe in Lake Washington beyond the existing private docks. Connection to the existing side sewers would be made near the lakeshore and extended out to the new sewer. A new, deeper pump station would be required. The existing lakeline would be abandoned in place. � � a 0 N "1 9 LEGEND — --> — — Existing 8" Sewer Line -�--------------------- Existing Side Sewer � Existing Cleanouts --�— New Sewer Line ----------- New Side Sewer Approximate Inner Harbor Line � oo� o � oo� 200� soo� aoo� Approximate Scale: 1" = 200' ESTIMATED PROJECT COST: . Z, a`+ z � Sta 35+00 • Flushing of line no longer required • Less maintenance of line required • Connection to existing side sewers requires little disruption to residenYs property New 6" Gravity Sewer Installed Beyond Existing � Docks at 0.4% S N Abandon Existing Lakeline in Place end Existing Sid ewers to New Gr ty Line (14 To \ l� Lake Washin on � sta '�. � � 40+00 � - ` � % � � � ( �~� �x_ Existin Lift �'�h 1 Statio � � (Sta.47+ ) � i �� �` a�oo , . , , �� '� • Lift station must be lowered approximately 12 feet to accommodate gravity flow • Sewer line remains vulnerable to damage • Disproportionate costs required to continue line to serve tf�e two homes south of Kennydale Beach � New Lift Station Invert Elevation of New 6" Sewer Aaarox. -6.0' � ., �� ; ���a . � . :` . � ,�C �Z � �� ��,`�''���� ��� i5 � �;�` a� 1���. NOTES: 1. Homes and docks on map based on 1984 survey by HoRon Dennis Associates. 2. New 6inch gravity sewer has a minimum of 2 feet of cover. Tetra Tech/ City of Renton KCM, Inc. ALTERNATIVE N1 f917FirstAvenue KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT Seattle, Washington 98101 PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Project Alternative N1 PROJ. NO: 2830120 CLIENT : Cit of Renton BY: JWL DATE: 18-May-99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Northend Alternative N1 New Gravity Sewer in the Lake 1 MOBILIZATION (8%) LS 8% $67,800 2 6" SEWER PIPE - 2 TO 4 FEET OF COVER 880 LF $175 $154,000 3 6" SEWER PIPE - 4 TO 8 FEET OF COVER 400 LF $225 $90,000 4 6" SIDE SEWER PIPE 420 LF $150 $63,000 5 CONNECT SIDE SEWER TO MAIN 14 EA $4,000 $56,000 6 NEW LIFT STATION (Incoming IE=-6.0) 1 EA $450,000 $450,000 7 MAINTENANCE MANHOLE 1 EA $35,000 $35,000 SUBTOTAL $916,000 CONTINGENCY 25.0% $229,000 SUBTOTAL $1,145,000 SALES TAX 8.6% $98,000 CONSTRUCTIONCOST� $1,243,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0% $373,000 TOTAL ESTIMATED PROJECT COST $1,616,000 �� sta y 25+00 ��� ; � \ \ „ � �„ h � e�n R ��R ��e u. � @��d �� vr y� / Maintenance Manhole at Kennydale Beach ,i � eethho��� ;� '�� � �_ � ��� �� Kennydale � � -, Beach Park � _ Burnett Ave. LEGEND --►— = Existing 8" Sewer Line -------------- Existing Side Sewer � Existing Cleanouts --n— New Sewer Line ----------- New Side Sewer - -- -- Approximate Inner Harbor Line 1 DO' 0 100' 200' 300' 400' Approximate Scale: 1" = 200' The existing lakeline would remain in service. Sections of the line that have sags in the profile would be re-routed to improve hydraulics. Access to the line would be provided to simpliiy maintenance of the system and pipe joints would be restrained where the line is in jeopardy of pulling apart. � � a a N s m � ESTIMATED PROJECT COST: .� • Zl � 3 � Existing Lakeline to Remain in Service; Provide Joint Restraint at Piae Joints in Jeopardv of Separatin Sta 5+00 o \ i � \ i � $t3 � ��•. � �. �+Q � �� Dock Cleanouts at wo Locations Accessible to City Jetting Equipment Lake Washington \ Re-Route -20' of \ Existing LI1t � Line to Remove Sag `'�.� ` Station '' � i��� (Sta 47+35) � � �� � Sta `� � 45+00 ,\ � ;' � . � �� z � �� � , � • The least amount of in-water work of all the alternatives that involve a lakeline • Least cost of all the north-end altematives • Little work required on the residential properties �� �� � / ���fj.O�n• Abiliry of alternative to achieve required 20-year design life is questionable because of uncertainty regarding structural integrity of existing lakeline Pumping rates and flushing velocities of existing system would remain low Line remains vulnerable to damage Maintenance access to the line remains difficult Repositioning pipe joints for strengthening could cause leaks in the line NOTES: 1. Homes and docks on map based on 1984 survey by Horton Dennis Associates. 2. Cost estimate based on restraining a total of 25 pipe joints, approximately 25°� of the total number of joints between Station 27+50 and the lift station. Tetra Tech/ City of Renton KCM, lnc. ALTERNATIVE N3 1917FirstAvenue KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT Seatt/e, Washington 98101 Re-Route -400' of Line Next to Shoreline to Remove Saq �- PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Re tacement Project Alternative N3 PROJ. NO: 2830120 CLIENT : Cit of Renton BY: JWL DATE: 18-May-99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Northend Alternative N3 Existing Lakeline to Remain; Restrain Joints; Remove Sags; Add Access 1 MOBILIZATION (8%) LS 8% $28,600 2 8" SEWER PIPE - 2 TO 4 FEET OF COVER 600 LF $300 $180,000 3 PIPE JOINT RESTRAINTS 25 EA $3,000 $75,000 4 6" SIDE SEWER PIPE 180 LF $150 $27,000 5 CONNECT SIDE SEWER TO MAIN 6 EA $4,000 $24,000 6 DOCK CLEANOUT 2 EA $8,000 $16,000 7 MAINTENANCE MANHOLE 1 EA $35,000 $35,000 SUBTOTAL $386,000 CONTINGENCY 25.0% $97,000 SUBTOTAL $483,000 SALES TAX 8.6% $42,000 CONSTRUCTION COST ; $525,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0% $158,000 TOTAL ESTIMATED PROJECT COST $683,000 �� s� �s+oo � c� � � .� ��� �4�"'�0 � �o,�h i �e�� RR �_ .� �� � � � 30+00 s��d ` �� ` � � nydale ;h Park _ Open Cut 8" Gravity Sewer in Kennydale Beach Park F�+r 6urnelt Ave. x, � z w LEGEND — —� — — Existing 8" Sewer Line --------------------------- Existing Side Sewer � Exis6ng Cleanouts —D-- New Sewer Line ----------- New Side Sewer -- -- -- Approximate Inner Harbor Line 10D' 0 100' 200' 300' 400' Approximate Scale: 1" = 20�' A new 24-inch-diameter casing pipe and 8-inch-diameter carrier pipe is installed by microtunneling in the frontage road next to the homes. Side sewers would be re- routed to the new sewer by installing new pipe from the lake between the existing houses by pipe ramming or directional drilling. The existing lakeline would be abandoned in place. � E � ¢ 'o N O M ESTIMATED PROJECT COST: . • Sewer line is removed from the lake • New line can be accessed for maintenance from Lake VVashington Boulevard rather than irom private propefies • Sewer line no longer vulnerable to damage \ Sta � qp+00 � X�_ New 8" Gravity Main in Microtunneled 24" Casing Pipe at 0.4% Slope NOTES: 1. Homes and docks on map based on 1984 survey by Horton Dennis Associates. 2. Cost of new sewer main would be reduced if installed by directional drilling, however, flat slope of the line may make this option unfeasible. Tetra Tech/ City of Renton KCM, lnc. ALTERNATIVE N6 1917FrrstAvenue KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT Seattle, Washington 98101 Abandon Existing Lakeline in Place Side Sewers Re-Routed to New Gravity Main by Directional Drilling or Pipe Ramming From Lake Sta 35+00 � �. � \ 1 � `J \ � � Lake Washington `` � �- .\ � Exisdng Lift Station \� � (Sta.47+35) `� � Sta 45+00 �\x � � / "> •�, y ; . � : s ,,� r `"\ � , t. �� �i 1: af^o�.. , PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Project Alternative N6 PROJ. NO: 2830120 CLIENT : Cit of Renton BY: JWL DATE: 18-May-99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Northend Alternative N6 New Onshore Gravity Sewer 1 MOBILIZATION (8%) LS 8% $63,600 2 8" MICROTUNNELED SEWER PIPE W/ 24" CASING 1240 LF $350 $434,000 3 8" SEWER PIPE - 5 TO 10 FEET DEEP 340 LF $80 $27,200 4 MANHOLES 6 EA $3,800 $22,800 5 6" TRENCHLESS SIDE SEWER PIPE 900 LF $150 $135,000 6 CONNECT TO EXISTING SIDE SEWER 14 EA $2,000 $28,000 7 CONNECT SIDE SEWER TO MAIN 14 EA $4,000 $56,000 8 RESTORE LANDSCAPING / PATIO / BULKHEAD 14 EA $6,000 $84,000 9 ASPHALT OVERLAY, CLASS B 1,400 SY $6.00 $8,400 SUBTOTAL $859,000 CONTINGENCY 25.0% $215,000 SUBTOTAL $1,074,000 SALES TAX 8.6% $92,000 CONSTRUCTIONCOST� $1,166,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0% $350,000 TOTAL ESTIMATED PROJECT COST $1,516,000 � sta �� �s+oo �� � e``/��91 � � `\ o� �N�he�' � w� �RR ! )- -� ► Side Sewers Re-Routed to Microtunneled Gravity Main by Directional Drilling or Pipe Ramming From the Lake � 30+00`�.. ;'' \ Sta ' y � 35+00 � dale � �� � � Park • _ —_ r>,,, � . 4eo� 3891��e.� B/�� New 8" Gravity Main in Microtunneled 24" Casing Pipe in Lake Washington Boulevard at 0.4% Slope A new 24-inch-diameter casing pipe and 8-inch-diameter carrier pipe are installed by microtunneling in Lake Washington Boulevard. Side sewers would be re-routed to the new sewer by installing new pipe from the lake, between the existing houses and under the railroad tracks, by pipe ramming or directional drilling. The exiting lakeline would be abandoned in place. e � � � — --> — — Existing 8" Sewer Line ------------�---�---- Existing Side Sewer � Existing Cleanouts —n— New Sewer Line ----------- New Side Sewer - Approximate Inner Harbor Line 100' 0 100' 200' 300' 400' Approximate Scale: 1" = 200' ESTIMATED PROJECT COST: . z� w � � � • Sewer line is removed from the lake • New line can be accessed for maintenance from Lake Washington Boulevard rather than from private properties • Sewer line no longer vulnerable to damage Abandon Existing Lakeline in Place � \ � - � \ S�d '��� \ � 40t�� ���. � J Lake Washfngton '� �'� �'� '�. o� N Existing Lirt Station ` � (Sta.47+35) � s� �as+oo � -� � dief�o�^` • Connection to the existing side sewers and installation of new side sewers to Lake Washington Boulevard will damage yards and bulkheads of residential properties • Very difficult to accurately install side sewers to grade to match elevation of new line in Lake Washington Boulevard • Connections of new side sewers to new main would require 30-foot deep excavations in Lake Washington Boulevard • Casing of side sewers may be required under railroad crossing NOTES: 1. Homes and docks on map based on 1984 survey by Horton Dennis Associates. 2. New side sewers would need to be installed at approximately 1°b slope or less to match grade of new sewer line in Lake Washington Boulevard. Tetra Tech/ City of Renton KCM. lnc. 1917FirstAvenue KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT Seattle, Washington 98101 Burnelt Ave. LEGEND ALTERNATIVE N8 PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Project Alternative N8 PROJ. NO: 2830120 CLIENT : Cit of Renton BY: JWL DATE: 18-May-99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Northend Alternative N8 New Microtunneled Gravity Sewer in Lake Washington Boulevard 1 MOBILIZATION (8%) LS 8% $135,900 2 8" MICROTUNNELED SEWER PIPE W/ 24" CASING 2000 LF $500 $1,000,000 3 MANHOLES 5 EA $3,800 $19,000 4 6" TRENCHLESS SIDE SEWER PIPE 2,800 LF $150 $420,000 5 CONNECT TO EXISTING SIDE SEWER 17 EA $2,000 $34,000 6 CONNECT SIDE SEWER TO MAIN 17 EA $7,000 $119,000 7 RESTORE LANDSCAPING / PATIO / BULKHEAD 17 EA $6,000 $102,000 8 ASPHALT PAVEMENT PATCH 700 SY $7.50 $5,250 SUBTOTAL $1,835,000 SALES TAX 8.6% $158,000 SUBTOTAL $1,993,000 CONTINGENCY 25.0% $498,000 CONSTRUCTION COST $2,491,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0% $747,000 TOTAL ESTIMATED PROJECT COST $3,238,000 \ � sta Lake WashMgion � Y25+0o 7 --�� �� .@ " � ' ��i�9ra,� N /' ,�� ��he�n RR � <a�e ,. Extend Existing Side Sewers to New Gravity Line (17 Total) Maintenance Manhole at Kennvdale Beach � St� , 30+00�� 1 Barhhause� � Burnett Ave. @��d y` Park New 8" Flush Line Installed Beyond Existing Abandon Existing Docks w/Minimum Lakeline in Place 2 Feet of Cover Sta 35+00 � a � -� \ Sta ���� � ?�� 40�0 Z, a�+ s � A new 8-inch-diameter gravity sewer is installed in Lake Washington beyond the existing private docks. Connection to the existing side sewers would be made near the lakeshore and extended out to the new lakeline. A new, deeper pump station would be required. The existing lakeline would be abandoned in place. 3 � � a — --> — — Existing 8" Sewer Line -----------------------�---� Existing Side Sewer V Existing Cleanouts —D— New Sewer Line ----------- New Side Sewer Approximate Inner Harbor Line 100' 0 100' 200' 300' 400' Approximate Scale: 1" = 200' ESTIMATED PROJECT COST: . Dock Cleanouts at Two Locations Accessible to Citv Jettina Eauiament r • Lowering the lift station increases the amount of flow that can be flushed through the line • Connection to existing side sewers requires little disruption to resident's property � � , _,, _ � \ � Ex(sting Lif� Station (Sta.4T+35)- Sta 45+00 New Lift Station Invert Elevation of New S" Flush Line Approx. -2.0 • The new alignment would need to be outside the existing docks for constructability. This requires lowering the line to an approximate elevation of -2.0' to provide 2 feet of cover • Lift station must be lowered approximately 8 feet to accommodate lowered flush line • Sewer line remains vulnerable to damage \� � S�,� � NOTES: 1. Homes and docks on map based on 1984 survey by Horton Dennis Associates. 2. New 8-inch flush line has a minimum of 2 feet of cover. 3. Cost of new flush station is included in Atternative 513. Tefra Tech/ KCM. Inc. 1917 First Avenue Seattle, Washington 98101 LEGEND City of Renton KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT ALTERNATIVE N13 PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Replacement Project Alternative N13 PROJ. NO: 2830120 CLIENT : Cit of Renton BY: JWL DATE: 18-May-99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Northend Alternative N13 New Gravity Flush Line in the Lake 1 MOBILIZATION (8%) LS 8% $80,500 2 8" SEWER PIPE - 2 TO 4 FEET OF COVER 880 LF $200 $176,000 3 8" SEWER PIPE - 4 TO 8 FEET OF COVER 1,020 LF $250 $255,000 4 6" SIDE SEWER PIPE 540 LF $150 $81,000 5 CONNECT SIDE SEWER TO MAIN 17 EA $4,000 $68,000 6 NEW LIFT STATION (Incoming IE=-2.0) 1 EA $375,000 $375,000 7 DOCK CLEANOUT 2 EA $8,000 $16,000 8 MAINTENANCE MANHOLE 1 EA $35,000 $35,000 SUBTOTAL $1,087,000 CONTINGENCY 25.0% $272,000 SUBTOTAL $1,359,000 SALES TAX 8.6% $117,000 CONSTRUCTION COST : $1,476,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0% $443,000 TOTAL ESTIMATED PROJECT COST $1,919,000 � sta � „ 25+00 �'�. . \� _ � �� 8��91on N ti, �� `\ �o nher' RR �� . <a'�e � e��a �� - �, Maintenance Manhole at Kennydale Beach for Maintenance Access Sta 30+� %� �\ �� ,, �� Sta r� \ ` � 35+0 ��us� ,� , � ( �Kennydale , Beach Park � _ ¢-... ' ( ;; , , Burnett Ave. LEGEND —�-- Existing 8" Sewer Line Existing Side Sewer �� Existing Cleanouts Grinder pump stations are installed at each of the existing side sewer connections between Station 25+00 and the lift station. The existing 8" lakeline is sliplined with a new 3-inch-diameter plastic force main pipe. The existing side sewers are sliplined with a 1-1/2-inch pressure sewer and connected to the 3-inch main. The new force main discharges to the existing lift station --�-- New Sewer Line ----------- New Side Sewer — -- Approximate Inner Harbor Line • New Grinder Pump Station 100' 0 100' 200' 300' 400' Approximate 5cale: 1" = 200' ESTIMATED PROJECT COST: . z� w � s � Lake Vlpashington 5lipline Existing Lakeline With 3" Plastic Force Main Pipe C '�- i � \ 11i , \ � Sta i� � 40t00 � �: Dock Cleanout at One Location Accessible to City Jettinq Equipment ��. � • Flushing of line no longer required • 5liplined installation of pressure main much easier than installation of a new lakeline 0 City has 18 additional pump stations to maintain and spare pumps to stock Connection to the existing side sewers and installation of new grinder pump stations will damage yards and bulkheads of residential properties Sewer line remains vulnerable to damage Repairs to "pipe inside a pipe" will be difficult in the event of a break � d,� ' NOTES: 1. Homes and docks on map based on 1984 survey by Horton Dennis Associates. 2. Telemetry for monitoring by City included in cost. � J Install New 1-1/2" Pressure Sewer Inside Existing Side Sewers and Connect to 3" Pressure Main Install Grinder Pump Station at � Each Side Sewer Location � (18 Total ) ��� � Existing Lift � Station S� (Sta.47+35j � as+oo � �C /% Tetra Tech/ City of Renton KCM. Inc. ALTERNATIVE N15 1917FirstAvenue KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT Seattle, Washington 98101 PROJECT COST ESTIMATE KCM PROJECT: Kennydale Lakefront Sewer Replacement Project Alternative N15 PROJ. NO: 2830120 CLIENT : Cit of Renton BY: JWL DATE: 18-May-99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Northend Alternative N15 New Grinder Pump Stations 1 MOBILIZATION (8%) LS 8°/a $46,600 2 SLIPLINED 3" PRESSURE SEWER 2235 LF $55 $122,925 3 SLIPLINED 1-1/2"" PRESSURE SEWER 600 LF $35 $21,000 4 GRINDER PUMP STATION 18 EA $10,000 $180,000 5 CONNECT SIDE SEWER TO MAIN 18 EA $4,000 $72,000 6 TELEMETRY 18 EA $2,000 $36,000 7 RESTORE LANDSCAPING / PATIO / BULKHEAD 18 EA $6,000 $108,000 8 DOCK CLEANOUT 1 EA $8,000 $8,000 9 MAINTENANCE MANHOLE 1 EA $35,000 $35,000 S U BTOTAL $630, 000 CONTINGENCY 25.0% $158,000 SUBTOTAL $788,000 SALES TAX 8.6% $68,000 CONSTRUCTION COST � $856,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0% $257,000 TOTAL ESTIMATED PROJECT COST $1,113,000 � sta � �25+00 `�� �."F � �y` .. ' \� � _ . B�hyn9lon c�, �ti� � 7he�n R R � \� aa� � � 30+00 s��d \� � 1 Abandon Existing Lakeline in Place New 1 1/2" Pressure Side Sewers to New Force Main Bv Directional Drillinp � Sta y ` 35+00 `\ hPark ' ��� i`' • - � � i80� 3817I,----� '� . � \ � \ �►. 40+00 Burnett Ave• Grinder pump stations are installed at each of the existing side sewer connection between Kennydale Beach Park and the lift station. New pressure side sewers would discharge to a new 3" pressure main installed by open cut in the frontage road. The existing lakeline would be abandoned in place. � � � � 100' 0 100' 200' 300' 400' Approximate Scale: 1" = 200' ESTIMATED PROJECT COST: � . z, w a z '� • Sewer line is removed from the lake • New line can be accessed for maintenance from frontage road rather than from private properties • Sewer line no longer vulnerable to damage • Pressure side sewers can be drilled from frontage road Install new 3" Open Cut Pressure Sewer \ / Lake Washingion � install Grinder Pump Station at Each Side Sewer Location � (14 total) Existing LiTt StaUon (Sta. 47+35) � sta � as+oo ' �� . .� . ,�,. > • Connection to the existing side sewers and installation of the grinder pump stations will damage yards and bulkheads of residential properties • City has 14 additional pump stations to maintain and spare pumps to stock � � 1�-: NOTES: 1. Homes and docks on map based on 1984 survey by HoRon Dennis Associates. 2. Telemetry for monitoring by City include cost. Tetra Tech/ KCM, Inc. 1917 First Avenue 5eattte. Washington 98101 LEGEND — --> — — Existing 8" Sewer Line --�------------------------- Existing Side 5ewer � Existing Cleanouts --�— New Pressure Sewer Main ----------- New Pressure Side Sewer -------- - Approximate Inner Harbor Line I - New Grinder Pump Station I City of Renton KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT ALTERNATIVE N15-a � � � � � � � � � � � � � � � � � � � PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Project Alternative N15-a PROJ. NO: 2830120 CLIENT : Cit of Renton BY: JWL DATE: 18-Ma -99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Northend Alternative N15-a New Onshore Pressure Sewer System 1 MOBILIZATION (8%) LS 8% $37,000 2 3" PRESSURE SEWER 1,580 LF $30 $47,400 3 1-1/2" TRENCHLESS PRESSURE SIDE SEWER 900 LF $50 $45,000 4 CONNECT SIDE SEWER TO MAIN 14 EA $2,500 $35,000�- 5 CONNECT TO EXISTING SIDE SEWER 14 EA $2 � 6 GRINDER PUMP STATION 14 EA 1,0 $140,000 7 TELEMETRY 14 EA 2,000 $28,000 8 RESTORE LANDSCAPING / PATIO / BULKHEAD 22 EA 6,Q00 $132,000 SUBTOTAL $499,000 CONTINGENCY 25.0% $125,000 SUBTOTAL $624,000 SALES TAX 8.6% $54,000 CONSTRUCTION COST $678,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0% $203,000 TOTAL ESTIMATED PROJECT COST $881,000 ���D �� � ' ' � ' � , � � � ' ' ' � � � � � / .� / i . / / /,. �. /,. �, / / / Sta i_ � / • � s+oo 1� ,� ��X t� FLUSH � STATION (Sta. 0+00) � � \� . `' � � 100' 0 10D' 200' 300' 400' _—' Approximate 5cale: 1" = 200' � i / � 2 � � r z w � � � Existing Lakeline to Remain in Service; Provide Joint Restraint at �•�� �� Pipe Joints in Jeopardy �" t -•� of Separating `:: \ ..ao�a'� � � - � � Sta �5+00 --.. � �� � , 4 � �\ �� � 1� ��j, . ? �� 8 Z w J � t'� The existing lakeline remains in service. � S0.45 million � • The least amount of in-water work One section of the line that has a sag in of any of the alternatives that involve the profile would be re-routed to improve a lakeline hydraulics. Access to the line would be • Least cost of all the south-end provided to simplify maintenance of the alternatives system and pipe joints would be restrained where the line is in jeopardy of separating. • Little work required on residential properties _--�-1 , � 8205 ' ,, _� i w N 7 a � Lake Washington � ■ 1' � � Sta � � 20+00 a ��� 2 w n � LEGEND — --i — — Existing 8" Sewer Line -----�--�---�---��----�----- Existing Side Sewer ° Existing Cleanouts --D-- New Sewer Line ----------- New Side Sewer — - - — Approximate Inner Harbor Line �� Maintenance Manhole at Kennydale Beach for Maintenance Access � (3 Total) � . \ I � I ��� ;� � - �� � � Sta � \ � � +�Q ._\ �� ����I y �a�e� �—�%1'_`_ Ste dsh� �. �,o, � �- y` 30+00 '�Oo '�� � � � � e��a �� . � `� � ' �— � eathh�u e� Kennydale` Beach Park 4n��9ton bonheln �'R • Ability of alternative to achieve required 20-year design life is questionable because of uncertainty regarding structural integrity of existing lakeline • Pumping rates and flushing velocities of existing system would remain low • Line remains vulnerable to damage • Maintenance access to the line remains difficult • Repositioning pipe joints for strengthening may cause leaks in the line • Negotiating easements for locating maintenance manholes or dock cleanouLs on private property may be difficult Metro Sewer Burnett Ave• Z "o+ N NOTES: 1. Homes and docks on map based on 1984 survey by Horton Dennis Associates. 2. Cost estimate based on restraining a total of 30 pipe joints, which is approximately 25°� of the total number of pipe joints between Station 4+00 and Station 27+50. ' Tetra Tech/ City of Renton KCM, Inc. ALTERNATIVE S3 1917FirstAvenue KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT Seattle, Washrngton 98101 Sta 10+00 �/ ?C i� ..;�' / � �. i . Vie`d Re-Route Approximately 250' of Line to Remove Sag � � a� � � � rw ar� � w� � r � � � � r� � � �■ PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Replacement Project Alternative S3 PROJ. NO: 2830120 CLIENT : Cit of Renton BY: JWL DATE: 18-May-99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Southend Alternative S3 Existing Lakeline to Remain; Restrain Joints; Remove Sags; Add Access 1 MOBILIZATION (8%) LS 8% $18,700 2 8" SEWER PIPE - 5 TO 10 FEET DEEP 250 LF $80 $20,000 3 PIPE JOINT RESTRAINTS 30 EA $3,000 $90,000 4 6" SIDE SEWER 50 LF $45 $2,250 5 CONNECT SIDE SEWER TO MAIN 1 EA $4,000 $4,000 6 MAINTENANCE MANHOLE 3 EA $35,000 $105,000 7 RESTORE LANDSCAPING / PATIO / BULKHEAD 2 EA $6,000 $12,000 SUBTOTAL $252,000 CONTINGENCY 25.0% $63,000 SUBTOTAL $315,000 SALES TAX 8.6% $27,000 CONSTRUCTION COST ; $342,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0% $103,000 TOTAL ESTIMATED PROJECT COST $445,000 ! � 1 � � � � � , � � lJ � � l� � � � 0 / /,. �. /,. /. /. /,• �, � � �� _ / / . Replace Existing Flush Station With New Lift Station Sta 5+00 ? Bore & Jack Crossing N of Burlington Northern � Railroad �, r ,.. , i� P ' Connect New Force Main to Existing Gravity Sewer in N Lake Washington Boulevard 100' 0 100' 200' 300' 400' Approximate Scale: 1" = 200' ESTIMATED PROJECT COST: • 2 w � � ��, � Abandon Existing �' Lakeline in Place 1 ��.. :� , '�� 'r � 1 `�a,s� � � '� � � �� 15 00 �� \ � t � �' ,h��; �� �� . '�. � � ! �!•' ' ! ` � � '�� Install New 8" Open Cut Gravity Sewer z w � � • Sewer line is removed from the lake • Flushing of line no longer required • New line can be accessed for maintenance from Mountain Vew Avenue North • Sewer line is no longer vulnerable to damage z w N 7 a � Re-Route Side Sewers to New Gravity Main by Directional Drilling � or Open Cutting Sta ` ���0+00 �'-� i -�.�� � % �\`� Install Grinder �� Pump Stations r � at Two Homes Z m w c r Install New 1-1/2" Open Cut Pressure Sewer to New Gravitv Sewe LEGEND --►-- Existing 8" Sewer Line �------�---�-�--�---�------ Existing Side Sewer = Existing Cleanouts --�— New Gravity Sewer Line —�— New Force Main ----- New Side Sewer --------- Approximate Inner Harbor Line _ • New Grinder Pump Station Lake Washington � � '� '-� � �� � � Sta � \ Z�Jt�O `� \ � � � �T�\ ' . �a�'e � % � � Sta � , �ash� �., sao, � r y 30+00 '��O � ;�I \�,,\ �1 ] e'✓a �� r, ``� � � `y � eathh�U �� 1 \�' Kennydale .. . Beach Park • The new gravity main must be installed from 14 to 18 feet deep to serve the homes with lower floor elevations • Access to homes during construction will be very difficult to coordinate • Re-routing side sewers to Mountain View Avenue North will damage yards of residential properties /V o�he R Metro Sewer Burnett Ave. Z � 3 � NOTES: 1. Homes and docks on map based on 1984 survey by Horton Dennis Associates. A new 8-inch-diameter gravity sewer is installed by open cut in Mountain ViewAvenue North. Side sewers would be re-routed to the new sewer by directional drilling or open cutting. The existing flush station would be replaced with a lift station, and flows from the new main would be pumped to the gravity sewer in Lake Washington Boulevard. Grinder pump stations would service the residences at 3233 and 3307 Mountain Vew Avenue North. The pressure sewer from these two homes would discharge to the new graviiy sewer. The existing lakeline would be abandoned in place. ' Tetra Tech/ City of Renton KCM, Inc. ALTERNATIVE S6 1917FirstAvenue KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT Seattle. Washrngton 98101 Sta 10+00 �/ �ix�. / �` �,, � �. ' � s �w � � � � � �r � w w� r � � �■ � � w PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Replacement Project Alternative S6 PROJ. NO: 2830120 CLIENT : Cit of Renton BY: JWL DATE: 18-May-99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Southend Alternative S6 New Onshore Gravity Sewer 1 MOBILIZATION (8%) LS 8% $79,200 2 8" SEWER PIPE - 10 TO 15 FEET DEEP 200 LF $96 $19,200 3 8" SEWER PIPE - 15 TO 20 FEET DEEP 1,445 LF $128 $184,960 4 6" SIDE SEWER 2,060 LF $75 $154,500 5 CONNECT SIDE SEWER TO MAIN 16 EA $4,000 $64,000 6 CONNECT TO EXISTING SIDE SEWER 17 EA $2,500 $42,500 7 3" PRESSURE SEWER 420 LF $30 $12,600 8 GRINDER PUMP STATION 2 EA $10,000 $20,000 9 NEW LIFT STATION (Incoming IE=8.0) 1 EA $300,000 $300,000 10 6" FORCE MAIN 100 LF $75 $7,500 11 BORED AND JACKED RAILROAD CROSSING 100 LF $225 $22,500 12 RESTORE LANDSCAPING / PATIO / BULKHEAD 27 EA $6,000 $162,000 SUBTOTAL $1,069,000 CONTINGENCY 25.0% $267,000 SUBTOTAL $1,336,000 SALES TAX 8.6% $115,000 CONSTRUCTION COST : $1,451,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0% $435,000 TOTAL ESTIMATED PROJECT COST $1,886,000 / New 8" Flush Line /•" Installed Beyond Existing Docks With / Minimum 2' of Cover /•� �`` ` , Abandon Existing ` Lakeline in Place 1$0'�:Oa 0 �/ ��� ��t Extend Side Sewers to ' New Flush Line / (15 Total ) � � / / , i / / ,. / . Existing Flush Station � -�S�d. 0+�0� � , � � Sta �/' 5+00 � � . � Rebuild Existing Flush Station � � Z m � � N 100' 0 100' 200' 3D0' 400' Approximate Scale: 1" = 200' �I� A new 8-inch-diameter flush line is installed in Lake Washington beyond the existing private docks. Connection to the existing side sewers would be made near the lakeshore and extended out to the new lakeline. The existing flush station would be upgraded to increase flushing capacity. The existing lakeline would be abandoned in place. ESTIMATED 1 PROJECT COST: � . �� � \ � � � ! J � ��'/ Z td � Z W � N Sta 15+00 �� , � � � � 4 �� � ; � �( � • A new, deeper lift station is required because of the lower profile of the new flush line. Lowering the lift station increases the amount of flow that can be flushed through the line • Connection to existing side sewers requires little disruption to residents' property z W N 7 a (N l.ake Wasirington �_ sta �.� 20+00 L w W c N r Maintenance Manhole on Private Property (3 Total) LEGEND --►-- Existing 8" Sewer Line -------�-�-���-�----------- Existing Side Sewer = Existing Cleanouts —�— New Sewer Line ----------- New Side Sewer Approximate Inner Harbor Line 1 ��� 1 ��f J � \\ Sta � ZrJiO� \ \ \ � . � � i \ �a'fe `r � � � Sta Wash�' � xo� � r y` 30+00 9ta'e'yq �` �.`\��``` ' ,' ` �� $athhous � � � ei Kennydafe .. . Beach Park _,,, RR Metro Sewer Burnett Ave. 7, � � • The new lakeline alignment would need to be outside the existing docks for constructability. This requires lowering the line to an approximate elevation of -2.0' to provide 2 feet of cover. • Lift station must be lowered about 10 feet to accomodate lowered flush line • Sewer line remains vulnerable to damage • Maintenance access to the line remains difficult • Negotiating easements for locating maintenance manholes or dock deanouts on private property may be difficult NOTES: 1. Homes and docks on map based on 1984 survey by Horton Dennis Associates. 2. Maintenance manholes could be located at end of private docks if easements could be negotiated and if they are accessible by City maintenance equipment. 3. New 8-inch flush line has a minimum of 2 feet of cover. 4. Cost of new lift station is ir�cluded in Aftemative N-13. / / V�8`N Tetra Tech/ City of Renton KCM, lnc. ALTERNATIVE S13 1917FirstAvenue KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT Seattle. Washington 98101 � r� � � � � �r a� r � r � � � � � � ir � PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Replacement Project Alternative S13 PROJ. NO: 2830120 CLIENT : Cit of Renton BY: JWL DATE: 18-May-99 ITEM DESCRIPTION (�UANTITY UNIT UNIT AMOUNT NO. PRICE Southend Alternative S13 New Gravity Flush Line in the Lake 1 1010 MOBILIZATION (8%) LS 8% $86,900 2 300 8" SEWER PIPE - 2 TO 4 FEET OF COVER 300 LF $200 $60,000 3 310 8" SEWER PIPE - 4 TO 8 FEET OF COVER 2,100 LF $250 $525,000 4 340 6" SIDE SEWER PIPE 1,240 LF $150 $186,000 5 350 CONNECT SIDE SEWER TO MAIN 15 EA $4,000 $60,000 6 610 NEW FLUSH STATION - SUBMERSIBLE PUMP 1 EA $150,000 $150,000 7 420 MAINTENANCE MANHOLE 3 EA $35,000 $105,000 SUBTOTAL $1,173,000 1000 CONTINGENCY 25.0% $293,000 SUBTOTAL $1,466,000 1020 SALES TAX 8.6% $126,000 CONSTRUCTION COST : $1,592,000 1030 ENG., ADMIN. & CONSTRUCTION MGMT 30.0% $478,000 TOTAL ESTIMATED PROJECT COST $2,070,000 � � � � � , � � � � � � � � � � m E � � � o , � / /. / . /,. /,. /. / / // st� � "A_ � � 5+00� / /' / �% �� �- Replace Existing Flush Station With New Lift Station / / Sta 10+00 �I �� // f �'� � ". i� Install new 8" open cut iravitv sewer 2 W � w Abandon Existing Lakeline in Place � k� ^ �' � t:,,; \ � �a�a� � . � . \ ��\ S� � 15+00 c !� � T ��. _ � � 1 � �'d � l�-•. � •'_ ` �. � .� Install New 3" Open Cut Pressure Sewer w J .N. r z w N � Q N Z W w a � Z Bore & Jack Crossing „ of Burlington Northern � Railroad � ' Connect New Force Main to Exis6ng Gravity Sewer in N Lake Washington Boulevard 100' 0 100' 200' 300' 400' Approximate Scale: 1" = 200' Grinder pump stations are installed at each of the existing side sewer connection between Station 3+00 and Station 25+00. New pressure side sewers would discharge to a new 3" pressure main in Mountain Vew Avenue North. The four southerly homes would drain by gravity to a new gravity sewer. The existing flush station would be replaced with a lift station, and flows from the new main would be pumped up to the gravity sewer in Lake Washington Boulevard. ESTIMATED PROJECT COST: -- — � — � . Sewer ►ine is removed from the lake Flushing of line no longer required New line can be accessed for maintenance irom Mountain VewAvenue North • Sewer line is no longer vulnerable to damage • More flexibility in routing pressure side sewers. New pressure sewer main can be easily installed in Mountain View Avenue North. � — —� — — Existing 8" Sewer Line -------------���--�---------- Existing Side Sewer � Existing Cleanouts --�— New Gravity Sewer Line —�-- New Force Main ----------- New Side Sewer — Approximate Inner Harbor Line • New Grinder Pump Station � ��� � � Lake Washfngton �'� � �- � \�'� I ���. �� � �� � � Si2 \\� t� \ T� -_, --"'� � 4',�ey, �—�%r`\` s� ash�n �� �, � � y\ 30+00 9jo'e/` ��r�� �,��,R`_ q •.� � �� � '' _ Bathh�USA� �'' Kennydafe ,,_.. Beach Park • Connection to the existing side sewers and installation of new grinder pump stations will damage yards • City has 15 addi6onal pump stations to maintain and spare pumps to stock • Re-routing side sewers to Mountain View Avenue North will be difficult _,,, RR Metro Sewer Burnett Ave. Z � 7 .N. NOTES: 1. Homes and docks on map based on 1984 survey by Horton Dennis Associates. 2. Telemetry for monitoring by City included in cost. Tetra Tech/ City of Renton KCM, Inc. ALTERNATIVE S15 1917FirstAvenue KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT Seattle. Washington 98101 Re-Route New 1 1/2" Pressure Side Sewers to New Force Main by Directional Drilling Of OD8f1 CUtU�O LEGEND Install Grinder Pump Station at each Side Sewer Location (14 totall _ � i 1� � i ��- � sta � ��' Zo+oo ' ``�.�C � �>� i��� � : �`�� � � s � � w s � � �r � � r � � � � w� � PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Project Alternative S15 PROJ. NO: 2830120 CLIENT : Cit of Renton BY: JWL DATE: 18-May-99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Southend Alternative S15 New Onshore Pressure Sewer System 1 MOBILIZATION (8%) LS 8% $65,600 2 8" SEWER PIPE - 5 TO 10 FEET DEEP 370 LF $80 $29,600 3 3" PRESSURE SEWER 1,700 LF $30 $51,000 4 1-1/2" TRENCHLESS PRESSURE SIDE SEWER 2,060 LF $50 $103,000 5 CONNECT SIDE SEWER TO MAIN 15 EA $2,500 $37,500 6 CONNECT TO EXISTING SIDE SEWER 15 EA $2,500 $37,500 7 GRINDER PUMP STATION 15 EA $10,000 $150,000 8 NEW LIFT STATION (Incoming IE=8.0) 1 EA $300,000 $300,000 9 6" FORCE MAIN 100 LF $75 $7,500 10 BORED AND JACKED RAILROAD CROSSING 100 LF $225 $22,500 11 RESTORE LANDSCAPING / PATIO / BULKHEAD 27 EA $3,000 $81,000 SUBTOTAL $885,000 CONTINGENCY 25.0% $221,000 SUBTOTAL $1,106,000 SALES TAX 8.6% $95,000 CONSTRUCTION COST $1,201,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0% $360,000 TOTAL ESTIMATED PROJECT COST $1,561,000 1 ' , L� � ' , , � ' , � ' � lJ � , � ' ,� /,. / Abandon Existing Flush 5tation i � ? N t0 w � N \ / 100' 0 100' 200' 300' 400' Approximate Scale: 1" = 200' / /,. Sta 10+00 �I �X . i �� � ,� ` �� ��� � Abandon Existing � Lakeline in Place From Station �• �� �,� 0+00 to Station 28+00 1� ► -� �4 � � ois` � � st� � ._�� �� �s+oo � �� � �, � .. , �\ --\` � �.l � /�` - , \ , _`>F � !` ; \ . i �.I� * I�� Sta y � 20+00 ��� �: � � � �z � 1�! '`\\ V�e`N ESTIMATED PROJECT COST: • Install New 8" Gravity Sewer Between Station 0+00 and Station 28+00 ? w w y q� `• � • Sewer line is removed from the lake • Flushing of line no longer required • New line can be accessed for maintenance from Mountain Vew Avenue North • Sewer line in Mountain VewAvenue North not vulnerable to damage z w N � a N 2 � w a N � \� � LEGEND --►-- E�cisting 8" Sewer Line �------------------�-- Existing Side Sewer Existing Cleanouts —� New Open Cut Gravity Sewer Line --�— New Trenchless Gravity Sewer Line i ----------- New Side Sewer ------- Approximate Inner Harbor Line New Force Main � .\ � � � � Lake Washington � �� ,{ 4 �,.\ \ r`� \ � r \�� �-_ \ \�� 25 00 New Lift Station � Invert Elevation of New 8" `T� Sewer-8.0' <a�e z �ash�°Sr �� 9 ��Q; Direct Flow in the Existing Lakeline From Station 34+00 South to New Lift Station � �F Sta �� r- � 30+00 �� � � ,\ � � `•, ; �R � � �� ��� �Qathh�use� � Kennydale .. . Beach Park Bore 8 Jack Crossing of Connect New Burlington Force Main to Northern Railroad Existing Gravity Sewer in Lake shinqton Boulevard • The new gravity main must be installed from 14 to 18 feet deep to serve the homes with lower floor elevations • Access to homes during construction will be very difficult to coordinate • Re-routing side sewers to Mountain Vew Avenue North will damage yards of residential properties • Routing gravity sewer from south to north increases depth of cover, requiring trenchless installation of pipe along majonty of route. • Remaining lakeline vulnerable to damage. � �Onh� �,� RR Metro Sewer Burnett Ave. Z � z � NOTES: 1. Homes and docks on map based on 1984 survey by Horton Dennis Associates. Tetra Tech/ City Of Re11tOn KCM, Inc. ALTERNATIVE S21 1917FirstAvenue KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT Seattle. Washington 98101 / �. /.. /.. / � /•' �i!/ / �� �. /� Sta ��,. �' 5+00 ��� � � � � S � � � i � � � � � � � � PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Project Alternative S21 PROJ. NO: 2830120 CLIENT : Cit of Renton BY: JWL DATE: 18-May-99 ITEM DESCRIPTION (�UANTITY UNIT UNIT AMOUNT NO. PRICE Southend Alternative S21 New Onshore Gravity Sewer Sta 0+00 to Sta 28+00 1 MOBILIZATION (8%) LS 8% $98,200 2 8" SEWER PIPE - 10 TO 15 FEET DEEP 800 LF $96 $76,800 3 8" MICROTUNNELED SEWER PIPE W/ 24" CASING 1,135 LF $350 $397,250 4 6" SIDE SEWER 2,060 LF $75 $154,500 5 CONNECT SIDE SEWER TO MAIN 16 EA $4,000 $64,000 6 CONNECT TO EXISTING SIDE SEWER 17 EA $2,500 $42,500 7 NEW LIFT STATION (Incoming IE=8.0) 1 EA $300,000 $300,000 8 6" FORCE MAIN 100 LF $75 $7,500 9 BORED AND JACKED RAILROAD CROSSING 100 LF $225 $22,500 10 RESTORE LANDSCAPING / PATIO / BULKHEAD 27 EA $6,000 $162,000 SUBTOTAL $1,325,000 CONTINGENCY 25.0% $331,000 SUBTOTAL $1,656,000 SALES TAX 8.6% $142,000 CONSTRUCTION COST $1,798,000 ENG., ADh41N. & CONSTRUCTION MGMT 30.0% $539,000 TOTAL ESTIMATED PROJECT COST $2,337,000 Memo Tetra Tech/KCM, InG l� Date: Nlarch 24, 1999 Ta Dave Christensen City of Renton Utility Systems 1055 Grady Way South, 5th Floor Renton, WA 98005 �� � �� ' � -« . Workshop Participants Central Files (2-2) Jeff Lykken 2830120-003 Subject: City of Renton Kennydale Lakefront Sewer Replacement Project Workshop 2—Alternatives Generation and Evaluation Workshop This memorandum presents the results of the Kennydale Lakefront Sewer Replacement Project Workshop 2, which was conducted by KCM for the City of Renton on March 9, 1999. Workshop 2 was the second of three workshops that will be conducted during project predesign. Goals for the workshops are as follows: Workshop 1—Establish goals and constraints for the project Workshop 2—Identify and rank alternatives for repair, rehabilitation and replacement of the sewer system • Workshop 3—Refine the alternatives developed in Workshop 2 and narrow the potential solutions for final design. The list of options will be reduced to up to three alternatives, and a final design solution will be chosen by the City of Renton. Workshop 1 was a project initiation workshop, conducted on February 16, 1999. Objectives completed at Workshop 1 included bringing the consultant team and City staff to a common understanding of the problem and issues associated with the e�usting facilities, conceptualizing initial alternatives, confirming project goals and constraints, and establishing criteria for ranking the alternatives. Goals for Workshop 2 were to brainstorm alternative solutions for the sewer replacement, conduct an initial screening of available alternatives, and select the top ranking alternatives for further evaluation. PROJECT BACKGROUND The Kennydale lakefront sanitary sewer is an 8-inch line in Lake Washington that serves approximately 51 homes and the Kennydale Beach Park along the lake in Renton. The Tetra Tech/KCM, Ina • 1917 F�xst Avenue • Seattle, WA 98101-1027 • Te1206 443-5300 • Fax 206 443-5372 � , 4,700-foot-long cast-iron line begins at the north end of Gene Coulon Park and ends at North 40th Street. Except for the southern 300 feet of pipe, the sewer was installed in the , lake. A flush station (Lake Washington Flush) at the south end of the facility flushes lake water north through the pipe to a City of Renton lift station (Lake Washington #2) in the 3900 block of Lake Washington Boulevard North. From there, sewage is pumped up to Metro's Eastside Interceptor sewer in Lake Washington Boulevard. The facility has been difficult to maintain due to sags in the pipe and limited access for maintenance. Sediment accumulates in the sags, causing backups in the line and overflows , into Lake Washington. City workers are able to access only about one-third of the line to rod and flush it with their e�usting equipment. The top of the pipe is exposed above the lake bottom along much of the alignment. Where the pipe is buried, the depth of cover does ' not exceed 2 feet. The pipe has been snagged and damaged by boaters and contractors more than a half-dozen times. Because of the past problems with the line and continued uncertainty about the pipe's condition, the City wishes to assess upgrading or replacing the facility. KCM, Inc. has been selected by the City of Renton to provide predesign and iinal design services on the project. , Because of this project's many permitting, constructability and community issues, KCM is conducting workshops to identify alternatives and select a preferred alternative for implementation. IWORKSHOP PROCESS ' Workshop 2 was conducted as a facilitator-led working group, organized by the agenda included in Appendix A to this memorandum. It was facilitated by Don Stafford of Robinson, Stafford & Rude, Inc. (RSR). The day-long workshop consisted of the foliowing steps: • Discuss the findings of the pipeline condition assessment performed February 15 through March 2, 1999. • Summarize the results of community outreach activities to date. • Discuss regulatory constraints relating to alternative solutions. ' • Brainstorm and conduct an initial screening of alternative solutions that meet all the project objectives developed at Workshop 1; the screening � involved workshop participants voting on alternatives and a group discussion of the general categories of alternatives to be carried forward. • Conduct a weighted matrix evaluation of the top rated alternatives using the weighted criteria developed at Workshop 1. • Finalize selection of the top ranked alternatives for further evaluation; additional preliminary engineering and cost estimating will be performed for the top ranked alternatives, and a final preferred alternative will be selected at Workshop 3. ' Workshop participants included the following City staff, design team members and agency representatives: ' Page 2 ' ' ' ' , Dave Christensen, City of Renton Wastewater Utility Supervisor John Thompson, City of Renton Wastewater Maintenance Division Leslie Betlach, City of Renton Parks Department Jennifer Henning, City of Renton Planning Barry Scott, KCM, Inc. Jeff Lykken, KCM, Inc. Molly Adolfson, Adolfson Associates Jennifer Kauffman, EnviroIssues Dave Clark, D L Clark Corporation Larry Fisher, Department of Fish and Wildlife . . FINDINGS OF PIPELINE CONDITION ASSESSMIN'r � In the two weeks before Workshop 2, the design team performed an assessment of the ' existing pipe condition to gauge the feasibility of alternatives that would make use of the existing pipe. The assessment included the following methods: , Geophysical assessment of the pipeline and adjacent lakebed Ultrasonic testing of exposed portions of the pipeline to assess corrosion Dye testing of the flush station system. Geophysical Assessment ' Golder Associates performed a one-day geophysical assessment of the pipeline and lakebed on February 15, 1999. Conditions along the lakeline were inspected using a side scan sonar, which produces an acoustic image of the lakebed and objects resting on the lakebed, such as the pipeline, pilings, logs and anchors. An underwater camera was then used to inspect selected portions of the pipeline to augment the side scan sonar findings. The survey findings were as follows: ' � • Areas where the pipeline was exposed above the lakebed were confirmed. Approximately 1,000 feet of the lakeline is fully or partially exposed. • Short sections of pipeline that may be suspended above the lake bottom were documented. • Five locations where logs are resting on the pipeline were documented. � � Concrete debris was dumped on top of the pipe at Station 40+40. The debris was likely the remains of a bulkhead replaced by the homeowner. ' , � Possible abrasion from logs chaiing the pipe was noted in three areas. A report from Golder Associates summarizing the investigation results is included in Appendix B. Page 3 � , ' , Ultrasaruc Testing � On March 2, 1999 Ballard Diving and Guardian Inspection Services, Inc. performed one day of ultrasonic testing on exposed sections of the pipe. The test involved a diver placing a calibrated transducer on the outside of the pipe. The transducer transmits an ultrasonic signal that measured the wall thickness of the 8-inch cast iron pipe. Instrumentation recording the readings was monitored and documented by a technician on the dive boat. Prior to the field work, the transducer and instrumentation were calibrated to a test section of 8-inch cast iron pipe provided by the City. Guardian Inspection Services estimated the level of accuracy of the readings to be within plus or minus 10 to 15 percent. In addition to the ultrasonic testing, the diver provided a visual assessment of the ' horizontal alignment and general appearance of the pipe. Results of the ultrasonic testing and visual assessment were as follows: ' ' C� • Approximately 53 measurements were taken at 24 locations along the pipe. The measurements started on the north end of the project, where most of the exposed pipeline sections are located, and proceeded south. Measurements were taken as far south as Station 28+00. In general, the diver attempted to get three measurements (one on the top and one on each side of the pipe) at each location. The bottom of the pipeline was buried, so measurements at the pipe invert were not possible. The ultrasonic inspection readings are included in Appendix C. • Side and top readings at the same location indicated relatively uniform � thickness. No discrete zones of corrosion were found in any of the locations surveyed. , , � � ' • Thickness readings varied from 0.308 inches to 0.515 inches. 1Vlost of the readings were in the range of 0.375 to 0.400 inches. • Original project specifications designating the design thickness class of the pipe to be used were not available from the City. The Handbooh of Ductile Iron Pipe by the Ductile Iron Pipe Research Association lists six thickness classes of gray cast iron (Class 22 through Class 27) for 8-inch diameter pipe, ranging from 0.41 inches to 0.60 inches. It is possible that the contractor who installed the line used different thickness classes of pipe along the length of the pipeline. • Accurate ultrasonic measurements for wall thickness are not possible unless the outside of the pipe is relatively free of scale and rust. Numerous areas along the outside of the pipeline were too rusted and scaled to get accurate thickness readings. • In areas where the pipe goes from being exposed to being buried, the diver uncovered short sections of the buried pipe. It appeared that the buried pipe has much less rust and scale than the exposed pipe. • The horizontal alignment of the pipe was very crooked from approximately Station 34+00 to the lift station. Some joints appeared to be deflected in excess of 5 degrees. , • Both mechanical and push-on joints were used. Page 4 L� , , , , • A 2-inch hole was found in the line at approximately Station 44+00. The flush station was operating when the hole was discovered, and water was being drawn into the hole. The hole is next to a dock, and the pipe wall around the edge of the hole appeared to be solid. This may indicate that the pipe was damaged from work being done on the dock rather than from corrosion. • The horizontal alignment and pipeline exposure problems appear to be more serious than the issue of remaining pipe wall thickness. ■�.L`J , Dye Testing � ' , LJ ' Two dye tests were performed on March 2, 1999 to check for leaks from the pipe into the lake and to assess the pumping performance of the flush station. Pipe leakage was investigated by pumping fluorescein dye through the lakeline and visually inspecting for signs of leaks. No signs of leaks were evident during the two tests. The dye tests were also used to estimate the average flushing velocity through the pipeline and to assist in estimating pump output from the flush station. The average flushing velocity through the pipe was determined by measuring the travel time of the dye through the appro�mately 4,800 feet of lakeline from the flush station to the downstream pump station. The travel times for the two tests were 105 minutes and 102 minutes, which translates to an average flushing velocity of 0.8 feet per second (fps). Using this average velocity and the visual observation that the 8-inch pipe discharging to the downstream pump station was flowing about one-third full during the tests, KCM estimates that the flush station pump output is between 100 and 150 gallons per minute. A general rule of thumb is that a minimum flushing velocity of 2 fps should be maintained ' in gravity sewers to prevent the deposition of solids in the pipe. Flushing velocities of about 3 fps are required to resuspend solids that have settled in a pipe. Where there are sags in the profle, as there are in the Kennydale pipeline, significantly higher flushing velocities are required to flush solids up the adverse grade. With an average flushing velocity of 0.8 fps in the Kennydale sewer, significant solids deposition can be expected in the sags. ' Lunitations of Conditiari Assessment Findings The condition assessment investigations provide valuable information for assessing , solutions that would use the existing pipeline. However, since the entire pipeline could not be accessed and tested, its ability to remain in service another 20 years remains uncertain. This uncertainty will be factored into the �nal evaluation of alternatives. COMM[JNITY OUTREACH ACTIVITIES AND FINDINGS ' Jennifer Kauffman provided a summary of community outreach activities that have taken place on the project to date. On March 6, 1999, EnviroIssues conducted a small survey among the 51 residents who live along the lakeshore between the north end of Gene Coulon Park and North 40th Street. Each residence was visited. Flyers with survey information and project contact information were left at residences where no one was home. , Page 5 '�i � � � , � A total of 16 residents were contacted directly, and three others mailed or faxed in their responses. The survey revealed that the residents had received the previous door-to-door distribution of flyers announcing the sonar and ultrasonic testing and that the residents are generally aware of the project. A number of residents have moved to the area in the last several years and were not aware ' of the sewer's location in the lake or the problems experienced in the previous 10 years. A homeowner education effort may be helpful to them. Key survey findings were as follows: C�I � ' , , ' ' � ' , ' l� ' , � Most residents said they have had no problems with flooding or overflows associated with the sewer line. One resident with a documented history of flooding was not home. Another resident recounted a flooding incident that occurred 10 years ago. • One resident discussed problems with a City crew that performed cleanout activities fve years ago. The complaint was that the crew disturbed the resident's property when accessing the cleanout at the end of the resident's yard and did not restore it to its previous condition. • Several residents north of Kennydale Beach commented on drainage problems between the railroad bank and their homes. Their concern is that an onshore line might exacerbate these drainage problems. EnviroIssues noted that the swampy area east of the railroad tracks might be a wetland. • Three residents expressed opposition to an upland line. One of these noted that if a surface line were installed, the resident would need to use a sump pump because the water table is 2 feet below the house. • �vo residents said they would favor an upland line. They are in favor of getting the sewer out of the lake to prevent environmental problems in case of leaks. • Several residents expressed no opinion regarding solution alternatives. Two said that they think the City will do the right thing. • Most residents were aware of past problems with boat anchors snagging the line, but none had experienced such problems themselves. � One resident north of Kennydale Beach noted that he has smelled a sewage odor near the front of his house in the fall for the past two years. • All residents contacted indicated that they would be willing to attend a neighborhood meeting. REGUI.ATORY CONSTRAINTS Larry Fisher of the Washington Department of Fish and Wildlife identified the following as issues related to the alternatives that the department is likely to be concerned about: • The summer fisheries window for construction will be June 16 to the end of October. There may also be a winter window within portions of the project limits. Larry will check on this. Page 6 1 ' ' ' � ' , ' , • Parts of the project area are in a beach spawning area for sockeye salmon. Alternatives that involve a loss of shoreline spawning habitat cannot be permitted. • Alternatives that involve extending bulkheads further into Lake Washington will probably not be allowed because of the loss of habitat. • Pipes will need to be fully buried beneath the lakebed for alternatives that include a line remaining in the lake. An exposed pipe along the lake bottom provides an area for predators to hide and feed on juvenile salmon. • Placing fill in the lake to remove the sags in the pipe profile could be allowed if the correct fill material is used. Supporting the pipe above the lake bottom will probably not be allowed because it provides additional areas for predators to hide. Other agencies such as the Corps of Engineers may not allow fill in the lake. DEVELOPMIIVT AND INITIAL SCREINING OF ALTERNATNES � Using brainstorming techniques, workshop participants identified a list of alternatives that accomplish the following project objective, which was developed in Workshop 1: Provide a cost-effective, reliable and maintainable sewage disposal system ' with a minimum 20-year life that can be implemented in the current regulatory and community setting. , The north and south ends of the lakeline have different physical constraints affecting the feasibility of solutions, so the project was divided into two parts, but without precisely defining the dividing point between the two. The foremost difference between the two ends , of the project is that the homes north of Kennydale Beach Park are very closely spaced, and the small frontage road serving them is very narrow, making upland alternatives much more difficult to construct. The road serving the homes near Coleman Point (Mountain ' View Avenue N) is much wider, and the homes are not as closely spaced. Additionally, the alignment of the existing lakeline is relatively straight from approximately Station 23+00 to the pump station (the north portion), whereas the south portion of the line has , significant bends. �vo distinctly different alternatives may provide the most feasible overall project solution because of these differing constraints. ' �venty alternatives were identified for the north end of the project. This list was duplicated for the south end, and workshop participants noted appropriate modifications for the south end, identified north end alternatives that are not appropriate for the south � end, and identified two new south end alternatives that are not appropriate for the north end. l� ' , , After identifying the alternatives, participants voted for those they believed to have the most merit. Each participant indicated up to six north end and six south end alternatives they felt are most feasible and meet the project objective. Tables 1 and 2 list the alternatives and the votes they received. Based on the voting and subsequent discussion, workshop participants agreed to further evaluate five alternatives for the north end and five for the south end. The screened Page 7 ' �� ralternatives are listed in Table 3. Nine of the 10 screened alternatives were those with the most votes in the initial screening. Alternative N7 was included so that a sufficient number � of upland alternatives will be evaluated. The description of Alternative N7 was also modified so that it included both grinder pump systems and the vacuum system noted in the original description. � ' , C� ' , ' , � ' , � � �1 , Page 8 ' ' _ , , # N1 � N2 N3 , N4 , N5 N6 , N7 ' N8 , N9 N10 ' N11 � N12 N13 I N14 � N15 � N16 � N17 N18 N19 � N20 ' ' TABLE 1. NORTH END ALTERNATIVES Replace the e�sting lakeline with a new minimum 6-inch diameter gravity sewer in the lake. Leave the e�cisting lakeline in place, restrain pipe joints, and add access points for maintenance. Leave the existing lakeline in place, restrain pipe joints, add access points for maintenance, and re-lay a portion of the line to remove sags in the profile. Slipline the existing pipe with the minimum hydraulically acceptable plastic line size and provide access points for maintenance. Slipline the e�usting pipe with the minimum hydraulically acceptable plastic line size and provide access points for maintenance. Slipline the existing side sewers. Construct a new gravity sewer between the homes and the railroad using trenchless pipeline installation methods. Install a vacuum sewer between the homes and the railroad and construct a new vacuum/pump station at the existing pump station site. Microtunnel a new gravity sewer in Lake Washington Boulevard and install new side sewers using directional drilling from the lake side. Install grinder pumps for each home and install a new 3-inch diameter force main between the homes and the railroad that discharges to the eacisting force main from the pump station. Line the existing pipe with an "In Situ Form" liner or similar and provide access points for maintenance. Line the existing pipe with an "In Situ Form" liner or similar and provide access points for maintenance. Slipline the existing side sewers. Replace the existing lakeline with a new small diameter pressure sewer. Replace the e�usting lakeline with a new 6-inch or 8-inch diameter sewer in the lake with flushing capacity. Direct flow in the existing pipe from approximately Station 36+00 to the south. Eliminate the sag at Station 40+00, slipline the existing lakeline and side sewers from Station 36+00 to the pump station with high density polyethylene (HDPE), and add access for maintenance. Slipline the existing lakeline to Station 22+50 with 3-inch diameter plastic pipe and install grinder pumps at homes and new pressure side sewers. Eliminate the e�cisting pump station and add access to the lakeline at 1,000-foot intervals. Slipline the ea�isting lakeline to Station 22+50 with 3-inch diameter plastic pipe to act as a vacuum sewer. Convert the e�cisting pump station to a vacuum/pump station. Install a new HDPE sewer along the existing bulkheads in the lake. Install a new ductile iron sewer along the e�cisting bulkheads in the lake. Build new bulkheads outside the existing bulkheads and install a new sewer line on the land side of the new bulkhead. Restrain the existing pipe joints, add access points in the lakeline for maintenance and install permanent flushing nozzles inside the existing pipe to clean the sags. � Votes 6 2 9 0 0 5 2 7 0 0 0 3 10 3 6 1 0 0 0 0 Page 9 ' ' � � a �J � � � � � ' , ' S � ' ' � TAB LE 2. SOUTH END ALTERNATNES _ # _ Description S1 Replace the existing lakeline with a new minimum 6-inch diameter gravity sewer in the lake. Construct a new pump station to pump flows to the existing gravity sewer in Lake Washington Boulevard. S2 Leave the existing lakeline in place, restrain pipe joints, and add access points for maintenance. S3 Leave the e�usting lakeline in place, restrain pipe joints, add access points for maintenance, and re-lay a portion of the line to remove sags in the profile. S4 North-end alternative N4 (sliplining the e�cisting line) is not feasible for the south end because of the extreme horizontal curvature of the south end of the lakeline. S5 North-end alternative N5 (sliplining the existing line) is not feasible for the south end because of the extreme horizontal curvature of the south end of the lakeline. S6 Construct a new gravity sewer between the homes and the railroad using open cut pipeline installation. Construct a new pump station to convey flows to Lake Washington Boulevard. S7 Install a vacuum sewer between the homes and the railroad and construct a new vacuum station at the e�sting flush station site. S8 Microtunnel a new gravity sewer line in Lake Washington Boulevard and install new side sewers using directional drilling from the lake side. The flush station would remain in service to intermittently flush the new gravity sewer for cleaning purposes. S9 Install grinder pumps for each home and install a new 3-inch diameter force main between the homes and the railroad that discharges to a new force main that crosses under the railroad track and discharges to the City of Renton gravity sewer in Lake Washington Boulevard. S10 North-end alternative N10 (lining the existing line) is not feasible for the south end because of the extreme horizontal curvature of the south end of the lakeline. S11 North-end alternative N11 (lining the e�cisting line) is not feasible for the south end because of the extreme horizontal curvature of the south end of the lakeline. S12 Replace the existing lakeline with a new small diameter pressure sewer. S13 Replace the e�usting lakeline with a new 6-inch or 8-inch diameter sewer in the lake with flushing capacity. S14 North-end alternative N14 is not applicable to south end. S15 North-end alternative N15 is not applicable to south end. S16 North-end alternative N16 is not applicable to south end. S17 Install a new HDPE sewer along the existing bulkheads in the lake. S18 Install a new ductile iron sewer along the e�usting bulkheads in the lake. S19 Build new bulkheads outside the e�usting bulkheads and install a new sewer line on the land side of the new bulkhead. S20 Restrain the e�usting pipe joints, add access points in the lakeline for maintenance and install permanent flushing nozzles inside the existing pipe to clean the sags. S21 Construct a new b avity sewer between the homes and the railroad north to Station 28+00. Use the e�sting lakeline from Station 36+00 south; construct a new pump station at Station 28+00. S22 Use the e�sting lakeline for gravity flow from Station 36+00 to Station 28+00. Install a new pump station that draws from the sag at Station 21+00. Re-lay the pipe to remove the sag at Station 4+50. and provide access to the lakeline for maintenance. Page 10 � Votes 4 1 8 N/A N/A 8 3 7 1 N/A N/A 1 5 N/A N/A N/A 0 0 0 1 fl 1 ' , � � � � TABLE 3. SCREENED ALTERNATIVES North End Alternatives N1 N3 N7 N8 N13 South End Alternatives S3 S6 S8 S13 S21 WEIGHTED CRITERIA EVALUATION �� , Workshop participants ranked the screened alternatives using a weighted matrix evaluation. This evaluation used the criteria developed in Workshop 1 and the weighting factors for each criterion developed after that workshop. The criteria and weighting factors �, are included in Appendix D. The evaluation process was as follows: • Each workshop participant gave each alternative a score of 1 to 5 for each � evaluation criterion. Lower scores indicate that the alternative does not satisfy the criterion well; higher scores indicate that it does. � The score for each criterion was multiplied by the weighting factor for that ' criterion, and each participant's total score for each alternative was calculated as the sum of the weighted scores for each criterion. � � ' • Each alternative's overall score was calculated as the sum of its total scores from all participants. • The alternatives were ranked based on the overall score. Table 4 shows individual participants' scores, overall scores, and rank for the north end alternatives. Table 5 shows the results for the south end alternatives. Individual ranking forms from the workshop members are included in Appendix D. The �nal point total for the south end alternatives was very close, so none of the � alternatives is clearly the preferred alternative. The highest and lowest overall scores differ by only 7 percent. The same is true for all the north end alternatives except Alternative N7, which have overall scores differing by only 4 percent � � i i � SELECTION OF TOP ALTERNATIVES FOR FUR'I�R EVALUATION After consulting with City staff, the decision was made to further develop all the screened alternatives except Alternative N7. The City's concern with Alternative N7 is that the narrow spacing of the homes would be difficult to overcome in rerouting side sewers to a new vacuum sewer in the frontage road. Page 11 � TABLE 4. RESULTS OF WEIGHTED MATRIX EVALUATION FOR NORTH END ALTERNATIVES Total Score for All Weighted Criteria Alternative: N1 N3 N7 N8. N13 146 158 111 141 156 179 149 152 161 141 173 191 166 186 167 186 166 133 168 192 152 159 164 240 152 186 178 115 190 195 196 183 125 130 172 184 161 193 247 186 205 229 140 176 185 198 176 168 177 216 Overall 1,805 1,750 1,467 1,816 1, 762 Soore Rank 2 4 5 1 3 TABLE 5. RESULTS OF WEIGHTED MATRIX EVALUATION FOR SOUTH END ALTERNATIVES Total Score for All Weighted Criteria Alternative: S3 S6 S8 S13 S21 187 218 236 188 194 150 190 165 144 159 155 166 153 131 168 187 195 192 194 185 166 123 107 152 126 163 151 126 191 124 171 172 190 190 179 150 227 231 155 196 172 178 211 154 186 214 192 183 182 181 Overall 1, 715 1,812 1, 794 1,681 1,698 Soare Rank 3 1 2 5 4 Page 12 � � � ' ' ' ' ' 1 � � ' ' ' ' r ' ' � It also was decided to further develop Alternatives N6 and N15. Alternative N6— trenchless construction of a gravity sewer between the homes and the railroad—may be acceptable if the side sewers can be rerouted to the new sewer using trenchless methods. Alternative N15 is a mechanical solution using grinder pumps and a small diameter pressure sewer sliplined through the existing lakeline. Table 6 summarizes the alternatives that will be evaluated further. Additional preliminary engineering and cost estimating will be performed for these alternatives. The results will be reviewed at Workshop 3 and a preferred alternative will be selected at that workshop. TABLE 6. ALTERNATIVES FOR FURTHER EVALUATION No. Descri tion N1 Replace the existing lakeline with a new minimum 6-inch diameter gravity sewer in the lake. N3 Leave the existing lakeline in place, restrain pipe joints, add access points for maintenance, and re-lay portion of the line to remove sags in the profile. N6 Construct a new gravity sewer between the homes and the railroad using trenchless pipeline installation methods. Re-route side sewers to the new gravity sewer using trenchless installation methods. N8 Microtunnel a new gravity sewer in Lake Washington Boulevard and install new side sewers using directional drilling from the lake side. N13 Replace the existing lakeline with a new 6-inch or 8-inch diameter sewer in the lake with flushing capacity. N15 Slipline the existing lakeline to Station 22+50 with 3-inch diameter plastic pipe, install grinder pumps at homes and new pressure side sewers. Eliminate the existing pump station and add access to the lakeline at 1000-foot intervals. S3 Leave the existing lakeline in place, restrain pipe joints, add access points for maintenance, and re-lay a portion of the line to remove sags in the profile. S6 Construct a new gravity sewer between the homes and the railroad using open cut pipeline installation methods. Construct a new pump station to convey flows to Lake Washington Boulevard S8 Microtunnel a new gravity sewer in Lake Washington Boulevard and install new side sewers using directional drilling from the lake side. The flush station would remain in service to intermittently flush the new gravity sewer for cleaning purposes. S13 Replace the existing lakeline with a new 6-inch or 8-inch diameter sewer in the lake with flushing capacity. S21 Construct a new gravity sewer between the homes and the railroad north to Station 28+00. Direct flow in the existing lakeline from Station 36+00 south and construct a new pump station at Station 28+00. Page 13 � 1 , APPENDIX A. , ' ' ' , , ' , r �� �� � WORKSHOP AGENDA � , ' ' ' ' ' , , ' , , , � � , Kennydale Lakefront Sewer R,eplacement Project Workshop 2 Agenda Alternatives Generation & Evaluatian Wvrkshap March 9, 1999 9:00 — 9:30 9:30 — 9:45 9:45 — 10:00 10:00 — 10:15 10:15 — 11:15 11:15 — 12:00 12:00 — 1:00 1:00 — 2:30 2:30 — 3:15 3:15 — 3:30 3:30 Introduction Identify participants Review workshop objectives Review agenda Discussion of Pipeline Condition Assessment Summary of Community Outreach Activities Discussion of Regulatory Constraints Brainstorm Solution Alternatives Conduct Initial Screening (Voting/Discussion Method) Lunch/Continue Initial Screening Conduct Weighted Matrix Evaluation of Top 10-12 Alternatives Finalize Selection of Top �vo or Three Alternatives for Further Evaluation Summarize workshop results Close ' ' ' ' ' APPENDIX B. , GEOPHYSICAL ASSESSMENT LETTER REPORT �J ' ' ' , , 1 ' , , ' �� Golder Associates Inc. 4104 -148th Avenue. N.E. Redmond, WA 98052 Telephone (425) 883-0777 Fax (425) 882-5498 March 29,1999 KCM, Inc. 1917 First Avenue Seattle, WA 98101-1027 ATTENTION: Mr. Teff L�kken � � = Golder � ASSOCIc'iteS Our ref. 993-1392 RE: KENNYDALE LAI�FRONT SEWER REPLACEMENT PROJECT Dear Mr. Lykken: Golder Associates Inc. (Golder) is pleased to submit this letter report that summarizes the resulis of the geophysical investigation that we conducted on January 20,1999. The purpose of the investigation was to evaluate the general condition of the Kennydale sewer pipeline and the adjacent lake floor. 1. PROJECT BACKGROUND An offshore geophysical investigation was performed as part of the evaluation of the condition of the existing Kennydale sewer system. The underwater portion of the pipeline is located on the lakebed of Lake Washington immediately offshore from the Kennydale shoreline. The information from this geophysical inspection will be used to aid in the process of making recommendations for the future of the pipeline and assess if the pipeline will eventually need to be replaced or repositioned. 2. FIELD OPERATIONS Two instruments, side scan sonar and underwater video, were used to inspect the underwater portion of the pipeline. Both instruments were deployed from a small survey vessel on two separate runs along the pipeline route. The runs extended from Station 4+00 northwards to station 47+00. The side scan survey was conducted first, followed by the underwater video inspection. The video inspection was done at selected locations that were determined from preliminary analysis of the side scan sonar data. The position of the survey vessel was determined by referencing shoreline features such as docks, houses, and other cultural featu.res. These fieatures, particularly house or street addresses, could be identified on the four sifie maps provided by the client (Kennydale Sewer Line Sanitary Sewer L.I.D. 270 Side Sewer Improvement Project, Sheets 2, 3, 4 and 5). �� March 29,1999 2 993-1392 2.1. Side Scan Sonar A total of 4 passes were made along the entire length of the pipeline with the side scan sonar. To obtain the best overall images possible each pass was made at a different range scale, variations in frequency, amplification and filtering. The range scale or full swath width of the image varied from 50 to 150 meters. In some areas it was necessary to move offshore to avoid log rafts or extreme shallow water areas. The side scan sonar produced excellent acoustic images of the lake floor and discrete objects, such as the pipeline, pilings, anchors etc., resting on the lake floor. The sonar images were displayed on a paper record as well as being recorded on digital tape for archiving and data analysis. The paper records were to evaluate the data in the field and to make adjustments to the survey program and to select locations for obtauung underwater videos. The side scan sonar images clearly showed: • The lateral extent of exposed and buried pipeline • The position of the pipeline relative to piers and docks • Presence of cultural debris on the pipeline • Miscellaneous debris, and logs on the lake floor 2.2. Underwater Video Camera A drop camera was used to inspect selected portions of the pipeline. These areas were selected based on field interpretation of the side scan sonar data. The video images were recorded on a VCR with voice annotation desmbing the general conditions of the lake floor and pipeline. 3. SURVEY RESULTS Table 1 summarizes the condition of the pipeline, desmbes general conditions of the ]ake ' � floor and comments on other conditions that may impact the pipeline. The location of this information is refierenced to the stationing that is shown on the site maps. , ' � , �I � �J Table 1: Summary of Side Scan and Video Observations Station Buried Exposed Comments 3+60 to 4+20 X Pipe entry into lake. 4+20 to 28+00 X Pipe not observed on entire section. 7+00 to 14+00 Wood and miscellaneous debris. 18+60 to 19+50 Numerous ]arge sunken logs offshore of piers. 21+40 to 22+00 Large log on pipeline location. 28+10 to 28+90 X Pipeline clearly evident on side scan. Possible lo and ri-ra on sections of i line. 2,g �-3p Sunken boat oflshore. 28+90 to 38+00 X No evidence of pipeline. Golder Associates �. , , , ' r ' , ' , , ' ' ' ' ' � ' ' Mazch 29,1999 3 993-1392 Station Buried Exposed CommenE.s 38+00 to 42+?A X Pipeline clearly evident. Some possible sus nsion areas. �}p-�4p Debris on pipeline. 42+2A to 43+2A X Pi line buried. 43+2A to 44+80 X Pipeline exposed, possible suspensions and some debris on i line. 4. SUMMARY AND CONCLUSIONS A side sran sonar and underwater video camera were used to image the offshore Kennydale sewer pipeline between Stations 4+00 and Station 47+00. Over most of this length the pipeline is apparently buried under the lake mud. There was no evidence on these data to indicate that the pipeline is damaged. However, at several locations it appears that logs, riprap and miscellaneous debris are ]aying on the pipeline. At other locations the pipeline appears to be suspended above the lake floor. Both of these conditions will be more clearly defined during the diver inspection. We have appreciated worldng with you on this project. If you have any questions or require additional information, please contact us. Sincerely, GOLDER ASSOCIATES INC. �C�� �' �,///e�- 1N��� Richard E. Sylwester Associate RES/ta Q129cesidoc Golder Associates , , 1 ' � APPENDIX C. � � � 1 ' �� � , , ' r � � ULTRASONIC TESTING RESULTS � 03/05:i1�99 03:57 2967675994 GUARDIAN INSPECTION PAGE 02 , ' . :° ):: .. . . - . REPORT �TO. : c„ +ma90 �°"s�s..�w�,:wan.oe, 49835 — 1 ; ��� P*,:aaaaeaoea �:�as�e•are� , r m�aoae�a�,►rrtEw+a DA'�`� �$$ZTED. : inspec ion serv�ces� inc. �, :,�,.�,�,,�,;,�,�, s i 2/ 9 9 CUSTOMER P.0-2 8 3 012 0 � INSPECTIUN REPORT CUSTO]V�R V4'ORK SIT� LOCATION � KCM Tnc. . ' 1917 Firs� Avenue Gene Coulon Park Seattle, WA 9810I : -. Lake Washington , AT'!'EN'T�4N: . � SPECI�zCATION: ' CLASS: � Customer Iriforma�ion PART NO: 8" S ewe r E ip`e I i n e Qi1AN�'I1Y: 1 � MA't''L: , - . DESCRiF'�aN OF '�"�ST: ' Ultrasonic Thickness.Examination of: . Iea . 8 �� Sewer Pipe]:ine. ' Kennydale Sewer:Re.placemen�. � � UVSPECI'fON 1�ESULTS: Readings and Locati'oiis::can.be Found.on �he A��ached Sheets. � Note: Some Areas:.Wer�.Too.Hea�ril� Carroded to ObCain Readings, r � ' CUSTOM�It APPRQV.4L AATE: Kevizl . Maahs ,- :� - ... . II ' ,. .� -..- � �• ,., . � ' � ARED BY �' .,�-a > yd . ;_� ASNT r.�VEL DATE . .: ,. :.: , . ._:• , . . �•: ' �--r. � .. .��� . � -. �.:.-. _.., .. � � ..�-' !'..=,•• .. �� ,�.,a......:..,. . � ��_ _.,• _ .. - ` _ {�:� �;"�,:,,,�.��:..�.,,,,n T Y �i�, l� J� s. � • .: ..� .. . ,.. . °` � �PRROVEp BX � ASIVT T..�EL, DATE iJOTE: This rcport �s unbiascd Wc asatme no respoiisiGility iar losaqi of aqy:�kind �x w onr intupretation of il�e qaai.iry of tDe maztrisl snbmeuod. 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Project Background .........................................................................3 Existing Facility Design and Operation ..................................................... 3 , Flush Station ...................................................................................... 3 Lakeline.............................................................................................. 4 LiftStation ......................................................................................... 6 � Maintenance of E�sting Facility ............................................................... 6 Condition Assessment ................................................................................ 7 ' 3. Alternative Analysis ........................................................................9 Workshop1 ................................................................................................. 9 Workshop2 ................................................................................................. 9 Workshop3 ................................................................................................. 11 4. Final Replacement Alternatives .....................................................13 1. Alternative Pair N13/S13 ........................................................................... 13 Lakeline Construction ........................................................................ 13 Lift Station and Flush Station Construction .................................... 14 , Permitting Issues ............................................................................... 14 Estimated Project Cost ...................................................................... 15 Alternative Pair N15a/S15 ......................................................................... 16 ' Grinder Pump Stations ...................................................................... 16 Pressure Side Sewers ......................................................................... 17 ForceMains ........................................................................................ 18 � Permitting Issues ............................................................................... 19 Estimated Project Cost ...................................................................... 20 Implementation of Replacement Alternatives ........................................... 20 5. Interim Maintenance Alternative ...................................................23 LakelineAccess ........................................................................................... 23 LakelineCleaning ....................................................................................... 24 PermittingIssues ........................................................................................ 25 Overall Permit Timeline .................................................................... 26 Estimated Project Cost ............................................................................... 27 6. Summary and Recommendations ....................................................29 ' ' , 1 TABLE OF CONTENTS' Appendices A. Workshop 1 Technical Memorandum B. Workshop 2 Technical Memorandum C. Workshop 3 Technical Memorandum D. Alternative Pair N13/S13 Project Cost Estimate E. Alternative Pair N15A1S15 Project Cost Estimate F. Permitting Matru� G. Interim Maintenance Alternative Project Cost Estimate II ' ' , ' ' , ' ' ' ' , � � , ' ... TABLE OF CONTENTS LIST OF TABLES No. Title Page No. 1 Alternatives Developed at Workshop 2 for Further Evaluation ............... 10 2 Combinations of North and South Alternatives that Meet ProjectObjectives ....................................................................................... 11 3 Final Replacement Alternatives ................................................................. 12 LIST OF FIGURES No. Title Page No. 1 Project Vicinity ............................................................................... after page 2 2 Existing Flush Station System ...................................................... after page 4 3 Location of Sags and Exposed Sections in E�sting Lakeline ...... after page 6 4 Lakeline Plan and Profile at Kennydale Beach ............................. after page 6 5 Lakeline Maintenance .................................................................... after page 6 6 Alternative Pair N 13 and S 13 ..................................................... after page 14 7 Alternative Pair N15a and S15 ................................................... afterpage 16 8 Interim Maintenance Alternative ................................................ after page 24 9 Maintenance Manhole Section ..................................................... after page 24 � ' ' ' , ' , � � � , , , � � 1. INTRODUCTION This report presents the results of a predesign study to investigate the feasibility of replacing the Kennydale lakefront sewer for the City of Renton. The 4,700-foot sewer is located in Lake Washington and serves 52 lakefront homes. The City retained Tetra Tech/KCM to assess the potential for upgrading or replacing the facility because of past problems with the line and uncertainty about its condition. Figure 1 shows the project vicinity. The project's many permitting and constructability issues dictated a workshop approach be used to investigate potential improvement alternatives. The workshops identified project goals and constraints and used traditional brainstorming techniques to identify alternatives for repair, rehabilitation and replacement. The predesign effort consisted of three workshops with the following goals: Workshop 1—Establish goals and constraints for the project Workshop 2—Identify and rank alternatives for repair, rehabilitation and replacement of the sewer system Workshop 3—Refine the alternatives developed in Workshop 2 and narrow the potential solutions for final design. Reduce the list of options to as few as three alternatides, perform additional preliminary engineering, and choose a final design solution. The original goal of the predesign effort was to identify a single preferred final design option for implementation. However, as the predesign progressed and available alternatives were evaluated and ranked, issues such as permitting uncertainties, budget constraints and community impacts changed the direction. As costs were developed and constraints identified, it was concluded that an interim solution to maintain the e}usting facility should be developed and implemented. This report summarizes the alternatives developed and evaluated during the predesign and documents the results of the workshops. Further details about each workshop can be found in the technical memoranda included in the appendi�c. 1 C� � � � � � � � � � � � � � � � � � � � I� '`r + t � - --�;--- -__ __ - - . .._..__...._ . . _ ._..._._. . _.... _ -= - - �J Mercer Island ; N Lake � �shington , ,� ,,� � PROJECTi '� � !. SI TE ��� � L ,4 m � Figure 1. PROJECT VICINITY O Tetra Tech/ City of Renton KCM, lnc. KENNYDALE LAKEFRONT SEWER 1917FirsiAvenue REPLACEMENT PROJECT Seattle, Washington 98101 � ' 2.0 PROJECT BACKGROUND ' The Kennydale lakefront sanitary sewer is an 8-inch line in Lake Washington that serves � two small residential neighborhoods along the lake in Renton. The 4,700-foot-long line begins at the north end of Gene Coulon Park and ends at North 40th Street. Since its construction, the line has been difficult to maintain due to sags in the pipe profile and � limited access for maintenance. Sediment accumulates in the sags, causing backups in the line and overflows into Lake Washington. City workers are able to access only about one- third of the line for cleaning. The top of the pipe is exposed above the lake bottom along ' much of the alignment. The depth of cover for the buried pipe does not exceed 2 feet. The pipe has been snagged and damaged by boaters and contractors more than a half-dozen times. ;, EXISTING FACILITY DESIGN AND OPERATION � The e�sting lakeline system was constructed in 1972 as a local improvement district (Sanitary Sewer LID 270). It consists of 4, 700 feet of 8-inch-diameter cast iron pipe connecting a flush station at the south end of the facility to a lift station at the north end. ' With the exception of the southern 300 feet of pipe, the sewer is in the lake. The flush station at the south end of the facility (Lake Washington Flush) flushes lake water north through the pipe to a lift station in the 3900 block of Lake Washington Boulevard North , (Lake Washington #2). From there, sewage is pumped to Metro's Eastside Interceptor sewer in upper Lake Washington Boulevard. The existing facility is shown on Figure 2. The facility serves 52 single-family waterfront residences and the Kennydale Beach ' bathhouse. The homes are primarily in two areas—along Mountain View Avenue North and along lower Lake Washington Boulevard. There are thirty-six 6-inch-diameter side sewer connections to the lakeline. Many of the side sewer connections serve more than one ' home. Flush Station ' The flush station is on Mountain View Avenue North just beyond the north end of Gene Coulon Park. Lake water is drawn into a 72-inch diameter concrete wet well and pumped � through the lakeline by a single 1.5-horsepower submersible non-clog sewage pump. The pumping rate for the station is adjusted by raising or lowering an overflow pipe within the structure. ' � ' , ' 3 Kennydale Lakefront Sewer Predesign Report... � The flush station is currently operated for 2 hours, twice a day, to reduce the potential of solids collection in the pipeline. The system is operated in the morning and evening peak hours at approximately 10 a.m. and 10 p.m. Generally, a minimum flushing velocity of 2 feet per second (fps) should be maintained in gravity sewers to keep solids from settling in the pipe. Flushing velocities of about 3 fps are required to resuspend solids that have settled in a pipe. However, because of tlie low floor elevations in many of the waterfront homes served by the Kennydale lakeline, the system must be operated at a flow velocity significantly below 2 fps to prevent sewage backups into the homes. Tetra Tech/KCM estimates the average flushing velocity in the pipeline is less than 1 fps. Lakeline Most of the 8-inch lakeline was installed within 40 feet of the shoreline. It passes beneath most of the residential docks. Brass tags were originally installed on the docks to indicate the location of the line. Most of them were later removed as the docks were rebuilt. Along much of the existing pipeline alignment the lake is less than 6 feet deep. According to anecdotal information provided by a contractor, much of the line was installed using a backhoe operating in the lake. Installation of the line was apparently very difficult because of the limited equipment available to install pipe in these shallow depths. During construction, sections of the existing docks were removed and replaced as the pipe installation progressed. 4 The existing flush station is located at the north end of Gene Coulon Park � � � i � 1 i , , ' � � , � � � � ' 1 � ��.�/ '�� sm 5+00 � � �, `u�. �, r s� .�,. ti �o+oa s \ '/� � \� sm i -����� , `� � ... � _ . , ��- , _��_� � f _ �i i .�.��'�'�"�'��'"'�Z � = a; 'r N � � r i L.�kN W.�.chrnptor, � ,� � � sm � � 25+00 �� \ _ 1 �d�'e � � � � � � ` sta eah� � s.o, !�� 30+00 . n -�, 9ro' ,y_� ;' � ` 6�, ` � Sm �^� ��� ,,,� 35�00 Bayho� ' �--- � Kennydale Bon��yroR � 8each Park � : N� - c�, - _ Metro Sewer �.\, aurnett Ave. z_ ` • N 100' 0 100' 200' 300' 400' � � � � � � LEGEND --fl--- Existing 8" Sewer Line ----------------------------- Existing Side Sewer � Existing Cleanouts — — Approximate Inner Harbor Line � � �' `,, \ � ,► � 40+00 Z � �� ,� \ ~v� � .o "'Lt. � �� � l� � � e� ♦ Tetra Tech/ City of Renton Figure 2. KCM, Inc. 1917FirstAvenue KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT EXISTING FLUSH STATION SYSTEM SeatUe, Washington 98101 �� , , , ' , ' ' .2. PROJECT BACKGROUND , The original design documents called for the line to be buried with a minimum of 2 feet of cover over the top of the pipe, however, in many areas it was installed at or above the lake , bottom. According to a 1984 survey performed by Horton Dennis & Associates, appro�mately 900 feet of the line is exposed along the lake bottom. � The pipeline was not installed at a constant grade; it generally follows the profile of the lake bottom. As a result, the pipe's profile has several significant sags. Sediment accumulation in these sags has caused backups in the line and overflows into Lake , Washington. The overflows occur at a cleanout located near the shore at Coleman Point. The cleanout cap is intentionally left loose so that when overflows occur the sewage flows out of the cleanout rather than backing up into homes. Sag locations and the areas of � exposed pipe are indicated on Figure 3. Sags in the pipeline profile are located at the following pipeline stations: ' : Station 3+60 Station 21+50 • Station 28+30 ! • Station 40+20 � The profile sag at Station 28+30 is illustrated in Figure 4. The profile drops about 5 feet at this location. Significantly higher flushing velocities are required to move solids up the adverse grade. With an average flushing velocity of less than 1 fps in the line, significant , solids deposition can be expected in these sags. ' � 5 The lakeline is generally located near the shoreline and passes beneath residential docks. Kennydale Lalrefront Sewer Predesign Report... Lift Station The lift station is at the north end of Lake Washington Boulevard. It is a submersible station with a 23-foot deep wet well. Flush water and sewage from the lakeline discharges to the station, which then pumps it to King County's Eastside Interceptor sewer. The lift station was completely rebuilt in 1994 and is in excellent condition. MAINTENANCE OF EXISTING FACILITY The City of Renton performs maintenance on the lakeline each summer to minimize sediment accumulation in the pipe. Following a considerable number of overflows from the line between 1990 and 1994, the City reassessed its maintenance practices for the system. Since then, maintenance crews have spent two weeks each July jetting accessible portions of the lakeline. The increased cleaning has reduced the number of overflows but has not eliminated them. The pipe is accessed through cleanouts located onshore at the following locations: • 3013 Mountain View Avenue North • 3233 Mountain View Avenue North • 3111 Mountain View Avenue North • Kennydale Beach • The lift station north of 3901 Lake Washington Boulevard. The City is able to jet a 700-foot length of the line from each of these locations with their current equipment. The only location where sediment can be removed from the line during the jetting operation is at the lift station. Figure 5 shows the sections of lakeline that are cleaned during the annual maintenance. The lack of access to clean the entire line and remove accumulated sediment is a major drawback of the facility. C� The e�stinglift station is a submersible station located on the Lake Washington shoreline ' 1 � ' ' ' ' , 1 � 1 ' , ' t ' FLUSH STATION C SIa.0+00) . �� � � �� � So uo ✓� � �C `—'' �\ /i �. � � ` ���"� sm ; . ._�..�_ ,s�oo � /��•• ? � �`1 � Sd " ', � 5+00 � _ � > - xa ;� V � Me��ta����ew � � � N iao• o ioo� zoc 30o aoo �� � � a N O P1 N LEGEND i --�---- Existing 8" Sewer Line ------�-�--�------------------ Existing Side Sewer � Existing Cleanouts --- Approximate Inner Harbor Line Location of Lakeline Sags Location of Exposed Segments of Lakeline �� �� �' Iti�"�" � \ � � �� 1 � � � � Sm �. �,�� o \� : � <d,�e � •,,y��er� �� e tia. �+.� �� - ` 1 � a� sm b4�,"� r�� r 35+00 �e�h�u� ? Kennydale � �.� Beach Park �; 9r�� - ��;�.� N�� � Me..., cw�uar F� _ . --.r, gumat . � �[ �'�.. � � _ �_� I � Tetra Tech/ KCM. Inc. 1917 Firsf Avenue Seattle, Washington 98901 City of Renton KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT Laks Washfnpton �igure 3. LOCATION OF SAGS AND EXPOSED SECTIONS IN EXISTING LAKELINE UFT srennu 1 ' ' i ' ' ' ' ' ' ' , , ' ' ' , ' ' LEGEND ' =���-? 8° Sewer Line � � Side Sewers 0 o Cleanouts � Z6 � ' / - _�� 3307 ''�� ��. 25. � 25. ��� �� Lake Washington 2B+00 , y "'. ' •. ' �. _ r----1 � '� � � � �J� : , � � , _ -- _ 1 � ��-�_ , i o , 3405 , - - - 'sb-.". .: -L -� • ❑ ---- -- - - - -_------ � �. 3s ;oo �� � 16' ----- — --}{iqh..t�ke- — ------- - — Low Lake Level-13.2' 12' - Lake Bed R�� _ 8' - 4' - --- ------ ----- 0 - �Is 26+00 AI NOTE: Plan and profile information based on 1984 survey of lakeline by HoRon Dennis 8� Associates V _ 2g+00 Side Sewer Connection (Typ.} 30+00 32+00 _ - ---�----- . � i _ -- ---- 34+00 36+00 O Teira Tech/ KCM, lnc. 1917 First Avenue Seattle, Washing[on 98101 City of Renton KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT ��h� Figure 4. LAKELINE PLAN AND PROFILE AT KENNYDALE BEACH (STA. 24+50 TO STA. 36+45) , ' , � ' ' ' ' ' ' , ' , ' ' , , , ' FWSH � STATION {Sfa.0+00) �> \ + I \\ . nl � \ \ �, sb � �,� , o+oa I �, • � ,' _ , /ir ' ` � s� /� /' � 1 � ts+oo ` _ � / i \ 1 r ,;., �� /�t ,\ � �' : ; `� . ""� � '�`\' i .' � / � �. r Sta ,, � � S+QO � � sn ' � a N�.-- v1eW A� . � Mo���a�� � � . . \ / 100' 0 100' 200' 3G0' 400' ";-� z � z � �' N . O ' r• � S r i � LEGEND ---�-�-- Existing 8" Sewer Line --�����-�--------�------------ Existing Side Sewer � Existing Cleanouts �� Lakeline Accessible for Jetting , Jetting Access Location ---- — Approximate Inner Harbor Line � 1 ��. Sta 20+00 \ "� \ z � i �m Z }'� W a r � Z -�� � �' � LIFT STATION ( Sta. 47+35j Sta �5+00 �� ,._1� , ` �: � l�� ��� / O Teira Tech/ KCM, lnc. 1917 First Avenue Seattle, Washington 98101 City of Renton KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT \ �� Sta 2swo _ \ Lak� Wsahlnpton � �d�a � sd h'ayh. � 30*00 n ���eti . � �� `�� d �� Sta � �� y 3i+00 8ay� �� � f; 1 ` � Kennydale 9 ~ � — _ ury,� Beach Park � � \ B 9(uq � .. �� . Nc.I�_ � � pA � •�•� `\ Sfa Metro Sewer � y���a �`li ` - � � � . J 6umett Ave. y •- � e� V � �_ 3 v� .� \ o�< k ' � •� L �ew ��� \ah��� o� e . � tia Figure 5. LAKELINE MAINTENANCE ' 1 ' ' ' ' ' ' ...2. PROJECT BACKGROUND The system was modified in 1986 to facilitate pipeline cleaning. Ball valves were installed on each side sewer so that the lakeline could be pressure-pigged. The valves were meant to prevent backups into the homes, but were not appropriate for this use and did not seat effectively. During the initial attempt to pig the line, a significant amount of sewage backed up into the basement of one home, and the process was not tried again. City staff considered replacing the ball valves with a different valve after the incident, but did not feel their credibility in the neighborhood was strong enough and did not want to risk another backup. CONDITION ASSESSMENT The design team assessed the existing condition of the pipe to gauge the feasibility of alternatives that would make use of the existing pipe. The assessment included ultrasonic testing of exposed portions of the pipeline, dye testing of the flush station system, and a geophysical assessment of the pipe and adjacent lake bed. In general, the condition assessment provided valuable information for assessing alternatives that involve use of the existing pipeline. However, since the entire pipeline could not be accessed and tested, its ability to remain in service another 20 years remains uncertain. Significant results of the condition assessment were as follows: ' • Approximately 53 ultrasonic reading were taken of the lakeline to measure remaining wall thickness. Thickness readings varied from 0.308 inches to 0.515 inches. Most of the readings were in the range of 0.375 to 0.400 ' inches. Remaining wall thickness appears to be adequate at the locations where measurements were taken. • Accurate ultrasonic measurements for wall thickness are not possible ' unless the outside of the pipe is relatively free of scale and rust. Numerous areas along the outside of the pipeline were too rusted and scaled to get accurate thickness readings. , , ' , • Concrete debris has been dumped on top of the pipe at Station 40+40. The debris is likely the remains of a bulkhead replaced by the homeowner. The condition of the line beneath the debris could not be verified. • Dye tests were performed to estimate the average flushing velocity through the pipeline and to assist in estimating the pump output from the flush station. The average flushing velocity through the pipe was determined by measuring the travel time of the dye through the appro�mately 4,700 feet of lakeline from the flush station to the downstream lift station. The travel times for the two tests were 105 minutes and 102 minutes, which translates to an average velocity of 0.8 fps. Using this average velocity and the visual observation that the 8-inch pipe discharging to the downstream ' lift station was flowing about one-third full during the tests, Tetra Tech/KCM estimates that the flush station pump output is between 100 and 150 gallons per minute. � , ' The horizontal alignment of the pipe is very crooked from approximately Station 34+00 to the lift station. Some joints appear to be deflected in excess of 5 degrees. 7 Kennydale Lalrefront Sewer Predesign Report... • A 2-inch hole was found in the line at approximately Station 44+00. The flush station was operating when the hole was discovered, and water was being drawn into the hole. The hole is next to a dock, and the pipe wall around the edge of the hole appears to be solid. This may indicate that the pipe was damaged from work being done on the dock rather than from corrosion. • Horizontal alignment and pipeline exposure problems appear to be more serious than the issue of remaining pipe wall thickness. Additional information on the condition assessment is included in the Workshop 2 technical memorandum in Appendix B. � ' ' 1 ' �J ' ' ' ' ' ' ' 3.0 ALTERNATNES ANALYSIS WORKSHOP PROCESS A workshop approach was used to investigate and rank potential alternatives for implementation. Workshop participants included City staff and design team members. Following is a summary of each of the three workshops conducted. Detailed information is available in the attached appendices as noted. Workshop 1 Workshop 1 was a project initiation workshop, conducted on February 16, 1999. Objectives completed at Workshop 1 included bringing the consultant team and City staff to a common understanding of the problems and issues associated with the e�usting facilities, conceptualizing initial alternatives, confirming project goals and constraints, and establishing criteria for ranking alternatives. The following broad categories of solutions were identified at the workshop: Alternatives to lmprove maintenance of the e�sting fTush station and Iakelin�These alternatives include providing access manholes in the lakeline to facilitate rodding and jetting the line, providing pipeline cleanouts at existing docks, and removing the sags in the pipeline profile where solids collect. Rehabilitation alternatives to improve the structural and operational integrity of the system--These alternatives include lining or slip-lining the e}cisting lakeline to improve hydraulic efficiency and modifying the flush station to increase flow velocity in the pipeline. Replacement alternatives--These alternatives include replacing the existing facility with a new lakeline system or a new upland system located out of the lake. ' Additional information on the development of project goals and constraints and the establishment of criteria for ranking alternatives is included in the Workshop 1 technical memorandum in Append� A. ' ' ' , ' ' Workshop 2 Workshop 2 was conducted on March 9, 1999. Objectives completed at the workshop included brainstorming alternative solutions for the sewer replacement, conducting an initial screening of available alternatives, and selecting the top-ranking alternatives for further evaluation. Conceptual alternatives developed at the workshop were split into north end and south end groupings. The two ends of the lakeline have different physical constraints affecting the feasibility of solutions, so the project was divided into two parts, but without precisely defining the dividing point between the two. �vo distinctly different alternatives could provide the most feasible overall project solution because of these differing constraints. � Kennydale Lakefront Sewer Predesign Report... Forty-two conceptual alternatives were developed, and workshop participants voted for those they believed to have the most merit. Based on the voting and subsequent discussion, participants selected 13 alternatives for further evaluation. Table 1 summarizes the selected alternatives. Additional information on the development and ranking of conceptual alternatives is in the Workshop 2 technical memorandum in Appendix B. TABLE 1. ALTERNATIVES DEVELOPED AT WORKSHOP 2 FOR FURTHER EVALUATION No. Descri tion N1 Replace the existing lakeline with a new minimum 6-inch gravity sewer in the lake. N3 Leave the existing lakeline in place, restrain pipe joints, add access points for maintenance, and re-lay portions of the line to remove sags in the profile. N6 Construct a new gravity sewer between the homes and the railroad using trenchless pipeline installation methods. Reroute side sewers to the new gravity sewer using trenchless installation methods. N8 Microtunnel a new gravity sewer in upper Lake Washington Boulevard and install new side sewers using directional drilling from the lake side. N13 Replace the existing lakeline with a new 6-inch or 8-inch diameter sewer in the lake with flushing capacity. N15 Slip-line the existing lakeline to Station 22+50 with 3-inch diameter plastic pipe, install grinder pumps at homes and new pressure side sewers. N15a Install grinder pumps at each existing side sewer connection between Kennydale Beach Park and the existing lift station. New pressure side sewers would discharge to a new 3-inch force main installed by open-cut construction in lower Lake Washington Boulevard. S3 Leave the existing lakeline in place, restrain pipe joints; add access points for maintenance, and re-lay a portion of the line to remove sags in the profile. S6 Construct a new gravity sewer between the homes and the railroad using open cut pipeline installation methods. Construct a new lift station to convey flows to upper Lake Washington Boulevard. S8 Microtunnel a new gravity sewer in upper Lake Washington Boulevard and install new side sewers using directional drilling from the lake side. The flush station would remain in service to intermittently flush the new gravity sewer for cleaning purposes. S13 Replace the existing lakeline with a new 6-inch or 8-inch diameter sewer with flushing cap acity. S15 Install grinder pumps at each existing side sewer connection between Station 3+00 and Station 25+00. New pressure side sewers would discharge to a new 3-inch force main installed by open cut construction in Mountain View Avenue North. The four southerly homes would drain by gravity to a new gravity sewer. The existing flush station would be replaced with a lift station, and flows from the new main would be pumped up to the existing gravity sewer in upper Lake Washington Boulevard. S21 Construct a new gravity sewer between the homes and the railroad north to Station 28+00. Direct flow in the existing lakeline from Station 36+00 south and construct a new lift station at Station 28+00. 10 ' ' 1 ' Workshop 3 ...3. ALTERNATIVESANALYSIS ' Following Workshop 2, Tetra Tech/KCM performed additional preliminary engineering and cost estimating for the top-ranked alternatives. Refinement of the alternatives included the following elements: , • Additional field information was gathered to address construction issues regarding work on individual residential properties and construction within the lake. • Several contractors were contacted to discuss the feasibility of employing various construction methods to install new side sewers, a new lakeline, and new onshore gravity and pressure sewers. Construction methods investigated included directional drilling, microtunneling, pipe ramming, marine construction and shore-side construction. • City mapping and as-built drawings were assembled for the project area. • A preliminary layout was developed for each alternative. The layouts included an approximate profile for gravity sewers and new lakelines. • Planning level cost estimates were prepared for each alternative. Each of the top-ranked alternatives presented technical challenges that affect its feasibility. Space constraints present the greatest challenge for alternatives that involve construction of a new pipe in the lake. The existing pipeline is generally constructed close to the shoreline, running beneath most of the existing docks. Lake depth along the alignment is often shallow, in the 4- to 6-foot range, and there is little space between the docks. For alternatives that include construction of a new on-shore sewer, the greatest technical challenge would be rerouting the existing side sewers to the new line. After further review and discussion of the alternatives, Workshop 3 participants identified the alternatives that met the project objective. They paired north and south end alternatives to form a list of options for overall solutions. Table 2 shows the paired alternatives. TABLE 2. COMBINATIONS OF NORTH AND SOUTH ALTERNATIVES THAT MEET PROJECT OBJECTIVES Paired Alternatives N1/S13 N1/S15 N13/S13 N13/S15 N15/S 13 N15/S15 N15a/S13 N15a/S15 Estimated Total Cost w/o $3.7 million $32 million $4.0 million $3.5 million $3.5 million $2.7 million $3.3 million $2.4 million 11 Kennydale Lalrefront Sewer Predesign Report... Following Workshop 3, City staff decided on the alternative pairs that best met the project objective and should be evaluated further; these are listed in Table 3. Additional information on the development of alternative pairs and screening of alternatives is included in the Workshop 3 technical memorandum in Appendu� C. Alternative Pair N13/S 13 N15a/S15 TABLE 3. FINAL REPLACEMENT ALTERNATIVES Description Replace the existing lakeline with a new 6-inch or 8-inch diameter sewer in the lake with flushing capacity. Install a 3-inch diameter force main in the frontage roads adjacent to the homes; install grinder pump stations and new pressure side sewers at existing side sewer locations. 12 ' ' 4.0 FINAL REPLACEMENT ALTERNATNES ' Both preferred alternative pairs involve a total replacement of the existing flush station ' system. Alternative pair N13/513 would replace the system with a similar, in-lake flushing system. Alternative pair N15a/S15 would replace it with new grinder pump stations and force mains installed onshore. Each alternative pair is discussed below. , ALTERNATIVE PAIR N13/S13 t This alternative pair involves constructing a new flush station system that is similar to the e�usting facility. A new 8-inch-diameter flush line would be installed in Lake Washington with a minimum burial depth of 2 feet below the lake bottom. Connection to the existing , side sewers would be made near the lakeshore, and new side sewers would be extended out to the new flush line. A new flush station and lift station would replace the e�sting facilities. This alternative is shown on Figure 6. � ' ' 1 1 ' ' � Lakeline Construction A major difference between this alternative and the e�sting system is the location of the flush line in the lake. Tetra Tech/KCM met with General Construction Company, a marine contractor, to discuss the feasibility of constructing a new lakeline. A company representative felt that it would be very complicated and costly to construct a new line inside the docks similar to the e�sting line. A new line would have to be installed with barge-mounted equipment. A custom barge would be necessary because of space constraints and shallow water unless the existing docks were removed during construction and subsequently rebuilt. It was assumed that a new pipe would be aligned immediately beyond the existing docks because of these restrictions. The representative from General said that a new line should be located 10 to 15 feet outside the docks to provide sufficient room for installation using a conventional barge. The profile of the new line would be lower than the existing line since the lake bottom is considerably deeper outside the existing docks. Tetra Tech/KCM took approximately 24 soundings outside of the docks and found that the lake bottom varies in elevation along the alignment from 8.0 feet to -2.0 feet (LJ.S.C.&G.S. Datum). For estimating purposes it was assumed that a new line would be installed at an average invert elevation of —2.0 feet. Although the elevation of the pipe would vary slightly along its length, the grade would be kept fairly constant. This would ensure the new line has no significant low spots where sediment could accumulate. Between Station 7+00 and Station 26+00, the lake bottom elevation remains fairly ' constant outside the docks. The average lake bottom elevation along this 1,900-foot distance is approximately 5.0 feet. Significant excavation would be required to install the new line at an invert elevation of —2.0 feet in this area. ' ' , General Construction identified pipeline excavation and backfill as being one of the costliest portions of the lakeline construction. It is likely that the Department of Fish and Wildlife would not allow excavated material to be backfilled into the lake after the pipe is 13 Ken�dale Lakefront Sewer Predesign Report... installed. A clean, granular material more suited to fish habitat would probably be required. The excavated bottom material would need to be removed from the site for disposal. The disposal options for the material are offshore dumping and upland disposal. The cost difference between these options is significant. General estimates that offshore disposal costs are about $20 per cubic yard, while upland disposal costs are about $120 per cubic yard. Dumping material offshore would require regulatory approval, and the ability to do so would not be known until the project permits were attained. The cost estimate developed for this alternative is based on offshore disposal of excavated material, since upland disposal costs are prohibitive making the alternative unfeasible. Besides the burial depth of the pipe, excavation quantities will depend on the stability of the material being excavated. If the lake bottom material is highly organic, the side walls of the trench will not stand, and higher excavation quantities will_ be required. General Construction has had good success with the stability of bottom materials on nearby projects. Trench side walls commonly stood on a 1 vertical to 1 horizontal line. General recommends contacting contractors who have recently built docks in the area. The pile driving records from these contractors would provide valuable information on the strength of material that will likely be encountered. Lift Station and Flush Station Construction The lowered lakeline profile would require the lift station at the north end of the project to be rebuilt. The current station is approximately 23 feet deep and would need to be lowered an additional 8 to 10 feet to serve the deeper lakeline. Construction of the new lift station would be difficult because of the station's proximity to the lake and adjacent homes, and because of high groundwater elevations at the site. A major advantage of lowering the lift station is that the flushing rate could be increased through the lakeline without causing backups into homes. Lowering the elevation of the lift station would result in a lower hydraulic profile for the system. Under this alternative, the existing flush station would also be rebuilt so that flushing rates could be increased. The new lift station and flush station would be built at the locations of the existing facilities. Permitting Issues This alternative has the most significant impact on aquatic resources of all alternatives considered because it involves the most in-lake construction. The following permit issues have been identified for this alternative: A U.S. Army Corps of Engineers Individual 404 permit will likely be needed, as construction will cause a discharge of dredged and fill material into a waterway. An Individual 404 permit requires an alternative analysis demonstrating that project impacts are justifiable and that the preferred alternative provides the best overall solution. Much of the work performed l4 � ' ' � 1 � , i � ' � � i , , � ' ' i New 8" Flush Line Installed Beyond Existing Docks With Minimum 2' of Cover Extend Side � Sewers to __ New Fiush Line '— sti s+oo FLUSH � iTATION � ih. 6+00) / \ �1 sn �� : tDtioo =. 1� ,� � ► < < � , � ` + � � � � -'J 1 !' %=l. i '� •.. ' `,�/. ' � � , Y . 1�, i � �� � � � � � �n��ew?'°° N� `" ,-- — o���a . / � � Rebuild Existing Flush Station NOTES: 1. Homes and docks on map based on 1984 survey by Horton Dennis Associates. 2. New 6-inch flush line has a minimum of 2 feet of cover. 0 L ; � � � A new 8-inch�iiameter flush line is installed in Lake Washington beyond the existing � private docks. Connection to the existing ', side sewers would be made near the I, lakeshore and extended out to the new lakeline. The existing flush station would ' be upgraded to increase flushing capacity. I A new, deeper pump station would be � required. The existing lakeline would be abandoned in place. 2 u 0 z�� Z w w r Abandon Existing', Lakeline in Place ; sm is+oo � z N � r� ESTIMATED PROJECT COST wlo PERMITTING: . ESTIMATED RANGE OF PERMITTING COST: �, �� i�� � � c.�k�� w.�,m„yr��-� ` / �oa o �oo t00' 30G' a00 sm zo+oo z w a N Maintenance Manhole on Private Properry � Sta � 25+0� � ` � --.•` \ [a�e � ��a�'�'or °'s tid ; LEGEND '� — —� -- Existing 8" Sewer Line ' --�--�-------��----��-�----- Existing Side Sewer � Existing Cleanouts �---�— New Sewer Line ----------- New Side Sewer — - — - ---- Approximate Inner Harbor Line New 8° Flush Line � Installed Beyond � Existin Docks Abandon Existing Lakeline in Place :� � � � . � . ��o �++��� J ,.t Cr `� `� �'wer��k��Vj+h � .� 4rp�an e� � d , � .: ; ,� Dock Cleanouts at Two Locations Accessible to City Jettinq Equipment LIFT sTnnoN �Sta.47+35) - Sti �o ��New Lift Station � Invert Elevation of New 8" Flush Line = -2.0' :. • A new, deeper lift station is required �i • The new lakeline alignment would need to be outside the existing docks for constructability. This because of the lower profile of the requires lowering the line to an approximate elevation of -2.0'. new flush line. L�wering the lift '• Lift station must be lowered about 10 feet to accomodate lowered flush line. station increases the amount of flow Sewer line remains vulnerable to damage. that can be flushed through the line 'I � • Connection to existing side sewers �• Maintenance access to the line remains difficult. requires little disruption to residents' ; �• Negotiatin easements for locating maintenance manholes or dock cleanouts on private property property � j may be di�cult. I• Regulatory approvals may be diificult to attain. • The new line may extend beyond private properry limits between Sta 15+00 and Sta 20+00, which ' would require Department of Natural Resources approval. \ ' Tetra Tech/ KCM, lnc. 1917 First Avenue Seattle, Washrngton 98101 City of Renton KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT Extend Existing Side Sewers to New Gravity Line Maintenance Manhole at Kennydale Beach for Maintenance Access Sta � so+oo �_ \(1` ' �� 35+00 �� B �' �'=- g�hou�� � �� - Kennydale � 84tlinB(cq .. BB2Ch P�rk � -vorr5: ��,�. , , �� Metro Sewer � Bumatt Ave Z, ��`-' � � ow+ ' i �� Figure 6. ALTERNATIVE PAIR N13 AND S13 ' ' ' • C� ' ' .. 4. FINAL REPLACEMENT ALTERNATIVES for this predesign could be repackaged to meet the Corps requirement for alternatives analysis. If the Corps permit is required, then a Biological Assessment (BA) is needed. The BA cannot begin until design is 60 percent complete. • The Department of Fish and Wildlife will have requirements for construction timing and technique. The summer fisheries window for construction will be June 16 to the end of October. There may also be a winter window within portions of the project limits. Parts of the project area are in a beach spawning area for sockeye salmon. Alternatives that involve a loss of shoreline spawning habitat may not be permitted. Pipes must be buried in the lake bed; exposed pipes would provide an area for predators to hide and feed on juvenile salmon. • The City does not have a defined water right for the flush water. If lake ' water availability should become a problem, the system may need to be retrofitted to use a City water source rather than lake water in the future. ' , ' The City of Renton will require an environmental review under the State Environmental Policy Act (SEPA). The City's Environmental Review Committee would issue an environmental threshold determination approximately four weeks after the application is submitted. A 14-day appeal period would follow the issuance of the environmental determination. Issues that would likely be addressed and require mitigation would be erosion and sedimentation, water quality, environmental health hazards, air quality, noise, and wildlife. • A Shoreline Substantial Development Permit will likely be required. The ' requirement for this permit would be determined following coordination with the City. The City would issue the Shoreline Permit after the SEPA environmental review appeal period has ended and no appeals are filed. , Recommendations from the Biological Assessment should be made available to the City prior to issuing the Shoreline Permit to the Department of Ecology. , ' � ' , , A Special Permit for Fill and Grade would likely be required for N 13/S 13 filling and grading activity involving 500 cubic yards or more of material. A public hearing with the City's Land Use Hearing Examiner is needed to approve a Special Permit for Fill and Grade. The length of time necessary to process City environmental and land use permits for this alternative is approximately 12 weeks. An additional four weeks is needed for the City to issue the Shoreline Substantial Development Permit and for the State Department of Ecology to run a 21- day appeal period, for a total of approximately 16 weeks. Estimated Project Cost After Workshop 3, additional evaluation of alternative costs was performed. Revised costs were based on estimated construction methods and production rates provided by General Construction. The estimated project cost, excluding permitting, for alternative pair ' 15 Kennydale Lakefront Sewer Predesign Report... N13/S13 is $4.2 million. Adolfson Associates, Inc. estimates that the cost to secure the required permits for this alternative would range from $100,000 to $220,000. A project cost estimate for this alternative is included in Appendix D. Additional information on permitting costs is included in Appendix F. ALTERNATIVE PAIR N15a/S15 This was the only feasible alternative pair for replacing the existing flush station system with a new sewage system located out of the lake. Under this alternative, grinder pump stations would be installed at each side sewer that currently discharges to the lakeline. New 1-1/2-inch pressure side sewers would route flow away from the lake to new 3-inch diameter force mains installed by open cut construction in Mountain View Avenue North and lower Lake Washington Boulevard. This alternative is shown on Figure 7. Grinder Pump Stations A minimum of 34 new grinder pump stations would be required to serve the 52 residential properties and Kennydale Beach. Most of the stations would be installed on the lake side of the properties so that they intercept the existing side sewers. Some of the stations would serve more than one home. Grinder pump stations are low-pressure, below-ground sewer systeins that incorporate a grinder pump, motor controls and a level-sensing device in a compact housing. The pumps grind solids into fine particles, allowing them to pass through the pump, check valve and outlet piping without clogging. The pump and controls are generally housed in a polyethylene tank that is about 48 inches in diameter. A number of residential pre- packaged stations are available through local suppliers. A high-liquid-level alarm is activated if a malfunction of the station occurs. This can be a light mounted on the outside of a home or an audible alarm that can be silenced by the resident. The resident then notifies the City maintenance department, who can then respond to make necessary repairs. The units can also be connected to the City's telemetry system so that malfunctions can be monitored from the City maintenance shop. Installation of the grinder pump stations would be very difficult at some of the existing homes, particularly along lower Lake Washington Boulevard. The lots for these homes are generally narrow, and improvements such as decks and patios extend to the water's edge. A representative of Magnolia Contractors, a pump station contractor, visited the site to investigate the feasibility of installing the grinder pump stations. Magnolia believes that the pump station installation would be very difficult at a number of the e}dsting homes. In some cases, installation would require hand digging because of lack of access and staging room for construction equipment. At locations such as that shown in the photo below, installation would be very disruptive to the homeowner's yard and inconvenience them personally. An extensive amount of community relations time would be required during design and construction to work with the homeowners. 16 Replace Existing Flush Station With New Lift Station � fLUSH STATION �sr.. o+ao� � / /fC"' ; .` sn � �' � ���.�:/ � Install New 8" Open Cut �ravi Sewer Z � Abandon Existing Lakeline in Place j � Install Grinder ' \' ; � � { �, Pump Station ;,_ ` at each Side Sewer Location � _-j se� ,' � ' ., .: ,� _, , ts+oo �� � � � � T�.�-�1�.1 � { '�. 1 ', l \ i '� I� i i � Sta zowo Reroute New 1-1/2° Pressure� Side Sewers to Nev�rForce Main byDirectional D�illing or'' Open Cutting at Homes Along, Mountain View Ave. N. \ Install New 3" ` Open Cut Pressure Sewer� _ ? ? � � � � � � � Bore & Jack Crossing of Burlington Northern Railroad Connect New Force Main to Existing Gravity Sewer in Lake Washington Boulevard � \ s� _ � ss+oa � � a �, \ �� * � ��e ��'h�n � ��� e'�a Lakc W,ishrnymn r� � �cuc�vu — —� — — Existing 8" Sewer Line ----�---�-�--��-�---------�-- Existing Side Sewer ° Existing Cleanouts --�--- New Gravity Sewer Line —�— New Force Main ----------- New Side Sewer lOD' 0 700� 200' 30G' 400- � Sa a� -_.a T0+00 '��Y�� � � �. `�"' ti�:, ; �! p� . Metro Sewer ' Burn�tt A�e Z -- ---- Approximate Inner Harbor Line p New Grinder Pump Station �\'� � � Grinder pump stations are installed at each of the , existing side sewer connections. New pressure side 'i i sewers would discharge to new 3" pressure mains in I Mountain View Avenue North and in Lower Lake Washington Blvd. The four southerly homes would drain by gravity to a new gravity sewer. The existing i flush station would be replaced with a lift station, and flows from the new main would be pumped up to a City of Renton gravity sewer in Lake Washington Boulevard. The existing lakeline would be abandoned in place. ESTIMATED PROJECT COST wlo PERMITTING: . ESTIMATED RANGE OF PERMITTING COST: �, � ��� �. � ��� '� • Sewer line is removec! from the lake. • Flushing of line no longer required. New sewer lines can be accessed for maintenance from Mountain View Avenue North and from Lower Lake Washington Blvd rather than from private properties. Sewer line is no longer vulnerable to damage New pressure sewer main can be easily installed in Mountain View Avenue North. i' I �' I . . Connection to the exisbng side sewers and installation of new grinder pump stations will damage yards and bulkheads of residential properties. City has 34 additional pump stations to maintain and spare pumps to stock. Re-routing side sewers to Mountain View Avenue No�th will be di�cult. Odors from grinder pump stations may be an issue. Overflows to the lake are still possible if the grinder pumps fail. NOTE: 1. Homes and docks on map based on 1984 survey by Horton Dennis Associates. O Tefra Tech/ City of Renton Figure 7. KCM, Inc. 1917FirstAvenue KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT ALTERNATIVF PAIR N15a AND S15 Seattle, Washington 98101 1 , ' LJ 1 , �I lJ ' , ' , � ..4. FINAL REPLACEMENTALTERNATIVE,S Although the lakeline would no longer be in service with this alternative, there would still be potential for effluent spills into Lake Washington. Most of the grinder pump stations would be located near the shoreline, and overflows from the station into the lake could result if a malfunction occurs and the station's capacity is exceeded. City staff has indicated that if this alternative were implemented, they would want to investigate installation of commercial grade duplex pump stations rather than the residential grinder pump stations typically available on the market today. A duplex station would be considerably larger than the single-pump residential stations, making installation more difficult on confined properties. The cost estimate developed for this alternative is based on the use of single-pump residential stations. Equipment and installation costs would increase significantly if duplex stations were used. ' Pressure Side Sewers One of the most challenging aspects of this alternative would be the installation of ' pressure side sewers to convey sewage from the grinder pump stations to the new force mains. The pressure side sewers would be 1-1/4-inch to 1-1/2-inch lines that extend from the grinder pump stations to new force mains along the east side of the homes. ' ' ' C, ' 17 Declrs and patios extend beyond the lake's edge at many properties, makinginstallation ofnewgrinderpumps difficult and disruptive. Kennydale Lakefront Sewer Predesign Report... ' Many of the homes along lower Lake Washington Boulevard are constructed very close together, making installation of the side sewers difficult. On most of these properties there is very little room between the e�sting homes, sometimes as little as 8 feet, making it difficult to install a new side sewer. In most cases this space includes improvements such as patios, stairways, decks and rockeries that would have to be removed and replaced if the side sewers were installed using open-cut construction. For this reason, it was assumed that side sewers for the homes along lower Lake Washington Boulevard would need to be installed using trenchless methods. A representative from Loy Clark Construction, a pipeline contractor, visited the site to assess the feasibility of installing the side sewers using directional drilling or other trenchless techniques. The major challenge to trenchless pipeline installation in this area is the lack of staging and setup area for equipment along lower Lake Washington Boulevard. He believes that the only way to successfully install the side sewers with a trenchless technique would be to use a small pipe-ramming piece of equipment. This could be successful because the required pipe length is short and the lines are small in diameter. Side sewers for some of the properties along Mountain View Avenue North could be installed by open cut methods without causing serious damage or requiring extensive mitigation. Force Mains The pressure side sewers would discharge to new force mains installed in Mountain View Avenue North and lower Lake Washington Boulevard. The force mains could be installed by open cut methods using a Ditch Witch or similar equipment since the required pipe size is small and would only require a burial depth of 4 feet. The new mains would be 3 or 4 inches in diameter � Open cut installation ofpressure side sewers at homes along lowerLake Washington Boulevard would cause major damage to landscaping and other improvements. ... 4. FINAL REPLACEMENT ALTERNATIVES Further design is required to determine whether the grinder pump stations would have sufficient capacity to pump sewage along the alignment and then lift it to upper Lake Washington Boulevard. If an intermediate lift station is required, the force main serving the homes adjacent to lower Lake Washington Boulevard could discharge to the e�sting lift station. The e�sting lift station could serve the area north of Kennydale Beach with little or no modifications. A new intermediate lift station would be required to serve the homes south of Kennydale Beach. For estimating purposes, it was assumed that intermediate lift stations would be required. If individual grinder pump stations have the capacity to lift sewage to upper Lake Washington Boulevard, then the new and existing lift stations would not be required. This would reduce capital costs for the alternative and future operations and maintenance costs. Permitting Issues In-lake work is largely eliminated with this alternative. Installing a new pressure main and side sewers would reduce beach construction and associated aquatic concerns. The following permit issues have been identified for this alternative: Construction staging will be difficult in the area; access to homes during construction will be difficult. Connection to the existing side sewers and installation of new side sewers to Mountain View Avenue North and lower Lake Washington Boulevard. will damage yards and bulkheads of residential properties and require extensive mitigation. • The construction of a new pressure sewer will require a Utility License ' Agreement with Burlington Northern Santa Fe Railroad (BNSF). Approval of plans and application forms by BNSF engineering must be completed before construction begins. Pipelines crossing under tracks must be ' ' 19 Co�ned roadway width alonglowerLake Washington Boulevard makes shallow, small diameter pressure pipeline construction the onlyfeasible upland sewerinstallation alterna ti ve. Kennydale Lakefront Se wer Predesign Report... installed by boring and jacking methods only. Processing of plans and forms by BNSF will take approximately 30 to 60 days. There is a potential for sewage spills with the grinder pump stations. If a power outage were to occur, backups at the stations could spill into Lake Washington. The City of Renton will require the same permits and review period as discussed in the N13/S13 alternative. In addition, a conditional use permit may also be required. Estimated Project Cost After Workshop 3, additional evaluations of alternative costs were performed. The estimated project cost, excluding permitting, for alternative pair N15a/S15 is $3.0 million. Adolfson Associates, Inc. estimates that the cost to secure the required permits for this alternative would range from $20,000 to $30,000. A project cost estimate for this alternative is included in Appendix E. Additional information on permitting costs are included in Appendix F. IMPLEMENTATION OF REPLACEMENT ALTERNATIVES Following the final evaluation of the two alternative pairs and the development of the final predesign costs, City staff convened to consider a recommendation for implementation. The consensus of staff was that a final recommendation couldn't be made at this time. The factors that most affected their decision were the budgeting impacts, community impacts and permitting uncertainties of the alternatives. Project costs for either of the alternatives will likely exceed $3 million. This equates to a cost of over $56,000 for each of the 53 properties served. The City determined that either project would require a significant increase in city-wide sewage utility rates to fund the improvements. At this time, there are not sufficient funds in the City's capital budget to pay for either alternative. Other factors affecting the City's decision are as follows: The remaining service life of the existing lakeline remains uncertain. Under normal conditions, a cast iron line should last 40 or 50 years until it needs to be replaced. Permitting conditions and environmental compliance requirements cannot be well defined for construction of a new flush station in the lake until the preliminary design of the system is complete and can be reviewed by the various regulatory agencies. The alternative to replace the flush system with grinder pump stations has major constructability and community impact issues. These issues include damage to properties, odor and aesthetic concerns. The City decided that until a replacement alternative can be implemented, interim measures to better maintain the line to prevent overflows into the lake should be � ...4. FINAL REPLACEMENTALTERNATIVES investigated. The following section describes an interim maintenance alternative developed subsequent to the workshops. This interim action upgrades capability to maintain the line and increase its service life. 21 ' 1 5.0 INTERIM MAINTENANCE ALTERNATIVE ' Lakeline maintenance currently performed by City crews is not completely effective. Major obstacles faced by the City include a lack of entry points into the line, lack of equipment access to the line for the City's cleaning equipment, and the inability to remove ' accumulated sediment from the line. As shown on Figure 5, only about one-half the line can be partially cleaned by the City. 1 ' ' , , 1 ' ' 1 ' LJ alternative is shown on Figure 8. This alternative includes the addition of lakeline access points at locations where sediment can be removed from the line. A total of four additional access points are included. The A major difference of this alternative from the maintenance alternatives developed during the workshops (N3 & S3) is that access to the line must be made from the lake. The City would require the services of an outside cleaning contractor to accomplish this. LAKELINE ACCESS The two main goals of this alternative are to provide sufficient access so that a majority of the lakeline can be jetted and to provide a means to remove accumulated sediment from the line during cleaning operations. Because the line is so difficult to access from the shore, the only feasible approach to accomplishing these goals is to locate new in-line structures along the lakeline and access these structures from the lake during cleaning. Locating the access points near the existing sags in the pipe profile would facilitate sediment removal from the line. Under this alternative, manholes would be installed along the line at the following locations: • Station 40+00 • Station 28+30 • Station 21+70 • Station 9+70 Station 40+00, Station 28+30 and Station 21+70 are near the low points of three of the four sags in the pipeline profile. The manhole at Station 9+70 would allow portions of the line south of Coleman Point to be cleaned. The existing pipeline is exposed along the lake bottom at Station 40+00 and Station 28+30. At Station 21+70 and Station 9+70 the e}usting pipe is buried appro�mately one foot below the lakebed. There are two potential drawbacks to installing new manholes in the lake. One is that ' they could pose a potential navigational hazard to boaters, and the other is that the structures would provide an area for aquatic predators to hide and feed on juvenile salmon. Larry Fisher of the Department of Fish and Wildlife raised the latter issue at Workshop 2. ' To address these concerns, new manholes could be designed as shallow structures to limit their projection above the lake bottom. , ' 23 Kennydale Lakefront Sewer Predesign Report... Figure 9 shows a schematic section of a manhole that projects 2 to 3 feet above the lake bottom. The new structure would be precast and retrofit to the existing line by removing a short section of the existing pipe and setting the new manhole in place. A portable shaft that extends above the lake level would be temporarily installed to access the manhole and lakeline. The King County Department of Natural Resources uses a similar system to access manholes along their interceptor sewers that are located in Lake Washington and Lake Sammamish. Tetra Tech/KCM designed these interceptor pipes, manholes and access shafts in the 1960s. The new manholes for the Kennydale lakeline could be designed so that the e�usting shafts owned by the County could be used to access the line. The shafts fit around the perimeter of the manhole. A gasket along the bottom of the shaft provides a watertight seal. Once the shafts are set in place, they are attached to the manhole with chain binders, and the shaft is pumped dry. Once dry, the water pressure around the outside of the shaft helps to seal it against the manhole. Divers would be required to initially set the access shafts in place. LAKELINE CLEANING With the new manholes in place, the concept for cleaning the lakeline would be to jet the pipe upstream and downstream from each location with a barge-mounted vactor truck. Standard vactor truck mounted jetting equipment has from 700 to 800 feet of hose, therefore nearly all of the pipe could be jetted from these four locations. The vactor truck would remove sediment that is drawn back towards the manholes. Shore-side access to the manhole locations in not possible with a vactor truck. Cleaning activities would need to be staged from a barge in the lake. City crews are not equipped to perform this type of work, therefore, an outside cleaning company would need to provide this service. Gelco Services, a sewer rehabilitation and cleaning contractor, indicated that they have performed similar inspection and cleaning services for King County on their trunk sewer in Lake Washington. A vactor truck staged from a barge was used to jet the line. Gelco teamed with Advanced Commercial Divers, Inc. on the project. Advanced provided divers and barges for the operation. Gelco estimates that the Kennydale lakeline could be cleaned in 7 to 10 days. They typically assume a cleaning rate of 800 feet per day for a municipal sewer, however the cleaning rate would be slower for the lakeline because of staging from the lake. Advance Commercial Divers indicated they would use "porta-barges" for this project. Three 10-foot by 40-foot barges rafted together would be large enough to support a 66,000-pound vactor truck. The barges could operate in water as shallow as five feet. The cleaning rate for the lakeline would depend on how often the vactor truck would need to be emptied. A typical vactor truck will hold between 1,000 and 1,500 gallons of liquid. The volume of the existing 4,700-foot lakeline is approximately 12,000 gallons, so it would require 8 to 12 trips just to empty the existing line. The truck could likely be loaded and unloaded from the barge at the Gene Coulon Park boat ramps. 24 ' ' 1 ' , , ' 1 ' ' ' ' ' i 1 1 ' 1 ' i / I �� �: / i /. � M ssoo I' �� FLUSH � STATION (Sta.0+0o) � / I � . � D � � 2 > � � � V 7 i - , � ` sc� �, 1 ,o+oo� ,� /, �' �'• ♦ / : `� sw � , "� 1Sr00 � �� � �.� � '� � ,�� -i, ' ; i;� i � � �� � �} � / � : � � r � z � N Py' D � L.ake W;�s!nnqtcn sa \? io+oo '� � ' �. ` � ��\� � Sn \ � ZS*�� Z � a --a���� � — <d�.a �iah�"or �� @ tid � � �' � , . • • '' Four new manholes are installed in the , �$479 000 • Maintenance access can be made existing lakeline to provide access for ----- - from the lake rather than across ; maintenance. Three of the manholes are '� �- • residential properties. i installed at existing sag locations and the � � • Installing manholes at sag locations fourth is south of Coleman Point. '$30,000 -$90.000 ; would facilitate removal of Maintenance of the line would be ________ —1 , accumulated sediment from the line. , performed from the water by an outside i i contractor with barge-mounted equipment. ' • ', $69,000 per cleaning j ' � Tetra Tech/ � O KCM, Inc. 1917 First Avenue � .Seaftla Wa.chinnfon 98'101 City of Renton KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT � � ioo� c �o0 200 30o soa Install Maintenance Manholes in Four Locations \\ � � sea � .�� 30+00 � , ���� t �7p _ �_ / �� BBthho4 0 — � (J� � _ � ��f Kennydale 8wu_ 8each Park �, ■ Metro Sewer Bum�tl Av�. 7 u � N Sta 35+00 LEGEND i --�--- Existing 8" Sewer Line �I I� � ��•---�-----�----------------- Existing Side Sewer � Existing Cleanouts --- — Approximate Inner Harbor Line ' , �: Proposed Maintenance Manhole \ _ _� .,\ � '- \ � � (oy.o� �'��r LIFT STATION �Sta. 47+35) $h � J��� �:� ^_ J • Cleaning the line with barge-mounted equipment req �ires the wo�k to be , performed by an outside contractor. I • Divers are required to install temporary access shafts at manholes each time the line is cieaned. • Pipeline sag at Station 3+60 is not accessible for sediment removal. • Sediment removal will be difficult if existing lakeline and side sewers leak significantly. �• Cleaning services will be expensive. ;• Requlatory approvals may be difficult to attain. NOTE: 1. Homes and docks on map based on 1984 survey by Horton Dennis Associates. Figure 8. INTERIM MAINTENANCE ALTERNATIVE —� -- �— � � � � � - -��--� �- '_� � - io M O v N � � � � 0 m � m 0 L C N � O N O m �i _-_ _ Tetra Tech/ City of Renton KCM, Inc. KENNYDALE LAKEFRONT SEWER 1917FirstAvenue REPLACEMENT PROJECT Seatt/e, Washington 98101 igton Existing 8" Cast Iron Sewer ,� � _ -� ---� Lake Bottom Figure 9. MAINTENANCE MANHOLE SECTION [� ' ' ... 5. INTERIM MAINTENANCE AL TERNA TI VE Cleaning operations would be hindered if the lakeline or side sewers leak significantly. The line could still be jetted, however the vactor truck would not be able to keep the line evacuated of lake water, and sediment in the line could not be effectively removed. The alternative does not provide additional access to the pipeline sag located at Station ' 3+60 for sediment removal. The pipeline is located just offshore of the existing bulkhead and between two closely spaced docks at this location, making barge access very difficult. It may be possible to jet this sag location by accessing the lakeline through the overflow pipe at the flush station. Another alternative would be to install a new on-shore cleanout in the line upstream of the sag. The cleanout could be accessed from Mountain View Avenue North by a vactor truck, however it is unlikely that sediment could be removed from the line. Staging cleaning operations from the lake will be expensive because of the specialized equipment and crews required. If budget is not available for annual maintenance, the cleaning could be performed every two or three years, augmented by continued summer cleaning by City maintenance staff. PERMITTING ISSUES Like the new lakeline alternative, this alternative would have significant impact on aquatic resources because it involves in-lake construction. The following permit issues have been identified for this alternative: The City of Renton would require a SEPA environmental review and environmental threshold determination, similar to what was described for Alternative N13/513. An exemption from the City's shoreline permit process may be allowed if the City considers the project to be normal maintenance or repair of existing structures or developments. If not, a Shoreline Substantial Development Permit would be required. Building of any kind within the water will require a JAR,PA application. It would be prudent to provide agency-specific submittal packages for complex or sensitive projects in an attempt to keep the review of each agency focused on issues associated with their specific permits. Typically, the review time for each individual JAR,PA-related permit would range up to 45 days, depending on the agency and specific issues encountered. This review time may be expedited through early, informal pre-application consultation with each agency. • Recognizing that some of the JARPA permits can only be reviewed by an � agency after other JAR,PA permits have been approved, total processing time for JAR,PA permits is estimated to be 90 days once the project is developed and completed applications are submitted. ' ' ' Given the location of the project below the OHWM of Lake Washington, the proximity of the location to the Cedar River and its listed salmonid stocks, and the general tendency to move away from in-water infrastructure, it is 25 Kennydale Lakefront Sewer Predesign Report... expected that some level of additional supporting documentation will be required above and beyond the information contained in the JARPA form and construction plans. • Although not a permit, a new permit application element that is now being required by the COE is a Biological Assessment. A BA can take approximately 2 to 3 months to complete depending on the project. It is recommended that the BA be submitted with a JAR,PA application. • The BA will need to include data on spawning and fish-use in the project area. The optimum fish window time for data gathering opportunities for this project will be between April — June. Without site specific data, agencies tend to assume the worst case scenario when evaluating the effects of the action. Providing an accurate and site specific assessment of project impacts is important for this project since the worst case scenario could require formal consultation to complete the BA review process. While review of a BA through the informal process may take from 30 to 90 days, the formal consultation process can extend to six months or beyond depending on agency workload. The Department of Fish and Wildlife may have concerns that the new manholes provide an area for aquatic predators to hide and feed on juvenile salmon. Overall Permit Timeline In Appendix F, the Permit Matru� for the Interim Maintenance Alternative provides an aggregate estimate of the time required for obtaining all of the permitting issues identified above. This estimate is based on previous permitting experience and/or the review of the BA through the informal consultation process. Actual permitting time may be shorter or longer based on final project design and consultation with agency staff. The process to obtain permits would be to develop a preliminary design in order to begin work on the BA. Work on a BA could begin as soon as 60 percent of the design work is completed, although final design is likely to be necessary for submittal. Data gathering for the BA and in support of the various permit applications would optimally occur sometime during April to June. Once the BA is completed, a JAR,PA application could be submitted. A Shoreline Substantial Development Permit application, if needed, and SEPA checklist could also be submitted at the same time to the City of Renton. An important consideration regarding schedule is whether the project can be designed within the parameters of the existing COE nationwide permit system. If a nationwide permit is pursued, it would take appro}cimately 30 to 45 days to obtain a Corps 404/10 permit once a completed JAR,PA package is submitted and the BA has received the necessary agency concurrence. An approximate time to complete this process is 7 to 8 months. If an individual permit is necessary, the timeline for a COE permit may be significantly extended. An approximate time period for an individual permit would be at least 4 to 6 months once the JAR,PA package is submitted and the BA has received agency concurrence. Similarly, if the project cannot be designed or constructed to avoid any potential for adverse impacts on aquatic life, review of the BA would have to obtain formal 26 . 5. INTERIM MAINTENANCE AL TERNA TI VE consultation from National Marine Fisheries Service and/or U.S. Fish and Wildlife Service, which is likely to extend the permit process by at least 6 months as discussed above. ESTIMATED PROJECT COST Costs for installation of the new access manholes and lakeline cleaning were estimated. The estimated project cost, excluding permitting, for installation of the four maintenance manholes is $479,000. Adolfson Associates, Inc. estimates that the cost to secure the required permits for this alternative would range from $30,000 to $90,000. The estimated cost to clean the line is $69,000 per occurrence. Cost estimates for this alternative are included in Appendu� G. Additional information on permitting costs are included in Appendix F. � 27 , , 6.0 Si;fMMARY AND RECOMMENDATIONS ' Through the course of the project predesign, there has been no definitive indication that the existing flush station system cannot continue to function for the next 20 years. Although the system has several distinct drawbacks such as low flushing velocities, sags in ' the pipe profile and a lack of access for maintenance, the system has worked for over 20 years and does not appear to be on the verge of failure. ' Because the cost of the replacement alternatives is so great, and the remaining service life of the e�usting lakeline remains uncertain, it is recommended that interim measures to better maintain the line and prevent overflows into the lake be implemented. Ll ' 1 ' ' Based on the findings of the predesign study, the following actions are recommended: Additional maintenance equipment access points in the lakeline are recommended. The access points should be installed as "in-line" structures, and should be located as close to the existing low points in the pipeline profile as possible. Locating the structures at these low points will facilitate the removal of sediment from the line. The new structures could also provide benefits for future replacement or rehabilitation work performed on the system. The structures would provide sewer bypassing locations if a new flush system were later installed. If future rehabilitation methods were developed that are appropriate for this type application, the structures would provide required access to the lakeline. • Predesign meetings with the Department of Fisheries, Ecology and Corps ' of Engineers should be scheduled to help establish permitting requirements and constraints. C� , �� , , ' ' ' • A lakeline cleaning program by an outside contractor should be established after the new access structures are installed. The new structures will need to be accessed from the lake, which will require special expertise, equipment and insurance. The cleaning program should be scheduled once every two or three years. • City maintenance crews should continue their annual program of cleaning sections of the lakeline that are accessible from the shore. • The hole discovered in the e�sting lakeline at Station 44+00 should be repaired. • Brass tags should be re-established on the existing docks to mark the lakeline location when a new survey of the lakeline is performed. The tags will help to alert homeowners and contractors of the pipe when future work is performed on the docks. • A community information program should be implemented that informs the homeowners of the location and operation of the line. A number of residents contacted during the predesign were not aware that they were served by. a sewer line in the lake. The program could include a mailer that goes out with the utility bill every year or two that shows the location of 29 Kennydale Lakefront Sewer Predesign Report... ' the line and provides some general "do's and don'ts" for homeowners that ' would help extend the longevity of the facility. ' ' I� '� ' ' ' � �J i� � � ' t C� �� � �I� 30 ' � '�� LJ � � ' ' ' APPENDIX A. . WORKSHOP 1 TECHNICAL MEMORANDUM ' ' r� li � ' ' ' ' a i � �� � � , ' ' ' ' ' , , Memo Tetra Tech/KCM, Inc. l� Date: March 4, 1999 To: Dave Christensen City of Renton Utility Systems 1055 Grady Way South, 5th Floor Renton, WA 98005 c.• From: Project No.: Workshop Participants Central Files (2-2) Jeff Lykken 2830120-003 Subject: City of Renton Kennydale Lakefront Sewer Replacement Project Workshop 1—Project Initiation Workshop ' This memorandum presents the results of the Kennydale Lakefront Sewer Replacement Project Workshop 1, which was conducted by KCM for the City of Renton on February 16, 1999. Workshop 1 was the first of three workshops that will ' be conducted during project predesign. Goals to be accomplished at the three workshops are as follows: �' ' ' � � ' ' ' Establish goals and constraints for the project Identify and rank appropriate alternatives for repair, rehabilitation and replacement of the sewer system. The goal of Workshop 1 was to bring the consultant team and City staff to a common understanding of the problem and issues associated the existing facilities, conceptualize initial alternatives, identify and confirm project goals and constraints, and establish ranking criteria for evaluating the alternatives. WORKSHOP PROCESS Workshop 1, the project initiation workshop, was conducted to ensure that members of the design team and City staff have a common understanding of project goals and constraints. The workshop was conducted as a facilitator-led working group, organized by the agenda included in Appendix A to this memorandum. It was facilitated by Don Stafford of Robinson, Stafford & Rude, Inc. (RSR). The day-long workshop consisted of the following steps: Provide an overview of potential solution alternatives—prior to the workshop, three categories of solutions were established: Alternatives to improve maintenance of the existing system , Tetra Tech/KCM, Inc. • 1917 Firat Avenue • Seattle, WA 98101-1027 • Te1206 443-5300 • Fas 206 443-5372 ' � — Rehabilitation alternatives , — Replacement alternatives. Discuss past maintenance and operating problems experienced by City of Renton staff. Develop a"project objective" statement by combining the general objectives of the project into a single concept statement that clarifies the purpose of the project. Determine and agree upon the goals, constraints and objectives of the project This part of the workshop gave the City and design team a chance to point out questions to be resolved, likely limitations on project design, and other challenges that can be expected when formulating and evaluating alternatives for improvements. This step ensures that the final recommended alternative will accomplish the goals the City intends for the Kennydale Lakefront Sewer Replacement Project. • Identify evaluation criteria for ranking the alternatives—.Specific criteria for evaluating alternatives were established from the discussion of key issues, constraints and other considerations. Alternatives identified in Workshops 2 and 3 will be ranked using these criteria. • Summary—At the end of the workshop, the results of the meeting were summarized to ensure that all participants agreed on them, and a final opportunity was provided to raise any additional points or concerns. Participants included the following City staff and design team members: • Dave Christensen, City of Renton Wastewater Utility Supervisor • Jennifer Henning, City of Renton Senior Planner • Barry Scott, KCM, Inc. • Jeff Lykken, KCM, Inc. • Molly Adolfson, Adolfson Associates • Jennifer Kauffman, EnviroIssues. PROJECT BACKGROUND The Kennydale lakefront sanitary sewer is an 8-inch line in Lake Washington that serves approximately 51 homes and the Kennydale Beach Park along the lake in Renton. The 4,700-foot-long cast-iron line begins at the north end of Gene Coulon Page 2 � Park and ends at North 40th Street. A flush station (Lake Washington Flush) at the south end of the facility flushes lake water north through the pipe to a City of Renton lift station (Lake Washington #2) in the 3900 block of Lake Washington Boulevard North. From there, sewage is pumped up to Metro's Eastside Interceptor sewer in Lake Washington Boulevard. The flush system was installed in 1972. From its inception, the facility has been difficult to maintain due to sags in the pipe and limited access for maintenance. Except for the southern 300 feet of pipe, the sewer was installed in the lake. The pipe generally follows the shoreline, 5 to 60 feet offshore. Because its profile follows the lake bed elevation, the line has several signiiicant sags. Sediment accumulates in these "bellies," causing backups in the line and occasional overflows into Lake Washington. The flush station is operated twice a day, during the morning and evening peak hours. It is run for approximately 2 hours each cycle, and pumps 400 gallons per minute (gpm). According to a 1986 survey by Horton Dennis & Associates, the top of the pipe is exposed above the lake bottom along roughly 900 feet of the alignment. Where the pipe is buried, the depth of cover does not exceed 2 feet. The lake depth varies from 3 to 10 feet along the alignment. Because of the line's proximity to the shore and its minimal depth of cover, the pipe has been snagged and damaged by boaters and coritractors more than a half-dozen times. The sewer line has only one access point onshore, at Coleman Point, making it very � difficult to maintain. City workers are able to access only about one-third of the line to rod and flush it with their existing equipment. This access point is also where the line overflows to the lake when blockages occur. Increased maintenance over the past several summers to better flush and rod the line has reduced the frequency of overflows to the lake. However, because of the past problems with the line and continued uncertainty about the pipe's condition, the City wishes to assess upgrading or replacing the facility. KCM, Inc. has been selected by the City of Renton to provide predesign and final design services on the project. The predesign scope of services consists of an evaluation of the existing pipeline condition and a thorough review and evaluation of alternatives for rehabilitating or replacing the facility. Because of this project's many permitting, constructability and community issues, KCM is conducting workshops to identify alternatives and select a preferred alternative for implementation. The workshops will use "brainstorming" to establish project goals and constraints of the project, and to identify and rank alternatives for repair, rehabilitation and replacement. Operations and Maintenance History of System Dave Christensen made the following points in summarizing the performance and maintenance history of the system: Page 3 . ' � • The flush station system was constructed in 1972 under a utility local improvement district. Historical land use in the service area was recreationallvacation homes, which discharged directly to the lake before the existing system was constructed. • The flush station is currently operated for 2 hours twice a day to reduce the potential of solids collecting in the pipeline. The system is operated after the morning and evening peak hours at approximately 10:00 a.m. and 10:00 p.m. • The flush station is operated at appro�mately 400 gpm. Sewage will back up into homes near the station if the pump is operated at a higher pumping rate. • Some of the flush station pumping capacity is lost during winter when the elevation of Lake Washington is lowered by 2 feet. The system pumping rate is adjusted at the flush station by raising and lowering the pump to control the wet well level. The City finds this operation cumbersome and wishes to change it in the future. • In 1986, the City had a consultant design a project to facilitate pipeline cleaning. Ball valves were installed on each side sewer so that the lakeline could be pressure-pigged. The ball valves were not appropriate for the use, and did not adequately close the first time the City pigged the pipe. Up to 2 feet of sewage backed up into several homes. City staff contemplated replacing the ball valves with a different valve after the incident, but did not feel their credibility in the neighborhood was strong enough. There is one cleanout on the lakeline that is located onshore at Coleman point. The cleanout cap is intentionally left lose so that when overflows occur, sewage flows out of the cleanout rather than backing up into homes. The cleanout is in the yard of one of the residences. The property owner informs the City when overflows occur. The City has a good relationship with this property owner. There were a considerable number of overflows between 1990 and 1994. At that time the City reassessed its maintenance practices of lakeline cleaning and flush station operation. Since then, maintenance crews have spent two weeks each July rodding and flushing the lakeline. The increased cleaning has reduced the number of overflows. City crews own 500 feet of rodding. They rod the lakeline from the flush station, the cleanout at Coleman Point, and the lift station. Their biggest area of concern with the lakeline is the sags at the north end of the alignment that cannot be reached with the rodding. Page 4 � City crews visit the flush station and lift station weekly to ensure that they are operating properly. They say that the lift station seems to be pumping less volume over time. The City is concerned that this is due to the lakeline filling with solids. The flush station draws lake water to pump through the pipeline. The City has permits from the Washington State Department of Ecology and the Corps of Engineers for pumping the lake water, but the City does not have a defined water right for the flush water. If lake water availability should become a problem the system may need to be retrofitted to use a City water source rather than lake water in the future. The location of the lakeline was initially marked with a brass tag at each dock. Many of the tags are now missing because of docks being rebuilt or homeowners removing the tags. • The City has easements on each residential parcel for the lakeline. The easement descriptions may have been written so that they cover the entire parcel for each property. The City will research the easement language. • The lakeline has been very susceptible to damage from boaters and from contractors working in the lake. • The lift station is essentially new. It was completely rebuilt in 1994. • There is no standby power at the flush station or lift station. The City must bring in generators to address power outages. Odor has not been a problem at the lift station. A liberal estimate of the peak sewage flow rate from the service area is 60,000 gallons per day. • The City pays a flat rate per home to King County for sewage discharge, so there is no penalty for the volume of lake water pumped through the system and discharged to the County system. The City expects to be able to grandfather the system, and believes that imminent changes in County inflow and infiltration policy and rate structure will not preclude the use of a flush station system. Some property owners may have connected roof and area drains to their side sewer connection, which would allow grit into the lakeline. The service area is zoned only for residential use for the next 20 years. There is some historical evidence of contaminated soils in the area. Creosote contamination is present on the Barbee Mill Company site ' Page 5 ' � just north of the lift station. An environmental impact statement , completed for the site may provide additional information. • Creosote was found during rehabilitation of the lift station when the wet well was lowered. The creosote may have been a remnant of old timber pilings. The contamination was not extensive enough to require remediation. • Environmental concerns about the Gene Coulon Park site in the late 1970s or early 1980s kept the site from being developed more extensively than it was. Dave will discuss the history with the City Parks Department. • The flush station is on Gene Coulon Park property. The lift station is on Barbee Mill Company property. The City has a permanent easement for the lift station. • The City believes the pipeline joints are fairly tight. City staff would like to be able to drain the lakeline so they can television the pipe. POTENTIAL SOLUTION ALTERNATIVES KCM has identified three general categories of potential solution alternatives: • Alternatives to improve maintenance of the e�sting flush station and pipeline system—These alternatives include providing access manholes in the pipeline to facilitate rodding and jetting the line, providing pipeline cleanouts at existing docks, and removing the sags in the pipeline profile where solids are collecting. Rehabilitation alternatives to improve the structural and operational integrity of the system—These alternatives include lining or slip-lining the existing lakeline to improve hydraulic ef�iciency and modifying the flush station to increase flow velocity in the pipeline. • Replacement alternatives—These alternatives include replacing the existing facility with a new lakeline system or a new system onshore. These alternatives and combinations of them will be refined and additional alternatives will be developed at Workshops 2 and 3. The feasibility of many of the alternatives will depend on the condition of the existing lakeline. The design team is currently assessing the condition of the existing pipe using the following methods: Geophysical assessment of the pipeline and adjacent lakebed by Golder Associates. Ultrasonic testing of exposed portions of the pipeline to assess corrosion. Page 6 ' � , Dye testing of the flush station system. ' A level of uncertainty regarding the lakeline condition will remain when the assessment is complete because the entire pipeline cannot be accessed. This uncertainty will have to be factored into the evaluation of alternatives. � i r PROJECT OBJECTIVE STATEMENT DEVELOPMENT Workshop attendees discussed the general, overall objective of the project. Based on these discussions, the following concept statement was developed for the project: Provide a cost-effective, reliable and maintainable sewage disposal � system with a minimum 20-year life that can be implemented in the current regulatory and community setting. ' ' PROJECT GOALS AND CONSTR.AINTS The group identified the following issues that must be considered in developing and evaluating project alternatives: • Portions of the small frontage roads serving the residential properties are located on Burlington Northern Railroad (BNRR) property. Railroad permitting and easement requirements could become difficult and time-consuming if a new gravity or pressure sewer is proposed along these frontage roads. ; • Existing utilities along the residential frontage roads include ,, , , overhead power, overhead telephone, and water. Existing utilities along Lake Washington Boulevard include overhead power, overhead telephone, water, sanitary sewer, storm sewer and natural ' ' � ' gas. • Kennydale Beach Park is very busy in the summer. Since access to the park is walk-in, it is mostly used by neighborhood residents. The City Parks Department would prefer that any construction in the park occur in May and June or after Labor Day. • The fisheries window for in-lake construction is mid-June to mid- September. This window conflicts with the Parks Department's preferred construction window. • Construction staging will be difficult in the area. � • Lake Washington Boulevard is not a designated truck route, however it is accessible to large construction equipment. The frontage roads at the residences are very tight, particularly at the , north end of the project. City crews have a hard time getting their jetting truck down the road to the lift station. , � ' Page 7 � � • Residents served by the lakeline are mostly working couples who are , not home during weekdays. The City is not having relations problems with any of the current residents. There was no response to door hangers distributed in the neighborhood regarding the ongoing pipeline condition assessment. The City is going to provide all the funding for any new construction on the system. The Muckleshoot Indian Tribe will likely be interested in the project. Water rights may become an issue. In order for the project to receive a mitigated Determination of Non- Significance through the State Environmental Policy Act process, the predesign must address the following items: — The alternative evaluation and selection process must be well documented. — The selected alternative must demonstrate long-term reliability. Construction impacts must be identiiied and mitigated. • Residential property lines extend well into Lake Washington, so the lakeline probably lies entirely within easements on private property. The Washington State Department of Natural Resources, therefore, probably will not be a stakeholder in the project. • The City will dedicate the necessary resources to maintain the existing system and/or any improvements to the system that are implemented. The City will not make the homeowners responsible for upkeep on any part of the system, such as if the lakeline were replaced with individual grinder pump/force main systems. • The City currently has some single-family residences serviced by individual grinder pump systems. These systems were installed as part of new construction, and they are serviced and maintained by the property owner. If new individual grinder pump systems were installed as part of this project, they would be the only such systems that City crews would be responsible for. Project Goals Based on the past maintenance problems the City has experienced with the existing sewage system and the issues identified above, the group established the following goals for the project: 1. Proactively incorporate community values. Page 8 , ' � , 2. Positively deal with solids deposition to reduce the risk of backups and overflows. 3. Be able to address the uncertainty of pipeline condition. 4. Balance impacts on the natural and built environment. 5. Provide a system that is easy to maintain. 6. Base solutions on adequate data to facilitate sound decision-making. 7. Favor facilities that require routine access from public property. 8. Minimize summer impacts on City parks. 9. Locate facilities sited in City parks underground. 10. Design new facilities to be aesthetically acceptable and fit in with their surroundings. Project Constraints Participants identified the following constraints that will affect the feasibility of alternatives: 1. The solution must comply with Department of Fish and Wildlife 2 � requirements for construction timing and technique. Any new facilities located in the lake cannot be susceptible to pulling apart. Sewer service must be maintained during construction unless residents are relocated during construction. 4. Improvements to the system must be implemented as a stand-alone project. System improvements will not be implemented as part of any other future projects, such as development of the Barbee Mill site, and the service area for the system will not be expanded. 5. Project costs cannot have a significant impact on sewer rates. 6. The implementation process must be procedurally accurate. 7. The implemented solution must use proven technology. 8. The system must be maintainable with equipment the City owns, or the solution must address new equipment that the City needs to purchase. 9. The City will be solely responsible for maintenance of the system. Page 9 , ' � EVALUATION CRITERIA , The workshop attendees developed a set of evaluation criteria to ensure that the project will meet the established objectives. The following criteria were established to use in evaluating alternatives at Workshops 2 and 3: 1. Impacts on the built environment These include impacts on the 51 residences and the park served by the system, impacts on the BNRR railroad, and impacts on the community during construction. 2. Maintainability—This criterion addresses the ability to provide adequate maintenance for an alternative. 3. Ease of permitting—Alternatives involving in-lake construction or work on railroad property will be the most difficult to permit. This criterion addresses the time and difficulty of permitting the different alternatives. 4. Performance reliability This criterion addresses the operational dependability of an alternative. 5. Constructability—Limited access, restricted staging areas, underwater construction and other factors during construction will limit the feasibility of certain alternatives. 6. Impacts on the natural environment This criterion addresses potential degradation of the natural environment, both on a long- term basis and on a short-term basis during construction. 7. Level of uncertainty—There will be a level of uncertainty regarding the integrity of the lakeline after the condition assessment is completed. This uncertainty will have to be factored into the ranking of alternatives that involve rehabilitating the existing lakeline. 8. Ancillary multipurpose benefits�pportunities for incorporating additional improvements or enhancing existing conditions in the lake, in the neighborhood, and in the parks increase the feasibility of an alternative. 9. Rate impact/benefit comparison—This criterion is similar to a cost/benefit comparison, except that the impact of the implementation cost on sewer rates will be examined. 10. Neighborhood acceptanc�This criterion addresses the acceptance of an alternative by residents served by the facility. 11. Amount of facilities in the lak�Alternatives that remove all or portions of the existing facilities from the lake will be more desirable. Page 10 1 � ' After the workshop, each of the criteria was weighted using a paired comparison method. In this method, each criterion is compared to every other criterion to rank � its relative importance. As the key decision-makers on the project, City staff weighted the criteria. The results of the weighting determination are shown in Table 1. The ranking form from City staff is included in Appendix B. TABLE 1 RESULTS OF PAIRED COMPARISON FOR EVALUATION CRITERIA Evaluation Criteria 1. Impacts on the built environment 2. Maintainability 3. Ease of permitting 4. Performance reliability 5. Constructability 6. Impacts on the natural environment 7. Level of uncertainty 8. Ancillary multipurpose beneiits 9. Rate impact/benefit comparison 10. Neighborhood acceptance 11. Amount of facilities in the lake Weight 4 10 0 10 8 5 1 1 7 5 2 " Criteria 3, ease of permitting, received a weight of zero in the ranking. The City's �, � .. rational for this ranking is that they are willing to delay construction of a preferred , alternative if that alternative requires a longer permitting schedule. ' WORKSHOP SUMMARY AND ADDITIONAL DISCUSSION After development of the evaluation criteria, Don Stafford summarized the � workshop results. The group spent the remainder of the workshop discussing the following technical issues associated with the project: � ' , . � ' ' • The alternative of providing access manholes to the lakeline for maintenance was discussed. The City of Bellevue recently constructed onshore access manholes to its lakelines. The City of Renton has some concerns regarding the configuration of these manholes. A variation of this alternative that City of Renton staff has discussed is constructing a manhole directly over the lakeline in Kennydale Beach Park and constructing a new dock out to the lakeline for maintenance access. The new dock would likely be seen as an amenity by City of Renton Parks staff. Page 11 ' � • An alternative for removing sags in the pipeline profile may be to ' place fill in the lake where the bottom drops off, and raise the pipe. Placing fill in the lake may be difficult to permit. • The minimum pipe diameter to attain a velocity of 3 feet per second for the 60,000 gallon per day peak flow rate was calculated to be 2.5 inches; this indicates how small the service area for the facility is. • The concept of dividing the project in two—north half and south half—was discussed. It is possible for two separate alternatives to prove most feasible for the two clusters of homes divided by Kennydale Beach Park. Page 12 , ' 1 ' ' APPENDIX B. , WORKSHOP 2 TECHNICAL MEMORANDUM � , ' ' � ' , � � LJ u ' ' ' Memo Tetra TechlKCM, Inc. ' Date: March 24, 1999 ' , ' ' ' � ' ' � 1 ' ' ' ' ' ' To: Dave Christensen City of Renton Utility Systems 1055 Grady Way South, 5th Floor Renton, WA 98005 c: From: Project No.: Workshop Participants Central Files (2-2) Jeff Lykken 2830120-003 Subject: City of Renton Kennydale Lakefront Sewer Replacement Project Workshop 2—Alternatives Generation and Evaluation Workshop � This memorandum presents the results of the Kennydale Lakefront Sewer Replacement Project Workshop 2, which was conducted by KCM for the City of Renton on March 9, 1999. Workshop 2 was the second of three workshops that will be conducted during project predesign. Goals for the workshops are as follows: Workshop 1—Establish goals and constraints for the project Workshop 2—Identify and rank alternatives for repair, rehabilitation and replacement of the sewer system Workshop 3—Refine the alternatives developed in Workshop 2 and narrow the potential solutions for final design. The list of options will be reduced to up to three alternatives, and a final design solution will be chosen by the City of Renton. Workshop 1 was a project initiation workshop, conducted on February 16, 1999. Objectives completed at Workshop 1 included bringing the consultant team and City staff to a common understanding of the problem and issues associated with the existing facilities, conceptualizing initial alternatives, confirming project goals and constraints, and establishing criteria for ranking the alternatives. Goals for Workshop 2 were to brainstorm alternative solutions for the sewer replacement, conduct an initial screening of available alternatives, and select the top ranking alternatives for further evaluation. PROJECT BACKGROUND The Kennydale lakefront sanitary sewer is an 8-inch line in Lake Washington that serves approximately 51 homes and the Kennydale Beach Park along the lake in Renton. The ' Tetra Tech/KCM, Inc. • 1917 First Avenue � Seattle, WA 98101-1027 • Te1206 443-5300 • Fax 206 443-5372 � 4,700-foot-long cast-iron line begins at the north end of Gene Coulon Park and ends at North 40th Street. Except for the southern 300 feet of pipe, the sewer was installed in the lake. A flush station (Lake Washington Flush) at the south end of the facility flushes lake water north through the pipe to a City of Renton lift station (Lake Washington #2) in the 3900 block of Lake Washington Boulevard North. From there, sewage is pumped up to Metro's Eastside Interceptor sewer in Lake Washington Boulevard. The facility has been difficult to maintain due to sags in the pipe and limited access for maintenance. Sediment accumulates in the sags, causing backups in the line and overflows into Lake Washington. City workers are able to access only about one-third of the line to rod and flush it with their existing equipment. The top of the pipe is exposed above the lake bottom along much of the alignment. Where the pipe is buried, the depth of cover does not exceed 2 feet. The pipe has been snagged and damaged by boaters and contractors more than a half-dozen times. Because of the past problems with the line and continued uncertainty about the pipe's condition, the City wishes to assess upgrading or replacing the facility. KCM, Inc. has been selected by the City of Renton to provide predesign and final design services on the project. Because of this project's many permitting, constructability and community issues, KCM is conducting workshops to identify alternatives and select a preferred alternative for implementation. Q�� t� �f.�� . . ���Z��•� Workshop 2 was conducted as a facilitator-led working group, organized by the agenda included in Appendu� A to this memorandum. It was facilitated by Don Stafford of Robinson, Stafford & Rude, Inc. (RSR). The day-long workshop consisted of the following steps: • Discuss the findings of the pipeline condition assessment performed February 15 through March 2, 1999. • Summarize the results of community outreach activities to date. • Discuss regulatory constraints relating to alternative solutions. • Brainstorm and conduct an initial screening of alternative solutions that meet all the project objectives developed at Workshop 1; the screening involved workshop participants voting on alternatives and a group discussion of the general categories of alternatives to be carried forward. • Conduct a weighted matrix evaluation of the top rated alternatives using the weighted criteria developed at Workshop 1. • Finalize selection of the top ranked alternatives for further evaluation; additional preliminary engineering and cost estimating will be performed for the top ranked alternatives, and a final preferred alternative will be selected at Workshop�3. Workshop participants included the following City staff, design team members and agency representatives: Page 2 � • Dave Christensen, City of Renton Wastewater Utility Supervisor • John Thompson, City of Renton Wastewater Maintenance Division • Leslie Betlach, City of Renton Parks Department • Jennifer Henning, City of Renton Planning • Barry Scott, KCM, Inc. • Jeff Lykken, KCM, Inc. • Molly Adolfson, Adolfson Associates • Jennifer Kauffman, EnviroIssues • Dave Clark, D L Clark Corporation • Larry Fisher, Department of Fish and Wildlife FINDINGS OF PIPELINE CONDITION ASSESSMENT � In the two weeks before Workshop 2, the design team performed an assessment of the existing pipe condition to gauge the feasibility of alternatives that would make use of the existing pipe. The assessment included the following methods: Geophysical assessment of the pipeline and adjacent lakebed Ultrasonic testing of exposed portions of the pipeline to assess corrosion Dye testing of the flush station system. Geophysical Assessment Golder Associates performed a one-day geophysical assessment of the pipeline and lakebed on . February 15, 1999. Conditions along the lakeline were inspected using a side scan sonar, which produces an acoustic image of the lakebed and objects resting on the lakebed, such as the pipeline, pilings, logs and anchors. An underwater camera was then used to inspect selected portions of the pipeline to augment the side scan sonar findings. The survey findings were as follows: • Areas where the pipeline was exposed above the lakebed were confirmed. Approximately 1,000 feet of the lakeline is fully or partially exposed. • Short sections of pipeline that may be suspended above the lake bottom were documented. • Five locations where logs are resting on the pipeline were documented. • Concrete debris was dumped on top of the pipe at Station 40+40. The debris was likely the remains of a bulkhead replaced by the homeowner. • Possible abrasion from logs chafing the pipe was noted in three areas. A report from Golder Associates summarizing the investigation results is included in Appendix B. Page 3 �i � Ultrasonic Testing On March 2, 1999 Ballard Diving and Guardian Inspection Services, Inc. performed one day of ultrasonic testing on exposed sections of the pipe. The test involved a diver placing a calibrated transducer on the outside of the pipe. The transducer transmits an ultrasonic signal that measured the wall thickness of the 8-inch cast iron pipe. Instrumentation recording the readings was monitored and documented by a technician on the dive boat. Prior to the field work, the transducer and instrumentation were calibrated to a test section of 8-inch cast iron pipe provided by the City. Guardian Inspection Services estimated the level of accuracy of the readings to be within plus or minus 10 to 15 percent. In addition to the ultrasonic testing, the diver provided a visual assessment of the horizontal alignment and general appearance of the pipe. Results of the ultrasonic testing and visual assessment were as follows: Approximately 53 measurements were taken at 24 locations along the pipe. The measurements started on the north end of the project, where most of the exposed pipeline sections are located, and proceeded south. Measurements were taken as far south as Station 28+00. In general, the diver attempted to get three measurements (one on the top and one on each side of the pipe) at each location. The bottom of the pipeline was buried, so measurements at the pipe invert were not possible. The ultrasonic inspection readings are included in Appendix C. Side and top readings at the same location indicated relatively uniform thickness. No discrete zones of corrosion were found in any of the locations surveyed. Thickness readings varied from 0.308 inches to 0.515 inches. Most of the readings were in the range of 0.375 to 0.400 inches. Original project specifications designating the design thickness class of the pipe to be used were not available from the City. The Handbook of Ductile Iron Pipe by the Ductile Iron Pipe Research Association lists six thickness classes of gray cast iron (Class 22 through Class 27) for 8-inch diameter pipe, ranging from 0.41 inches to 0.60 inches. It is possible that the contractor who installed the line used different thickness classes of pipe along the length of the pipeline. • Accurate ultrasonic measurements for wall thickness are not possible unless the outside of the pipe is relatively free of scale and rust. Numerous areas along the outside of the pipeline were too rusted and scaled to get accurate thickness readings. • In areas where the pipe goes from being exposed to being buried, the diver uncovered short sections of the buried pipe. It appeared that the buried pipe has much less rust and scale than the exposed pipe. • The horizontal alignment of the pipe was very crooked from approximately Station 34+00 to the lift station. Some joints appeared to be deflected in excess of 5 degrees. • Both mechanical and push-on joints were used. Page 4 � ' A 2-inch hole was found in the line at appro�cimately Station 44+00. The flush station was operating when the hole was discovered, and water was , being drawn into the hole. The hole is next to a dock, and the pipe wall around the edge of the hole appeared to be solid. This may indicate that the pipe was damaged from work being done on the dock rather than from ' corrosion. The horizontal alignment and pipeline exposure problems appear to be more serious than the issue of remaining pipe wall thickness. ' Dye Testing , ' Two dye tests were performed on March 2, 1999 to check for leaks from the pipe into the lake and to assess the pumping performance of the flush station. Pipe leakage was investigated by pumping fluorescein dye through the lakeline and visually inspecting for signs of leaks. No signs of leaks were evident during the two tests. The dye tests were also used to estimate the average flushing velocity through the pipeline , and to assist in estimating pump output from the flush station. The average flushing velocity through the pipe was determined by measuring the travel time of the dye through � the approximately 4,800 feet of lakeline from the flush station to the downstream pump ' -: station. The travel times for the two tests were 105 minutes and 102 minutes, which translates to an average flushing velocity of 0.8 feet per second (fps). Using this average velocity and the visual observation that the 8-inch pipe diseharging to the downstream , pump station was flowing about one-third full during the tests, KCM estimates that the flush station pump output is between 100 and 150 gallons per minute. ' A general rule of thumb is that a minimum flushing velocity of 2 fps should be maintained in grayity sewers to prevent the deposition of solids in the pipe. Flushing velocities of about 3 fps are required to resuspend solids that have settled in a pipe. Where there are sags in ' the profile, as there are in the Kennydale pipeline, significantly higher flushing velocities are required to flush solids up the adverse grade. With an average flushing velocity of 0.8 fps in the Kennydale sewer, significant solids deposition can be expected in the sags. ' ' ' �1 ' �-, II �� ' Limitations of Condition Assessment Findings The condition assessment investigations provide valuable information for assessing solutions that would use the e�sting pipeline. However, since the entire pipeline could not be accessed and tested, its ability to remain in service another 20 years remains uncertain. This uncertainty will be factored into the final evaluation of alternatives. COMMUIVITY OUTREACH ACTIVITIES AND FINDINGS Jennifer Kauffman provided a summary of community outreach activities that have taken place on the project to date. On March 6, 1999, EnviroIssues conducted a small survey among the 51 residents who live along the lakeshore between the north end of Gene Coulon Park and North 40th Street. Each residence was visited. Flyers with survey information and project contact information were left at residences where no one was home. Page 5 � A total of 16 residents were contacted directly, and three others mailed or faxed in their responses. The survey revealed that the residents had received the previous door-to-door distribution of flyers announcing the sonar and ultrasonic testing and that the residents are generally aware of the project. A number of residents have moved to the area in the last several years and were not aware of the sewer's location in the lake or the problems experienced in the previous 10 years. A homeowner education effort may be helpful to them. Key survey findings were as follows: • Most residents said they have had no problems with flooding or overflows associated with the sewer line. One resident with a documented history of flooding was not home. Another resident recounted a flooding incident that occurred 10 years ago. • One resident discussed problems with a City crew that performed cleanout activities iive years ago. The complaint was that the crew disturbed the resident's property when accessing the cleanout at the end of the resident's yard and did not restore it to its previous condition. • Several residents north of Kennydale Beach commented on drainage problems between the railroad bank and their homes. Their concern is that an onshore line might exacerbate these drainage problems. EnviroIssues noted that the swampy area east of the railroad tracks might be a wetland. • Three residents expressed opposition to an upland line. One of these noted that if a surface line were installed, the resident would need to use a sump pump because the water table is 2 feet below the house. • Two residents said they would favor an upland line. They are in favor of getting the sewer out of the lake to prevent environmental problems in case of leaks. • Several residents expressed no opinion regarding solution alternatives. Two said that they think the City will do the right thing. • Most residents were aware of past problems with boat anchors snagging the line, but none had experienced such problems themselves. • One resident north of Kennydale Beach noted that he has smelled a sewage odor near the front of his house in the fall for the past two years. • All residents contacted indicated that they would be willing to attend a neighborhood meeting. REGULATORY CONSTRAINTS Larry Fisher of the Washington Department of Fish and Wildlife identified the following as issues related to the alternatives that the department is likely to be concerned about: • The summer fisheries window for construction will be June 16 to the end of October. There may also be a winter window within portions of the project limits. Larry will check on this. � Page 6 ' 1 ' ' , ' ' , , � ' ' ' , 1 � � , I� � � • Parts of the project area are in a beach spawning area for sockeye salmon. Alternatives that involve a loss of shoreline spawning habitat cannot be permitted. • Alternatives that involve extending bulkheads further into Lake Washington will probably not be allowed because of the loss of habitat. • Pipes will need to be fully buried beneath the lakebed for alternatives that include a line remaining in the lake. An exposed pipe along the lake bottom provides an area for predators to hide and feed on juvenile salmon. • Placing fill in the lake to remove the sags in the pipe profile could be allowed if the correct fill material is used. Supporting the pipe above the lake bottom will probably not be allowed because it provides additional areas for predators to hide. Other agencies such as the Corps of Engineers may not allow fill in the lake. DEVELOPMENT AND IIVITIAL SCREENING OF ALTERNATIVES Using brainstorming techniques, workshop participants identified a list of alternatives that accomplish the following project objective, which was developed in Workshop 1: ' Provide a cost-effective, reliable and maintainable sewage disposal system " � with a minimum 20-year life that can be implemented in the current regulatory and community setting. The north and south ends of the lakeline have different physical constraints affecting the feasibility of solutions, so the project was divided into two parts, but without precisely defining the dividing point between the two. The foremost difference between the two ends '� of the project is that the homes north of Kennydale Beach Park are very closely spaced, and the small frontage road serving them is very narrow, making upland alternatives much more difficult to construct. The road serving the homes near Coleman Point (Mountain View Avenue I� is much wider, and the homes are not as closely spaced. Additionally, the alignment of the existing lakeline is relatively straight from approximately Station 23+00 to the pump station (the north portion), whereas the south portion of the line has significant bends. Two distinctly different alternatives may provide the most feasible overall project solution because of these differing constraints. Twenty alternatives were identified for the north end of the project. This list was duplicated for the south end, and workshop participants noted appropriate modifications for the south end, identified north end alternatives that are not appropriate for the south end, and identified two new south end alternatives that are not appropriate for the north end. After identifying the alternatives, participants voted for those they believed to have the most merit. Each participant indicated up to six north end and six south end alternatives they felt are most feasible and meet the project objective. Tables 1 and 2 list the alternatives and the votes they received. Based on the voting and subsequent discussion, workshop participants agreed to further evaluate five alternatives for the north end and five for the south end. The screened , Page 7 � � alternatives are listed in Table 3. Nine of the 10 screened alternatives were those with the ' most votes in the initial screening. Alternative N7 was included so that a sufficient number of upland alternatives will be evaluated. The description of Alternative N7 was also ' modified so that it included both grinder pump systems and the vacuum system noted in the original description. � ' ' ' 1 ' 1 � ' , � ' � � 1 , 1 Page 8 ' , ' ' # ' 1 ' ' , , ' ' , , , ' , , , TABLE 1. NORTH END ALTERNATIVES N1 Replace the existing lakeline with a new minimum 6-inch diameter gravity sewer in the lake. N2 Leave the existing lakeline in place, restrain pipe joints, and add access points for maintenance. N3 Leave the existing lakeline in place, restrain pipe joints, add access points for maintenance, and re-lay a portion of the line to remove sags in the profile. N4 Slipline the existing pipe with the minimum hydraulically acceptable plastic line size and provide access points for maintenance. N5 Slipline the existing pipe with the minimum hydraulically acceptable plastic line size and provide access points for maintenance. Slipline the existing side sewers. N6 Construct a new gravity sewer between the homes and the railroad using trenchless pipeline installation methods. N7 Install a vacuum sewer between the homes and the railroad and construct a new vacuum/pump station at the existing pump station site. N8 Microtunnel a new gravity sewer in Lake Washington Boulevard and install new side sewers using directional drilling from the lake side. N9 Install grinder pumps for each home and install a new 3-inch diameter force main between the homes and the railroad that discharges to the existing force main from the pump station. N10 Line the existing pipe with an "In Situ Form" liner or similar and provide access points for maintenance. N11 Line the existing pipe with an "In Situ Form" liner or similar and provide access points for maintenance. Slipline the existing side sewers. N12 Replace the existing lakeline with a new small diameter pressure sewer. N13 Replace the existing lakeline with a new 6-inch or 8-inch diameter sewer in the lake with flushing capacity. N14 Direct flow in the existing pipe from approximately Station 36+00 to the south. Eliminate the sag at Station 40+00, slipline the existing lakeline and side sewers from Station 36+00 to the pump station with high density polyethylene (HDPE), and add access for maintenance. N15 Slipline the existing lakeline to Station 22+50 with 3-inch diameter plastic pipe and install grinder pumps at homes and new pressure side sewers. Eliminate the existing pump station and add access to the lakeline at 1,000-foot intervals. N16 Slipline the existing lakeline to Station 22+50 with 3-inch diameter plastic pipe to act as a vacuum sewer. Convert the existing pump station to a vacuum/pump station. N17 Install a new HDPE sewer along the existing bulkheads in the lake. N18 Install a new ductile iron sewer along the existing bulkheads in the lake. N19 Build new bulkheads outside the existing bulkheads and install a new sewer line on the land side of the new bulkhead. N20 Restrain the existing pipe joints, add access points in the lakeline for maintenance and install permanent flushing nozzles inside the existing pipe to clean the sags. � Votes 6 2 9 0 0 5 2 7 0 0 0 3 10 3 6 1 0 0 0 0 ' Page 9 TABLE 2. SOUTH END ALTERNATIVES # Description S1 Replace the existing lakeline with a new minimum 6-inch diameter gravity sewer in the lake. Construct a new pump station to pump flows to the existing gravity sewer in Lake Washington Boulevard. S2 Leave the existing lakeline in place, restrain pipe joints, and add access points for maintenance. S3 Leave the existing lakeline in place, restrain pipe joints, add access points for maintenance, and re-lay a portion of the line to remove sags in the profile. S4 North-end alternative N4 (sliplining the existing line) is not feasible for the south end because of the extreme horizontal curvature of the south end of the lakeline. S5 North-end alternative N5 (sliplining the existing line) is not feasible for the south end because of the extreme horizontal curvature of the south end of the lakeline. S6 Construct a new gravity sewer between the homes and the railroad using open cut pipeline installation. Construct a new pump station to convey flows to Lake Washington Boulevard. S7 Install a vacuum sewer between the homes and the railroad and construct a new vacuum station at the existing flush station site. S8 Microtunnel a new gravity sewer line in Lake Washington Boulevard and install new side sewers using directional.drilling from the lake side. The flush station would remain in service to intermittently flush the new gravity sewer for cleaning purposes. S9 Install grinder pumps for each home and install a new 3-inch diameter force main between the homes and the railroad that discharges to a new force main that crosses under the railroad track and discharges to the City of R,enton gravity sewer in Lake Washington Boulevard. S10 North-end alternative N10 (lining the existing line) is not feasible for the south end because of the extreme horizontal curvature of the south end of the lakeline. S11 North-end alternative N11 (lining the existing line) is not feasible for the south end because of the extreme horizontal curvature of the south end of the lakeline. S 12 R,eplace the existing lakeline with a new small diameter pressure sewer. S13 Replace the existing lakeline with a new 6-inch or 8-inch diameter sewer in the lake with flushing capacity. S14 North-end alternative N14 is not applicable to south end. S15 North-end alternative N15 is not applicable to south end. 516 North-end alternative N16 is not applicable to south end. 517 Install a new HDPE sewer along the existing bulkheads in the lake. S18 Install a new ductile iron sewer along the existing bulkheads in the lake. S 19 Build new bulkheads outside the existing bulkheads and install a new sewer line on the land side of the new bulkhead. S20 Restrain the existing pipe joints, add access points in the lakeline for maintenance and install permanent flushing nozzles inside the existing pipe to clean the sags. S21 Construct a new gravity sewer between the homes and the railroad north to Station 28+00. Use the existing lakeline from Station 36+00 south; construct a new pump station at Station 28+00. S22 Use the existing lakeline for gravity flow from Station 36+00 to Station 28+00. Install a new pump station that draws from the sag at Station 21+00. Re-lay the pipe to remove the sag at Station 4+50, and orovide access to the lakeline for maintenance. � ' ' Votes , 4 ' 1 8 , N/A t N/A 8 ' 3 ' 7 ' 1 � N/A N/A � 1 ,5 N/A N/A N/A 0 0 0 1 7 1 Page 10 TABLE 3. SCREENED ALTERNATIVES North End Alternatives N1 N3 N7 N8 N13 South End Alternatives S3 S6 S8 S13 S21 WEIGHTED CRIT�RIA EVALUATION Workshop participants ranked the screened alternatives using a weighted matrix evaluation. This evaluation used the criteria developed in Workshop 1 and the weighting factors for each criterion developed after that workshop. The criteria and weighting factors are included in Appendix D. The evaluation process was as follows: •-��-Each workshop participant gave each alternative a score of 1 to 5 for each ��', "�._ evaluation criterion. Lower scores indicate that the alternative does not satisfy the criterion well; higher scores indicate that it does. =' •- The score for each criterion was multiplied by the weighting factor for that � criterion, and each participant's total score for each alternative was ,._ calculated as the sum of the weighted scores for each criterion. q, • Each alternative's overall score was calculated as the sum of its total scores - �from all participants. • The alternatives were ranked based on the overall score. Table 4 shows individual participants' scores, overall scores, and rank for the north end alternatives. Table 5 shows the results for the south end alternatives. Individual ranking forms from the workshop members are included in Appendix D. The iinal point total for the south end alternatives was very close, so none of the alternatives is clearly the preferred alternative. The highest and lowest overall scores differ by only 7 percent. The same is true for all the north end alternatives except Alternative N7, which have overall scores differing by only 4 percent SELECTION OF TOP ALTERNATIVES FOR FURTHER EVALUATION After consulting with City staff, the decision was made to further develop all the screened alternatives except Alternative N7. The City's concern with Alternative N7 is that the narrow spacing of the homes would be difficult to overcome in rerouting side sewers to a new vacuum sewer in the frontage road. Page 11 a TABLE 4. RESULTS OF WEIGHTED MATRIX EVALUATION FOR NORTH END ALTERNATIVES Total Score for All Weighted Criteria Alternative: N1 N3 N7 N8 N13 146 158 111 141 156 179 149 152 161 141 173 191 166 186 167 186 166 133 168 192 152 159 164 240 152 186 178 115 190 195 196 183 125 130 172 184 161 193 247 186 205 229 140 176 185 198 176 168 177 216 Overall 1,805 1, 750 1, 467 1,816 1, 762 Score R,ank 2 4 5 1 3 TABLE 5. RESULTS OF WEIGHTED MATRIX EVALUATION FOR SOUTH END ALTERNATIVES Total Score for All Weighted Criteria Alternative: S3 S6 S8 S13 S21 187 218 236 188 194 150 190 165 144 159 155 166 153 131 168 187 195 192 194 185 166 123 107 152 126 163 151 126 191 124 171 172 190 190 179 150 227 231 155 196 172 178 211 154 186 214 192 183 182 181 Overall 1, 715 1, 812 1, 794 1, 681 1, 698 Score Rank 3 1 2 5 4 � ' , ' 1 , ' , , ' ' ' ' , , , ' ' , Page 12 , � It also was decided to further develop Alternatives N6 and N15. Alternative N6— trenchless construction of a gravity sewer between the homes and the railroad—may be acceptable if the side sewers can be rerouted to the new sewer using trenchless methods. Alternative N15 is a mechanical solution using grinder pumps and a small diameter pressure sewer sliplined through the existing lakeline. Table 6 summarizes the alternatives that will be evaluated further. Additional preliminary engineering and cost estimating will be performed for these alternatives. The results will be reviewed at Workshop 3 and a preferred alternative will be selected at that workshop. TABLE 6. ALTERNATIVES FOR FURTHER EVALUATION No. Descri tion N1 Replace the existing lakeline with a new minimum 6-inch diameter gravity sewer in the lake. N3 Leave the existing lakeline in place, restrain pipe joints, add access points for maintenance, and re-lay portion of the line to remove sags in the profile. N6 Construct a new gravity sewer between the homes and the railroad using trenchless pipeline installation methods. Re-route side sewers to the new gravity sewer using trenchless installation methods. N8 Microtunnel a new gravity sewer in Lake Washington Boulevard and install new side sewers using directional drilling from the lake side. � N13 Replace the existing lakeline with a new 6-inch or 8-inch diameter sewer in the lake with flushing capacity. N15 Slipline the existing lakeline to Station 22+50 with 3-inch diameter plastic pipe, install grinder pumps at homes and new pressure side sewers. Eliminate the existing pump station -and add access to the lakeline at 1000-foot intervals. S3 Leave the existing lakeline in place, restrain pipe joints, add access points for maintenance, and re-lay a portion of the line to remove sags in the profile. S6 Construct a new gravity sewer between the homes and the railroad using open cut pipeline installation methods. Construct a new pump station to convey flows to Lake Washington Boulevard S8 Microtunnel a new gravity sewer in Lake Washington Boulevard and install new side sewers using directional drilling from the lake side. The flush station would remain in service to intermittently flush the new gravity sewer for cleaning purposes. S13 Replace the existing lakeline with a new 6-inch or 8-inch diameter sewer in the lake with flushing capacity. S21 Construct a new gravity sewer between the homes and the railroad north to Station 28+00. Direct flow in the existing lakeline from Station 36+00 south and construct a new pump station at Station 28+00. ' Page 13 ' ' ' ' LJ , ' ' ' ' �� ' 1 II ' ' � ' APPENDIX A. WORKSHOP AGENDA ' ' ' ' ' ' ' ' , ' ' ' , ' ' ' , ' ' ' 0 Kennydale Lakefront Sewer Replacement Praject W orkshop 2 Ag'enda Alternatives Generation & Evaluation Workshop March 9, 1999 9:00 — 9:30 9:30 — 9:45 9:45 — 10:00 10:00 — 10:15 10:15 — 11:15 11:15 — 12:00 12:00 — 1:00 1:00 — 2:30 2:30 — 3:15 3:15 — 3:30 3:30 Introduction Identify participants Review workshop objectives Review agenda Discussion of Pipeline Condition :�ssessment Summar�- of Community Outreach Activities Discussion of Regulatory Constraints Brainstorm Solution Alternatives Conduct Initial Screening (Voting/Discussion Method) Lunch/Continue Initial Screening Conduct Weighted l�Iatrix Evaluation of Top 10-12 �lternatives Finalize Selection of Top 'h�vo or Three Alternatives for Further Evaluation Summarize �vorkshop results Close a , ' ' ' � APPENDIX B. , GEOPHYSICAL ASSESSMENT LETTER REPORT ' ' ' 1 r � �� � � � � � � � ' - Golder Associates Inc. , 4104 -148th Avenue, N.E. Redmond, WA 98052 Telephone (425) 883-0777 Fax(425)882-5498 ' ' ' ' ' ' ' ' � , ' ' �I , ' ' March 29,1999 KCNi, Inc. 1917 First Avenue Seattle, WA 98101-1027 ATTENTION: Mr.leff Lykken � � - Golder c ASSOC1c1�eS Our ref: 993-1392 RE: KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT Dear Mr. Lykken: Golder Associates Inc. (Golder) is pleased to submit this letter report that summarizes the results of the geophysical investigation that we conducted on January 20,1999. The purpose of the investigation was to evaluate the general condition of the Kennydale sewer pipeline and the adjacent lake floor. 1. PROJECT BACKGROUND An offshore geophysical investigation was performed as part of the evaluation of the condition of the existing Kennydale sewer system. The underwater porhon of the pipeline is located on the lakebed of Lake Washington immediately offshore from the Kennydale shoreline. The information from this geophysical inspection will be used to aid in the process of making recommendations for the future of the pipeline and assess if the pipeline will eventually need to be replaced or reposihoned. 2. FIELD OPERATIONS Two instruments, side scan sonar and underwater video, were used to inspect the underwater portion of the pipeline. Both instruments were deployed from a small survey vessel on two separate runs along the pipeline route. The runs extended from Station 4+00 northwards to station 47+00. The side scan survey was conducted first, followed by the underwater video inspection. The video inspection was done at selected locations that were determined from pmliminary analysis of the side scan sonar data. The position of the survey vessel was determined by refierencing shoreline features such as docks, houses, and other cultural features. These features, particularly house or street addresses, could be identified on the four sifie maps provided by the client (Kennydale Sewer Line Sanitary Sewer L.I.D. 270 Side Sewer Improvement Project, Sheets 2, 3, 4 and 5). ' March 29,1999 2.1. Side Scan Sonar 2 A total of 4 passes. were made along the entire length of the pipeline with the side scan sonar. To obtain the best overall irnages possible each pass was made at a different range scale, variations in frequency, amplification and filtering• The range scale or full swath width of the image varied from 50 to 150 meters. In some areas it was necessary to move offshore to avoid log rafts or extreme shallow water areas. The side scan sonar produced excellent acoustic images of the lake floor and discrete objects, such as the pipeline, pilings, anchors etc., resting on the ]ake floor. The sonar images were displayed on a paper record as well as being recorded on digxtal tape for archiving and data analysis. The paper records were to evaluate the data in the field and to make adjustments to the survey program and to select locations for obtaining underwater videos. The side scan sonar images clearly showed: • The lateral extent of exposed and buried pipeline • The position of the pipeline relative to piers and docks • Presence of cultural debris on the pipeline • Miscellaneous debris, and logs on the lake floor 2.2. Underwater Video Camera A drop camera was used to inspect selected portions of the pipeline. These areas were selected based on field interpretation of the side scan sonar data. The video images were recorded on a VCR with voice annotation desmbing the general conditions of the lake floor and pipeline. 3. SURVEY RESULTS Table 1 sl�mmarizes the condition of the pipeline, descz�ibes general conditions of the lake floor and comments on other conditions that may impact the pipeline. The locahon of this information is ref�renced to the stationing that is shown on the site maps. 993-1392 ' ' Golder Associates Table 1: Summary of Side Scan and Video Observations � 1 ' ' , ' , , ' ' 1 t ' � � 1 , , ' March 29,1999 3 993-1392 Staiion Buried Exposed Comments 38+00 to 42+2A X Pipeline clearly evident. Some possible sus nsion areas. 4p+4p Debris on pipeline. 42+20 to 43+20 X Pi line buried. 43+?A to 44+80 X Pipeline exposed, possible suspensions and some debris on i line. 4. SUMMARY AND CONCLUSIONS A side sran sonar and underwater video camera were used to image the offshore Kennydale sewer pipeline between Stations 4+00 and Station 47+00. Over most of this length the pipeline is apparenfly buried under the lake mud. There was no evidence on these dafia to indicate that the pipeline is damaged. However, at several locations it appears that logs, riprap and miscellaneous debris aze laying on the pipeline. At other locations the pipeline appears to be suspended above the lak,e floor. Both of these conditions will be more clearly defined during the diver inspection. We have appreciated working with you on this project. If you have any questions or require additional information, please contact us. Sincerely, GOLDER ASSOCIATES INC. �C���G /° � Richard E. Sylwester Associate RES/ta ���a � Golder Associates ' ' 1 ' ' APPENDIX C. t ' i 1 1 C i 1 1 r � � � ULTRASOIVIC TES'TIl�TG RESULTS � t�3�'05%1999 0,�:5' 2957675994 GUARDIAN INSPECTION PAGE 02 ' _.� . ' _ REPORT NO. : � �am�"�se.. �nc w.r, w,� woo, 4 9 8 3 5 — 1 rn.:nae�eaao r�:�as�ns. , 'w"^�"* DATE ISSLJED. : inspec ion ser�nces �nc. M°°��,� � s i 2� g g CUSTOMER P.O� $ 3 a 12 0 INSPE.CTION REPORT C�STOMER I ' KCM Inc. ! 1917 Fir�t Avenue i Seattle, WA 98101 . �- ATTEN7'lON: SPECff ZCATTON: PART NO: M4'i"L DESCRLP7'�ON OF TEST: Ultrasonic Thicb:ness Examir,ation of : lea . 8 �� Sewer Pi�Qeline �ennydule Sewer Replacement. WORK SITE LOCATION Gene Coulon Park Lake washington CLASS: Qu�rv�rny: 1 � L\SPEC770N x�sL2rs: . Read?ngs and Locati'ons ca:�.b`e Found.on the Attached Sheets. � Note: Some Areas.Were Too Heavily Corrodea to Obtain Readings. ' . ' � CUST01►i�R APPROV.4L p�.Z.E: Kevin . Maahs � -- � � . . II , P :�IRED BY �- , -.�-. �`yd:. ASNT LEVEL DATE -- - - ' � . '""-.�.,..,:..,. . , - _ .. - - '�'- ,:+x�-;.:rK'`,;,:s�^,,,����.s T i � l� Jr o"�. �u � �'r+'� • e:.,. - =.:!1'� '""'��t...._,. �APRROVED BX : � ASMti.�'EL DATE i�1�TE: This rcpat is unbwsed Wc assume no respoaQ6i7iq� far losar� of say� kind dnc fn aar insuprotatioa o£t!►e queiity of the autaol sabm'ruod. All data aud infamanon will De hNd svitdy coafideatial . - � � . 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' WORKSHOP 3 TECHNICAL MEMORANDUM , � ' � � , ' ' , ' ' l� � ' , Memo Tetra TechlKCM, Inc. , Date: July 28, 1999 ' , CI ' To: Dave Christensen City of Renton Utility Systems 1055 Grady Way South, 5th Floor Renton, WA 98005 c: Workshop Participants Les]1'e Betlach, City ofRenton Parks Department Larry Fisher, Department ofFish and Wildlife Cen tral Files (2-2) From: ' Project No. 1 ' ' ' ' ' , ' Jeff Lykken 2830120-003 Subject: City of Renton Kennydale Lakefront Sewer Replacement Project Workshop 3—Alternative Evaluation Workshop � This memorandum presents the results of the Kennydale Lakefront Sewer Replacement Project Workshop 3, which was conducted by KCM for the City of Renton on May 19, 1999. Workshop 3 was the third of three workshops conducted during project predesign. Goals for the workshops were as follows: Workshop 1—Establish goals and constraints for the project Workshop 2—Identify and rank alternatives for repair, rehabilitation and replacement of the sewer system • Workshop 3—Refine the alternatives developed in Workshop 2 and narrow the potential solutions for final design. Reduce the list of options to as many as three alternatives, perform additional preliminary engineering, and choose a final design solution. Workshop 1 was a project initiation workshop, conducted on February 16, 1999. Objectives completed at Workshop 1 included bringing the consultant team and City staff to a common understanding of the problems and issues associated with the existing facilities, conceptualizing initial alternatives, confirming project goals and constraints, and establishing criteria for ranking the alternatives. , Workshop 2 was conducted on March 9, 1999. Objectives completed at the workshop included brainstorming alternative solutions for the sewer replacement, conducting an initial screening of available alternatives, and selecting the top-ranking alternatives for , further evaluation. Following the workshop, KCM performed additional preliminary engineering and cost estimating for the top-ranking alternatives. , ' Tetxa Tech/KCM, Inc. • 1917 Firat Avenue • Seattle, WA 98101-1027 • Te1206 443-5300 • Fax 206 443-5372 � Goals for Workshop 3 were to present the results of the preliminary engineering and cost estimating and narrow the potential solutions for final design. PROJECT BACKGROUND The Kennydale lakefront sanitary sewer is an 8-inch line in Lake Washington that serves appro�cimately 51 homes and the Kennydale Beach Park along the lake in Renton. The 4,700-foot-long cast-iron line begins at the north end of Gene Coulon Park and ends at North 40th Street. Except for the southern 300 feet of pipe, the sewer was installed in the lake. A flush station (Lake Washington Flush) at the south end of the facility flushes lake water north through the pipe to a City of Renton lift station (Lake Washington #2) in the 3900 block of Lake Washington Boulevard North. From there, sewage is pumped up to Metro's Eastside Interceptor sewer in Lake Washington Boulevard. The facility has been difficult to maintain due to sags in the pipe and limited access for maintenance. Sediment accumulates in the sags, causing backups in the line and overflows into Lake Washington. City workers are able to access only about one-third of the line to rod and flush it with their existing equipment. The top of the pipe is exposed above the lake bottom along much of the alignment. Where the pipe is buried, the depth of cover does not exceed 2 feet. The pipe has been snagged and damaged by boaters and contractors more than a half-dozen times. Because of the past problems with the line and continued uncertainty about the pipe's condition, the City wishes to assess upgrading or replacing the facility. KCM, Inc. has been selected by the City of Renton to provide predesign and final design services on the project. Because of this project's many permitting, constructability and community issues, KCM is conducting workshops to identify alternatives and select a preferred alternative for implementation. WORKSHOP PROCESS Workshop 3 was conducted as a facilitator-led working group. It was facilitated by Don Stafford of Robinson, Stafford & Rude, Inc. (RSR). The five-hour workshop consisted of the following steps: Present the results of the preliminary engineering and cost estimating completed for the top-ranking alternatives developed in Workshop 2. Discuss technical issues associated with the alternatives and refine the alternatives as appropriate. Narrow the list of available alternatives for further evaluation. Workshop participants included the following City staff and design team members: • Dave Christensen, City of Renton Wastewater Utility Supervisor • John Thompson, City of Renton Wastewater Maintenance Division • Jennifer Henning, City of Renton Planning • Barry Scott, KCM, Inc. Page 2 � • Jeff Lykken, KCM, Inc. • Molly Adolfson, Adolfson Associates • Jennifer Kauffman, EnviroIssues • Dave Cotton, Golder Associates, Inc. �ii������s�'�+�� _ � � � : �� _ Using brainstorming techniques, participants at Workshop 2 identified a list of alternatives to accomplish the following project objective, which was developed in Workshop 1: Provide a cost-effective, reliable and maintainable sewage disposal system with a minimum 20-year life that can be implemented in the current regulatory and community setting. The north and south ends of the lakeline have different physical constraints affecting the feasibility of solutions, so the project was divided into two parts, but without precisely defining the dividing point between the two. Table 1 summarizes the 11 north and south end alternatives that were screened and ranked at Workshop 2 for further evaluation. Two additional alternatives that were not originally screened at Workshop 2 were also ' developed. They were identified as Alternative N15-a and Alternative S15 and are shown in Table 2. Both alternatives involve installing individual grinder pumps stations at the existing side sewer locations and pumping to a new low-pressure sewer located onshore. ' These additional alternatives were developed because of feasibility issues related to constructing onshore gravity sewers. ' ' ' � ' 1 ' ' Page 3 �i � TABLE 1. ALTERNATIVES DEVELOPED AT WORKSHOP 2 FOR FURTHER EVALUATION No. Descri tion N1 Replace the existing lakeline with a new minimum 6-inch diameter gravity sewer in the lake. N3 Leave the existing lakeline in place, restrain pipe joints, add access points for maintenance, and re-lay portion of the line to remove sags in the profile. N6 Construct a new gravity sewer between the homes and the railroad using trenchless pipeline installation methods. Re-route side sewers to the new gravity sewer using trenchless installation methods. N8 Microtunnel a new gravity sewer in Lake Washington Boulevard and install new side sewers using directional drilling from the lake side. N13 Replace the existing lakeline with a new 6-inch or 8-inch diameter sewer in the lake with flushing capacity. N15 Slipline the existing lakeline to Station 22+50 with 3-inch diameter plastic pipe, install grinder pumps at homes and new pressure side sewers. S3 Leave the existing lakeline in place, restrain pipe joints, add access points for maintenance, and re-lay a portion of the line to remove sags in the profile. S6 Construct a new gravity sewer between the homes and the railroad using open cut pipeline installation methods. Construct a new lift station to convey flows to Lake Washington Boulevard S8 Microtunnel a new gravity sewer in Lake Washington Boulevard and install new side sewers using directional drilling from the lake side. The flush station would remain in service to intermittently flush the new gravity sewer for cleaning purposes. S13 Replace the existing lakeline with a new 6-inch or 8-inch diameter sewer in the lake with flushing capacity. S21 Construct a new gravity sewer between the homes and the railroad north to Station 28+00. Direct flow in the existing lakeline from Station 36+00 south and construct a new lift station at Station 28+00. � ' r , ' ' ' , 1 , ' ' !I �� � , ' ' Page 4 ' TABLE 2. ADDITIONAL ALTERNATIVES EVALUATED FOR WORKSHOP 3 No. Descri tion N15-a Install grinder pumps at each of the existing side sewer connections between Kennydale Beach Park and the existing lift station. New pressure side sewers would discharge to a new 3-inch force main installed by open-cut construction in the frontage road. S15 Install grinder pumps at each of the existing side sewer connections between Station 3+00 and Station 25+00. New pressure side sewers would discharge to a new 3-inch force main installed by open cut construction in Mountain View Avenue North. The four southerly homes would drain by gravity to a new gravity sewer. The existing flush station would be replaced with a lift station, and flows from the new main would be pumped up to the existing gravity sewer in Lake Washington Boulevard. PRELIMINARY ENGINEERING AND COST ESTIMATING After Workshop 2, additional preliminary engineering and cost estimating were performed for each of the alternatives listed above. Refinement of the alternatives included the following: • Additional field information was gathered to address construction issues regarding work on individual residential properties and construction within the lake. • Six contractors were contacted to discuss the feasibility of employing various construction methods to install new side sewers, a new lakeline, ' and new onshore gravity and pressure sewers. Construction methods � investigated included directional drilling, microtunneling, pipe ramming, marine construction and shore side construction. • City mapping and as-built drawings were assembled for the project area. • A preliminary layout was developed for each alternative. The layouts included an appro�cimate profile for gravity sewers and new lakelines. • Planning level cost estimates were prepared for each alternative. • A plan drawing was prepared for each alternative, showing the primary features of the alternative, advantages and disadvantages, and a preliminary project capital cost. The drawings are included in Appendix A. Cost estimates for each alternative are included in Appendix B. Each evaluated alternative presents technical challenges that affect its feasibility. For alternatives that involve construction of a new pipe in the lake, space constraints present the greatest challenge. The existing pipeline is generally constructed close to the shoreline, running beneath most of the existing docks. Lake depth along the alignment is often shallow, in the 4- to 6•foot range, and there is little space between the docks. Page 5 � General Construction Company, a marine contractor, was contacted about building a new pipeline along .the same general alignment. The company said that it would be very complicated and costly to construct a new line along this same alignment. The new line would have to be laid with equipment mounted on a barge. Unless the existing docks were removed during construction and subsequently rebuilt, a custom barge and equipment would be necessary because of the space constraints and shallow water depth. Because of these restrictions, it was assumed that a new pipe will need to be aligned immediately beyond the existing docks for alternatives that include a new lakeline. For alternatives that include construction of a new on-shore sewer, the greatest technical challenge would be rerouting the existing side sewers to the new line. A connection to the existing side sewers would have to be made on the west (lake-side) side of the homes, and new side sewers would be routed inland to the new line. On most of the properties, there is very little room between the existing homes, sometimes as little as 8 feet, making it difficult to install a new side sewer. In most cases, the little space available includes improvements such as patios, stairways, decks and rockeries that would have to be removed and replaced if the side sewers were installed using open-cut construction. For this reason, it was assumed that most new gravity side sewers would need to be installed using trenchless methods. It may be possible to install small-diameter pressure side sewers by open-cut construction since the line could be installed at a shallow depth. Findings of the preliminary engineering and cost estimating for each alternative were presented at Workshop 3. The findings are described below, along with technical, permitting and regulatory issues identified for each alternative at the workshop. Alternative N1 A new 6-inch diameter gravity sewer would be installed in Lake Washington beyond the e�usting docks. The new gravity sewer would have a minimum burial depth of 2 feet below the lake bottom and would have a minimum slope of 0.004 feet per foot. Connection to e�usting side sewers would be made near the lakeshore, and new side sewers would be extended out to the new lakeline. To attain the minimum burial depth and pipe slope, the existing lift station at the north end of the project would need to be lowered approximately 12 feet. The estimated project cost for Alternative N1 is $1.62 million. Advantages of this alternative are that flushing of the new line would no longer be required, gravity flow in the line would reduce maintenance requirements for the sewer, and side sewer connections would cause little disruption to residential properties. The line would remain vulnerable to damage from homeowners doing work on their docks, and lowering the lift station an additional 12 feet would be difficult and expensive. Adolfson Associates believes this alternative will be the most difficult to permit because of the extent of in-lake work and habitat disturbance, and that the permitting costs during project design could be in the $100,000 to $200,000 range. This level of permitting costs was not accounted for in the cost estimate. Page 6 , , Alternative N3 LL'J , The existing lakeline would remain in service. Two sagging sections of the line would be rerouted closer to the shoreline to improve hydraulic characteristics of the line. Additional access to the pipeline would be added to simplify maintenance, and pipe joints would be � restrained where the line is in jeopardy of pulling apart. The exact number of joints needing restraint is not known; for cost estimating purposes, it was assumed that 25 pipe joints would be restrained. This represents approximately 25 percent of the pipe joints , between Station 27+50 and the lift station. The estimated project cost for Alternative N3 is $0.68 million. � Of the in-lake alternatives, this alternative would involve the least amount of work in the lake. It has the least cost of the north-end alternatives and requires little work on the residential properties. , ' Disadvantages of this alternative are that pumping rates and flushing velocities of the existing system would remain low, the line would remain vulnerable to damage, and maintenance access to the system would remain difficult. The group agreed that since the structural integrity of the existing 8-inch cast iron lakeline remains questionable, this alternative does not meet the required project objective. Alternative N6 ' A new 24-inch diameter casing pipe and 8-inch diameter carrier pipe would be installed by microtunneling in the frontage road next to the homes. The frontage road is too narrow to install the sewer using open cut construction. Side sewers would be re-routed to the new �' :' sewer by installing new pipe from the west side of the homes using pipe ramming or , directional drilling. The estimated project cost for Alternative N6 is $1.52 million. Advantages of this alternative are that the sewer line is removed from the lake, the line can be more easily maintained, and the sewer is no longer vulnerable to damage. Feasibility issues regarding installation of the side sewers and connections to the new sewer main in the frontage road are the major drawbacks of this alternative. Loy Clark Construction, a pipeline contractor, made a visit to the site to assess the feasibility of installing gravity side sewers using directional drilling. The company's opinion was that the space constraints of the sites would present serious problems in setting up the equipment and installing the side sewer pipe. The risk of failure to install the pipe to grade would be high should a contractor attempt directional drilling or pipe ramming. It would also be very difficult to provide access for homeowners during construction of the gravity sewer along the frontage road and connection of the new side sewers. The group agreed that this alternative would not receive further consideration because of the feasibility issue of installing the new side sewers. Page 7 �i � Alternative N8 A new 24-inch diameter casing pipe and 8-inch diameter carrier pipe would be installed by microtunneling in Lake Washington Boulevard. Side sewers would be rerouted to the new sewer by installing new pipe from the west side of the homes using pipe ramming or directional drilling. Each of the new side sewers would need to cross under the Burlington Northern Railroad tracks. The estimated project cost for Alternative N8 is $3.24 million. Advantages of this alternative are that the sewer line would be removed from the lake, the line could be more easily maintained, and the sewer would no longer be vulnerable to damage. As with Alternative N6, the questionable feasibility of installing the side sewers is the major drawback of this alternative. The risk of failure to install the side sewers to grade is much higher with Alternative N8 because of increased side sewer length. Given these drawbacks and the high cost of this alternative, the group concurred that cost and risk are too high to consider this alternative further. The City also believed that it would be impossible to get permits from Burlington Northern Railroad for the number of side sewer crossings required. Alternative N13 A new 8-inch diameter flush line would be installed in Lake Washington beyond the existing docks. The new flush line would have a minimum burial depth of 2 feet below the lake bottom. Connection to the existing side sewers would be made near the lakeshore, and new side sewers would be extended out to the new line. To attain the minimum burial depth, the existing lift station at the north end of the project would need to be lowered approximately 8 feet. The estimated project cost for Alternative N13 is $1.92 million. Advantages of this alternative are that lowering the lift station would increase the amount of flow that can be flushed through the line without backing up into homes, and that side sewer connections would require little disruption to residential properties. The line would remain vulnerable to damage from homeowners doing work on their docks, and lowering the lift station an additional 8 feet would be difficult and expensive. As with Alternative N1, Adolfson Associates believes this alternative may be expensive to permit. The required level of permitting costs was not accounted for in the cost estimate. Alternative N15 Grinder pump stations would be installed at each of the 18 existing side sewer connections between Station 25+00 and the lift station. The existing 8-inch lakeline would be sliplined with a new 3-inch diameter plastic force main pipe. Existing side sewers would be sliplined with new 1.5-inch pressure sewer pipe and connected to the 3-inch main. The new force main would discharge to the existing lift station. The estimated project cost for this alternative is $1.11 million. � Page 8 � Advantages of Alternative N15 are that flushing of the lakeline would no longer be required and the sliplined installation of the 3-inch force main inside the existing 8-inch pipe would be easier and less expensive than installation of a new lakeline. Drawbacks of this alternative are that the City would have 18 additional pump stations to maintain, the sewer line would remain vulnerable to damage in the lake, and repairs to the lakeline would be difficult with the configuration of one pipe inside another. Installation of the grinder pump stations and connection to the existing side sewers would be difficult because of the improvements in place at existing side sewer locations. City staff said they would require installation of a commercial grade duplex pump station for this alternative rather than the residential grinder pump station typically installed for single-family homes. This requirement was not accounted for in preliminary engineering and cost estimating, and would increase the cost of this alternative. The City is also concerned about sewage spills into the lake during power outages or in the event of a mechanical failure, since most of the pump stations would be located near the lake shore. Alternative N15-a Grinder pump stations would be installed at each of the 14 existing side sewer connections between Kennydale Beach Park and the lift station. New 1-1/2-inch pressure side sewers would discharge to a new 3-inch diameter force main installed by open cut construction in the frontage road. It was not known whether the grinder pump stations would have enough head to pump sewage along the alignment and then lift it Lake Washington Boulevard, so it was assumed that the new force main would discharge to the existing lift station. If the individual pump stations have the capacity to lift sewage to Lake Washington Boulevard, the existing lift station would no longer be required, reducing future City operations and maintenance costs. The estimated project cost calculated for this alternative is $0.88 million. Advantages of this alternative are that the sewer line is removed from the lake, the line can be more easily maintained, and the sewer is no longer vulnerable to damage. Since the side sewers would only need to be 1-1/2-inch diameter with minimal burial depth, the new lines could likely be installed using trenchless construction techniques. The new 3-inch force main could be installed by open-cut methods in the frontage road since it will require a minimal burial depth and would not need to be laid to grade. Drawbacks of this alternative are that the City would have 14 additional pump stations to maintain, and installation of the grinder pump stations and connection to the existing side sewers will be difficult because of the improvements present at the e�sting side sewer locations. As with Alternative N15, the cost of this alternative would increase with the requirement to install commercial grade duplex pump stations. Page 9 �i � Alternative S3 The existing lakeline would remain in service. One sagging section of the line would be rerouted overland to improve the line's hydraulic characteristics. Additional access to the pipeline would be added to simplify maintenance of the system, and pipe joints would be restrained where the line is in jeopardy of pulling apart. The exact number of joints needing restraint is not known; for cost estimating purposes, it was assumed that 30 pipe joints would be restrained. This represents approximately 25 percent of the pipe joints between Station 4+00 and the Station 27+50. The estimated project cost for Alternative S3 is $0.45 million. The group agreed that since the structural integrity of the existing 8-inch cast iron lakeline remains questionable, this alternative does not meet the required project objective. Alternative S6 A new 8-inch gravity sewer would be installed by open-cut construction in Mountain View Avenue North. This road is less constricted than the frontage road on the north end of the project, making open-cut construction possible. While still very difficult, gravity side sewer construction is more feasible on the south end of the project because of fewer space constrictions. Side sewers in constricted areas would be rerouted to the new sewer by installing new pipe from the west side of the homes using directional drilling. In less constricted areas, side sewers could be installed by open-cut construction. Two homes at the far north end of the alternative project limits are too low to be served by the new gravity sewer. These homes would be served by grinder pump stations that pump up to the new gravity sewer. The estimated project cost for Alternative S6 is $1.89 million. Advantages of this alternative are that the sewer line would be removed from the lake, the line could be more easily maintained, and the sewer would no longer be vulnerable to damage. Mountain View Avenue North is as much as 14 feet higher than the elevation of the lowest floor elevation of the homes. This would require the new sewer to be installed 14 to 18 feet deep to serve the homes with low floor elevations. Dave Cotton noted that construction dewatering would be a big concern for this alternative because of the burial depth and groundwater conditions near the lake. Providing access for homeowners during construction would be difficult because of the large equipment required to construct a deep sewer line. The group agreed that this alternative would not receive further consideration because of the required burial depth and the feasibility issue of installing the new side sewers. Alternative S8 A new 24-inch diameter casing pipe and 8-inch diameter carrier pipe would be installed by microtunneling in Lake Washington Boulevard. Side sewers would be rerouted to the new sewer by installing new pipe from the west side of the homes using pipe ramming or directional drilling. Each of the new side sewers would have to cross under the Burlington Northern Railroad tracks. This alternative proved to be unfeasible because of the excessive � Page 10 burial depth required. The elevation of Lake Washington Boulevard varies from 39 feet to 74 feet within the alternative project limits. The new sewer line would need to be at elevations between 10 and 15 feet to serve the homes. This would require microtunneling pits and side sewer connection excavations in excess of 60 feet. The group agreed that this alternative would not receive further consideration. A project cost was not estimated for this alternative. Alternative S13 A new 8-inch diameter flush line would be installed in Lake Washington beyond most of the existing docks. The new flush line would have a minimum burial depth of 2 feet below the lake bottom. Connection to the existing side sewers would be made near the lakeshore, and new side sewers would be extended out to the new flush line. The existing flush station would be upgraded to increase flushing capacity. To attain the minimum burial depth, the existing lift station at the north end of the project would need to be lowered approximately 8 feet. The estimated project cost for Alternative S13 is $1.92 million. Advantages of this alternative are that lowering the lift station increases the amount of ' flow that can be flushed through the line without backing up into the e�usting homes and the side sewer connections would require little disruption to residential properties. The line would remain vulnerable to damage from homeowners doing work on their docks, and lowering the lift station an additional 8 feet would be difficult and expensive. Adolfson Associates believes that, like the other lakeline alternatives, this alternative may be expensive to permit. The required level of permitting costs was not accounted for in the cost estimate. Alternative S15 Grinder pump stations would be installed at each of the 15 e�cisting side sewer connections between Station 3+00 and Station 25+00. New 1.5-inch pressure side sewers would discharge to a new 3-inch diameter force main installed by open cut construction in Mountain View Avenue North. It is not known whether the existing grinder pump stations would have enough head to pump sewage along the alignment and then lift it to Lake Washington Boulevard, so it was assumed that the new force main would discharge to a new lift station at the location of the existing flush station. If the individual pump stations have the capacity to lift sewage to Lake Washington Boulevard, the new lift station would not be required. The estimated project cost calculated for this alternative is $1.56 million. Advantages of this alternative are that the sewer line would be removed from the lake, the line could be more easily maintained, and the sewer would no longer be vulnerable to damage. Since the side sewers would need to be only 1.5-inch diameter, with minimal burial depth, the new lines could likely be installed using trenchless construction in constricted areas. The new 3-inch force main could be installed by open-cut methods in Mountain View Avenue North since it to would require a minimal burial depth and would not need to be laid to grade. Page 11 � Drawbacks of this alternative are that the City would have 15 additional pump stations to maintain, and installation of the grinder pump stations and connection to the existing side sewers would be difficult at many of the side sewer locations. The new lift station included in the alternative accounts for approximately $530,000 of the overall project cost. The project cost could be reduced by this amount if the individual pump stations have the capacity to lift sewage to Lake Washington Boulevard. The cost of the individual grinder pumps would increase with the requirement to install commercial grade duplex pump systems. Alternative S21 A new 8-inch gravity sewer would be installed in Mountain View Avenue North from the flush station to a new lift station at Station 28+00. The direction of flow in the new line would be from south to north. The existing lakeline would remain in service as gravity sewer between Station 28+00 and Station 31+00 to serve the Kennydale Beach Park. Flows from the new gravity main and remaining lakeline would be pumped up to the existing gravity sewer in Lake Washington Boulevard. Side sewers in constricted areas would be re- routed to the new sewer in Mountain View Avenue North by installing new pipe from the west side of the homes by directional drilling. In less constricted areas, side sewers could be installed using open-cut construction. A project cost of $2.34 million was estimated for Alternative 521. Advantages of this alternative are that most of the sewer line would be removed from the lake and would no longer be vulnerable to damage, and the line could be more easily maintained. Since Mountain View Avenue North is as much as 14 feet higher than the elevation of the lowest floor elevation of the homes and the new sewer would be laid opposite to the e�sting road grade, the new sewer would have to be installed 16 to 22 feet deep to serve the homes with low floor elevations. Because of the excessive burial depth, it was assumed that roughly 1,100 feet of the new gravity main would need to be installed by microtunneling. Providing access for homeowners during construction would be difficult because of the size of jacking pits required to microtunnel the new sewer line and casing pipe. The group agreed that this alternative would not receive further consideration because of the project cost, required burial depth for the new sewer and the feasibility issue of installing the new side sewers. ALTERNATIVES SCREEIVING RESULTS Table 3 lists the alternatives that workshop participants, after review and discussion of all alternatives, concluded do meet project objectives. Of these, the north and south end alternatives were paired to form a list of options for an overall project solution. Order-of- magnitude operations and maintenance costs were estimated for each overall solution and added to the project costs previously developed. Table 4 shows the paired alternatives and costs. Page 12 � TABLE 3. ALTERNATIVES THAT MEET PROJECT OBJECTIVES North End Alternatives South End Alternatives N1 S13 N13 S15 N15 N15-a TABLE 4. COMBINATIONS OF NORTH AND SOUTH ALTERNATIVES THAT MEET PROJECT OBJECTIVES Estimated Cost ($million) q Paired Alternatives Ca ital Cost O& M Cost Total Pro'ect Cost N1 & S13a $3.7 $0.3 $4.0 N1 & S15 $3.2 $0.6 $3.8 N13 & S13 $4.0 $0.2 $4.2 N13 & S15a $3.5 $0.6 $4.1 N15 & S13a $3.5 $0.7 $4.2 N15 & S15 $2.7 $1.0 $3.7 N15-a & S13a $3.3 $0.7 $4.0 N15-a & S15 $2.4 $1.0 $3.4 a. A new flush station would be required for this combination of alternatives. Capital and O&M costs for a new flush station are not included above. ALTERNATIVES FOR FURTHER EVALUATION A meeting was held at City Hall in Renton on June 1, 1999 to further narrow the list of paired alternatives. Meeting attendees included the following City staff and design team members: • Dave Christensen, City of Renton Wastewater Utility Supervisor • Jennifer Henning, City of Renton Planning • Leslie Betlach, City of Renton Parks Page 13 � , • Barry Scott, KCM, Inc. ' • Jeff Lykken, KCM, Inc. It was decided at the meeting that the alternative pairs shown in Table 5 best meet the 1 project objective. These two project solutions will be evaluated further. Alternative Pair N13 & S13 N15-a & S15 TABLE 5. REMAINING ALTERNATIVES Description Replace the existing lakeline with a new 6-inch or 8-inch diameter sewer in the lake with flushing capacity. Install a 3-inch diameter force main in the frontage roads adjacent to the homes, install grinder pump stations at existing side sewer locations and new pressure side sewers. ' , ' � ' , ' � � ' ' Page 14 _, ' , ' r , LJ ' ' 1 ' ' , � �'i , �j � 1 � , � ' 1 , APPENDIX A. PREDESIGN ALTERNTIVES ' 1 l J� 1 ' ' ' � , �� 1 ' 1 1 ' L� ' � L ,O N O C7 ,N , :` :;;� , . ,�, r, Extend Existing \ ` Lake Wash�ngton � Side Sewers to � � g� � r New Gravity Line a r: . � 25+.00 �.,,, ` {17 Total) New 8" F�ush Line ' ..�., :. ` � ' ~�� ' 3 a = ' Installed Be ond Existin = � � 1 \ %� � , `Y" ` 6 ' �` � ' Y 9 n ` Abandon Existing i N . : ; � , •` , -. ` �� M ena nh Docks w/Minimum aint nce Ma ole : '�g � �.; „' .� " ` at Kennydale Beach : 2 Feet of Cover � Lakeline m Place 5 � .���� �� Y� �.'�\ . . ` �ry��9fan` ., � �o,, �y \_ : s��� No�� y � �y s � r A � � he,n : � � S� �,a �•,,: , �w ; � ; '�,..,RR, • so+oo ��x -,` = ` 1.. �ake; *.� � ` � �,„�, 3500 V'`^ �.�;: h'as 's g � ,:_ ,._,.� � � h, `�. . � at � ;;� —� ' �. � ��, >� �• tl,� hhou �,<, �_='�^� � t ` � on F'" �. 4 Se' ,z Y. �v,x 'o '�^. �x� 9 �` B�Y ` «, �� � Kenn dale � 3 4 �Y� �+ `'�k � ��4� � "f �� ��. � ' s ,'.;r Beaeh Park� �- f� ' � ;� ,.,,, F �� R�� t ry .R "� ``�'�. � az � � C r"l±_ �� �� s 3' R � �K �.�,,. � � 1 J�p �� v -5.--:� W >,�;!�� f,y ".�a '� s„��:� a � 4 �� ' }� � �''� � � : t � 40#00 �,. ; > . . : �: ..c ��(. � G. L ) 4 F,>w..�,Y. £ .^wiP `��.+ `j ) # `..'` rt ' Burnett Ave. �:�3 ~ �� � ,j � .� y f � g; � '. Wh ,�� � � -\b � � 3 � ��� � : . . ' . �' o . ..J ' . + ; '. � z 'S � Y S /' %�: -... ^ 1 s s `t ?� N� v� r .i �:�` .. �s ��"� v � ���Ia .: '�.. z � � .� ���� i: EXI$QIII :Llft � � g�-:� � �� .� � 9 '�.., � s. � '� s i� t � Sf�uon ��: � � 1 l' LEGEIUD �, � �r (Sta:47+35):. --�--- Existin 8" Sewer Line Rrt ' # ` ' � ` � : � � %� a5oo ° 9 �s �r b a � �`s . � � � ; r_—_______-' Existing Side Sewer E F a p�•< r.. .._,_� �� F Z� �T ° 3� � ' �Dock Cieanouts at � �� � r °` Existing Cleanouts � iwo Locations Accessibie to � E `V , r a City Jetting Eqwpment y`` 9� � � —�— New Sewer Line fi " ;�" z w ,N �'' � , , ac : r �;»� , , 4 - 4 S ( ' A 3 `a .> ...• � . --�-�-��----�— New Side Sewer '� "< s^�; New Lift Station � • Invert Elevation � � ___�__ ' ofNew8" y`\ �� —. Approximate Inner Harbor Lme u < �.. y n > � ,� Flush Line � j -�„x �V : � __ . . . . . .... . . . . _ � , . ._ . , . � . . , , , . , < < .. <. � . � ., _ � �F<. _ .. � > . ,_ .�°; r . . . :r�:. APProx. -2A R<= 0 NOTES: 1. Homes and docks on map based on 1984 survey by Horton Dennis Associates. 2. New 8-inch flush line has a minimum of 2 feet of cover. 3. Cost of new flush station is included in Alternative S13. Tetra Tech/ KCM, Inc. 9917 First Avenue Washington 98101 City of Renton KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT ALTERNATiVE N 13 C� :; .; C 1 1 1 1 1 r t � � � � � ' ' � � r � n c v: � NOTES: 1. Homes and docks on map based on 1984 survey by Horton Dennis Associates. 2. Telemetry for monitoring by City included in cost. Tetra Tech/ City of Renton KCM, Inc. ALTERNATIVE N15 9917FirstAvenue KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT SeattJe, Washington 98109 ' . A ., _ . . . � II � ' ' ' ' ' ' ' ' 1 ' � ' ' ' ' � � � � �o N O M W 'N ' \, � .. _,, --�--- Existing 8" Sewer Line 9 ' 5 ((r � k ' � , .` � 3 ; �. : F LEGEIVD' ..'�;�t�•. � NOTES: 1. Homes and docks on map based on 1984 survey by Horton Dennis Associates. 2. Telemetry for monitoring by City include cost. Tetra Tech/ City ofi Renton KCM, Inc. ALTERNATIVE N15-a 1917FirstAvenue KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT Seatt/e, Washington 98101 Existing Side Sewer �,: :� .'� ... "� � � �g a} . �.. � �'-: : � � '\. ~ ''� ..�, � Sta �n,Vo ; � � 5401 � , � 3g+00 ` '�. � x S .. �h�'?.A_'.as".._ ` ,. y�'`�>.s ,._. .,,. ., .'`�;....<. � Existing Cleanouts }--- New Pressure Sewer Main —�-----a------- New Pressure Side Sewer ` , � Y4 -------- Approximate Inner Harbor Line ' � ` � s� ,� _ . �. . .. . , .. « New Grinder Pump Station � z: N ` Abandon Existing f Lakeline in Place � { Y L 'Q � ('- �� � �, r x �_ �`.;� -� �� , � ..� , ` . ' & ,. £ � . 3 � r:� L'ake Washmgton A � • `��' ` � 3 £ � Ste `:... � 40+00 � .� �� ' � �:. 3 ,� �'� �`` �� Install Gnnder Pump Station � at Each Side Sewer Location "� " � ' f � (14 total) � �=" �.` .. �' . . & �`iv' & y :.:' p \� . .;� i :W c Ex�s:�ng Lift -.� : � � �-.,,,\. � � Stat�on :: -.,,� . ` �''�,, , {Sta:`47+35)., , �� ,,� r 4, 1 ,� � 45+00 .�; t k �'u r . . x'`' 3 t t �i "'^A .! v ^', \ . � 9 w z..':. . x_ . a .rG � . r.j i� �:'9 s.. � Install new � "" �'�� � �' �� t.' 3" Open Cut �-� � �� � ' > - Pressure Sewer - r , � � j a z f� , s � �� .�,. . .� _�. �.., _...:� ._ _.._...�.y��._. _�. �_>��.. ,. < . > . . ;,.��p , . ,., _ .. . . � 4. �. _ .K�� :, ( �.#.._ � \`������� �. 4x. G a'� W R t. a �y . T b k. I Y � 2 R, C' f�.Ok ! 3 (� x F ., 5 � .,' � �@�X. V I� . ! y , . . , . , f n . . . . ... , . . . .. < L .• .. _ , _ . .. . , , n , , ., . ., < .. . �.. � .^>..<. . , , . E . .. . �YL . . , . New 1 1/2 Pressure Side Sewers to New Force Mam By Direct�onal Dnlling 1 , C ' ' , ' ' ' 1 ' ' ' ' � ' �'. ..� / �: s / - ;.z' _` "� `i' / _ ; Stas .�' � a �—`� '. e,; 10+00 A ; ` i � :: LEGEND Existing Lakeline to Remain in Service; —�-- Existing 8" Sewer Line Provide Joint Restraint at Pipe Joints in Jeopardy ----------•--- Existing Side Sewer of Separating ,��. � � �,' �i�� , �� , '���, � ; � ,�'`` t � � p I , ��°'' �� • � II� i � i�� I �� fi ��� •� � t �� �n. ��� ��� �;� >,� ��'v � � � � � .A�« ���d r '�'�'a � z3,�',.'�.� � � l � ����� �s �,. � � 1, i y�il �, �"��{:. A,�sk,'��,�t 7 ri���, „� _�-;.e ���'��,' �'�., I�� �� 'E .���'� 5�F' � ; ` �' � F� �Y� � � I � � � � � h f I t ,�S✓,,,�."r; . ! �b���� �. � -, sa.as a ��� �ve �� ls2a.h� � .'X'� .,.3 � Y i •��. �,. ��� � � � ��t � �� - `�. ��� �� '�; ��" ���` , � �>�.. � �� ��`���� .t ��, � `��4� ����'� ���"���5���`.��.. ��„ � �i �� � � 1� � �3 �� � ��3' ,�. �4 ..d 1 11 ,�`a�y s _ .. � �'�� '• �• • "��. <.�_.,�._ .�r.� � � � � - - ' �� � 1 to Remove Saq � � Existing Cleanouts Lake Washrngion,° �_ � New Sewer Line `" �v�--�-----��-�� New Side Sewer � � '`-• °' : \ �- �_ � -- --- Approximate Inner Harbor Line �� .�� ` ,. y i `�' �r e � `:. ��'; -� ' �JtB • y '� � • Zaf'0� ' ~ � �. .;�.. :�' ,x � _c%�` t K � `^w,�:.�' .� i:'�"a . � � , u'. � ` � e ; � " Maintenance Manhole ; ; �'J ' , ;" s ���+ at Kennydale Beach �, 5�� � = for Maintenance Access > `''� � � (3 Total) .,� y ' `(: �Ra �t� ~ \ � �� � ;�:�, :Za � ``�,y , ..w A \'` S� ��� �� , . :� ,s ' �� �� 25+00 "-•. M w �� .� ; ` �. f�, J ..(, '�`b \ ` „';` \ '~ wF ��YbN :aL, G �� j�. 1� ♦�'., � T� . jJ.. ��` ..� �W i n a �as/� � A + '4� ;,�, `'T,� so+oo � , ,h = � . gfohe £ � �`�_ _ `._. � , . ..< ., .�.9 � �3 �....a..a�/ya. .�A,.z „� _., bg�r � . � ..� �E .��,� --.:.�. �. 4 : 3.. I_ �:�.. 7:. • .. . . , .. . � , , ,. .��',a x5. _ . .. �<. � . .. NOTES: 1. Homes and docks on map based on 1984 survey by Horton Dennis Associates. 2. Cost estimate based on restraining a total of 30 pipe joints, which is approximately 25% of the total number of_pipe joints between Station 4+00 and Station 27+50. • Tetra Tech/ KCM, mc. City of Renton ALTERNATIVE S3 ,9917FirstAvenue KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT Seattle, Washingfon 98901 . . e . . ... . : ... . > , .. . i . .< . . .. , . .. . . . .ye r A ,. . , r .. �- x . _ . a .. / / ./ , / / / / �,: �i. �' . � �-�'�` .- , � � .�^� � � � �� " � / i; :..�� 1 = � �* a {`�' �+s /, sr "r t �� � � ° l II � L /� Sfa �, � � ,�� , x rJ�'Q�..-��_ t o � �. � ° c � ''� js � //�� --� �( / �� ' µpu��,� �.��.. 3 `rt ` Replace Existmg r � : � Flush Station , n & '` � `�- ,xsoi'� ' With New -> }�,� �^` '< y $ " Lift Station � � �� 3 � �' \ y � /; f� M r F 1 / t :;v �Z ;, � Bore & Jack Crossing ' ',;, F� r�. u' x of Bur�ington Northem ;s ,�'• Railroad ' �; � � � � a � i .. . ..:`��) a S . .. . .. . , . .' , ., . . .M ., i . ... �. :,`» -., : ;= tEGEND 4 � Abandon ExisUng ' ��" ` Lakeline in Place --�-- Existing 8" Sewer Line ,.,; . -:sta r�, a -�� � _____._._._._.__ Existin Side Sewer ��+oo � �, _ �.-� �, 9 ���e a � � � � o � g� A , � `, �': Existing Cleanouts ; y , �<. �; � .�' ` sta , � - --�--- New Gravity Sewer Line , e.,. . _°' . ;� - ,� �; 7 � �` 15+00 s Re-Route Side , . , �� '-�, Sewers to New � '� s Y� K ,�� � x, �,., .; 1•.. Graviry Main by �-- New Force Main , ��,: � , `m�� �� �.. Directional Drilling �:$ sr� x :�yµf � i ynf° f� ''; . .~�:; ____,��.___.,m New Side Sewer i y � �rs,3 E � or Open Cutting u��v ::� � % � � � , °i �. � ;a� �.. r � . h'� � �. � j 3 Y�t »'i M i'i . ,� y S.. $ M � � � � � • � � � .�",'��i C�`"�ik �� �xr' /3' �.'#�. � ,f SiL s'F'e"N�' C�''Y � F. .. 4 �� .�°X6a �,�r� s 6�� � ��� 2 ��'33 � �� r 8���� a � � _ � yj �i .� . �.:. �� ,��� ��y �(�,���� �� � t t f • ' / • s�� q. � � `�i,�`� -� .�u �� � e' �'� Y� 8 z :� �t , � ..�.. �'�..� � �. ,3 ,✓"�i ; ��f� �� ..u^ �^�' �'�„`�,^a�...,...-K �� � �a �`� " ' i • - .m, �> : �,,,. ��� �" �, X ( s �, �,�� � �' � � s � i � � �� �, i 6 �: i � � ru.3 �. ��is � t� ,,.f '• . � ~��',a ��#,l? ' . • • Connect New Force Main to Existing Gravity Sewer in Lake Washinaton Boulevard � ;>., Open Cut ° .. , y Gravity Sewer ` � . clw t � W F � R x M < Y b' .a �� � S� S A 3 A ' c y_ H r � � [, 5µ 4 a fl t 5 � ~'' .,� ' --�, , ` � ^�. � ��' S�. .�` �•; 25+00� a;` � ;� �\ _,• � ` R�.° Qa l �� t �- . , �� ' . t � • �^' . \ _' �;� � � � 'Sta' �fj �� aao� ~i"'�s,,,. 30+00` ; ��9'fp� � , �' � ;� � � ` � ` �l'O� ' x � s _ � �` �" }�' ': P .3 x`� �'•'„ . 's . . . . . _ �. ,.... > , Bathh.,rSL �, a � "'`-'�_•,' N, � ��� �; ' : No�ern :. RR %r ` °z a >'s :,. N NOTES: 1. Homes and docks on map based on 1984 survey by Horton Dennis Associates. Install New 1-1/2" Open Cut Fressure Sewer to New Gravitv Sewer Tetra Tech/ City of Renton KCM, tnc. ALTERNATIVE S6 �s17FirstAvenue KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT Seatile, Washington 98109 �::� ' 1 1 1 1 , ' ' ' , ' 1 ' 1 �J , :.` � ti �t ; � }t t� � �. � � �. <. a �' � NOTES: 1. Homes and docks on map based on 1984 survey by Horton Dennis Associates. . 2. Maintenance rnanholes could be located at end of private docks if easements could be negotiated and if they are accessible by City maintenance equipment. 3. New 8-inch flush line has a minimum of 2 feet of cover. 4. Cost of new lift station is included in Alternative N-13. / : New 8" Flush Line �° Installed Beyond �'� . Existin Docks With �. � ' 9 /', � Minimum 2 of Cover ; *�,� a � : ; �Sta »; . 1 Oar�00 Extend Side � � �� Sewers to � i j�;' : New Flush Lme ,� / ° (15 Total) °� /� �, , % ,� �, ' f ,/ � � ` � �.�,.� ;%' .� � �, / s . �v �' k�� , �� 4 i« .. 7 / , �� � b * x; f" u S�3 t, t3 � / P ` 'F 5 00 / � `� a ^ � • �'. / ..Y / ♦. ,j x:: �. •/ , > �' � � W�pve '' ' . . . ; . .. _' _ : �., ' ,. . .Vie - . . _ �n ;.ty. � ` n.. �, � 0. , a'. < M �: �� bi . `i i .j .ksY Existin 9: � � k. . 'n �Flush:Statio _ ... .. '.; , . n� zso� � , ; .; , .-• - _-.. .�... ,..�: _. . _ . . � . .. � .. . .. . . . . ._ � ��� ,W G�� _ , . .. , . . ..fo^'./ �\ , > _ o � .. � IY a z f'���� ' . "' __ . ,_ "' Rebuild Ezisting Flush Station � . ._ .. ., , „ _ - ^ " . ' . �: � �. .. . �.. :.:.: ,. , ._. ��. � . ,-.. . ...-�.- ..`.�..`� .`. ..- ... „��. ":" y<' LEGEND � ` 'L k W h�n ton ; Abandon Existing � e as g V�' „`Y Lakeline in Place —�-- Existing 8" Sewer Line , r --------------- Existing Side Sewer � � � � S� �1 � Existing Cleanouts � ' 1,5+00 � � � � , �� � _ � —�— New Sewer Line � �` > �� � °� ..�,�..w,��._�.. �� � �.,,� . r , - New Side Sewer � ` � •� 3 p ., . i `�: e -------• Approximate Inner Harbor Line � , � a s it i �`. \ t' { z ' Y - � .. �n z v � d ✓ <t �"� ; x �'fi :� �3�".sa�* ,�, + 'Z�ir' . �c.' .�� a ` �:. `\ �'. , �\ .,- \ $ .�,,.z \ �:. � i +� . h r , � \s - Maintenance Manhole "---*�---•-_'= �°:t nPi o r vate Pro . -'~---: �=bs� ert e ; � ,r,� P Y 'a- < �`�. � � �.� 3 Total � �. < ) � . ,, ��v � a a � _ � y - � > ` =-�-0 1 " F. S +"1 • 3 i '` 5 R f y 4 � S � h ::ri#' � � `�..� � �s �e;� �( , 'V. ` � . � ` "� � o�'' `Z 34"�=�` � �`�-. Ste � ` µrt ;:W* " j s ( s x� �\ ZS+OO �" •.,� � � , `N� s � ':e .. x �3 � '� � � �a \ - .,`.,, . � % :Vl �' Z s `>� � � e :.. � w? } t ' + s . -�"�is `� �.� � -'�:" � C.�; r. � ".� . . �, n , ,s.� N.�� � '<a�@ �� �. \ �. ,` - � �" ,�. S� .' "�'.. T � p a x h'ash s j� '';- 3oto0 r , � j � aau� v:` ; _ � " > � � '9f� . � `" �.... ` _ ; . � , - � . ° � �. .� , � Z : , e�i.°' ' "` 3 � � � � .... � � ,.: �^� ''�"=- -. . , . . .. . � . , ,,. . , . . , . . ... . ... , . . , , � , t .. . ,. .. .. . . . . . . �."ifL.. ..� . r' � .: . . " ' "'. '��.�`,,' ':;!; , Tetra Tech/ Clty of RentOn KCM, Inc. ALTERNATIVE S13 1997FirstAvenue KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT ' Seattle, Washington 98101 1 r - �i � /w 1 � � � `�� :� ' �i � i� , i � •1 i ;II I � � u��s ;�: .. :� >°"�>.. y.: �� ��� ��� ��s �,§ �� � ��y���� � ���„ "�� � �£< x�. � � d. z�.'; It � bG�f.��� C �i" . a:, � � .. �,�•k'�,� �hr h . ".� �#�..� ,� � ���..,�- � � �� ���� .`.�o'�`,.� �� � ..�^ 9^,,,,. � .., ! fj% � � �r �`� , ,�Y'��' �as�x ' � �.. lr i - � _ • �,�r �'�:� '��,'' ..�. ' �1 ' ' ' , us a ion �:zeo3� • With New .A,�': ,� x. •�. �: � � . . �» � n t I new sa Lift Station w ,. �� 8" open cut �./ � �° ravit sewe 9 Y � �• f,-, r< ,�°:.'� � ::� ,': � ;`'i' f ..'li •; 2.. ..i �: � .Z; ,'�` r -' Bore & Jack Crossm a 9 , ;� . ; of Burlington Northern , ,s. Railroad \"•% - vY". �e}-��. f ... x /,?. . ,ti'.',a < . .. . _ n�C�i .. ., . x . ., e � . 1 ' a � � 2 � @ t � � a a E N e � �l ^fL (' ._.� .: l .`n . r F... r; a r "` ' Connect New Force t �� Main to Existing � � � > Gravity Sewer in t N Lake Washington Boulevard � ._ . . . � .,. �„>�,�. , or���� .>...._.__ 1 ' 1 � 1 , � � � N O C7 � � e --� " z LEGEND , �`" ` ' Abanclon Existing � — -: Lakeline in Place ; ,; ` —�--- Existing 8" Sewer Line : �� , ; � ��.� =-..,� Instau Grinder � 3 --------- Existing Side Sewer �° Pump Station � �i= '. at each Side Sewer � Existing Cleanouts �,_u j ; LocaUon (14 total) f' �y ° .� S� � ` � �— New Gravity Sewer Line � 15+00 - Re-Route New 1 1/2 `' �::; Pressure Side ��,% F � �� —�-- New Force Main �, ° s �, ; Sewers to New ,� �; a ; � � . , ''�.. Force Main by �4 �'� ; � � ; �Y� ,�'" � ``."; � Dire.ctional Drilling ------�-,----- ew Sewer - N Side � .• : ; t f ,� + f � , '� ° '� or Open Cutting � � ` �� '� � � = e� -------- Approximate Inner Harbor Line � , ' L� � ; •�`�' � � �„ ����' ; 20+ o : �''-,� a New Grinder Pump Station � , �t � ::t ��,r � .:�7 ` �',� s i , ;,�. _ ! �: t�! � , s � t \ 3 3 9 �4 e F � `y� 9 �- Y�y , ,,s� y i lake WasNin tom' ; T, . ,, ,, ..::. .; .. : � � ` � , _ � �`.. 9 . < , . . „ �': .. _ -�__ . - .. �\ ; " ...:.. , . .:...-. ,. -�.-�'�.��... ,.� .., .n v <Y.� �- . '' . . R .. .. . Y .r . tt .... � ... .. ... . ., e .. . � . ..: . .. . � � . e r�. ¢ 4"S `� i. i < k ��� C�. �: ' � . _ F f ��3 , y a �. �� & � ` y 9 �� `.1 V� Install New 3 ~` '` y � � �; �{�'' a .� , Open Cut ' , 4 Pressure Sewer s �`' , , ,. ,� , :: .e . '� �''Z "�f �. : ms .r'y t \ �`: . ., w z_ ;��. z v� � 6 � S+ w `' s ._ � v �` ,��� . ?N H , � �' Sta '�;: ,N 3: ;� �.� � � + > �: 25 00`. `,`;' �a ,. > . ,,, � ,, �, . . , ,, , ; „ . .. : � , .4 , a „ .,, Z, r , ,.,: � . . .. � , . , . . :. , ... . � . . . . . .,,,. � -; . . : ,s, � � ,: .,,,. , , '\. `�..'. � 3 �'�.:. , e'M W � f• � "6,i` r .� :,� . ; : : ., . :: , : ; ., : .. ,.: ;� � :.r „ , ��, , .. ��: `:�� . .:�. : �. . �, , , . . �., � .� .. . . �,. . ., . .. : _ . -.. .-. , �,.��.. • . --� , H ,��. , .- -.: ::^. - �; . , ,,, ��'�, ,�\ � a , , � .:x . N. ' �`` <K ` � �.. `'`: , ; . , . .. 4 ..y.Y•. �_A; ,� ,.'; i e :Z"' � •'M Y w..� ..a:: � „�' ,�. , . , � . , .r .. .� . .. . . . . . ..... ���` ' � . �.. �;i.' , . � . � �. �.,... � '�F y.��. . . .. ;-� .'-.�.'. > ..... ...... . .. .a ,a e-. . . ...'. .....,.. . '�.: � . .. � .. . . '..' n .... . .. ..... . . ... nb t�.. .. . .. ..... .:�:: i �a .. .. �x>..> 0.1. .....Y! , e �-:; Qa. . � �. i r.._�. r . .x ".. �. . ,... .. : L:.,� -. � . •. .�...- �n....,.:v� i.-'. .r;.K.48 ,,.�-:,a�i:S�.�.. � .ff _�\� ,.. .. . .. . , . . �-.�:�� �"g ':� e . . _:. w,,,. -, - Sta _.. ... _ __ _ _ . � H �� ' -. �... , .s r :, a .. ..: .�. 5. R� ., ., .. .« .. , , . �. , ';. < ,. .:: ... .< _ � , ., . . ,. .,. .. �, I` .. 0. � z6 �-. �; sao� ''.-�, 30+00 f : � ash�n > �' , �°�- / ; . < � 9 �� to r.. , t , � ar +�, s �.. � !., .� . 1 ,r , Y i �y / "� Y !^ •d \ � `' V�d Y � •�� Q 5 v1 Y - � ro � . . . .n .. <a .:a., a.e ..x....e .,..:,mr.,A�... .< .>..e . ......0 _.,a.r., .".Ei.... ae� ���_ � e �. ,. .. . " . . NOTES: 1. Homes and docks on map based on 1984 survey by Horton Dennis Associates. 2. Telemetry for monitoring by City included in cost. Tetra Tech/ City of Renton KCM, 1nc. ALTERNATIVE S15 1917FirstAvenue KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT Seattle, Washington 98109 1 /. / k � `J. � % /' � Sta k � '` 7 0+00 �I,: ,. �% �x g a / �r � � : � � ,�� � � Y,.�' %i:` � � � � i� ¢"x q � t�` /►_- x �} R / > � .�� � ,� < r` � � R . Srk �` / t 3 i^�5�� �' / , ',Y ;« a � � �a,, �, /� � � . t " x �. � � � : : / Sta ` , '� ` �� }., � � � � � ` $+QO �� � 1 � � � �:. � "'I � .�� lt '< � , z �, / :"1� � �� _ ' v N r, /y �\ ` �ou��`�u",sY'! P�� �� r �c :� �_ 3 3 � ; a '� ' L�GEND Abandon Existmg �"` " Lakeline in Place From Station --�'�— Existing 8" Sewer Line ', �-`�; ; ' ° 0+00 to Station 28+00 .__._._______ , ,� Existing Side Sewer ��� � ��� T � e . ; �;` Existing Cleanouts �; , � Sta { < _ . � ' �� 15+00 , ; > ,: ' --'t��-- New Open Cut Gravity Sewer Line ,;- � � �.,,� � . �� k i. Y �� ��,x � ; ; � � --�— New Trenchless Gravity Sewer Line ^� � � � ' 3 4 y �- �+ ` > �` s;^ t, � -0,b "`�:' �. > z. � � .�......_�,�.,»...�,,..,. :� : ! <� {�: R �� � New Side Sewer .b �.^ � !! �; � a f( � $ '�.�.` \'\ . A:: ,.� i. � y :� s",f i ..Y: I . .� „ � r � s �.,;: -------- Approximate Inner Harbor Line n� . � �'"� i� <:�� t �. . �,` � „S� � . . . � ., .� . ... 3 . . ' ' �� � Install New 8° , ,`, � : ��. S �. �`o y f .-yS Abandon ExisUng '� `�" h > s° Gravity Sewer Flush Station ' f `� '�H a s�" Between Station ieo� � ��� � � 0+00 and.Station 28+00 ' � a �� Yx� �� r �' a 'F �. / ` � s a ��.� ;4 � j�' � h& $ a�' 'Z ``,ex a ° � fMJ: � � � � F e ; � � . � `.t � � ? i :? s; f �J� ,� � i ._ , � . �`+, z ; . . ., a �. . x , . . " .> . . . . .. . , . , , . . . . ,. :'. .c ., .a � � I � U b (h .. .. a , . .a.4 _ .. � . .. �,.r .., ... .<,< o, _ < .,..�u.. . _. � mY ;-': .:r ���., ,-". J . .: ;�. �t� ��� �'� �,� : �. ; , -�-� -- �- New Force Main �. ` ; , ''�. ` ; z , `� �„ ; Lake Washingfon ` ` :'� Y �N' . � � ''-= . � , Direct Flow Sta : ` in the Existing X`\� New Lift Station Lakeline From � . 25+00 Invert Elevation t,, ;�� : of New 8" '' Station 34+00 South �,' Sewer 8.0 to New Lift StaUon Y„ fitr � � ���."�, .e.� � k � � `_� . � � S� 30+00 �S�I�h�f � .t��K � � � 3CM ."x C � �� �\ � �.. <t Q h 'a 3 v,: ��.1 " �. �B� ' �� R 1j--..,,� , � �.o , La a k \ � , : �. -,: �^ ,^ � 9 \ �`^�. ` __ .' r . . ., .... . :. a�.. , e . ... , , . . . « . a. . n .. . :� , � �,"'+` Connect New Force Main to Existing Gravity Sewer in Lake Washinqton Boulevard Bore 8� Jack Crossing of Burlington Northern Railroad NOTES: 1. Homes and docks on map based on 1984 survey by Horton Dennis Associates. Tetra Tech/ City of Renton KCM, Inc. ALTERNATiVE S21. 1917FirstAvenue KENNYDALE LAKEFRONT SEWER REP�ACEMENT PROJECT Seattle, Washington 98101 ` ._ . ,.. . � , i ; - <',` ' � �Sta `r:; ! N y 25+00 \ > , • i � ` �� , �` -.� � • ` • Abandon ExisUng ti �� \ �°, • �. � ' �, .� --- ` New 6" Gravit Sewer Lakeline in Place Y � � � �-�..._ ;� Installed Beyond Existing ` 4 � � Docks at 0.4% Slope �•.&�ryin9 fo �"� �"� � ; "; �: Sta � ,,,� n � :', aao,,: � 30+00 :,� s- p�he� �'RH�„, � � y�T'�. ~` '`- - Extend Existin � � / x � g� 9 : Ca,� � ..�;;�,y , y= � Side Sewers to 8s�,�, � r�� � �.�,� � 35+oU �° New Gravity Line � ;, ash,�k � 1= athho � �—,:` �- "n � (14 Total ) � ' ��? ej�a � � Kennydale ' � ~ � _ � � Beach Park �x �� � x .; '�.,.,, � ' � �:,, Lake Washrngton ° Maintenance �Manhole , J � -t: at Kennydale Beach � , , - `'`� � � � i� Sta ''� j '� @ � n 40+00 `� . v :. a �����yt � � � e . , 3�;3 .y� d'� :`w�~� � �' 8 �\..-: � umet#Ave-` r` �,; '��i�� � - B £ ti.` y ��� �; y • ��, . / a- .`Z } �1 4� �` '�,� � a a 3 � :. � .l `�•�, i ` . N �� t ExisUng L"ift •.,,� � � � Stat�on. LEGEND ' \n'\ � � .% � `., (Sta'�47+35); ��`'' i � ° � �� y ' � ~ � a5 00 --�--- Existing 8" Sewer Line �� A � e� � V x ,? , ________.____ Existing Side Sewer ' � � �1 , �,, �• Existing Cieanouts � _ -�- New Sewer Line z � ;.� � -���--�-•�----�, New Side Sewer � � �, � � � � � � �' New Lift Station ` � , ; Inve�t Elevation � � .� -----•-- Approximate Inner Harbor Line � ,' = of New 6" Sewer - y� ; `�� . .. � . . . _ . _ ,. , � . . , . , . . AnnrnY _R fl' -�. �'�;: � .r/ , � 100' f` ✓!' � 5- T a s '.� r x` � ', NOTES: 1. Homes and docks on map based on 1984 survey by Horton Dennis Associates. 2. New 6-inch gravity sewe� has a minimum of 2 feet of cover. Tefra Tech/ City of Renton KCM, Inc. ALTERNATIVE N1 1997FirstAvenue KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT Seattle, Washington 98101 ' 1 1 1 ' , 1 ' 1 ' ' ' ' 1 ' ' � s 1 z c � a v: m , � ' ,�� . , . . . NOTES: 1. Homes and docks on map based on 1984 survey by Horton Dennis Associates. 2. Cost estimate based on restraining a total of 25 pipe joints, approximately 25% of the tatal number of joints between Station 27+50 and the lift station. Tetra Tech/ City of Renton KCM, Inc. ALTERNATlVE N3 1917FirsfAvenue KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT Seattle, Washington 98101 N Existing Lakeline to Remain in Service; Provide Joint Restraint at Pipe Joints in Jeopardy of Separating ° " ° �' ` Dock Cleanouts at Two Locations Accessible to City Jetting Equipment -,., : ' �. L'ake Washington �., ��`�.. 5ta, `: `"' `� 4U+00 .,,,,,,;;. _ ,� s \ �- , � \ : � `` , �° �,� � E�i ng Llft ..,� g � � Station % � �' � (Sta"47+35) ^�" . f - ��, � ' ``"- sta � � � 45+00 : <:;f . an�" 4,.. � ; : .'� �' � 3 r� 's� �, . � 4 �A��7�Y � & . ,. -k S •' � � � �� b �� x ��T a -��y� .> r 7: ` z N,� - �s� . � Y � yi � Ay 3 ` � s b�? �� "S: Y,. �Y � 3 R ; �' � W � �,\ � 4 .. R 9 '`'i � 1 ., . � v <'S . .. .. .. ,.. . . _ . >a..,... 'aid_ .. . d_ "\ .. _ . e 1 ' 1 1 i� l ' ' ' ' 1 1 ' t ' � � � z a 0 N O M � ' N ' `�,. �:. `--. \ ;: :�., � � sc� �.: � � � 5+00 �. ; N _ g � ?\ ;`� , -� < Abandon Existmg �' � ' \ : • ' 4 � � - A �� Lakeline in Place T = �---�.. � -;� " Side Sewers Re-Routed to ���/i �� � 9` =3ta `� New Gravity Main by n j"` � Directionai Driiling or � `�. 'y,9ton � Y CG= „o, , �-�;� 30+00 �`' '' � Pi e Rammin From Lake ' ' > , �. �Mo�;h�� y� , �.,, `P 9 ri <ak �' , �`<? ° '\ % � `'�• > ``. , Sta � ' Q �'�'a e �F a'"y^ �'�'-�.,,, � 35+OQ �'" , sh,h9t'` athhoU �''� l' —..,�_`1 �•, A` °?@�� � k,: �'`.'Kennydale ' ``�- d T , � -8each. Rark � -� 'ry '� '''�' ar a � `� � Open Cut 8° Gravity T y 3 � '�, Cake Washington , Sewer in Kennydale � Y 1 �>'��\ ` � � ''�' g� Beach Park , �y ��r��'� '� ` b' �� L i . t \ Sta � �. b �. 2 ._ �� , M . ` ,.�.r 9 d q s ' s ��`:: ��� , � 4�;��� �� { - �..t�.s.r Y: i�ks. 7 vF k.> \` �.< G � �R:s . } .4.a d�.Ys .� u H. .t �. rnett Ave"> s '`� �A�� a �.a Bu `�:,..�>�, ,�i �� `-� .. . . . . �E f Z '%,'f >., � . w� f.�" �'�6 `w'. �� 4. ( t .\ Z , 3 .?- � f c � � � - � t�' i� �� �,• � F� � � 'r � � 4" b ')b ! � �� "..,� `.. N �,^xw�, : y ' �ew Exis:ing Lift k V ! r�. X. {.� /� 4 z,. �'(ylf�b��di�� G � i�.� �� �K7t���• ` ^��. LEGEND = F + � (Sta:'47+35}; a � �> � � � � c♦� 9 J {p --�-- Existing 8" Sewer Line a � _ ,� as+oo ------------ Existin Side Sewer ��' v �� a `" � g k ; New 8' Gravity Mam m = � � � s ° Existin Cleanouts Microtunneled 24 Y p< a°� � , 9 Casing Pipe at - , � v ` g , 0 4% Slope ' z. \ � , �� '' --�-- New Sewer Line , 3 � k w : K,� �� r� �, � �yy � ��'v � s , �. � ��' �\ s�s �ti . �-��--«��•«��--� New Side Sewer ` , ,�m � � °�� $°=a � . �Y= ����gM$r�y � -------- Approximate inner Harbor l.ine , , , , �' �" , „ r . �- , � �-�,�, � . , � �� .� ,° � y � < <- _ ;_. _ ' _ . . . ,. . . _ ., NOTES: 1. Homes and docks on map based on 1984 survey by Horton Dennis Associates. 2. Cost of new sewer main would be reduced if instalied by directional drilling, however, flat slope of the line may make this option unfeasibie. Tetra Tech/ C11y Of RBntOt1 KCM, lnc. ALTERNATIVE N6 9917FirstAvenue KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT Seattle, Washington 98901 � ' ' � ' , 1 , , ' � � ' , � ' � L � 'O O W 'N ' , .:: .,,,� . , .;�:: ,`. \ '; '' ''"- ; � .� sca . . . ` 25+00 = Side Sewers Re-Routed `� N h � ' to Microtunneled Gravity `- Main by Directional Drilling � Abandon ExisUng �5� a, `�` or Pipe Ramming From the Lake ' Lakeline m Place ' � ; � - K � �4 Il <.:§ev�//� �.4 u � �"�. �'�•.;:.. . . � 9fa � --� : r " t��North `p��� a aeo,: �� � '`.. ��� �yz. "»�'�,e'!! fi ��/ y , RR � �f '�.. � ,,`; �8 � ��a 4 4 : . '} ~���,� `�� z 30+OOit �"�-�•., c`^ \ f JM. � �s �� e- 4;��aLe... . N atde�>c� A S 4 ` � � _>- g $ r �a - � 4 �`y$ath �,�r, , �',�, ,,�\ .-� '`�:_` 35+G0 �. , $' � .Sh�� >� h°Us�' -- .= .� 4 ,.. a `�p� ` � ��C? e g9t�n= �� ,; `� � a ``^. ' . �'' ak '° ' e�l� � -` a � _ , k &� n;: F y Kennydale _ ,� �,' r ih . -,Ta z e a� � �f � s `V' :Beach t?ark`- � £ � ' ",� 4 s fy "> R e x.>�� � a� ` a� ,.�\ ` .; R.. x z. �� � ? n ' a � 3 -:'� � Lake Wash�nry t0/I '� � d � � r � ��ti\� :g ~' II c t¢ r s�-� xe, �° '� `y s 1 p� �� � ` - > i `� g� New 8" Gravity Main � a � _�''�,, .;: � � g s: �'' Sta� ''� � in Microtunneled 24" x'a� '#� n- �� 40+00 `�. � �. � ' ; Casing Pipe in ; =" �� � X� �.. � � � `� fx e -y. � 3 ° ° Lake Washington Boulevard Burnett Ave.. - � � , � � 'Z ' � 4�` # ��'., ` , z ' F d � � ; at 0 4% Slope W � �� �` � � �� � �� �, � ' �. s r�. � �_ e = ."z _'i Y a.�� N $ I �'�k� 3 i. e ,� a. �'� s f a fi �:. ��; Exis�in ` Lif�'. x.s.:. ,a � i x�E � z .;s9 �� ���-; Stat on � '`'�. ��LEGEND , �.�� ra � (Sta 47+35j '�`'' , , �r �, ,-a� `� � "�s . � � ` sta ; --�--- Existing 8" Sewer Line ' y � ' $ �� � � s, �45+00 ¢ „ y A; i% ---------------- Existing Side Sewer ' < y � � � d '`r�� '`� � i �� ;�. g � Existing Cleanouts " � a---£---- New Sewer Line ? f� � -�.-•�-�---4n-�--� New Side Sewer u� F �ti � � �� : � , , \ �. , _ „ -------- Approximate Inner Harbor Line , , , , F_„ . °= ,� _� 400 , ' : •°. � � NOTES: 1. Homes and docks on map tiased on 1984 suryey by Horton Dennis Associates: 2. New side.sewers would: need to be.installed at approximately 1% siope or less to match grade of new sewer line in Lake Washington Boulevard. Tetra Tech/ City of Renton KCM, lnc. ALTERNATIVE N8 9917FirstAvenue KENNYDALE LAKEFRONT SEWER REPLACEMENT PROJECT Seattle, Washington 98101 , 1 ' , ' , ' ' ' ' ' � � , �1 , ' � APPENDIX B. ALTERNATIVE COST ESTIMATES ' � � � � � � � � � � � � � � � � � � � PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Pro'ect Alternative N1 PROJ. NO: 2830120 CLIENT : Cit of Renton BY: JWL DATE: 2-Au -99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Northend Alternative N1 New Gravity Sewer in the Lake 1 MOBILIZATION (8%) LS 8% $67,800 2 6" SEWER PIPE - 2 TO 4 FEET OF COVER 880 LF $175 $154,000 3 6" SEWER PIPE - 4 TO 8 FEET OF COVER 400 LF $225 $90,000 4 6" SIDE SEWER PIPE 420 LF $150 $63,000 5 CONNECT SIDE SEWER TO MAIN 14 EA $4,000 $56,000 6 NEW LIFT STATION (Incoming IE=-6.0) 1 EA $450,000 $450,000 7 MAtNTENANCE MANHOLE 1 EA $35,000 $35,000 SUBTOTAL $916,000 CONTINGENCY 25.0°/a $229,000 SUBTOTAL $1,145,000 SALES TAX 8.6% $98,000 CONSTRUCTION COST $1,243,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0% $373,000 TOTAL ESTIMATED PROJECT COST $1,616,000 PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Pro'ect Alternative N3 PROJ. NO: 2830120 , CLIENT : Cit of Renton BY: JWL DATE: 2-Au -99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Northend �Alternative N3 Existing Lakeline to Remain; Restrain Joints; Remove Sags; Add Access 1 MOBILIZATION (8°/a) LS 8°/a $28,600 2 8" SEWER PIPE - 2 TO 4 FEET OF COVER 600 LF $300 $180,000 3 PIPE JOINT RESTRAINTS 25 EA $3,000 $75,000 4 6" SIDE SEWER PIPE . 180 LF $150 $27,000 5 CONNECT SIDE SEWER TO MAIN 6 EA $4,000 $24,000 6 DOCK CLEANOUT 2 EA $8,000 $16,000 7 MAINTENANCE MANHOLE 1 EA $35,000 $35,000 SUBTOTAL $386,000 CONTING�,ENCY 25.0% $97,000 SUBTOTAL $483,000 SALES TAX 8.6% $42,000 � CONSTRUCTION COST $525,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0% $158,000 TOTAL ESTIMATED PROJECT COST $683,000 � � � � � � � � � � � � � O � � � � � � � � ' � � � � � � � � � � � � � � � PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Pro'ect Alternative N6 PROJ. NO: 2830120 CLIENT : Cit of Renton BY: JWL DATE: 2-Au -99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Northend Alternative N6 New Onshore Gravity Sewer 1 MOBILIZATION (8%) LS 8% $63,600 2 8" MICROTUNNELED SEWER PIPE W/ 24" CASING 1240 LF $350 $434,000 3 8" SEWER PIPE - 5 TO 10 FEET DEEP 340 LF $80 $27,200 4 MANHOLES 6 EA $3,800 $22,800 5 6" TRENCHLESS SIDE SEWER PIPE 900 LF $150 $135,000 6 CONNECT TO EXISTING SIDE SEWER 14 EA $2,000 $28,000 7 CONNECT SIDE SEWER TO MAIN 14 EA $4,000 $56,000 8 RESTORE LANDSCAPING / PATIO / BULKHEAD 14 EA $6,000 $84,000 9 ASPHALT OVERLAY, CLASS B 1,400 SY $6.00 $8,400 SUBTOTAL $859,000 CONTINGENCY 25.0% $215,000 SUBTOTAL $1,074,000 SALES TAX 8.6% $92,000 CONSTRUCTION COST $1,166,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0% $350,000 TOTAL ESTIMATED PROJECT COST $1,516,000 PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Pro�ect Alternative N8 PROJ. NO: 2830120 CLIENT : Cit of Renton BY: JWL DATE: 2-Au -99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Northend Alternative N8 New Microtunneled Gravity Sewer in Lake Washington Boulevard 1 MOBILIZATION (8°/a) LS 8% $135,900 2 8" MICROTUNNELED SEWER PIPE W/ 24" CASING 2000 LF $500 $1,000,000 3 MANHOLES 5 EA $3,800 $19,000 4 6" TRENCHLESS SIDE SEWER PIPE 2,800 LF $150 $420,000 5 CONNECT TO EXISTING SIDE SEWER 17 EA $2,000 $34,000 6 CONNECT SIDE SEWER TO MAIN 17 EA $7,000 $119,000 7 RESTORE LANDSCAPING / PATIO / BULKHEAD 17 EA $6,000 $102,000 8 ASPHALT PAVEMENT PATCH 700 SY $7.50 $5,250 SUBTOTAL $1,835,000 SALES TAX 8.6% $158,000 SUBTOTAL $1,993,000 CONTINGENCY 25.0% $498,000 CONSTRUCTION COST $2,491,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0°/a $747,000 TOTAL ESTIMATED PROJECT COST $3,238,000 � � � � � � � � � � � � � � � � � � � � � � ' � � � � � � � � � � � � � � � PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Pro'ect Alternative N13 PROJ. NO: 2830120 CLIENT : Cit of Renton BY: JWL DATE: 2-Au -99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Northend Alternative N13 New Gravity Flush Line in the Lake 1 MOBILIZATION (8%) LS 8% $80,500 2 8" SEWER PIPE - 2 TO 4 FEET OF COVER 880 LF $200 $176,000 3 8" SEWER PIPE - 4 TO 8 FEET OF COVER 1,020 LF $250 $255,000 4 6" SIDE SEWER PIPE 540 LF $150 $81,000 5 CONNECT SIDE SEWER TO MAIN 17 EA $4,000 $68,000 6 NEW LIFT STATION (Incoming IE=-2.0) 1 EA $375,000 $375,000 7 DOCK CLEANOUT 2 EA $8,000 $16,000 8 MAINTENANCE MANHOLE 1 EA $35,000 $35,000 SUBTOTAL $1,087,000 CONTINGENCY 25.0% $272,000 SUBTOTAL $1,359,000 SALES TAX 8.6°/a $117,000 CONSTRUCTION COST $1,476,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0°/a $443,000 TOTAL ESTIMATED PROJECT COST $1,919,000 PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Pro'ect Alternative N 15 PROJ. NO: 2830120 CLIENT : Cit of Renton BY: JWL DATE: 2-Au -99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Northend Alternative N15 New Grinder Pump Stations 1 MOBILIZATION (8%) LS 8% $46,600 2 SLIPLINED 3" PRESSURE SEWER 2235 LF $55 $122,925 3 SLIPLINED 1-1/2"" PRESSURE SEWER 600 LF $35 $21,000 4 GRINDER PUMP STATION 18 EA $10,000 $180,000 5 CONNECT SIDE SEWER TO MAIN 18 EA $4,000 $72,000 6 TELEMETRY 18 EA $2,000 $36,000 7 RESTORE LANDSCAPING / PATIO / BULKHEAD 18 EA $6,000 $108,000 8 DOCK CLEANOUT 1 EA $8,000 $8,000 9 MAINTENANCE MANHOLE 1 EA $35,000 $35,000 SUBTOTAL $630,000 CONTINGENCY 25.0% $158,000 SUBTOTAL $788,000 SALES TAX 8.6% $68,000 CONSTRUCTION COST $856,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0% $257,000 TOTAL ESTIMATED PROJECT COST $1,113,000 � � � ' � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Pro'ect Alternative N15-a PROJ. NO: 2830120 CLIENT : Cit of Renton BY: JWL DATE: 2-Au -99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Northend Alternative N15-a New Onshore Pressure Sewer System 1 MOBILIZATION (8%) LS 8% $37,000 2 3" PRESSURE SEWER 1,580 LF $30 $47,400 3 1-1/2" TRENCHLESS PRESSURE SIDE SEWER 900 LF $50 $45,000 4 CONNECT SIDE SEWER TO MAIN 14 EA $2,500 $35,000 5 CONNECT TO EXISTING SIDE SEWER 14 EA $2,500 $35,000 6 GRINDER PUMP STATION 14 EA $10,000 $140,000 7 TELEMETRY 14 EA $2,000 $28,000 8 RESTORE LANDSCAPING / PATIO / BULKHEAD 22 EA $6,000 $132,000 SUBTOTAL $499,000 CONTINGENCY 25.0% $125,000 SUBTOTAL $624,000 SALES TAX 8.6% $54,000 CONSTRUCTION COST $678,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0% $203,000 TOTAL ESTIMATED PROJECT COST $881,000 PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Pro'ect Alternative S3 PROJ. NO: 2830120 CLIENT : Cit of Renton BY: JWL DATE: 2-Au -99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Southend Alternative S3 Existing Lakeline to Remain; Restrain Joints; Remove Sags; Add Access 1 MOBILIZATION (8%) LS 8% $18,700 2 8" SEWER PIPE - 5 TO 10 FEET DEEP 250 LF $80 $20,000 3 PIPE JOINT RESTRAINTS 30 EA $3,000 $90,000 4 6" SIDE SEWER 50 LF $45 $2,250 5 CONNECT SIDE SEWER TO MAIN 1 EA $4,000 $4,000 6 MAINTENANCE MANHOLE 3 EA $35,000 $105,000 7 RESTORE LANDSCAPING / PATIO / BULKHEAD 2 EA $6,000 $12,000 SUBTOTAL $252,000 CONTINGENCY 25.0% $63,000 SUBTOTAL $315,000 SALES TAX 8.6% $27,000 CONSTRUCTION COST $342,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0% $103,000 TOTAL ESTIMATED PROJECT COST $445,000 � � � � r � � � � �■ � ■� � � � r � � � � � � � � � � � � � � � � � � � � � � PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Pro'ect Alternative S6 PROJ. NO: 2830120 CLIENT : Cit of Renton BY: JWL DATE: 2-Au -99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Southend Alternative S6 New Onshore Gravity Sewer 1 MOBILIZATION (8%) LS 8% $79,200 2 8" SEWER PIPE - 10 TO 15 FEET DEEP 200 LF $96 $19,200 3 8" SEWER PIPE - 15 TO 20 FEET DEEP 1,445 LF $128 $184,960 4 6" SIDE SEWER 2,060 LF $75 $154,500 5 CONNECT SIDE SEWER TO MAIN 16 EA $4,000 $64,000 6 CONNECT TO EXISTING SIDE SEWER 17 EA $2,500 $42,500 7 3" PRESSURE SEWER 420 LF $30 $12,600 8 GRINDER PUMP STATION 2 EA $10,000 $20,000 9 NEW LIFT STATION (Incoming IE=8.0) 1 EA $300,000 $300,000 10 6" FORCE MAIN 100 LF $75 $7,500 11 BORED AND JACKED RAILROAD CROSSING 100 LF $225 $22,500 12 RESTORE LANDSCAPING / PATIO / BULKHEAD 27 EA $6,000 $162,000 SUBTOTAL $1,069,000 CONTINGENCY 25.0% $267,000 SUBTOTAL $1,336,000 SALES TAX 8.6% $115,000 CONSTRUCTION COST $1,451,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0°/a $435,000 TOTAL ESTIMATED PROJECT COST $1,886,000 PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Pro�ect Alternative S13 PROJ. NO: 2830120 CLIENT : Cit of Renton BY: JWL DATE: 2-Au -99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Southend Alternative S13 New Gravity Flush Line in the Lake 1 MOBILIZATION (8%) LS 8% $86,900 2 8" SEWER PIPE - 2 TO 4 FEET OF COVER 300 LF $200 $60,000 3 8" SEWER PIPE - 4 TO 8 FEET OF COVER 2,100 LF $250 $525,000 4 6" SIDE SEWER PIPE 1,240 LF $150 $186,000 5 CONNECT SIDE SEWER TO MAIN 15 EA $4,000 $60,000 6 NEW FLUSH STATION - SUBMERSIBLE PUMP 1 EA $150,000 $150,000 7 MAINTENANCE MANHOLE 3 EA $35,000 $105,000 SUBTOTAL $1,173,000 CONTINGENCY 25.0% $293,000 SUBTOTAL $1,466,000 SALES TAX 8.6% $126,000 CONSTRUCTION COST $1,592,000 � ENG., ADMIN. & CONSTRUCTION MGMT 30.0% $478,000 TOTAL ESTIMATED PROJECT COST $2,070,000 � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � � PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Pro'ect � Alternative S15 PROJ. NO: 2830120 CLIENT : Cit of Renton BY: JWL DATE: 2-Au -99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Southend Alternative S15 New Onshore Pressure Sewer System 1 MOBILIZATION (8%) LS 8% $65,600 2 8" SEWER PIPE - 5 TO 10 FEET DEEP 370 LF $80 $29,600 3 3" PRESSURE SEWER 1,700 LF $30 $51,000 4 1-1/2" TRENCHLESS PRESSURE SIDE SEWER 2,060 LF $50 $103,000 5 CONNECT SIDE SEWER TO MAIN 15 EA $2,500 $37,500 6 CONNECT TO EXISTING SIDE SEWER 15 EA $2,500 $37,500 7 GRINDER PUMP STATION 15 EA $10,000 $150,000 8 NEW LIFT STATION (Incoming IE=8.0) 1 EA $300,000 $300,000 9 6" FORCE MAIN 100 LF $75 $7,500 10 BORED AND JACKED RAILROAD CROSSING 100 LF $225 $22,500 11 RESTORE LANDSCAPING / PATIO / BULKHEAD 27 EA $3,000 $81,000 SUBTOTAL $885,000 CONTINGENCY 25.0% $221,000 SUBTOTAL $1,106,000 SALES TAX 8.6% $95,000 CONSTRUCTION COST $1,201,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0% $360,000 TOTAL ESTIMATED PROJECT COST $1,561,000 PROJECT COST ESTIMATE KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Pro'ect Alternative S21 PROJ. NO: 2830120 CLIENT : Cit of Renton BY: JWL DATE: 2-Au -99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Southend Alternative S21 New Onshore Gravity Sewer Sta 0+00 to Sta 28+00 1 MOBILIZATION (8%) LS 8% $98,200 2 8" SEWER PIPE - 10 TO 15 FEET DEEP 800 LF $96 $76,800 3 8" MICROTUNNELED SEWER PIPE W/ 24" CASING 1,135 LF $350 $397,250 4 6" SIDE SEWER 2,060 LF $75 $154,500 5 CONNECT SIDE SEWER TO MAIN 16 EA $4,000 $64,000 6 CONNECT TO EXISTING SIDE SEWER 17 EA $2,500 $42,500 7 NEW LIFT STATION (Incoming IE=8.0) 1 EA $300,000 $300,000 8 6" FORCE MAIN 100 LF $75 $7,500 9 BORED AND JACKED RAILROAD CROSSING 100 LF $225 $22,500 10 RESTORE LANDSCAPING / PATIO / BULKHEAD 27 EA $6,000 $162,000 SUBTOTAL $1,325,000 CONTINGENCY 25.0% $331,000 SUBTOTAL $1,656,000 SALES TAX 8.6% $142,000 CONSTRUCTION COST $1,798,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0% $539,000 TOTAL ESTIMATED PROJECT COST $2,337,000 � � � � � � � � � � � � � � � � � � � ' ' , ' ' APPENDIX D. ' ALTERNATIVE PAIR N13/S13 PROJECT COST ESTIMATE ' ' ' ' ' ' r � � � � t � � � r � � � � � � � � �r � � � � � _ � PROJECT COST ESTIMATE TETRA TECH/KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Pro'ect � Alternative Pair N13 & S13 PROJ. NO: 2830120 CLIENT : Cit of Renton BY: JWL DATE: 27-Dec-99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE New Gravity Flush System in the Lake 1 MOBILIZATION (8%) LS 8% $179,400 2 8" LAKELINE 4,735 LF $275 $1,302,125 3 SIDE SEWER CONNECTIONS 36 EA $7,200 $259,200 4 NEW LIFT STATION (Incoming IE=-2.0) 1 EA $375,000 $375,000 5 NEW FLUSH STATION - SUBMERSIBLE PUMP 1 EA $150,000 $150,000 6 DOCK CLEANOUT 2 EA $8,000 $16,000 7 MAINTENANCE MANHOLE 4 EA $35,000 $140,000 SUBTOTAL $2,422,000 CONTINGENCY 25.0% $606,000 SUBTOTAL $3,028,000 SALES TAX 8.6% $260,000 CONSTRUCTION COST $3,288,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0% $908,000 TOTAL ESTIMATED PROJECT COST $4,196,000 CLIENT: r� v ��� � � �-r SUBJECT: t.._T��p�p,.`�ti J�' � 1,,. l�}L�IJN � �S C��� � � �� rw _ 1� C�r��+ \\ 1 ..ti� L..,s� � ,i'.' _. {,..il,��'.� ��";.:•; �� . `.F � PROJECT: (���L � � �? s-Oc� D� � ��;' � �► �� � � � /� � c�./-�1"�, " L �\j V `f `` —J : t . i ; / • f 1 „�, ' 7' �� � � ` " `.'� ' _ ._ i✓F�� . _� � ^�'. ^. , . _ -_ _ . `i,: ./ .,^ � � . �: .. _. r� �� -� . :1 ��� ,�..�.� 4� . . �. l�- . :�..� :� r.. • � _. . ' � ._.- �- ' _- ` �, � ' � y / � ��� �� . `'j ?'� . .. �• �f , � � _ �-,�— �j :� r=' � ; �T `1 _' ^ .1 ,"�. �! .�,, ! ` ." , __ . _ _ ; � � �.�� � �� � �-, �. ��:t , �(�_','•� I ♦ .n �'?" ..:�� � ` ..1�� ti - � --? ? , � 0 p � - �x;,r�v�-'���`: ' �`' S:� '� �`,�L I l�: (r � �'' Q� -�-r� 1 �SZ.1 ` � � � %''�-�"-'--� `. ,,\\ � � OTetra Tech/KCM i � _. �, �'-� JOB N0. � `, �:. -.. . !�: /_.i � . � � �..� !r- BY ---..,._..... .- ---�'` --- � ;c 1Z i �i�1 3 DATE SHEET NO CLIENT: SUBJECT: � � � X GA.-�: t�r I U� -. � �'- PROJECT: � ! � / '� ` • _. �, G. : � � . L.--' v ; �. U',�-L, �?� Gr?`uP:' � C�`�' -.--� �.� --- 1 � . �. �jrl�1t�� � �� , , : ., � �, . 9-� ( �� �z� �y � � �' 8� � � � o ._ C�, ?J�� � , , s -.�2.,,r . � seOsc..l�; �� � � ` �:, � � ,� , '� ' � `,� ��=s'� , N � � �' � G . � �� �- � �, .�. -- `� -� r-," � �. . �..� ._ .- � �. •' :.;-� pS ,� � : - �: � , � �: i% - J.. i�.9 -- . � _ -% - f . _ . . . _-�---- --- - � _ . � -� - : � � �j .�( . _ ..:. - - �-- ---� � ��` _ _ �fi_ -,r- _ _ � � ----- .� -,- . . . ., --� _� �'� . D�.. - �:�':':� W ... -, � � �.�:.: �� ;� ��-- r� i��:�, _� �� �v�-�, c � r^ _f_, .� v ��/y, � ?. .I�. ,/�� ; � �� u��.�. � � ' �-,� ��� ��'� � `t�� �� /fl� � � J '� � N'� `_ � '�! ; �,J �: � �. �7 � � ��:. `' � �,,,_, �-� � Z2- C; '=;/ � � =�.. ,w ' � ti. %--� —' ,�+,� { ,.� �- � , r -7 'ti � � X • . l.? � :`� `_ � � i ; ) �'-� ✓ OTetra Tech/KCM -��-�p !-� ^ _"� � _ 10 � l2, � �� / 3 JOB N0. BY DATE SHEET N0. CUENT: SUB.IECT: {✓J . .. , ,P� � �--� CAJA i 1v� PROJECT: I S� � x �� — � Z.i � �OC7 __ -- �� j �SS��. ����G� ��t -� . I �,1.� �c� b F— �{-- � . , . �- - -- � a' �, ,: `_ _. . _ . - ----i% - _�._ .--� f , \ ;.=: . =�,��. y,� _ ; 8� ;� L � � , : � . ',-` `�.._ —�—' � . � .� _ ; - ,. ' �, _-_. � � � ... . . � `,.- v; . . u f`_,' x c,,��� �.— �; ,.� ���-�� - 1 G �'� ! �, � �) l�'� � , _' -i �`�-; �j � � E--- � , � � � ' ` 1 .' ` �-� :� i � . -, -� � I� (''ti:L�.`.:� - � � �^ ,; � ) � , � l, ; t, ; � '� ,_, •` � . . � � J1�. _.���?v�� � �}:��: �T -� , r a� � +, o .- t,.4�o� �-��o� � 3 � , �oo z-----� � ; O Tetra Tech/KCM ��r-, ��'.,-, .: �,.1 � � � ��,Z C � �? ; JOB N0. HY DATE SHEET N0. '; , ' � r � APPENDIX E. ' ALTERNATIVE PAIR N15A/S15 PROJECT COST ESTIMATE ' C ' ' ' , � ' , ' ' ' ' 1 �� � � � r � � � i � � � � � � r � � � PROJECT COST ESTIMATE TETRA TECH/KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Pro�ect Alternative Pair N15a & S15 PROJ. NO: 2830120 CLIENT : Cit of Renton BY: JWL DATE: 27-Dec-99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE , New Onshore Pressure Sewer System 1 MOBILIZATION (8%) LS 8% $128,700 2 8" SEWER PIPE - 5 TO 10 FEET DEEP 370 LF $112 $41,440 3 3" PRESSURE SEWER 3,280 LF $30 $98,400 4 1-1/2" TRENCHLESS PRESSURE SIDE SEWER 2,960 LF $50 $148,000 5 CONNECT SIDE SEWER TO MAIN 31 EA $2,500 $77,500 6 CONNECT TO EXISTING SIDE SEWER 34 EA $2,500 $85,000 7 GRINDER PUMP STATION 34 EA $15,000 $510,000 8 NEW LIFT STATION (Incoming IE=8.0) 1 EA $300,000 $300,000 9 6" FORCE MAIN 100 LF $75 $7,500 10 BORED AND JACKED RAILROAD CROSSING 100 LF $225 $22,500 11 RESTORE LANDSCAPING / PATIO / BULKHEAD 53 EA $6,000 $318,000 SUBTOTAL $1,737,000 CONTINGENCY 25.0% $434,000 SUBTOTAL $2,171,000 SALES TAX 8.6% $187,000 CONSTRUCTION COST $2,358,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0% $651,000 TOTAL ESTIMATED PROJECT COST $3,009,000 � ' ' r � ' 1 � ' i 1 1 1 1 # C� � ,� APPENDIX F. PERMITTING MATRIX �� � � �r � r � � �■■ � � i � � � r � � � r Table 1 �sriei �ummary ot xen (:onsiderations Alternative Required Permits Permitting- Summary of Permit Considerations Related Costs Alternative N13 & S13 — • Joint Aquatic Resource Permit Cost for ■ This alternative results in the largest amount of aquatic resource Install new 8" diameter flush Application (JARPA) Individual Permit impacts of all alternatives considered because it involves the most line in the lake beyond the - Hydraulic Project Approval $100,000 - in-lake construction. The new lakeline would require burying the existing private docks with (HPA) $200,000 pipe to provide cover. The lift station must be lowered about 8 to flushing capacity. Connection - 404 Pernut, likely: Discharge 10 feet to accommodate the lowered flush line.. Negotiating to the existing side sewers of Dredge and Fill Material, Cost for Shoreline easements for locating new maintenance manholes or cleanouts on would be made near the Individual Pernut Substantial private property may be difficult. lakeshore and extended out to - Section 10 Permit: Work in Development the new lakeline. A new, Navigable Waters Permit -$1,000 • A U.S. Army Corps of Engineers Individual 404 pemut will likely deeper pump station would be - Water Quality Certification be needed, as construction will cause a discharge of dredged and fill required. Existing lakeline (401) Cost for CUP - material into a waterway.. An Individua1404 permit requires an would be abandoned in place. - Coastal Zone Consistency $1,000 alternative analysis demonstrating that project impacts are Deternunation justifiable and that the preferred alternative provides the best • City of Renton Shoreline Cost for BA - overall solution. Much of the work performed for the predesign Substantial Development Permit $10,000 -$20,000 could be repackaged to meet the Corps requirement for an • Street use/Right-of-Way pernuts alternatives analysis.. If the Corps pernvt is required, then a • Local building/construction pernut POSSIBLE Biological Assessment (BA) is needed. The BA cannot begin until • NEPA/SEPA review TOTAL design is 60% compete. BA could cost $10,000 —$20,000. BA is • Biological Assessment (BA) pERMITTING recommended on all alternatives. • Shoreline Conditional Use Permit COSTS (CUP) • The Dept. of Fish and Wildlife will have requirements for • Clearing/Grading Permit Permitting - construction timing and technique. The summer fisheries window • Sensitive Areas Review $100,000 - for construction will be June 16 to the end of October. There may $220,000 also be a winter window within portions of the project limits. Parts of the project area are in a beach spawning area for sockeye salmon. Alternatives that involve a loss of shoreline spawning habitat may not be permitted. Pipes will need to be buried in the lakebed; exposed pipes would provide an area for predators to hide and feed on juvenile salmon. ■ The City does not have a defined water right for the flush water. If lake water availability should become a problem, the system may need to be retrofitted to use City water source rather than lake water in the future. Kennydale Permitting Table - north and south.doc 12/29/99 Table 1 Brief Summary of Permitting Considerations (continued) Alternative Required Permits Permitting- Summary of Permit Considerations Related Costs Alternative N15a and S 15 - • City of Renton Shoreline Cost of Shoreline • Installing a new pressure main and side sewers would reduce beach (N15A) Install grinder pumps at Substantial Development Pernut Substantial construction and associated aquatic concerns. In-lake work is each existing side sewer. New • Local Right-of-way permit Development largely eliminated. Construction staging will be difficult in the area; pressure side sewers would . Local Building/Conshuction Permit -$1,000 access to homes during construction will be difficult. discharge to a new 3" pressure pernut main installed by open cut in the • SEPA review Cost of BA - ■ Connection to the existing side sewers and installation of new side frontage road. The existing � BA $10,000 -$20,000 sewers to the frontage road will damage yards and bulkheads of lakeline would be abandoned in . BNSF Utility License Agreement residential properties; mitigation will be required. place. for installation of new force main Cost of CUP- (S 15) Install grinder pumps at under the BNSF railroad tracks $1,000 � The construction of a new pressure sewer will require a Utility existing side sewer connections. � License Agreement with Burlington Northern Santa Fe Railroad Shoreline CUP New pressure side sewers would � Cost of BNSF (BNSF). Approval of plans and applications forms by BNSF discharge to a new 3" pressure Clearing and Grading Permit Utility License engineering must be done before construction begins. Pipelines main. The 4 southerly homes Agreement -$2,750 must be installed by boring and jacking only. Processing of plans would drain by gravity to a new POSSIBLE and forms by BNSF will take approximately 30 to 60 days. gravity sewer. Lift station would TOTAL replace existing flush station and PERMITTING ■ New pressure sewer would be difficult to install. Least disruption flows pumped to gravity sewer COSTS to aquatic environment. Re-routing side sewers to lower Lake in Lake WA Blvd. $20,000 -$30,000 Washington Blvd. will be difficult. There is a potential for sewage spills with the grinder pump stations. If a power outage were to occur, backu s at the stations could s ill into Lake Washin ton. Interim Alternative - Add • Joint Aquatic Resource Permit Cost for Corps ■ Building of any kind within the waters will require a JARPA additional maintenance access to Application (JARPA) Permit -$10,000 - application. the existing pipeline by adding - Hydraulic Project Approval $50,000 new maintenance manholes (HPA) ■ along the lakeline. - 404 Pernvt, likely: Discharge Cost for BA - of Dredge and Fill Material, $10,000 -$20,000 ■ Early discussions with Corps are needed to deternune whether a Individual Pernut Nationwide Pernut or Individua1404 Permit is needed. If an - Section 10 Pernvt: Work in Additional Agency individua1404 permit is needed, it will require an alternative Navigable Waters Coordination - analysis. Much of the work performed for the predesign could be - Water Quality Certification $10,000 -$20,000 repackaged to meet the Corps requirement for an alternatives (401) POSSIBLE analysis, but would lengthen the amount of time to obtain a permit. - Coastal Zone Consistency TOTAL If a Corps permit is required, then a BA is needed. When 60% of Determination PERMITTING design work is complete, then a BA can begin. • City of Renton Shoreline COSTS: Substantial Development Permit $30,000 - $90,000 • NEPA/SEPA review • Ri ht-of-Wa Use Page 2 L:\\...�Kennydale permitting table - combined alternatives � � � � � � � � � � � � � i � � � � i � . - � � ■� � � � � � � � � i � � � r s � � � Permit Matrix for Alternative N13/S13 Kennydale Sewer Replacement Permit Implementation/ Conditions Permitting Issues Contact Person Timing Costs Tri er Activit A enc U� L"11111 i`�. !ik "4��'Si4 .F S 3, 4 44 ,;� t t` l ! 1 � 1 ,x �' i j� � �.i .�. _ >.+ . , i � +,g �)...{ �431 .. ;. Y a �F + � � � �y Er � si ` x } z{°t �r y r al t .� � � i c . I � r = � n' } _ kC0'r,p"sof cx?-_ i 'Z ,�. fs` x � �o. s �-� ...� � t ���;� � �.Y`t { �.'. , � t f cx �{' �,i �'� sr ' A r x.. � -�.. � 1.."' ii u �� ��''� n i ;4 .� ' b a1 y` r a,' S i�, � '� `. F.O ilIlC81'S t' } ��`''r f } � �� < t �, s' , a� ..s � �-r?.� i ,',�m'^ .;�.. i J h i- , +' ` � , .ri�} f � '- - ��- t .5 . ,w+.-"�, Individua1404 Discharge of dredged � CZM (DOE) ~ BA would be� , Sandra Manning Approximately yNo fee and fill material into a required. BA cannot (Ecology) 3 to 4 months waterway begin until 60% (360) 407-6912 design complete. Corps: Regulatory Section 206 764-3495 Section 10 Any work in or CZM (DOE) BA would be Corps: regulatory Approximately No fee affecting navigable required. BA cannot section 3 to 4 months waters of U.S. (e.g., begin until 60% (206) 764-3495 piers, floats, outfalls, design complete dred in , etc. WA State t� 4 r •-� t� t - � ti F,r + k� i � 5. i y y 2 k+ 1� _ l F t� �'r t r . C g: (4 �,. t�`� 'i�� aF� � �' � � ,. �� �� : � � �� ^ . � �OpAI't1llCllt�:.Of ;'� # ., r i " � . 7 N � �..y � s _t ' � } _ 9�'"�i � d 7 � .4 t r " - � � �� y ' a.,y i, s 1 � t�� � t i � t � �:r r � �e�. ��. �i - �� 1 . -�.,.�- � . '' , , ,i_ . . r , Ecolo , a , _ �-�r_a � :' ,� z ., x �=• :�� .., t r � i,,, � , f r , x. �` � .,.. n. � . ... _ . .,.. _. , _. . . . �>r . .,, , .� .� �, . . , . . :.� ., _ ,..�. . _., . .,.�.:� . ..r ,, „ . �•,- •.;?. r, :.::, Coastal Zone Required for Corps Ecology will review Sandra Manning Typically 1 No fee Management authorized projects. proposed project for (Ecology) month Consistency Ecology reviews for consistency with state env. (360) 407-6912 (CZM) CZM consistency requirements. Corps: Regulatory Section 206 764-3495 Water Quality Federal pernuts to Public notification (30 Sandra Manning 2- 3 months; No fee Certification conduct any activity days); may be piggy- (Ecology) (agency has up (WQC) that may result in a backed with Corps public (360) 407-6912 to a year to act) discharge of dredge or notification Cotps: Regulatory fill material into water Section or wetlands 206 764-3495 Adolfson Associates, /nc., May ll, /999 Page / of2 Permit Matrix for Alternative N 13/S 13 Kennydale Sewer Replacement Permit Implementation/ Conditions Permitting Issues Contact Person Timing Costs Tri er Activit A enc .� WA State,.•�: ` ` 7 ' ' ` �� ' � �, `. , � ' ,. a � ;,. .� . Dept: of Fi§ti & - . ` � ' ' , '' _ � ` ` � ,. f `�` f . ; � ; . , , �, u r. _Wildl�fe � r. ::,� _.�? ,�" � ,,.. c = , - , Hydraulic . Work that uses, diverts, SEPA compliance WDFW: Up to 45 days No fee Project obstructs, or changes (360) 902-2534 Approval the natural flow or bed (assigned by region) (HPA)� of state waters ._ . .: ,.. -. �. � ek.; , r- � y�1 � S . r . i �. . �'._ � f �: y � � J � Ci of Renton. , � , , x � �. , x� ,�. N, ; � �,, s� 4... �, r•ax�. �M•. . �� ,...... � ... r .-.� -.n .'� . �. _ r...,.. . .i � � ':� r. i� ^��4 . �'. � i �{: Y-. ti la "M1. i.., f � �y Shoreline Activities valued at SEPA deternunation City of Renton 2 to 4 months $1,000 Substantial Use $2,500 or more on the Jennifer Henning Pemut water or shoreline area 425 430-7286 Shoreline Activities within 200 CZM; City of Renton Maximum 120 $1,000 Conditional Use feet of streams and river Public hearing; Jennifer Henning day review Pernvt segments with a mean SEPA determination (425) 430-7286 annual flow >20 cubic ft./sec., and associated wetlands Clearing and Excavation or fill in Critical Areas Study City of Renton Up to 120 days No fee Grading equal to or > 500 cu. review Jennifer Henning ards 425 430-7286 SEPA To determine if project Mitigation may be City of Renton 30 days No fee Threshold will have significant required Jennifer Henning Deternunation adverse environmental (425) 430-7286 impacts and as a result, re uire a SEPA EIS Building and/or Requried for all new � Would be needed to City of Renton Up to 6 weeks No fee Constuction building/construction inspect new Jennifer Henning flush/ um station 425 430-7286 Right-of-Way Construction activities Varies City of Renton Up to 6 weeks Use within a street right-of- Jennifer Henning way owned by local (425) 430-7286 'urisdiction � Additional review time may be necessary is a Biological Assessment (BA) is required (federal permit or funding). Adolfson Associates, Inc., May //, 1999 � � � � � � Page 2 of 2 � � � � � � � i � ! � � � �■ � r � �r � � � � � � � � � � � � � � Permit Matrix for Alternative N15a/S15 Kennydale Sewer Replacement Permit Implementation/ Conditions Permitting Issues Contact Person Timing Costs Tri er Activit A enc , Burlington � , `,, � , , � � �., � i , , _ . i � r� � � 4 � � `� � r 1� �� , ti� , ; � 4 ,y ' r . �� a� Northern , < > 3 r . ;_ ,� x4 a s ., � �� r{� � ,, , � , . . , r F 4.. � '4.: !R k�. �-� t ,L � �� . Z .���' 4 � t M 4 .Ra'ilfoad �.��," u � � } r_ =�� - , �.,� ., �:'� ,� �. �`, ;� � 'v � -`r � ,. -�,F �s�. , �. � ',q .r s Utility License Work that will occur Must submit plans and Approval must be Ron Jackson Approximately $2,750 Agreement within the BNR right- application forms to granted before Catellus for BNR 30 to 60 days of-way BNSF engineering for construction can (972) 719-6156 .. ,,• N a roval be in Ci ,rof�Renton�_ � �, �..�. � � ,.��, '� ,�"� � .�.�. .,�`�� �� ' �,..� ��ti � , °� s�� Shoreline Activities valued at SEPA deternunation City of Renton 2 to 4 months $1,000 Substantial $2,500 or more on the Jennifer Henning Development water or shoreline area (425) 430-7286 Pernvt Shoreline Activities within 200 CZM; City of Renton Maximum 120 $1,000 Conditional Use feet of streams and river Public hearing; Jennifer Henning day review Permit segments with a mean SEPA deternunation (425) 430-7286 annual flow >20 cubic ft./sec., and associated wetlands Clearing and Excavation or fill in Critical Areas Study City of Renton Up to 120 days No fee Grading equal to or > 500 cu. review Jennifer Henning ards 425 430-7286 SEPA To determine if project Mitigation may be City of Renton 30 days No fee Threshold will have significant required Jennifer Henning Determination adverse environmental (425) 430-7286 impacts and as a result, re uire a SEPA EIS Building and/or Requried for all new Would be needed to City of Renton Up to 6 weeks No fee Constuction building/construction inspect new Jennifer Henning flush/ um station 425 430-7286 Right-of-Way Construction activities Varies City of Renton Up to 6 weeks No fee Use within a street right-of- Jennifer Henning way owned by local (425) 430-7286 'urisdiction A�lolfson Associates, Inc., May 1/, 1999 Page l of l Permit Matrix for Interim Alternative Kennydale Sewer Replacement Permit Implementation/ Conditions Permitting Issues Contact Person Timing Costs Tri er Activit A enc `US Army ` . � ,� � > F y r �, Corps of � '< < T : � { � d... t �3 � l f t'' V. t . c , i �i k � ��: i . ; En � �ineers� ' ��, � t>�• ,, � , � �� �' � ,7,... � � � � � • . , . . . . ,.. �. �. . .,,_ . � . , . _ . . ,. . .. . � . .. . . . .., , . .. , _.,..,... , -. Individua1404 Discharge of dredged CZM (DOE) BA would be Sandra Manning Approximately No fee and fill material into a required. BA cannot (Ecology) 3 to 4 months waterway begin until 60% (360) 407-6912 design complete. Corps: Regulatory Section 206 764-3495 Section 10 Any work in or CZM (DOE) BA would be Corps: regulatory Approximately No fee affecting navigable required. BA cannot section 3 to 4 months waters of U.S. (e.g., begin unti160% (206) 764-3495 piers, floats, outfalls, design complete dred in , etc. WA`State ° , � � � , .- t �"` `. , ' ' .: � - , � > � , l. �( G� L � x � � � a K'., r �0�►Al'rIIlCllt� Of n j o f � st k> >' �-� � !. ' 1.�! '4 i t;;, , F � . � � .� :..-• K ,. � i . � �. i ' a z. � >. , ,. ; t , a � . , ' •FiC0�0 x, a.,_ � ; �� . ,.<r_� , �.'- '�-o" . 3.�� . ...:���:, .,� . ';� �r ��'���� S � r' A y .F �a�1 ,.4�.;...� .. . ., , . .. .. ..� . .... . . , , .. . . . ... � � -. :... '.. ., ,.. .. . . • .. <�.. . i Coastal Zone Required for Corps Ecology will review Sandra Manning Typically 1 No fee Management authorized projects. proposed project for (Ecology) month Consistency Ecology reviews for consistency with state env. (360) 407-6912 (CZM) CZM consistency requirements. Corps: Regulatory Section 206 764-3495 Water Quality Federal permits to Public notification (30 Sandra Manning 2- 3 months; No fee Certification conduct any activity days); may be piggy- (Ecology) (agency has up (WQC) that may result in a backed with Corps public (360) 407-6912 to a year to act) discharge of dredge or notification Corps: Regulatory fill material into water Section or wetlands 206 764-3495 Adolfson Associates. /nc., May I1, /999 � � � � � � Page ! of 2 � r � � � � � � � � �■ � a■� � � � � � � � � � � �■ � �■ � � � s � � � Permit Matrix for Interim Alternative Kennydale Sewer Replacement Permit Implementation/ Conditions Permitting Issues Contact Person Timing Costs r WA�State �= ' � ` � ` ` � �r . -s : ? b i4 � � s . Dept: of F�sh & `, ° �: ,' � � ; � �� ry� • �;�. tiWil`illife �€ : ��x � . e :; �: ' , R'k: t �' � }" , , ; : � " , _ � _ _ �, _ H draulic Work that uses, diverts ' � � � y , SEPA compliance WDFW: Up to 45 days ,No fee Pro�ect obstructs, or changes (360) 902-2534 Approval the natural flow or bed (assigned by region) (HPA)� of state waters �_CI � .Of �R@�t011 ,�: `'� � - _ ,.�. . .�'� ;rz �€ j;: r o � � t, S ,.� � •c'� s� Shoreline Activities valued at SEPA deterrnination � City of Renton � 2 to�4 months ��$1,000 � Substantial Use $2,500 or more on the Jennifer Henning Permit water or shoreline area (425) 430-7286 Right-of-Way Construction activities Varies City of Renton Up to 6 weeks No fee Use within a street right-of- Jennifer Henning way owned by local (425) 430-7286 'urisdiction � Additional review time may be necessary is a Biological Assessment (BA) is required (federal pernut or funding). Adoljson Associates, Inc., May ll, /999 Page 2 of 2 � , ' ' ' ' APPENDIX G. ' INTERIM MAINTENANCE ALTERNATIVE PROJECT COST ESTIMATE ' ' ' ' ' ' ' , ' , � ' ' � � � � � � � � � � � � � � � ' � � � PROJECT COST ESTIMATE TETRA TECH/KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Pro�ect Interim Maintenance Alternative ' PROJ. NO: 2830120 CLIENT : Cit of Renton BY: JWL DATE: 27-Dec-99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Installation of Maintenance Manholes in Lake 1 MOBILIZATION/DEMOBILIZATION (15%) LS 15% $36,000 2 MAINTENANCE MANHOLE 4 EA $60,000 $240,000 SUBTOTAL $276,000 CONTINGENCY 25.0% $69,000 SUBTOTAL $345,000 SALES TAX 8.6% $30,000 CONSTRUCTION COST $375,000 ENG., ADMIN. & CONSTRUCTION MGMT 30.0°/a $104,000 TOTAL ESTIMATED PROJECT COST $479,000 CUENT: PROJECT: N SUBJECT: ��c ' ►J- �Ai�_ � f�-t�1 � O LE I-1��Ho�. : t� S S'�� rti` - LX C,P+JPt\ � OrJ , I "\a.�a� � PNo�3 �, �O S'�" ''�,� : �x�xi� _ I�J���..�.s ' 4- x (� ��. 2 �. ��Z — � C� � i�. ., �r.. % ,,-_'� - _ � � F ►. $ �-o �T3 -`� �-Z � J ,`.� 3 , r� � _ �, � GJ i I � � ` .� _- ,` �� �. � T � � . � �,, .`' � . _�.�'�-' _. �. �, �_.. , � ��� ;; ::._: , . ' =`; iL-�-�:`'-`_ "- - - :.-_ �� %r' "' �;: �--� � .: � , - _ . . . �.. � �� . . - -_ � '1 . � ---�-:.1 - i_ �---.- - r( ,' � �- L�f--`. � _ .___ - , . . - � . _.._ � `� �"'�, �, ��- �.J: i� : .. � � • . : � . .. .. . . - , �� �:- � r� �;' ,- .. . . �.. • ����7.�� ���3�� x � \� V � ^ ^ ` � �."�j . � -, _,. .�� - _ . ___,"...�% .. . -r i r_ ` rj;-� J �,/ , _� �5 � � ��.' �_ . :�1 �� \ . .. . .. ,; ;` G r,. ,' � _� � .� `� `'�'� �- ..: � ' \ �., ;: ' , � S , v �r1, ti i;�.�; _. � `� � � . �O � { 1 � . v � a.J -�� � � l.' ' \{ ; � ' . Y �� ` -- -- `'" _ ��� �v+.�, r� '.:'�'_-1= r :� i:��`,�� �.. . f � �v_ ,, �.. � � ' " �' G`./ t, � / • �. -�,., �� ` _: .� :' riL � � �.� , . r c.� Z� .� ,� v` .I ; � !SG`� ..-. � 7 % � � ---� �i ' , � ; ' I '� Tetra Tech/KCM Z�a � � ,-> ^ +,.; ;_ �� ' } Z � 9 �, ! 2— j� O JOB NO.I BY DATE SHEE7 NO. ,, � , • CUENT: ' SUBJECT: � � � � 1 ' ' ' ' � , ' � � ' 1 _ _ �,;�� 4i � jO�c7 -� 4—� � � O '�- c S� � � 7 '� :; f � �� �a: �� ti/ PRWECT: � _� . , _ �-. . � �__ c.�s`� �-=- - � `� � s..:��� = � L�{-O� ���� - rt-�z� __ i � j�����, � OTetra Tech/KCM ' ��,. i � p �� � -Z. ' JOB N0. BY DATE SHEET N0. PROJECT COST ESTIMATE TETRA TECH/KCM PROJECT: Kenn dale Lakefront Sewer Re lacement Pro'ect Maintnenace Costs for Sewer Cleanin b Outside Contractor PROJ. NO: 2830120 CLIENT : Cit of Renton BY: JWL DATE: 27-Dec-99 ITEM DESCRIPTION QUANTITY UNIT UNIT AMOUNT NO. PRICE Cleaning Costs 1 MOBILIZATION/DEMOBILIZATION (15%) LS 15% $5,700 2 CLEANING SERVICE 7 DAYS $2,800 $19,600 3 BOAT, BARGE & OPERATOR 7 DAYS $1,800 $12,600 4 DIVE CREW 2 DAYS $3,000 $6,000 SUBTOTAL $44,000 CONTINGENCY 25.0% $11,000 SUBTOTAL $55,000 SALES TAX 8.6% $4,700 CONSTRUCTION COST $59,700 CITY ADMINISTRATION 15.0% $9,000 TOTAL ESTIMATED PROJECT COST $69,000 � � � i r � � r � � � � � � � � � � �