Loading...
HomeMy WebLinkAboutPrelim.Technical Informationspringline design LLC Civil Engineering I Site Oevaluptcient I Tramportalian 3131 Western Avenue, Suite 501 Seattle, Washington 98121 ph 206957.8311 fax 206.957.8313 City of Renton Planning Division JUN 3 0 -'ail PRELIMINARY REC *WED TECHNICAL INFORMATION REPORT Project: Renton Housing Authority Glennwood Townhomes 1 147 Glennwood Ave NE Renton, WA 98056 Prepared For: Bumgardner Architects 21 1 1 3rd Avenue Seattle, WA 98121 Prepared By: Ryan Itani, PE Reviewed By: Peter Apostol, PE Date: June 30, 2011 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 TABLE OF CONTENTS Section No. Subiect Pam SECTION I PROJECT OVERVIEW.....................................................................I SECTION II CONDITIONS AND REQUIREMENTS SUMMARY...................I I SECTION III OFFSITE ANALYSIS...................................................................... 14 SECTION TV FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN..........................................19 SECTION V CONVEYANCE SYSTEM ANALYSIS AND DESIGN ................21 SECTION VI SPECIAL REPORTS AND STUDIES.............................................21 SECTION VII OTHER PERMITS...........................................................................21 SECTION VIII EROSION AND SEDIMENT CONTROL......................................21 SECTION IX BOND QUANTITIES......................................................................22 SECTION X OPERATIONS AND MAINTENANCE MANUAL .......................22 LIST OF FIGURES FIGURE 1 VICINITY MAP.................................................................................4 FIGURE 2 TIR WORKSHEET............................................................................5 FIGURE 3 EXISTING SITE SOILS.....................................................................8 FIGURE 4 EXISTING LAND COVER...............................................................9 FIGURE 5 DEVELOPED LAND COVER ........................ ...10 ............................. FIGURE 6 OFF-SITE DRAINAGE SYSTEM...................................................17 LIST OF APPENDICIES APPENDIX A CIVIL PLANS APPENDIX B TDA #2 FLOW CONTROL & WATER QUALITY CALCULATIONS APPENDIX C OPERATION AND MAINTENANCE MANUAL APPENDIX D GEOTECHNICAL REPORT 1 1 1 r 1 1 1 1 1 SECTION I — PROJECT OVERVIEW General Description: The proposed Glennwood Townhomes Project includes the construction of two townhome buildings on a 0.61 acre site located at 1147 Glennwood Ave NE in the City of Renton (see Figure 1 for vicinity map). The site is bordered by developed parcels with duplexes to the north and south, a vacant parcel to the west, and by Glennwood Ave NE to the east. In addition to the two proposed buildings, the improvements will include construction of an access drive, parking lot, and walkways. Frontage improvement of the adjacent right-of-way will include construction of new curb, gutter, and sidewalk. 5 feet of right-of-way will be dedicated along the site's frontage. In addition, a City of Renton high pressure 12" water main will be extended to the project. The proposed project has been designed to meet the requirements of the 2010 City of Renton Amendment to the 2009 King County Surface Water Design Manual (KCSWD). A summary of the project data is provided in the TIR worksheet (see Figure 2). Site Soils The NRCS map (see Figure 3) of the site shows the presence of both "Arents, Alderwood Material" and "Ragnar-Indianola" soils located within the project area. Additional information on the site's soils is provided in a geotechnical report prepared by Soil & Environmental Engineers, Inc. The findings of the report are based on soil samples taken from test pits that were excavated on-site. In general, the results of the test pit data uncovered about one foot of topsoil mixed with loose fill underlain by a 2-3.5 foot thick layer of silty sand that was underlain by impermeable glacial till soil. For more information, see the geotechnical report included in Appendix D. Predeveloped Conditions: An existing duplex is located at southeastern corner of the site. The remainder to the site consists of lawn with some trees located along the western, boundary of the site. The limits of work is located within two separate Threshold Discharge Areas which is defined by the City of Renton Amendment to the KCSWD as; "an onsite area draining to a single natural discharge location, or multiple natural discharge locations that combine within one-quarter —mile downstream ". Threshold Discharge Area #I (TDA # 1) includes the frontage improvements and a portion of the on-site area located adjacent to the ROW. Grades within TDA #1 are less than 2%. Stormwater runoff drains overland to the flow line of the existing curb. The existing flow line is sloped to the south at grades ranging from 0.5% to 1%. Threshold Discharge Area #2 (TDA#2) includes the majority of the proposed site. Grades within TDA #2 slope downhill to the west. Slopes within the eastern half of TDA #2 are roughly between 2% and 5%. Grades within the western half of TDA #2 are steeper at approximately 10%. Workforce Housing Project Page I Project No. 11010 1147 Glennwood Ave NE springline Design LLC The existing land coverage of each TDA is presented in the table below. The existing site is presented graphically in Figure 4 which follows this section. The downstream path of stormwater runoff from both TDA #I and TDA #2 is described in the offsite analysis in Section 1I1. Table ;I - Existing Site Land Covera TDA# l 0.000 0.019 0.000 0.004 0,063 0.086 TDA#2 0.048 0.006 0.016 0.000 0.535 0.606 Total 0.048 0.025 0,017 0.004 0.598 0.692 Developed Conditions: The areas of proposed improvements include two townhouse buildings, an access drive, parking lot, and walkways. Frontage improvement of the adjacent right -of --way will include construction of new curb, gutter, sidewalk, planting strip, and a driveway. The following table quantifies the areas of the proposed land coverage of TDA #1 and TDA#2. The proposed site is presented graphically in Figure 5 which follows this . section. Table 2 - Redeveloned Site Land TDA# 1 0.000 1 0.041 0.003 0.000 0.056 0.100 TDA #2 0.094 0.033 0.039 0.119 0.308 0.592 Total 0.094 .0.073 0.042 0.119 0.364 0.692 The existing site topography will not be dramatically altered in the proposed condition. In general, the same areas of the site will continue to drain to TDA #1 and TDA #2. As in the existing condition, runoff from TDA #1 will flow as surface flow to the curb's flow line in Glennwood Ave NE. TDA #1 is under the thresholds which trigger the requirement of both flow control and water quality facilities. Stormwater runoff from TDA #2 will be collected by roof drains, catch basins, and area drains. Per Core Requirement #4 of the City of Renton Amendment to the KCSWDM, the proposed conveyance system will be designed to convey runoff resulting from the peak rates resulting from the 25 -year storm event. The improvements within TDA #2 will trigger the requirement of both a flow control and water quality facility. The Workforce Housing Project Page 2 Project No. 11010 1147 Glennwood Ave NE Springline Design LLC ' detention and water quality facilities for TDA #2 are proposed at the west end of the site and consist of a Sft diameter detention tank and a Stormfilter. See Section IV for detailed description of the design of the flow control and water quality facilities. 1 1 1 1 1 i Workforce Housing Project Page 3 Project No. 11010 1147 Glenwood Ave NE springline Design LLC NE %W S1 ^ Nr IE4h $1 T } 3 } ` 3 � Y Of pa a F 1 s 7 ro m m NSF 11M 61 9: iK y' Si PROJECT SITE # r 2 m NE 1Zt, 0! NE f hn g t',• S, b n • 2r` 4 9 �r 4 FIGURE I - VICINITY MAP Workforce Housing Project Page 4 Project No. 11010 1147 Glenwood Ave NE Springline Design LLC f7av,rnw tia r ,� d kF ;drtW 4<,� vCIO f � i 4 NE 101T a r . r4k 41A iR 1 Ar 92011 GDD k -M1: Oita WMI 6090 - -eras 4+lls FIGURE I - VICINITY MAP Workforce Housing Project Page 4 Project No. 11010 1147 Glenwood Ave NE Springline Design LLC 1 1 1 1 1 1 FIGURE 2 TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 1 PROJECT OWNER AND PROJECT ENGINEER" Project Owner: Renton Housing Authority Address : PO BOX 2316 Renton, WA 98056 Phone : 425-226-1850 Project Engineer: Peter.Apostol, PE Company: Springline Design, LLC Address/Phone: 206 957 8311 Part 3 TYPE OF PERMIT APPLICATION ❑ Subdivison ❑ Short Subdivision • Grading • Commercial ❑ Other Part 2 PROJECT. LOCATION AND.: DESCRIPTION Project Name : Workforce Housing Project at 1147 Glennwood AVE NE Location: 1147 Glennwood Ave NE, Renton, WA 98056 Township 23N Range 5E .............Section 9 Part 4 OTHER REVIEWS AND PERMITS. ❑ DFW HPA ❑ Shoreline Management ❑ COE 404 ❑ Rockery ❑ DOE Dam Safety ❑ Structural Vaults ❑ FEMA Floodplain ❑ Other ❑ COE Wetlands ❑ Depressions/Swales "Part 5 , SiTE COMMUNITY`AND:DRAINAGE' l3ASIN •r +'„ Community Renton Drainage Basin East Lake Washington - Renton Part,6 SITE CHARACTERISTICS '.1 i , ❑ River ❑ Floodplain ❑ Stream ❑ Wetlands ❑ Critical Stream Reach ❑ Seeps/Springs ❑ Depressions/Swales ❑ High Groundwater Table ❑ Lake ❑ Groundwater Recharge ❑ Steep Slopes ❑ Other Workforce Housing Project Page 5 1147 Glenwood Ave NE Project No, 11010 Springline Design LLC Part 7 SOILS Soil Type Slopes Erosion Potential Erosive Velocities Arents, Alderwood 6% to 15% Moderate Material Ragnar-Indianola 2%-15% Moderate ❑ Additional Sheets Attached Part 8 DEVELOPMENT -LIMITATIONS REFERENCE LIMITATION/SITE CONSTRAINT El El ❑ Additional Sheets Attached Workforce Housing Project Page 6 Project No. 11010 1147 Glenwood Ave NE Springline Design LLC Part 9' ESC`REQUIREMENTS 4 , r4J."q F MINIMUM ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS DURING CONSTRUCTION AFTER CONSTRUCTION • Sedimentation Facilities • Stabilize Exposed Surface • Stabilized Construction Entrance • Remove and Restore Temporary ESC Facilities • Perimeter Runoff Control • Clean and Remove All Silt and Debris • Clearing and Grading Restrictions • Ensure Operation of Permanent Facilities • Cover Practices ❑ Flag Limits of SAO and open space preservation areas • Construction Sequence ❑ Other ❑ Other Workforce Housing Project Page 6 Project No. 11010 1147 Glenwood Ave NE Springline Design LLC 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Part'10 SURFACE WATER SYSTEM Cast in Place Vault ❑ ❑ Grass Lined • Tank ❑ Infiltration Method of Analysis Other ChannelKCRTS ❑ Vault ❑ Depression • Pipe System El Dissipater FJFlow Dispersal Compe Mitigati on of Eliminated Site ❑ Open Channel ❑ Wetland �_� Waiver e Storage ❑ Dry Pond ❑ Stream �_� Regional N/A ❑ Wet Pond Detention Brief Description of System Operation: Piped conveyance to on-site detention tank. Facility Related Site Limitations Reference Facility Limitation -Part 11 STRUCTURAL ANALYSIS` ❑ Cast in Place Vault ❑ Retaining Wall ❑ Rockery > 4' High ❑ Structural on Steep Slope ❑ Other Part 12 EASEMENTS/TRACTS xX ; F 4 ❑ Drainage Easement ❑ Access Easement ❑ Native Growth Protection Easement ❑ Tract ❑ Other Part Il 5lGNATURE'OF.PROFESSIONAI=.ENGINEER tl " i or a civil engineer under my supervision my supervision have visited the site. Actual site conditions as observed were incorporated into this worksheet and the attachments. To the best of my knowledge the information provided here is accurate. Workforce Housing Project 1 147 Glennwood Ave NR Page 7 Project No. 11010 5pringline Design ILC PROJECT SITE )AW I !>- SOIL TYPE tib ARENTS, DIVISION LINE ALDERWOOD (MATERIAL, 6-1501 ..ice RAGNAR-INDIANOLA SLOPES (AmC) (RdC) . 4trl IA ONO *,SOL Ilk FIGURE 3 - EXISTING SITE SOIL CONDITIONS Workforce Housing Project Page A Project No. 11010 1147 Glenwood Ave NE Springline Design LLC u='Opul loupd>s•— £t£9 LN 9oi n tZt9a vm'em"s MOM= = 40 tog wlns'anuany Wenn IS IS AZ - A Envoy email I I—Clola"a"s I Cupraulcu311N0 SNOLLIaNOO !DNIlSIXS - v awnol=j ubisep auilbuiAs C)71 r W V 1 s•acc nii .oL� \ V ` I 1 9'9Cc IOk 57< co W Q�O(0cm q1p U Q �ooQ Cf)H7 u7 CO O U LQ Atln34] 'Q O Atltl� � 7 .w q* 9'9c4 b3N� .9 U8 1 s•acc nii .oL� \ V ` I 1 9'9Cc IOk 57< I saurie I S n3tlr •lt I N s N'd1�01H N01�3� 1 '� e'ass I \ LV7d 43103�i00�A00 101 1\ 4B£ t4 Z� ll 1 1 1 1 y5nvn yL ti I \ I AXtic .o I ':OK a Lys �, 1 \ ` AMM34.6 1 X \ ` 1 I ! \\ Aux •e LJi � I = 1 \ \ 0, L" 1 l a p \ � I> 1 1 AnN3rA�y9t L(,(l111/I,L(J6 J I \ �aan� i304ONCO1 I e ]OND 1NNIl NIYN] ,i '.Mv- -at IAn00KC 37N3i MNt1 NWH] ,4 1 ` (� 3a F'a ''� AWn MO 0socc ,693143.6 0. I Swi d.l ppfgi ` \ Y c'9ss 1 s,rLO i 4 cm:) 0 N3 SaNy�H01" �1d I 1 I LJ 1V"id 0310-1888)4 Z ONI I I a 0L£ U9LZ�Ig L ,0l 1 N U", I� oas� II Q f .15 A •L5 l •a1 � T i ikf(f5 wM� 1 ' � 1 ,c l'° lc1a •3•IBYa t3v N15R aVg3Y m Q�O(0cm q1p �ooQ Cf)H7 u7 CO d LQ In O O O .w q* CL U8 1 p a Q _j r• (Do U O O O Q Q d W U LL OD OD d I Q Q O o o o � I saurie I S n3tlr •lt I N s N'd1�01H N01�3� 1 '� e'ass I \ LV7d 43103�i00�A00 101 1\ 4B£ t4 Z� ll 1 1 1 1 y5nvn yL ti I \ I AXtic .o I ':OK a Lys �, 1 \ ` AMM34.6 1 X \ ` 1 I ! \\ Aux •e LJi � I = 1 \ \ 0, L" 1 l a p \ � I> 1 1 AnN3rA�y9t L(,(l111/I,L(J6 J I \ �aan� i304ONCO1 I e ]OND 1NNIl NIYN] ,i '.Mv- -at IAn00KC 37N3i MNt1 NWH] ,4 1 ` (� 3a F'a ''� AWn MO 0socc ,693143.6 0. I Swi d.l ppfgi ` \ Y c'9ss 1 s,rLO i 4 cm:) 0 N3 SaNy�H01" �1d I 1 I LJ 1V"id 0310-1888)4 Z ONI I I a 0L£ U9LZ�Ig L ,0l 1 N U", I� oas� II Q f .15 A •L5 l •a1 � T i ikf(f5 wM� 1 ' � 1 ,c l'° lc1a •3•IBYa t3v N15R aVg3Y m woo-011oull6updo-AvAm c L ce L96 90Z XBJ a&96 vm '814943S �LCqj.9890Z qd LOg qnS 'anusAV ujalsOM 4C4E 10a - A EMVOS uOREWodauej.L J jueLudolOAO(3 B;JS I BUIJGBUIBU3 JJAID SNOlJ11C3NOO CMMOIEMEM - 9 aunoi:=j oil ubisep auilbuijds CD CN N! z NIS bod Wol L- ove 31 0) CN u7Iq CO CN cm CD CL A .4, A CL m M A Lai 0 i9c 0 V) 0 C-4 CL L) CD C. C) o Z Z ;: rn L) r ro r - uj C) LA -j LA- W J C;� bod Wol L- ove 31 0) CN u7Iq CO CN cm CD CL A .4, A N; �v m M A Lu 0 i9c Vt' C-4 CD C. C) Z ti 3M M -4n MOO ar93a .L/ L 0-1 iv A0= HL qNr%G3 LO -49% 4" GNWI j SSWD --- \ I C) �D . C) 0) CN u7Iq CO CN cm CD CL A .4, A N; �v m M ci Lu 0 i9c W cr 0 0 0 a z wt C L 0 J 0 O C) C) �D . C) 0) CN u7Iq CO CN cm CD CL .4, A m M ci Lu 0 i9c Vt' C-4 CD C. C) Z 0 ro rn L) r ro r - CO C) LA -j LA- CY) C;� CDm C14 P Ol at I.H390 -9 \,Nakt( 0$ res A. 9 Is � US 3c Z ()t4�SGN,47HOIH oIN36 zj, �40019 6 10 dmv g lo) = = = = m = = = = = = = = = = = m m m o .4, A 0 i9c Vt' Ol at I.H390 -9 \,Nakt( 0$ res A. 9 Is � US 3c Z ()t4�SGN,47HOIH oIN36 zj, �40019 6 10 dmv g lo) = = = = m = = = = = = = = = = = m m m ' SECTION II — CONDITIONS AND REQUIREMENTS SUMMARY ' The proposed project is subject to a Full Drainage Review and is therefore subject to all eight core requirements and all six special requirements. These requirements are listed below along with a discussion of their applicability to this project. Core Requirements: 1 Req. #1 Discharge at Natural Location: Existing discharge locations will be maintained. Req. #2 Offsite Analysis: ' See Section III below. Req. #3 Flow Control: ' TDA #1 The project is required to meet the Peak Rate Flow Control Standard. TDA #1 is ' exempt from providing a flow control facility and flow control BMPs since it will not generate more than a 0.1 cfs increase in the existing site condition's 100 -yr ' peak flow. TDA #2 ' The improvements within TDA #2 trigger the requirement for a flow control facility and flow control BMPs. A 5ft diameter detention tank is proposed to satisfy the flow control facility requirement. The site is classified as a Large Lot High Impervious site. As such; 40% of the Targeted Effective Impervious Surfaces must be mitigated for by a flow control BMP. This requirement will be satisfied through the use of pervious asphalt pavement. ' For further details see Section IV. 1 Req. #4 Conveyance System: The new conveyance system has been designed to meet this requirement. A backwater analysis will be provided in the final TIR. I Req. #5 Erosion and Sediment Control: Construction ESC systems have been designed to meet this requirement. ' Req. #b Maintenance and Operations: Workforce Housing Project Page 11 ' 1147 Glennwood Ave NP Project No, 11014 Springline Design LLC A Declaration of Covenant may be necessary for this project. The proposed facilities will be owned and maintained by the Renton Housing Authority. Rey. #7 Financial Guarantees: A financial guarantee will be necessary for this project. Bonding will be required for the construction of improvements and will be obtained prior to construction. Req. #8 Water Quality: The proposed improvements located within TDA #1 are under the thresholds which trigger the requirement of a flow control facility. The proposed improvements within TDA #2 include areas of pollution generating impervious and pervious surfaces which trigger the requirement of a water quality facility. Normally, the Enhanced Basic Water Quality Menu would be applicable as it is multi -family site that is located within a Basic water quality area. However, since the site will meet all the criteria of Exemption #4 on page 1-69 of the KCSWDM, the requirement for a water quality facility is reduced to the Basic Water Quality Menu. A Stormfilter with ZPG cartridges is proposed downstream of the detention system to meet the requirements of the Basic Water Quality Menu. For further details see Section IV. Special Requirements: Req. #1 Area Specific Requirements: No area specific requirements are applicable to this project. Reg. #2: Floodplain/Floodway Delineation This project is not adjacent to any floodplains or floodways. Therefore no delineation is necessary. Req. #3 Flood Protection Facilities: This project is not adjacent to any applicable areas and will not affect any applicable facility. Req. #4 Source Controls: This project is a multi -family project and will provide appropriate source controls Req. #S Oil Control: Workforce Housing Project Page 12 Project No. 11010 1147 Glennwood Ave NE Springline Design LLC 1 1 No oil control requirements are applicable to this project I � 1 1 1 1 Req. ##6 Aquifer Protection Area The proposed project is within Zone 2 of the APA. There are no open flow control, water quality, or conveyance facilities proposed that will introduce stormwater to ground water given the project soil conditions. Workforce Housing Project Page 13 Project No. 11010 1147 Glennwood Ave NE Springline Resign LLC; SECTION III — OFFSITE ANALYSIS Task 1 — Study Area Definition and Maps Maps of the project site and surrounding area were obtained from the King County GIS website. Topographical site information is from the topographical survey for the project. Storm drainage system maps were compiled from City of Renton GIS maps and as -built plans. Aerial images were obtained from Google Earth. Task 2 — Resource Review The City of Renton Public Works Department was contacted regarding the resources listed in section 2.3.1.1 of the 2010 City of Renton Addendum to KCSWDM. The following is a summary of the resource review: • Adopted Basin Plans o King County Basin Name i Map) East Lake Washington (per King County • Basin Reconnaissance Summary Reports o None completed to our knowledge. • Floodplain/Floodway (FEMA) Maps o The site is not within a floodplain or floodway per FEMA mapping. • Other Offsite Analysis Reports o Other Offsite Analysis Reports were not available. • Environmentally Sensitive Areas Map o There are no Environmentally Sensitive areas mapped within the vicinity of the site. • USDA Soils Survey o A geotech report has been completed and site soils are primarily silty sand that was underlain by impermeable glacial till soil • Wetlands Inventory Maps o There are no Wetlands mapped within the vicinity of the site. Workforce Housing Project Page 14 Project No. 11010 1147 Cslennwood Ave NE springline Design LLC 1 ' Task 3 — Field Inspection A Level 1 downstream analysis was performed on the morning of June 20, 2011. Weather conditions during the downstream analysis consisted of overcast skies and temperatures of 55-60 degrees F. Periodic rainfall occurred in the week prior to the analysis. On-site landuse and topography was confirmed and the downstream conveyance of each threshold discharge area was identified. Additional information was provided by Sean ' McCarty who is the Maintenance Operations Foreman at the Renton Housing Authority. Mr. McCarty has been with the RHA for 26 years and is very familiar with the RHA properties. He was able to confirm and help clarify questions about the downstream ' conveyance described below. This section is complemented by the information found in Figure 6 and the Off-site Analysis Drainage system Table which follow this section. ' TDA #1 Runoff from TDA 41 originates form a small portion of on-site area as well as from the right-of-way where the proposed frontage improvements are located. Stormwater runoff sheet flows to southern curb in Glennwood Ave NE. Drainage from TDA #1 and other areas of the Glennwood Ave NE right-of-way flow along the curb's flow line to the south. A low spot is located approximately 3508 downstream from the site. A concrete ' curb and gutter begins at this point and continues to the south (see photo below). ' Stormwater pools at the low spot and backs up along the gutter to the south until reaching the intersection of Glennwood Ave NE & Sunset Ln NE. Pooling also backs up to the back of the sidewalk adjacent to the low spot and then flows onto private property to the t west. It was not clear which route occurs first as the back of sidewalk and gutter at the intersection appear to be roughly at the same elevation. 1 Workforce Housing Project Page 15 Project No. 11410 1147 Glenwood Ave NE Springfine Design LLC Mr. McCarty indicated that there have not been any drainage problems occurring from stormwater flowing over the back of sidewalk onto the private property to the west. He also confirmed that stormwater backs up along the gutter until reaching the intersection of Glennwood Ave NE and Sunset Ln NE. From this point, stormwater drains along the gutter of Sunset Ln NE to two catch basins located adjacent to one another at a low spot. The catch basin lids could not be removed at the time of the field visit. According Mr. McCarty, a piped conveyance line conveys stormwater from the catch basins to the southwest. He mentioned that this line was plugged during a roadway widening project of Sunset Blvd. He indicated that during large storm events pooling occurs at the low spot in Sunset Ln NE. However he has not witnessed any occurrences of storm water overtopping the curb. 11.��Pa Runoff from TDA #2 originates form the on-site areas. Stormwater runoff sheet flows onto the adjacent parcel to the west which is vacant and heavily vegetated. Grades within this parcel slope to the west at approximately 10%-15%. Sheet flow patterns persist in a westerly direction until flowing onto Edmonds Ave NE. A piped conveyance system in Edmonds Ave NE collects runoff from TDA #1 and conveys flows to the south. Due to heavy traffic conditions, the piped conveyance system was not inspected. Based on record drawings obtained from the City of Renton Department of Public Works, the piped conveyance continues to the south in Edmonds Ave NE beyond 'Amile downstream from the site. No open drainage complaints are associated with the downstream conveyance of TDA #2. Task 4 — Drainage System Description and Problem Description There are no known problems with the downstream system. Task 5 — Mitigation of Existing or Potential Problems Based on the observations made during the field inspection and the requirements for the design of the proposed drainage systems, no negative impacts to the systems downstream of TDA #1 and #2 are anticipated. Workforce I lousing Project Page 16 Project No. 11010 1147 Glennwood Ave NE Springline Design LLC CD C) 04 CD C—) U,) D z loon - A alvoe SISA-IVNV E311S =A=JO -9 Eiunoi� I= ===== m m = m m m m= m m m m r ow iz 110, 'E O1rG yJ co 4rtpr CI w to ',)WVtA 433"1 wV I= ===== m m = m m m m= m m m m r iz 110, co w ',)WVtA 433"1 wV n�cwvll N iu L gh: OF `hit" � it < 16 4JI 3h eilpizxyd 77 I= ===== m m = m m m m= m m m m r 1 1 1 1 1 N U yr y N d y C1 o E fA QNl v o V L_ d /4.•�� O L:.V N rr O ` 4) X m y C X 41 a a 0c��� .C-• R �O E�� c.G O ;. c (D o ma *'"o ¢gym aoa U�°=4 ro48 ro 10 U L d) c.Q ID �' U -L7 C ; C (I! C a _O ti a u-' C E Q% --, gro m o— U:C, 0] N • .Q o W ro'E cCa, m a �,b N O N O W CL o -. U3 O -z C C a?a)=moE c a,� .o .n C1 E. E u,�-T ro Dovm UD� ro�m. �> o 0� OCL N Q1PUS u}'iam� Ri "r- C Q -C .6 ro ;C 0fro. p dco E E �m� T 0 y�.`.. .O•, E e 1 1 1 1 1 1 1 SECTION IV — FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN Flow Control The project is located in a Peak Flow Control Standard area. This standard requires that the developed site discharge rates match the existing site conditions discharge rates for the 2-, 10-, and 100 -year return periods. The thresholds which trigger the requirement for a flow control facility are applied separately to each threshold discharge area. TDA #1 TDA #1 is exempt from the facility requirement because the developed condition results in no more than a 0.1 cfs increase in the existing site conditions 100 -year peak flow rate. Results from the KCRTS analysis of the 100 -yr peak flow rates resulting from the developed and existing conditions of TDA #1 is provided below: Flow Frequency Analysis Time Series File:tdal-dev.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates --- Flow Rate Rank Time of Peak (CFS) 0.016 5 2/09/01 2:00 Flow Frequency Analysis Time Series File:tdal_existinq.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates --- Flow Rate Rank Time of Peak (GFS) 0.011 4 2/09/01 2:00 -----Flow Frequency Analysis------- - - Peaks - - Rank Return Prob (CFS) Period 0.033'. `' 1 100.00 0.990 -----Flow Frequency Analysis------- - - Peaks - - Rank Return Prob (CFS) Period 0.024 1 100.00 0.990 TDA # 1 100 -yr Developed Peak Rate = 0.033 CFS ' TDA #2 100 -yr Existing Peak Rate = 0.024 CFS Net difference = 0.09 CFS < 0.1 CFS 1 TDA #2 TDA #2 triggers the requirement for a flow control facility per the Peak Flow Control Standard. As such, a 5 ft diameter detention facility is proposed to provide the required level of flow control. The site is classified as a Large Lot High Impervious Site. implementation of Flow Control BMPs is therefore required for 40% of the site's targeted effective impervious areas. To satisfy this requirement, 5190 SF of permeable pavement is proposed. Per Chapter 5 of the KCSWDM, this area should be modeled as 50% impervious and 50% Till Grass for the purpose of sizing a flow control facility. The targeted surfaces of TDA #2 have been adjusted accordingly in the flow control facility sizing calculations which. are provided in Appendix B. Workforce Housing Project Page 19 '1147 Glenwood Ave ME Project No. 11010 Springline Design LLC Water Quality TDA# 1 The targeted surfaces in TDA #1 are under the thresholds which trigger the requirement of a water quality facility. TDA #2 The pollution generating surfaces within TDA #2 trigger the requirement for a water. quality facility. Normally, the Enhanced Basic Water Quality Menu would be applicable to the site as it is a multi -family site that is located within a Basic water quality area.. Per Exemption #4 on page 1-69 (City of Renton Amendment to the KCSWDM) however, if the following criteria is met, this requirement is reduced to the Basic Water Quality Menu: a) No leachable metals (e.g., galvanized metals) are currently used or proposed to be used in areas of the site exposed to the weather, ANDI b) A covenant is recorded that prohibits future such use of leachable metals on the site (use the covenant in Reference Section 8-Q), AND c) Less than SO% of the runoff draining to the proposed treatment facility is from any area of the site comprised of one or both of the following land uses: , • Commercial land use with an expected ADT of 100 or more vehicles per 1, 000 square feet of gloss building area. • Commercial land use involved with vehicle repair, maintenance, or sales. The project will meet the above criteria explicitly, and is therefore providing treatment of pollution generating surfaces as outlined by the Basic Water Quality Menu. This will be provided by a Stormfilter with ZPG Cartridges located downstream of the proposed detention facility. Sizing calculations of the Stormfilter is provided in Appendix B. Workforce Housing Project Page 20 Project No. 11010 1147 Glenwood Ave Nr Springline Design LLC SECTION V — CONVEYANCE SYSTEM DESIGN AND ANALYSIS ' The new conveyance system has been designed to meet this requirement. Storrnwater from TDA ##2 will be tight -lined to a rock pad located approximately 100 ft west of the southwestern property corner within the adjacent parcel which is also owned by the Renton Housing Authority. The rock pad has been sized per table 4.2.2.A of the KCSWDM. A Backwater analysis of all proposed conveyance systems will be provided in the final TIR. SECTION VI — SPECIAL REPORTS AND STUDIES A geotechnical analysis of the site was performed and is included in Appendix D. ' SECTION VI I — OTHER PERMITS No other permits are required. ' SECTION Vill — EROSION AND SEDIMENT CONTROL ' ESC Measures are being addressed as follows: 0 Clearing Limits: Clearing limits are being delineated by perimeter silt fencing and ' chain link fencing. • Cover Measures: Temporary cover shall be installed if an area is to remain unworked for more than seven days during the dry season (May 1 to September 30) or for more than two consecutive working days during the wet season (October I to April 30). Any area to remain unworked for more than 30 days shall be seeded or sodded, unless the City of Renton determines that winter weather ' makes vegetation establishment infeasible. 0 Perimeter Protection: Perimeter protection will be implemented by silt fencing ' around the site perimeter where drainage paths require. • Traffic Area Stabilization: A stabilized construction entrance will be built for construction traffic. r• Sediment Retention: Catch basin protection has been provided and is shown on the projects TESC plans. • Surface Water Control: Surface water will be collected and conveyed via swales with check dams as necessary. • Dust Control: Dust control, if required, will be provided through the limited use ' of water trucks. C� 1 Workforce }lousing Project Page 21 1 W7 Glenwood Ave NE Project No. 11010 Springline Design LLC SECTION IX -- BOND QUANTITIES A bond quantity worksheet for the proposed improvements will be included with the final TIR. SECTION X -- OPERATIONS AND MAINTENANCE MANUAL An operation and maintenance manual which outlines required regular maintenance necessary for the proposed stormwater facilities is provided in Appendix C. The maintenance of the stonnwater facilities will by be performed by the Renton Housing Authority. Workforce Housing Project Page 22 Project No. 11010 1147 Glennwood Ave NE springline Design LLC ' 1 Appendix A Civil Plans 09 FI l IL�Ca YM •iG 4 IF'ai4a°�� la,:..a•r;q„Y :xwuui� � � Innum.+ui l au++tla��q as tOuwu dr3lma } 0,7 U6ISej12UIk6UI.idS AID 99086 dM 'uoIuad '9N anuany POOMUU910 Lb l 0 u7 c a (!) J W SWOHNMOl ❑OOMNN3TD o s � ? o Q^ Aluoylny 6ursnOH uojuaU jol 6uisnoy juawaoeldaH a o -i 4 N 3 3 ^ IMP g � Ica 4 a .pig q qo gn a � Ili v 11, pm.o 9 19 �si l-,�i� x h Ix I x s r yrs j N Pi 4 A m n vl rd S, !i = `a 9MIN iaaa r V NOiion iSNOO HOJ lON ,mta' i II-Yriet Kea i'.Y -,a: P -n CIC.:\sig•"'�0 r a{� II(7\:7 'R'� ® m o s a o -i 4 ,mta' i II-Yriet Kea i'.Y -,a: P -n CIC.:\sig•"'�0 r a{� II(7\:7 'R'� ® m g9 W11.�4+MO wilEuu..r A.9 r•J ubisap auil6uuds ++�, v NOIlonHiSNOO UOQ lON g Jmit to II nil III g 9r. lIxg 0 m X1 6XIM, M� '� I - � a,Ya• i � � r � 1` I F I � •. – �. I;�� I 4 tlL - y MEIN' � - 1.' - � _ � pC pL51 _ as"► ssr>r' � /1 1 �+ I � , t 19�cYi i 1. i UJ410 \ a v , o l Yi„{ MYfI hlYh. 4 I� �} N 0 I L'U rMa6 1 99086 VM 'uoauad '3N anuany poannuualE) Lb 11 i v U Z SWOHNMOl OOOMNNEDJ v co � Q J ,' T WW t~- a �uou;ny FulsnoH uo;uaa ao; bulsnou auawooeldaIj , Y v NOIlonHiSNOO UOQ lON g Jmit to II nil III g 9r. lIxg 0 m X1 6XIM, M� '� I - � a,Ya• i � � r � 1` I F I � •. – �. I;�� I 4 tlL - y MEIN' � - 1.' - � _ � pC pL51 _ as"► ssr>r' � /1 1 �+ I � , t 19�cYi i 1. i UJ410 \ a v , o l Yi„{ MYfI hlYh. 4 I� �} C I UJ410 \ a v , o l Yi„{ MYfI hlYh. 4 �I• I� �} C I L'U rMa6 1 i g - v 1 �I• �} C L'U rMa6 1 45 —+ � � tllHJ1H �.IlilN��s 1,07rioo�aaa� a oN Z4 MOO gL£t09LztL u 1y L L i ..i - I., -DOW J n."A ..—J 1 -- 11 tQ 44 IlC9( i� Iww�s'�-IV -MW Kit -wum.�w 4 a.+anwc +lro 16„w.r6.y � � u6isap auilBuuds 4.4 99086 VM `uoauaH '3N anuany poornuuaIE) Lb l l �A co Q 0 Z ? Z S3NOHNMOI OOOMNN3""iJ 'Qr ti d Z Q ¢�d /Uuoylny 6uisnoH uoivaa aol 6uisnouua ;uaaaejdaija _U, hit 1 I �r V A M��yiW��. y' oilladllM� V w•i� ttrn3u ate+ fy a �.ZalrkrKta —1dW Mph -Ul .l ak'16.{ lit C{�, l MyiV T L- A NoiionHiSNOO HO_� lON I` I1 II V IN, 1 �-Ndi HNn ror1r� ,� jj L} -so: i 1 'iP hYu"M21 flGa11Mi17\'�°N`. �wwoi Po :+ "1", I..,. . I Ro o� i.o�aYuuy I YwdowC A9 � �++�3 W7 u61sap ouil6upds .93 95086 dM 'uoluGH '3N onuany poaanuUGIS Lt, G l R 1- N`� Olt 1�`J11a so" SEy� N 0 o Z SWOHNMO.l QOOMNN3�9 VZ i~ co f a1 g d /qiaoglny 6u?snoH uoluea iol 6uisnoy auaweoelded I D 0 Its 0 I mee3: okypyyYO s• -,: -- -_ -; T. 41 1 � I I y � fI 0 II 5 70 yf III l V NOiionHiSNOO HOJ lON II Yi'V.J'I Iiia I L i C 11 1 li, WOkd ��•� OHf16! ` I ' �r— — -------- -- -- I—I --'_ .._,..—•—ash_ _f-'�— __ \--fps-•_ ---- — —�` 1 1 I l j 11 I 1 j I I oticsalu r4v1goo1,33a -Id 011)) 1a4 44 ,�4-m8 6 ion ,. t()gLZ$L Ella wain�- I' �JIFi! )tNC kPIIC! ► � - ' .._ ._ �. ,�.,�; ... n�:..'.0 il:.�sl '6i ::•a IIL4 iYY_W'. 11".a,vk,\IiwO�uMk �WNCj okontau..umo[!r,wc.. ,.Oi`d. �iCl 1- N`� Olt 1�`J11a so" SEy� ^ wsuW. VZ i~ a1 I II Yi'V.J'I Iiia I L i C 11 1 li, WOkd ��•� OHf16! ` I ' �r— — -------- -- -- I—I --'_ .._,..—•—ash_ _f-'�— __ \--fps-•_ ---- — —�` 1 1 I l j 11 I 1 j I I oticsalu r4v1goo1,33a -Id 011)) 1a4 44 ,�4-m8 6 ion ,. t()gLZ$L Ella wain�- I' �JIFi! )tNC kPIIC! ► � - ' .._ ._ �. ,�.,�; ... n�:..'.0 il:.�sl '6i ::•a IIL4 iYY_W'. 11".a,vk,\IiwO�uMk �WNCj okontau..umo[!r,wc.. ,.Oi`d. �iCl 1 6 to w O z Zw 3::CD 0 a - 0 a Z Z Z o W� J � ECC 0 6 z i I -90SC:4L VV -4�.r '..4'I +s:: ll'MY'd-Ai-J..S]IVLf J',c.ny. .tic".�,, it"_i ­ I i..: m �us40 }II � yZJ -90SC:4L VV -4�.r '..4'I +s:: ll'MY'd-Ai-J..S]IVLf J',c.ny. .tic".�,, it"_i ­ I i..: m J 31YVN 133r(Md eel K NM I djg ' y wS C Z O z Z LOm 0 U p a I g�: b M 8, b T SS �3 �i�g ��Z w �a 5i �� n � LL - a 00 �e a rtj i rr x e e € 91 Im 91 iv w A 5tn -19 * X11 1? 46 g :N 6�$ WN Z qb V WOO1= XP 6 age EH; i v 2 mg 7; r XV 16' Rim id a i C:�a } ��b UP 8 RA 0 @ R ,a AN .. io. M K K } 9 5 I'S Z � � 3 '1 : A d m = m m 1 1 1 1 1 Appendix B TDA #2 Flow Control & Water Quality Calculations 1 1 1 1 1 1 1 1 1 TDA #2 Flow Control Calculation Existing Conditions Land Use 0.00 0.00 0.00000 0.00 0.00 0.00000 0.54 0.00 0.00000 0.00 0.00 0.00000 0.00 0.00 0.00000 0.00 0.00 0.00000 0.00 0.00 0.00000 0.07 0.00 0.00000 TDA2-Existing.tsf • Peaks from Existing Conditions Land Use Flow Frequency Analysis Time Series File:tda2-existing.tsf Project Location:Sea-Tac ---Annual Peak Flow Rates --- Flow Rate Rank Time of Peak (CFS) 0.065 4 2/09/01 2:00 0.040 6 1/05/02 16:00 0.081 2 2/27/03 7:00 0.028 8 8/26/04 2:00 0.037 7 1./05/05 8:00 0.068 3 1/18/06 16:00 0.062 5 11/24/06 3:00 0.147 1 1/09/08 6:00 Computed Peaks 0 Till Forest 0 Till Pasture 0 Till Grass 0 Outwash Forest 0 Outwash Pasture 0 Outwash Grass 0 Wetland 0 Impervious -----Flow Frequency Analysis-------- - Peaks.- - Rank Return Prob (CFS) Period 0.147 1 100.00 0.990 0.081 2 25.00 0.960 0.068 3 10.00 0.900 0.065 4 5.00 0.800 0.062 5 3.00 0.667 0.040 6 2.00 0.500 0.037 7 1.30 0.231 0.028 8 1.10 0.091 0.125 50.00 0.980 1 1 1 1 1 • Developed Land Use 0.00 0.00 0.00 0.00 0.37 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.22 0.00 TDA2-Developed-Modified.tsf • Peaks from Developed Land Use 0.000000 Till Forest 0.000000 Till Pasture 0.000000 Till Grass 0.000000 Outwash Forest 0.000000 Outwash Pasture 0.000000 Outwash Grass 0.000000 Wetland 0.000000 Impervious Flow Frequency Analysis Time Series File:tda2-developed.tsf Project Location:Sea-Tac' ---Annual Peak Flow Rates--- -----Flow Frequency Analysis ------- Flow Rate Rank Time of Peak - - Peaks - - Rank Return Prob (CFS) (CFS) Period 0.087 5 2/09/01 2:00 0.184 1 100.00 0.990 0.065 7 1/05/02 16:00 0.106 2 25.00 0.960 0.106 2 2/27/03 7:00 0.092 3 10.00 0.900 0.063 8 8/26/04. 2:00 0.091 4 5.00 0.800 0.077 6 10/28/04 16:00 0.087 5 3.00 0.667 0.092 3 1/18/06 16:00 0.077 6 2.00 0.500 0.091 4 10/26/06 0:00 0.065 7 1.30 0.231 0.184 1 1/09/08 6:00 0.063 8 1.10 0.091 Computed Peaks 0.158 50.00 0.980 1 1 1 1 1 1 1 1 1 1 • Detention Facility Retention/Detention Facility Type of Facility: Detention Tank Tank Diameter: 5.00 ft Tank Length: 80.00 .ft Effective Storage Depth: 4.50 ft Stage 0 Elevation: 0.00 ft Storage Volume: 1489. cu. ft Riser Head: 4.50 ft Riser Diameter: 12.00 inches Number of orifices: 3 Full Head Pipe Orifice # Height Diameter Discharge Diameter (ft) (in) (CFS) .(in) 1 0.00 1.05 0.063 2 1.60 0.80 0.030 4.0 3 2.50 0.95 0.035 4.0 Top Notch Weir: None Outflow Rating Curve: None • Outflow from Detention Facility - - Rank Flow Frequency Analysis Prob Time Series File:rdout.tsf Project Location:Sea-Tac 0.141 ---Annual Peak Flow Rates --- Flow Rate Rank Time of Peak (CFS) 25.00 0.960 0.059 5 2/09/01 7:00 0.031 7 1/05/02 17:00 0.059 4 2/27/03 9:00 0.027 8 8/26/04 4:00 0.038 6 10/28/04 19:00 0.064 2 1/18/06 17:00 0.064 3 11/24/06 5:00 0.141 1 1/09/08 9:00 Computed Peaks 0.78 -----Flow Frequency Analysis------ - - Peaks - - Rank Return Prob (CFS) (ft) Period 0.141 4.50 1 100.00 0.990 0.064. 2.50 2 25.00 0.960 0.064 2.50 3 10.00 0.900 0.059 2.27 4 5.00 0.800 0.059 2.25 5 3.00 0.667 0.038 1.57 6 2.00 0.500 0.031 1.07 7 1.30 0.231 0.027 0.78 8 1.10 0.091 0.115 3.96 50.00 0.980 1 ' TDA #2 Water Quality Calculation Treat 2 -yr flow rate released by control structure ' • WQ flow rate for Stormfilter sizing = 2yr release rate from detention tank WQ flow rate for Stormfilter sizing = 0.038 cfs = 17 gpm • Each 18" ZPG StormFilter Cartridge can treat 7.5 gpm ' • Provide (3) 18" ZPG StormFilter Cartridges in a 48" Stormfilter Manhole 1 i 1 1 1 1 1 1 1 J 7 1 1 1 1 C i Appendix C Operation and Maintenance Manual 1 AI'PF..ND1X A MA1N'rI:NANCI,'iZEQiJIItliMliN'I'S FOR FLOW CON`IROI- CONVEYANCE, AND WO FACILITIES 1 1 1 1 1 1 1(' 1 1 NO.3 - DETENTION TANKS AND VAULTS Maintenance Defect or Problem Conditions When Maintenance Is Needed Results Expected When Component Maintenance is Performed site Trash and debris Any trash and debris which exceed 1 cubic foot Trash and debris cleared from site. per 1,000 square feet (this is about equal to the amount of trash it would take to fill up one standard size office garbage can). In general, there should be no visual evidence of dumping. Noxious weeds Any noxious or nuisance vegetation which may Noxious and nuisance vegetation constitute a hazard to County personnel or the removed according to applicable public. regulations. No danger of noxious vegetation where County personnel or the public might normally be. Conlaminanls and Any evidence of contaminants or pollution such Materials removed and disposed of pollution as oil, gasoline, concrete slurries or paint. according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Grass/groundcover Grass or groundcover exceeds 18 inches in Grass or groundcover mowed to a height. height no greater than B inches. Tank or Vault. Trash and debris Any trash and debris accumulated in vault or tank No trash or debris in vault. Storage Area (includes floatables and non-floatables). Sediment Accumulated sediment depth exceeds 10% of the All sediment removed from storage accumulation diameter of the storage area for % length of storage vault or any point depth exceeds 15% of area. diameter. Example; 72 -inch storage tank would require cleaning when sediment reaches depth of 7 inches for more than '/� length of tank. Tank Structure Plugged air vent Any blockage of the vent. Tank or vault freely vents. Tank bent out of Any part of tank/pipe Is bent out of shape more Tank repaired or replaced to design. shape than 10% of its design shape. Gaps between A gap wider than '/,inch at the joint of any tank No water or soil entering tank sections, damaged sections or any evidence of soil particles entering through joints or walls. joints or cracks or the tank at a joint or through a wall. tears in wall Vault Structure Damage to wall, Cracks wider than 1/2 -inch, any evidence of soil Vault is seated and structurally frame, bottom, and/or entering the structure through cracks or qualified sound. top slab inspection personnel determines that the vault is not structurally sound. Inlet/Outlet Pipes Sediment Sediment filling 20% or more of the pipe. Inlettoutlet pipes clear of sediment. accumulation Trash and debris Trash and debris accumulated in inlet/outlet No trash or debris in pipes. pipes (includes floatables and non-floatables). Damaged Cracks wider than '/:-inch at the joint of the No cracks more than %-Inch wide at inlet/outlet pipes or any evidence of soil entering the joint of the inlet/outlet pipe. at the joints of the inlet/outlet pipes. ' 2009 Surface Water Design Manual — Appendix A 1/9/2009 A-5 AF'P[3Nf)IX A MAIN,rI-NANCE REQL3llU_`MFNTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES I NO. 3 - DETENTION TANKS AND VAULTS Maintenance Defect or Problem Conditions When Maintenance is Needed Results Expected When Component Maintenance Is Performed Access Manhole Coverllid not in place Coverllid is missing or only partially in place. Manhole access covered. Any open manhole requires immediate maintenance. Locking mechanism Mechanism cannot be opened by one Mechanism opens with proper tools. not working maintenance person with proper tools. Bolls cannot be seated. Self-locking cover/lid does not work. Coverllid difficult to One maintenance person cannot remove Coverllid can be removed and remove cover/lid after applying 80 lbs of lift. reinstalled by one maintenance person. Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meets design standards. Allows maintenance person safe access. Large access Damaged or difficult Large access doors or plates cannot be Replace or repair access door so it doorslplate to open opened/removed using normal equipment. can opened as designed. Gaps, doesn't cover Large access doors not flat and/or access Doors close flat and covers access completely opening not completely covered, opening completely. Lifting Rings missing, Lifting rings not capable of lifting weight of door Lifting rings sufficient to lift or rusted or plate. remove door or plate. 1 1 1 11 1 1 1/9/2009 2009 Surface Water Design Manual —Appendix A I A -C 1 1 1 1 1 L 1 1 APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CON'T'ROL, CONVEYANCE, AND WQ FACILITIES NO.4 - CONTROL STRUCTURE/FLOW RESTRICTOR Maintenance Defect or Problem Condition When Maintenance is Needed Results Expected When Component Maintenance Is Performed Structure Trash and debris Trash or debris of more than % cubic foot which No Trash or debris blocking or is located immediately in front of the structure potentially blocking entrance to opening or is blocking capacity of the structure by structure. more than 10%. Trash or debris in the structure that exceeds '/3 No trash or debris in the structure. the depth from the bottom of basin to invert the lowest pipe into'or out of the basin. Deposits of garbage exceeding 1 cubic toot in No condition present which would volume. attract or support the breeding of insects or rodents. Sediment Sediment exceeds 60% of the depth from the Sump of structure contains no bottom of the structure to the invert of the lowest sediment. pipe into or out of the structure or the bottom of the FROP-T section or Is within 6 inches of the invert of the lowest pipe into or out of the structure or the bottom of the FROP-T section. Damage to frame Corner of frame extends more than'/, inch past Frame is even with curb. and/or top slab curb face into the street (If applicable). Top slab has holes larger than 2 square inches or Top slab is free of holes and cracks. cracks wider than 'A inch. Frame not sitting flush on tap slab, i.e., f=rame is sitting flush on top slab. separation of more than'/. inch of the frame from the top slab. Cracks in walls or Cracks wider than'/: inch and longer than 3 feet, Structure is seated and structurally bottom any evidence of soil particles entering structure sound, through cracks, or maintenance person judges that structure is unsound. Cracks wider than % Inch and longer than 1 fool No cracks more than '14 inch wide at at the joint of any inletloutlet pipe or any evidence the joint of inlet/outlet pipe. of sail particles entering structure through cracks. Settlement/ Structure has settled more than 1 inch or has Basin replaced or repaired to design misalignment rotated more than 2 inches out of alignment. standards. Damaged pipe joints Cracks wider than '/2 -Inch at the joint of the No cracks more than 'h -inch wide at inlet/outlet pipes or any evidence of soil entering the joint of inletloutlet pipes. the structure at the joint of the inlat/outlet pipes. - Contaminants and Any evidence of contaminants or pollution such Materials removed and disposed of pollution as oil, gasoline, concrete slurries or paint. according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil flim. Ladder rungs missing Ladder is unsafe due to missing rungs, Ladder meets design standards and or unsafe misalignment, rust, cracks, or sharp edges. allows maintenance person safe access. FROP-T Section Damage T section is not securely attached to structure T section securely attached to wall wall and outlet pipe structure should support al and outlet pipe. least 1,000 lbs of up or down pressure. Structure Is not in upright position (allow up to Structure in correct position. 10% from plumb). Connections to outlet pipe are not watertight or Connections to outlet pipe are water show signs of deteriorated grout. tight; structure repaired or replaced and works as designed. Any holes --other than designed holes—in the Structure has no holes other than structure. designed holes. Cleanout Gate Damaged or missing Cleanout gate is missing. Replace cleanout gate. ' 2009 Surface Water Design Manual — Appendix A 1/9/2009 A-7 APPENDIX A MAINTENANCE' REQUIREMENTS FLOW CONTROL, CONVEYANCE., AND WQ FACILITIES I NO.4 - CONTROL STRUCTUREIFLOW RESTRICTOR Maintenance Defect or Problem Condition When Maintenance is Needed Results Expected When Component Maintenance is Performed Cleanout gale is not watertight. Gate is watertight and works as designed. Gate cannot be moved up and down by one Gate moves up and down easily and maintenance person. is watertight. Chain/rod leading to gate is missing or damaged. Chain is in place and works as designed. Orifice Plate Damaged or missing Control device is not working properly due to Plate is in place and works as missing, out of place, or bent orifice plate. designed. Obstructions Any trash, debris, sediment, or vegetation Plate is free of all obstructions and blocking the plate. works as designed. Overflow Pipe Obstructions Any trash or debris blocking (or having the Pipe is free of all obstructions and potential of blocking) the overflow pipe. works as designed. Deformed or damaged Lip of overflow pipe is bent or deformed. Overflow pipe does not allow lip overflow at an elevation lower than design Iniet/Outlet Pipe Sediment Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. accumulation Trash and debris Trash and debris accumulated in inlet/outlet No trash or debris in pipes. pipes (includes floatables and non-floatables). Damaged Cracks wider than'/cinch at the joint of the No cracks more than %-Inch wide at inlet/outlel pipes or any evidence of soil entering the joint of the inlet/outlet pipe. at the joints of the inletloutlet pipes. Metal Grates Unsafe grate opening Grate with opening wider than 7)11 inch. Grate opening meets design (If Applicable) standards. Trash and debris Trash and debris that is blocking more than 20% Grate free of trash and debris. of grate surface. footnote to guidelines for disposal Damaged or missing Grate missing or broken member(s) of the grate. Grate is in place and meets design standards. Manhole Cover/Lid Cover/lid not in place CoverAid is missing or only partially in place. Coverllid protects opening to Any open structure requires urgent structure. maintenance. Locking mechanism Mechanism cannot be opened by one Mechanism opens with proper tools. Not Working maintenance person with proper tools. Bolts cannot be sealed. Self-locking cover/lid does not work. CoverAid difficult to One maintenance person cannot remove Cover/lid can be removed and Remove coverllid after applying 80 lbs. of lift. reinstalled by one maintenance person. 1 1 1 1 1/9/2009 2009 Surface Water Design Manual — Appendix A I A -8 1 APPENDIX A MAINTENANCE: REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 1 L 1( 1 1 NO.5 - CATCH BASINS AND MANHOLES Maintenance Defect or Problem Condition When Maintenance Is Needed Results Expected When Component Maintenance is Performed Structure Sediment Sediment exceeds 60% of the depth from the Sump of catch basin contains no bottom of the catch basin to the invert of the sediment. lowest pipe into or out of the catch basin or is within 6 inches of the invert of the lowest pipe into or out of the catch basin. Trash and debris Trash or debris of more than 1/2 cubic foot which No Trash or debris blocking or is located immediately in front of the catch basin potentially blocking entrance to opening or is blocking capacity of the catch basin catch basin. by more than 10%. Trash or debris in the catch basin that exceeds No trash or debris in the catch basin. 113 the depth from the bottom of basin to invert the lowest pipe into or out of the basin. Dead animals or vegetation that could generate No dead animals or vegetation odors that could cause complaints or dangerous present within catch basin. gases (e.g., methane), Deposits of garbage exceeding 1 cubic foot in No condition present which would volume. attract or support the breeding of insects or rodents. Damage to frame Corner of frame extends more than Y. inch past Frame is even with curb. and/or top slab curb face Into the street (If applicable). Top slab has holes larger than 2 square inches or Top slab is free of hales and cracks, cracks wider than''/, inch. Frame not sitting flush on top slab, i.e., Frame is sitting flush on top slab. separation of more than % inch of the frame from the top slab. Cracks in walls or Cracks wider than '% inch and longer than 3 feet, Catch basin is seated and bottom any evidence of soil particles entering catch structurally sound. basin through cracks, or maintenance person judges that catch basin is unsound. Cracks wider than % inch and longer than 1 foot No cracks more than 114 inch wide at at the joint of any inlet/outlet pipe or any evidence the joint of inlet/outlet pipe. of soil particles entering catch basin through cracks. Settlement/ Catch basin has settled more than 1 inch or has Basin replaced or repaired to design misalignment rotated more than 2 inches out of alignment. standards. Damaged pipe joints Cracks wider than '%-inch at the joint of the No cracks more than V.. -inch wide at inletloutlet pipes or any evidence of soil entering the joint of inlettoutlet pipes. the catch basin at the joint of the inlet/outlet pipes. Contaminants and Any evidence of contaminants or pollution such Materials removed and disposed of pollution as oil, gasoline, concrete slurries or paint. according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Inlet/Outlet Pipe Sediment Sediment filling 20% or more of the pipe. tnletioutlet pipes clear of sediment. accumulation Trash and debris Trash and debris accumulated In inlettoutlet No trash or debris in pipes. pipes (includes floatables and non-floatables). Damaged Cracks wider than Yrinch at the joint of the No cracks more than %-inch wide at Inlet/outlet pipes or any evidence of soil entering the joint of the inlettoullel pipe. at the joints of the inletloutlet pipes. ' 2009 Surface Water Design Manual -- Appendix A 1/9/2009 A-9 APPGNDIX A MAINTENANCE REQI11RF.MI7NTS FLOW CONTROL, CONVl-YANCF,, AND WQ FACILITIE=S NO. 5 -- CATCH BASINS AND MANHOLES Maintenance Defect or Problem Condition When Maintenance Is Needed Results Expected When Component Maintenance Is Performed Metal Grates Unsafe grate opening Grate with opening wider than '1B inch. Grate opening meets design (Catch Basins) standards. Trash and debris Trash and debris that is blocking more than 20% Grate free of trash and debris. of grate surface. footnote to guidelines for disposal Damaged or missing Grate missing or broken member(s) of the grate. Grate is in place and meets design Any open structure requires urgent standards. maintenance. Manhole Cover/Lid Coverllid not in place Coverflid is missing or only partially in place. Coverllid protects opening to Any open structure requires urgent structure. maintenance. Locking mechanism Mechanism cannot be opened by one Mechanism opens with proper tools. Not Working maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Coverllid difficult to One maintenance person cannot remove Cover/lid can be removed and Remove coverNid after applying 80 lbs. of lift. reinstalled by one maintenance person. 1/9/2009 2009 Surface Water Design Manual -- Appendix A A-10 1 1 1( 1 I 1i 1 1 1 APPENDIX A MAINTFNANCE REQU]REM ENTS FOR FLOW CONTROL., CONVEYANCE, AND WQ FAC I].IT]ES NO.6 - CONVEYANCE PIPES AND DITCHES Maintenance Defect or Problem Conditions When Maintenance is Needed Results Expected When Component Maintenance is Performed Pipes Sediment & debris Accumulated sediment or debris that exceeds Water flaws freely through pipes. accumulation 20% of the diameter of the pipe. Vegetation/roots Vegetation/roots that reduce free movement of Water !lows freely through pipes. water through pipes. Contaminants and Any evidence of contaminants or pollution such Materials removed and disposed of pollution as oil, gasoline, concrete slurries or paint. according to applicable regulations. Source control BMPs implemented If appropriate. No contaminants present other than a surface ail film. Damage to protective Protective coating is damaged; rust or corrosion Pipe repaired or replaced. coating or corrosion is weakening the structural integrity of any part of pipe. Damaged Any dent that decreases the cross section area of Pipe repaired or replaced. pipe by more than 20% or is determined to have weakened structural integrity of the pipe. Ditches Trash and debris Trash and debris exceeds 1 cubic foot per 1,000 Trash and debris cleared from square feet of ditch and slopes. ditches. Sediment Accumulated sediment that exceeds 20% of the Ditch deanedl(lushed of all sediment accumulation design depth. and debris so that it matches design. Noxious weeds Any noxious or nuisance vegetation which may Noxious and nuisance vegetation constitute a hazard to County personnel or the removed according to applicable public, regulations, No danger of noxious vegetation where County personnel or the public might normally be, Contaminants and Any evidence of contaminants or pollution such Materials removed and disposed of pollution as oil, gasoline, concrete slurries or paint. according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Vegetation Vegetation that reduces free movement of water Water flows freely through ditches. through ditches. Erosion damage to Any erosion observed on a ditch slope. Slopes are not eroding. slopes Rock lining out of One layer or less of rock exists above native soil Replace rocks to design standards. place or missing (If area 5 square feet or more, any exposed native Applicable) soil. ' 2009 Surface Water Design Manual — Appendix A 1/9/2009 A-11 APPENDIX A MAI N"T FNANC13 RFOUIRE-MENTS FLOW CONTROL, CONVEYANCE, AND WQ FACIL.1 FLS ' NO.7 - DEBRIS BARRIERS (E.G., TRASH RACKS) Maintenance Component Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance is Performed. Site Trash and debris Trash or debris plugging more than 20% of the Barrier clear to receive capacity flow, area of the barrier. Sediment Sediment accumulation of greater than 20% of Barrier clear to receive capacity flow, accumulation the area of the barrier Structure Cracked broken or loose Structure which bars attached to is damaged - pipe is loose or cracked or concrete structure is Structure barrier attached to is sound, cracked, broken of loose. Bars Bar spacing Bar spacing exceeds 6 inches. Bars have at most 6 inche spacing. Damaged or missing Bars are bent out of shape more than 3 inches. Bars in place with no bends more bars than % inch. Bars are missing or entire harrier missing. Bars in place according to design. Bars are loose and rust is causing 50% Repair or replace barrier to design deterioration to any part of barrier. standards. 1 l 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1/9/2009 2009 Surface Water Design Manual — Appendix A ' A-12 1 1 1 1 1( 1 1 1 1 1 APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CON'T'ROL, CONVEYANCE, AND WQ FACILITIES NO.8 - ENERGY DISSIPATERS Maintenance Defect or Problem Conditions When Maintenance is Needed Results Expected When Component Maintenance is Performed. Site Trash and debris 'Trash and/or debris accumulation. Dissipater clear of trash and/or debris. Contaminants and Any evidence of contaminants or pollution such Materials removed and disposed of Pollution as oil, gasoline, concrete slurries or paint. according to applicable regulations. Source control SMPs implemented it appropriate. No contaminants present other than a surface oil film. Rock Pad Missing or moved Only one layer of rock exists above native soil in Rock pad prevents erosion. Rock area five square feel or larger or any exposure of native soil. Dispersion Trench Pipe plugged with Accumulated sediment that exceeds 20% of the Pipe cleanedlflushed so that it sediment' design depth. matches design. Not discharging water Visual evidence of water discharging at Water discharges from feature by properly concentrated points along trench (normal sheet flow. condition is a "shoot flow" of water along trench). Perforations plugged. Over 114 of perforations in pipe are plugged with Perforations freely discharge flow. 'debris or sediment. Water flows out top of . Water flows out of distributor catch basin during No flow discharges from distributor 'distributor' catch any storm less than the design storm. catch basin. basin. Receiving area over- Water in receiving area is causing or has No danger of landslides. saturated potential of causing landslide problems. Gabions Damaged mesh Mesh of gabion broken, twisted or deformed so Mesh Is intact, no rock missing. structure is weakened or rock may fall out. Corrosion Gabion mesh shows corrosion through more than All gabion mesh capable of of its gage. containing rock and retaining designed form. Collapsed or Gabion basket shape deformed due to any All gabion baskets intact, structure deformed baskets cause. stands as designed. Missing rock Any rock missing that could cause gabion to No rock missing. loose structural Integrity. Manhole/Chamber Worn or damaged Structure dissipating flow deteriorates to '/p or Structure Is in no danger of failing. post, baffles or side of original size or any concentrated worn spot chamber exceeding one square foot which would make structure unsound. Damage to wall, Cracks wider than'/cinch or any evidence of soil Manholelchamber is seated and frame, bottom, andlor entering the structure through cracks, or structurally sound. top stab maintenance inspection personnel determines that the structure is not structurally sound, Damaged pipe joints Cracks wider than %-inch at the joint of the No soil or water enters and no water InleVoutlet pipes or any evidence of soil entering discharges at the joint of inlet/outlet the structure at the joint of the inletloutlet pipes. pipes. ' 2009 Surface Water Design Manual — Appendix A (/9/2009 A-13 APpENDlX A MA1NTE..NANCEi REQUIRFN1fiNTS FLOW CONTROL, CONVEYANCE, AND WQ FACILI"FIGS NO. 11 -GROUNDS (LANDSCAPING) Maintenance Defect or Problem Conditions When Maintenance is Needed Results Expected When Component Maintenance Is Performed Site Trash or litter Any trash and debris which exceed 1 cubic foot Trash and debris cleared from site. per 1,000 square feet (this is about equal to the amount of trash it would take to fill up one standard size office garbage can). In general, there should be no visual evidence of dumping. Noxious weeds Any noxious or nuisance vegetation which may Noxious and nuisance vegetation constitute a hazard to County personnel or the removed according to applicable public. regulations. No danger of noxious vegetation where County personnet or the public might normally be. Contaminants and Any evidence of contaminants or pollution such Materials removed and disposed of pollution as oil, gasoline, concrete slurries or paint. according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Grass/groundcover Crass or groundcover exceeds 18 inches in Grass or groundcover mowed to a height. height no greater than 6 inches. Trees and Shrubs Hazard Any tree or limb of a tree identified as having a No hazard trees in facility. potential to fall and cause properly damage or threaten human lite. A hazard tree identified by a qualified arborist must be removed as soon as possible. Damaged Limbs or parts of trees or shrubs that are split or Trees and shrubs with less than 5% broken which affect more than 25% of the total of total foliage with split or broken foliage of the tree or shrub. limbs. Trees or shrubs that have been blown down or No blown down vegetation or knocked over. knocked over vegetation. Trees or shrubs free of Injury. Trees or shrubs which are not adequately Tree or shrub in place and supported or are leaning over, causing exposure adequately supported; dead or of the roots. diseased trees removed. 1/9/2009 2009 Surface Water Design Manual — Appendix A A -l6 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 APPENDIX A MAIN"rENANCU REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES NO. 21- STORMFILTER (CARTRIDGE TYPE) Maintenance Defect or Problem Condition When Maintenance Is Needed Results Expected When Component Maintenance is Performed Site Trash and debris Any trash or debris which impairs the function of Trash and debris removed from the facility. facility. Contaminants and Any evidence of contaminants or pollution such Materials removed and disposed of pollution as oils, gasoline, concrete slurries or paint. according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Life cycle System has not been inspected for three years. Facility is re -inspected and any needed maintenance performed. Vault Treatment Sediment on vault Greater than 2 inches of sediment. Vault is free of sediment. Area floor Sediment on top of Greater than %s inch of sediment. Vault is free of sediment. cartridges Multiple scum lines Thick or multiple scum lines above top of Cause of plugging corrected, above top of cartridges. Probably due to plugged canisters or canisters replaced it necessary, cartridges underdrain manifold. Vault Structure Damage to wall, Cracks wider than Y: -inch and any evidence of Vault replaced or repaired to design Frame, Bottom, andlor soil particles entering the structure through the specifications. Top Slab cracks, or qualified inspection personnel determines the vault is not structurally sound. Baffles damaged Baffles corroding, cracking warping, and/or Repair or replace baffles to showing signs of failure as determined by specification. maintenance/inspection person. Filter Media Standing water in 9 inches or greater of static water in the vault for No standing water in vault 24 hours vault more than 24 hours following a rain event and/or after a rain event. overflow occurs frequently. Probably due to plugged filter media, underdrain or outlet pipe. Short circuiting Flows do not property enter filter cartridges. Flows go through filter media. Underdrains and Sediment/debris Underdrains or clean -outs partially plugged or Underdrains and clean -outs free of Clean -Outs filled with sediment and/or debris. sediment and debris. Inlet/Outlet Pipe Sediment Sediment filling 20% or more of the pipe. Inletloutlet pipes clear of sediment. accumulation Trash and debris Trash and debris accumulated in inlet/outtet No trash or debris in pipes. pipes (includes floatables and non-floatables). Damaged Cracks wider than '/2 -inch at the joint of the No cracks more than %-inch wide at inletloutlet pipes or any evidence of sell entering the joint of the inlet/outlet pipe, at the joints of the Inlet/outlet pipes. Access Manhole Cover/lid not in place Cover/lid is missing or only partially in place. Manhole access covered. Any open manhole requires Immediate maintenance. Locking mechanism Mechanism cannot be opened by one Mechanism opens with proper tools. not working maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Cover/lid difficult to One maintenance person cannot remove CoverAid can be removed and remove coverllid after applying 80 lbs of tilt. reinstalled by one maintenance person. Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meats design standards. Allows maintenance person safe access. Large access doors/plate Damaged or difficult to open Large access doors or plates cannot be opened/removed using normal equipment. Replace or repair access door so it can opened as designed. 1/9/2009 A-30 2009 Surface Water Design Manual — Appendix A APPENDIX A MAIN"PENANCE: REQUIREMENTS FOR Fl,0W CONTROL , CON VFYANCE, AND WQ FACILITIES NO. 21 - STORMFILTER (CARTRIDGE TYPE) Maintenance Defect or problem Condition When Maintenance Is Needed Results Expected When Component Maintenance is Performed Gaps, doesn't cover Large access doors not flat and/or access Boors close flat and cover access completely opening not completely covered. opening completely. Lifting Rings missing, Lifting rings not capable of lifting weight of door Lifting rings sufficient to lift or rusted or plate. remove door or plate. 2009 Surface Water Design Manual -- Appendix A 1/9/2009 A-31 1 1 1 Appendix D Geotechnical Report l 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 101orpc REPORT OF GEOTECHNICAL INVESTIGATION PROI'OSF.D RESIDENTIAL DEVELOPMENT EDMONDS AND GLENNWOOD AVE NE RENTON, WA S&EE JOTS NO. 1010 JANUARY 10, 2011 S&EE S&EE SOIL & ENVIRONMENTAL ENGINEERS, INC. ' 1 AQiRed and Wn 'te 2'1 a nd Washington 99052 5 68-580 IJanuary 10, 2011 IMr. Mark Cropper (mrg@rentonhousing.org) Renton Housing Authority Renton, WA CC: Mr. Joel Ing (Joeli@shelterresourcesine,com) 1 1 1 1 1 1 Report of Geotechnical Investigation Proposed Residential Development l+dmonds and Giennwood Ave NE Renton, Washington Dear Mr. Gropper: We are pleased to present herewith our Report of Geotechnical Investigation for the referenced project. Our services were authorized by Mr, Joel Ing on August 26, 2010, and have been provided in accordance with our proposal dated August 16, 2010. During the course of our investigation, the design added the multi- family ultifamily building at the southwestern portion of the site. Since this building may include one to two levels of underground parking, we suggested a supplemental exploration program which ineludes 2 soil test borings. This additional worlcwus approved by you on September 20, 2010. We appreciate the opportunity to provide our services. Should you have any question regarding the contents of this report or require additional information, please call. 101orpt Very truly yours, SOIL & ENVIRONMENTAL ENGINEERS, INC. 4NAL C. J. Shin, Ph.D., P.E. President S&I✓E TABLE ON CONTENTS ' Section Page 1.0 INTRODUCTION ........................................... .......................................................................................... I......... ! ' 2.0 SCOPE OF SERVICES...................................................................................................................................... 2 FIGURE 2: SITE AND EXPLORATION PLAN ' FIGURE 3: WALL AND FOUNDATION DRAINS FIGURE 4: LA'T'ERAL EARTH PRESSURES FOR CAN'T'ILEVER SHORING WALLS ' FIGURE 5: CALCULATION OF SURCHARGE LOADS ON SUB -SURFACE WALLS FIGURE 6: UNDER -SLAB DRAIN ' APPENDIX A: FIELD EXPLORATION, LOGS, SOIL CLASSIFICATION CHART AND KEY TO BORING LOGS t 1 1 iaiarpi S&EE 1. 3A SITE CONDITIONS .............. ............'..........................................:......,.............................................................. 2 3.1 SUR.FACECONDITIONS .......... .2 3.2 PLIBLISHE;DC3FOLOGICINFOR1vMKI'ION....................................................................................................3 3.3 TEST PIT AND BORING FINDINGS 3 ' 3.4 GROUNDWATER. ...........................................�...........,..............................................,........ 4 4.0 CONCLUSIONS AND RECOMMENDATIONS........................................................................................... 5 ' 4.1 ...................... 5 5 T......................................,........................................................................................ 4.2 FOUNDATION SUPPORT . FOUNDATION 4.3 EXCAVATION SHORING.............................................................................................................................. 7 4.4 LATERAL. EARTH PRESSURES ON PERMANENT RETAINING WALLS ................................................. 4.5 SITE PREPARATION, STRUCTURAL. FILLAND DRAINAGE.................................................................... 8 10 4.6 SLAB-ON-GRADE.................................................................................................................................... 1l 4.7 FLEXIBLE PAVEMENT ................ ..........................................................................................I....... 11 4.9 TEMPORARY AND PERMANENT EXCAVATIONS.................................................................................. 12 ' 4.9 SEISMIC CONSIDERATIONS ............ ...........................................................................................................12 4.10 ADDITIONAL SERVICES........................................................................................................................... 13 ' FIGURE 1: SITE LOCATION MAP FIGURE 2: SITE AND EXPLORATION PLAN ' FIGURE 3: WALL AND FOUNDATION DRAINS FIGURE 4: LA'T'ERAL EARTH PRESSURES FOR CAN'T'ILEVER SHORING WALLS ' FIGURE 5: CALCULATION OF SURCHARGE LOADS ON SUB -SURFACE WALLS FIGURE 6: UNDER -SLAB DRAIN ' APPENDIX A: FIELD EXPLORATION, LOGS, SOIL CLASSIFICATION CHART AND KEY TO BORING LOGS t 1 1 iaiarpi S&EE 1 1 1 1 1 1 1 1 1 1 REPORT OF GEOTECHNICAL INVESTIGATION PROPOSED DEVELOPMENT AT EDMONDS AND GLENNWOOD AVE NE RENTOR, WASHINGTON For Renton Housing Authority 1.0 INTRODUCTION We present in this report the result<4 of our geotechnical investigation for the project. The site is located between Edmonds Avenue NE and Glennwood Avenue NE in Menton. A site location map is shown in Figure 1 which is included at the end of this report. We understand that the project will have the following elements and they may be constructed in phases. 1) A multifamily building in the south-western portion of the site. The building will be a 3 or 4 - story, wood -framed structure with one or two levels of underground parking. This basement will required a maximum excavation of about 10 to 20 feet below the current site grade. Basement excavation will likely be achieved with a combination of open cut and excavation shoring. 2) A multifamily building in the mid portion of the site. The building may be a 4 -story, wood - framed structure and have one level parking basement daylighting to the west. The basement will required a maximum excavation of about 10 feet below the current site grade. [casement excavation will likely be achieved with open cut. 3) Two townhome buildings (3 And 5 units) and surface parking in the eastern portion of the site. The buildings will be 3 -story, wood -framed structures. No basement is proposed and cut -and -fill is expected to be minimal. 4) Anew access road connecting Edmonds Avenue NE and Glennwood Avenue NE. Based on our experience with similar buildings, we anticipate that the maximum column and wall loads will be on the order of 75 kips and 5 kips per lineal foot, respectively. 2.0 SCOPE OF SERVICES The purpose of our study is to develop geotechnical recommendations regarding site development and foundation support. Specifically, our services included: 1. Exploration of soil and groundwater conditions underlying the site by the excavation of 6 test pits and the drilling of two soil test borings. 2. Recommendations regarding type of foundation support. 3_ Recommendations regarding construction shoring. 4. Recommendations regarding active and at -rest earth pressures to be used for the design of any retaining structures. S. Recommendations regarding passive soil resistance and coefficient of friction for the rosistance of lateral loads. 6. Recommendations regarding temporary and permanent cut slopes. 7. Recommendations regarding support for slab -on -grade. 8. Recommendations regarding pavement design. 9. Recommendations regarding type of soil for seismic design. 10. Recommendations regarding site preparation, including removal of unsuitable soils, suitability of onsite soils for use as fill, fill placement techniques, and compaction criteria. 11. Five copies of a written geotechnical report containing a site plan, exploration logs, a description of subsurface conditions, and our findings and recommendations. 3.0 SITE CONDITIONS 3.1 SURFACE CONDITIONS The site is located in a residential area. A rockery wall, about 10 to 12 feet in height, flanks the western site boundary along Edmonds Avenue NE. From the top of this wall eastward, the site grade rises with about 10- to I5 -percent slopes to the mid portion of the site. From there to Glennwood Avenue NE, the 1010rpt 2 S&EE 1 1 'town site grades rise gently at about S to 10 percents. At the time of our field exploration, an existing Site surface home occupied the southeastern portion of the site and the rest of the areas are vacant. is covered with sparse trees, brushed and grass lawn. 3.2 PUBLISHED GEOLOGIC INFORMATION Published geologic information (Geologic Map of The Renton Quadran&, King County, Washington by U.R. Mullineaux, 1965) indicates that the site area is underlain by glacially deposited recessional outwash (Qpa). According to the neap, the material consists chiefly of sand and gravel. 3.3 TEST PIT AND BORING FINDINGS The soil conditions underlying the site were explored by the excavation of 6 test pits, TP -1 through TP -6 on ' August 27, 2010 and the drilling of 2 soil test borings, 13-1 and B-2 on October 28, 2010. The approximate locations of these explorations arc shown on Figure 2 which is included at the end of this report, Details of the exploration program and the Ings are included in Appendix A. The subsurface conditions are described in the following paragraphs: 1 �otnctx Area of the Proposed F.ast'I'ownhomc Buildings TP -1 and TP - '['he area is covered with about one foot of topsoil mixed with loose fill soil. `file soil is underlain by a surficial layer that consists of a brown silty sand with trace amount of gravel and cobbles. The layer is about 2 to 3.5 feet thick and the material is loose to medium dense. The surficial layer is in turn underlain by a silty sand with gravel and cobbles. This soil is cemented and is dense to very dense. Based on its appearance and density, we believe this is glacially deposited till or commonly term hardpan. Both TP -1 and TP -6 were terminated in till. Area of the Proposed _Multifamily Building in Mid -Portio f Site TP -2 to TP -5 The subsurface conditions here are similar to the above except that the surficial layer is about 2 feet thick and a sandy soil was found below the till layer at TP -3. This sand is dense and includes silt lenses. 3 S&EE Area of the Proposed Multiffimily Building; in Southwestern Portion of Site (B -I and B-2) The subsurface conditions here include a 1.5 -foot thick topsoil layer over a surficial layer that is 1.5 to 6.5 feet in thickness. This layer is medium dense to dense and overlies vety dense glacial till, The till is in tum underlain by a stiff to very stiff silt at depths from 15 to 25 feet below the Found surface. Both borings encountered very dense glacial till below the silt. The borings were terminated at a depth of 30 feet in till. 3.4 GROUNDWATER 101 orpt Only minor (about 1/100 gallon per minute) groundwater seepage was encountered in TP -3. The seepage occurred at a depth of 10 feet and appeared to perch over the relatively impermeable silt lens. Wet soils were also encountered just above the silt layer in Boring B -l. Based on our experience with the similar soil conditions, we believe that groundwater may perch on the relatively impermeable silt in the wet winter months. The depth of the perched groundwater table may vary with season and precipitation. 4 S&EE 1 ' 4.0 CONCLUSIONS AND RECOMMENDATIONS 4.1 GENERAL 1. Based on our investigation, we recommend that the proposed buildings be supported by ' conventional spread footings. Please note that loose to medium dense silty soils are present near the ground surface. If these materials are exposed at the footing subgrade, it must be properly prepared prior to concrete pour. Also, the soils near the ground surface arc generally loose and ' very silty. These soils will lose their strength when wet and become muddy when disturbed. Therefore, earthwork will be difficult in the wet winter months as wet soil cannot be used for ' backfill, export of wet soil.will be expensive, and erosion control will be difficult. 2. Minor groundwater seepage was encountered at a depth of 10 feet at'I'll-3. Based on this, we believe that the need of construction dewatering is unlikely. However, some localized wet zone may be exposed by basement excavation. For planning purposes, we recommend that under -slab ' drains be considered for basements. The purposes of these drains are to provide a stable work base and prevent future wet floor. 1 3. Elxcept for the existing fill soil, the onsite soils are suitable for use as structural fill material. ' However, most of the soils are silty in nature and will require moisture -conditioning prior to use. Details of our recommendations are presented below. ' 4.2 FOUNDATION SUPPORT We recommend that the proposed buildings be supported by conventional spread footings which must ' penetrate the existing fill and be founded on at least medium dense native soils or re -compacted onsite soils. Recommendation details are presented below. Footing Construction 1. Prior to re -bar and concrete placement, all footing bearing surfaces must be cleaned of loose soils. Except for glacial till, the upper 12 inches of the footing subgrade soil should be re -compacted to at least 55% of its maximum dry density as determined using ASTM D-1557 test procedures. 1910rpt 5 S&L, E 1 2. All existing fill, wet, soft and organic soils encountered at footing subgrade should be over - excavated. The over -excavation should be backfilled with structural fill, concrete or compacted crushed rock. The criteria of structural fill are presented in Section 4.5 of this report. 3. All exterior footings should be founded at least 18 inches below the adjacent finished grade to provide protection against frost action, and should be at least 18 inches in width to facilitate construction. 4. All footing bearing Surfaces must be inspected by a qualified geotechnical engineer prior to re -bars and concrete placements. The engineer should confirm the bearing capacity of the subgrade soil, and provide recommendations regarding repair, if necessary. Allowable Bearing Loads We recommend the following allowable bearing pressures for the footing designs: Footings at depths less than 5 feet from final grade: 3,000 pounds per square foot (psf) Footings at depths greater than 5 feet from final grade: 4,504 pounds per square foot (psf) The above bearing capacity values include a factor of safety of at least 3, and can be increased by one-third for wind and seismic loads. Se lement Interior column footings designed in accordance with the above recommendations are expected to experience approximately 112 inch of settlement. Continuous wall footings should experience settlement of about 114 to 1f2 inclr. Differential settlement between adjacent footings is expected to be about 114 inch. The settlement will occur rapidly, essentially as the loads are applied. Lateral Resistance Lateral resistance can be obtained from the passive earth pressure against the footing sides and the friction at the contact of the footing bottom and bearing soil. The former can be obtained using an equivalent fluid density of 250 pounds per cubic foot (peo, and the latter using a coefficient of friction of D.S. These values include a safety factor of 1.5. 1010rpt 6 S&EE 1 1 4.3 EXCAVATION SHORING 1 Excavation for basements may be achieved with a combination of temporary cut slope and shoring. The temporary out should be no steeper than IH:IV (Horizontal to Vertical). We recommend that the shoring be consisted of cantilever soldier pile with timber lagging. The soldier piles will consist of steel H -beams ' in drilled and grouted holes. As the excavation proceeds, timber fagging is installed between the H -beams. The voids behind the lagging must be filled with sand or pea gravel the same day lagging is installed. Un- filled voids may result in ground settlement behind lagging and thus severe damages to the neighboring ' buildings and properties. ' A permanent wall should be constructed in front of the temporary shoring wall. Drainage is provided by the installation of a geotextile drain mat attached to the shoring wall. The drain mat should be hydraulically connected to an interior footing drain by 2 -inch diameter weep pipes that Eire spaced at 5 feet on center. (See Figure 3 for details) 5 LATERAL LOADS AND RESISTANCES 1 1 1 1 1 1 Figure 4 shows our recommended earth pressures for the design of cantilever shoring walls. Additional lateral earth pressures will result from foundation loads adjacent to the excavation; surcharge loads by traffic, storage and slopes next to the excavation. The lateral earth pressure due to foundation loads can be estimated using the method presented in Figure 5. Traffic and storage surcharges can be accounted for by increasing the effective height of the wall by 2 feet. Slope surcharges can be accounted for by increasing the effective height of the wall to equal 112 (one-half} of the height of the slope. LAGGING DESIGN For shoring areas that are not adjacent to existing buildings, lagging can be, designed using 50 percent of the lateral earth pressures presented above. Such stress reduction is due to the anticipated soil arching effects. No reduction should be used for shoring adjacent to any neighboring building. SHORING MONITORING A shoring monitoring program should be installed to verify the performance of the shoring system and to evaluate any possible excavation effects on the adjacent buildings and properties. Prior to the excavation, 1010TI 7 S&EE the existing conditions of the adjacent buildings and properties should be photographed and recorded. After the installation of the soldier piles and before mass excavation, a base line survey should be conducted. Once excavation begins, the vertical and horizontal movements of every other pilo should be surveyed on it weekly basis. The weekly survey should continue until the bottoms of excavations are reached. Depending on the shoring performance and the construction season, the geotechnical engineer may choose to relax the survey frequencies. All survey results should be transmitted to the office of the project geotechnical engineer within 24 hours after they are obtained. 4.4 LATERAL EARTH. PRESSURES ON PERMANENT RETAINING WALLS Lateral earth pressures on permanent retaining walls, underground vaults or utility (renches/pits, and resistance to lateral loads may he estimated using the recommended soil parameters. presented in the following table. Note: >;lydrostatic pressures are not included in the above lateral earth pressures. "Ilia at -rest case applies to unyielding walls, and would be appropriate for walls that are structurally restrained from lateral deflection such as basement walls, utility trenches or pits. The passive earth pressure and coefficient of friction include a safety factor of I .S. The active case applies to walls that are permitted to rotate or translate away from the retained soil by approximately 0.002H to 0.004H, where It is the height of the wall. SURCHARGE MDUCED LATERAL LOADS 1) Additional lateral earth pressures will result from surcharge loads from floor slabs or pavements for parking that are localed immediately adjacent to the walls. The surcharge= induced lateral earth iaiorpt 8 ME E 1 tTt—. .� AYS Ptk- p.,- '� ; ' r Equivalent F�utd:Unit Welglat (f'CF} �, d of r S� r 1`c �s t,W. I' r + �,' , � '' ,rte r - * • — +� -� � uF' .t r 1 ' Act4ve i At -rest Passive �� 1 Structural fill and 40 SO 300 0.5 native soils Note: >;lydrostatic pressures are not included in the above lateral earth pressures. "Ilia at -rest case applies to unyielding walls, and would be appropriate for walls that are structurally restrained from lateral deflection such as basement walls, utility trenches or pits. The passive earth pressure and coefficient of friction include a safety factor of I .S. The active case applies to walls that are permitted to rotate or translate away from the retained soil by approximately 0.002H to 0.004H, where It is the height of the wall. SURCHARGE MDUCED LATERAL LOADS 1) Additional lateral earth pressures will result from surcharge loads from floor slabs or pavements for parking that are localed immediately adjacent to the walls. The surcharge= induced lateral earth iaiorpt 8 ME E 1 pressures are uniform over the depth of the wall. Surcharge -induced lateral pressures for the "active" case may be calculated by multiplying the applied vertical pressure (in psf) by the active earth pressure coefficient (Ka). 'rhe value of Ka may be taken as 0,4, The surcharge -induced lateral ' pressures -for the "at -rest" case are similarly calculated using an at -rest earth pressure coefficient (Ko) of 0,5. For surcharge loads that are not adjacent to the wall, the induced lateral earth pressure will depend on the magnitude of the surcharge and the distance from the wall. Such induced lateral load tcan be estimated using the equations shown on Figure 5. 1 1 1 1 1 1 2) The slope -induced lateral earth pressure can be accounted for by increasing the effective height of the wall by one-half the slope height. For back slope continues beyond a horizontal distance equal to the height of (lie wall, only the part of slope -rise within this horizontal distance should be considered. 3) The traffic -induced lateral earth pressure can be accounted for by increasing the effective wall height by 2 feet. SI✓ISMIC INDUCED LATERAL (AADS Seismic induced lateral loads can be assumed to act at 0.7 H above the wail base and the magnitude can be calculated using the following equation: Pe = 31VT*I '*a Where Pe = seismic -induced lateral load Y = soil density = 130 pcf H = wall height a = horizontal acceleration BACKFILL IN FRONT OP RETAINING WAL S Backfill in front of the wall should be structural fill. The material and compaction requirements are presented in Section 4.5 of this report. The density of the structural fill can he assumed to be 130 pounds per cubic feet. BACKFILL BEHIND LMTAIMNG WALLS Backfill behind the wall should be free -draining materials which are typically granular soils containing less than 5 percent fines (silt and clay particles) and no particles greater than 4 inches in diameter. The density 101 Orpt 4 S&EE of the backfill material can be assumed to be 1.25 pounds per cubic feet. The backfill material should be placed in 6 to 8 -inch thick horizontal lifts and compacted to at least 90 percent of the maximum density in accordance with ASTM D-1557 test procedures. in the areas where the dill will support pavement, sidewalk or slabs, the top two feet of the backfill should be compacted to at least 95 percent of the maximum density. Care must be taken when compacting backfill adjacent to retaining; walls, to avoid creating excessive pressure on the wall. DRAINAGE BEHIND RETAINING YVALLS Rigid, perforated drainpipes should be installed behind retaining walls. Drainpipes should be at least 6 inches in diameter, covered by a layer of uniform size drain gravel of at least 12 inches in thickness, and be connected to a suitable discharge location. An adequate number of cleanouts should be installed along the drain line for future maintenance. 4.5 SPIT PREPARATION, STRUCTURAL, FILL. AND DRAINAGE, Site preparation should begin with proof -rolling suhgrades using heavy construction equipment. Areas which are found to be wet, soft, or organic should be over -excavated. The geotechnical engineer should observe the proof -rolling to provide subgrade evaluation and over -excavation requirement, if needed. After stripping, over -excavation and excavation to the design grade, the top 12 inches of exposed subgrade soils should be re -compacted to at least 95% of their maximum dry density as determined using ASTM D- 1557 test procedures (Modified Proctor test). Structural fill can then be placed in the over -excavation and fill areas. The structural fill materials should meet both the material and compaction requirements presented below. Material Re uireme s: Structural fill should be free of organic and frozen material and should consist of hard durable particles, such as sand, gravel, or quany-processed stone, Except for the existing fill, the on-site soils are suitahle for structural fill. Due to their silty nature, these soils are moisture -sensitive and should be moisture -conditioned to +/- 2% from their optimum moisture contents prior to use. Please note that the use of this material in wet seasons may be difficult. Suitable imported structural fill materials incudo silty sand, sand, mixture of sand and gravel (pitrun), and crushed rock. tata�� 10 S&EE 1 1 1 1 1 1 1 1 1 1 1 1 All structural fill material should be approved by the geotechnical engineer prior to use Placement and Compaction Requirements: Structural fill should be placed in loose horizontal lifts not exceeding a thickness of 6 to 12 inches, depending on the material type, compaction equipment, and number of passes made by the equipment. Structural fill should be compacted to at least 95% of the maximum dry density as determined using the ASTM D-1557 test procedures. SITE DRAINAGE The site surface should be graded so that surfacewater is directed away from the structural areas. Standing water should not be allowed. Final site grades should be sloped away from the building unless the area is paved. Otherwise, yard drains should be installed to collect surface runoff 4.6 SLAB -ON -GRADE All slabs can be soil supported. We envision that the soil at the subgrade will be disturbed and loosened by construction activities at the time of stab construction. We therefore recommend that the subgrade be proof -rolled or probed prior to pour. Any wet and loose areas should be over -excavated and backfilled with structural fill. We recommend that slab -on -grade be underlain by a 15 -mil. vapor barrier over at least 4 -inch thick free - draining gravel. As previously mentioned, basement excavation may encountered perch groundwater and under -slab drains may be necessary to avoid future wet basement. The under -slab drain includes a trench with a perforated drain pipe and gravel backfill. A cross-sectional view of the drains is shown in Figure 6. The drain lines are typically spaced at 15 to 20 feet on center. We recommend that a qualified geotechnical en&cer observe the building subgrade and provide drainage details at the time of construction. 43 FLEXIBLE PAVEMENT. We recommend that the subgrade for flexible pavement be prepared in accordance with the recommendations presented in Section 4.5. Based on the, subsoil conditions, we believe that the prepared tntorpc l 1 S&EE sublrade will have a California Bearing Ratio (CBR) of at least 12. We therefore recommend the following flexible pavement sections for light and medium traffic conditions: Light traffic (Daily EAL = 5 or less): 2 inches asphaltic concrete over 6 inches base course Medium traffic (Daily EAL = 20 to 80): 3 inches asphaltic concrete over 8 inches base course The base course should be compacted to at least 95 percent of the maximum dry density as determined by ASTM D-1557 test method. "Che material should meet WSDOT aggregate specification 9-03.9(3) and have tho following gradation: Sieve Size Percent Passin 1 '/4 -inch 100 518 -inch 50-80 114 -inch 30-50 US No. 40 3-18 US No. 200 7.5 max. % Fracture 75 min. 4.8 TEMPORARY AND PI?RMANF-NT EXCAVKI'IGNS I' -or temporary excavations less than 3 feet in depth, the cut bank may be excavated vertically. For excavation deeper than 3 feet, the slope should bo cut no steeper than 11.1:IV, The slope should continue from top to bottom (without a vertical bank at the bottom). Flatter slope cuts may be required if seepage occurs. Temporary cut should be protected from weather during the time of constniction. All permanent slopes should be no steeper than 2H:IV. Water should not be allowed to flow uncontrolled over the lop of any slope. Also, all permanent slopes should be seeded with the appropriate species of vegetation to reduce erosion and maintain the slope stability. 4.9 SEISMIC CONSIDERATIONS We recommend that site class C as defined in the 2006 IBC be considered for the seismic design. The site is underlain by dense glacial till. As such, the liquefaction potential is negligible. ta1an,t 12 S&EE ' 1 4. 10 ADDITIONAL SERVICES 1 Additional services may be required during the design and construction of the project. We envision that these additional services may include the following: ' 1. Review excavation, foundation, and drainage (temporary and permanent) plans to confirm that our recommendations are properly interpreted and utilized in the design. 1 2. Monitor shoring installation and mass excavation. We will confirm that the contractor's equipment and procedures are adequate, and provide recommendations regarding dewatering and sidewall stabilization, if needed. ' 3. Monitor building subgrade conditions. We will evaluate the soil and groundwater conditions and provide recommendations regarding subgrade preparation and under -slab drains, if needed. ' 4. Monitor foundation subgrade preparation. We will confirm the bearing capacity of the subgrade soils, and will assist the contractor in evaluating the protection and over -excavation requirements, if 1 any. 1 5. Monitor the placement and compaction of structural fill. We will confirm the suitability of the fill materials, perform field density tests, and assist the contractor in meeting the compaction requirements. 6. Monitor the installation of subsurface drains. We will ensure these drains are installed in ' accordance with our recommendations. 7. Monitor site drainage and erosion control. 8. Other geotechnical issues deemed necessary. I 1 1 ' l al Drpt 13 S&EE SA CLOSURE e ' The recommendations presented in this report are provided for design purposes poses and are based on soil conditions disclosed by field observations and subsurface explorations. Subsurface information presented ' herein does not constitute a direct or implied warranty that the soil conditions between exploration locations can be directly interpolated or extrapolated or that subsurface conditions and soil variations different from those disclosed by the explorations will not be. revealed. The recommendations outlined in this report are ' based on the assumption that the development putt is consistent with the description provided in this report. If the development plan is changed or subsurface conditions different from those disclosed by the ' exploration are observed during construction, we should be advised at once so that we can review these conditions, and if necessary, reconsider our design recommendations. 1 1 1 1 totorpt 14 MME 1 1 1 1 1 1 1 1 1 1 1 1 1 1. 1 1 1 1 1 1 ��W •-5 r -.i- t "FncCoder�,+' t r � •at�i1;:�, .4=�� ��cAlliifti7la i�+ �bt� ;'� r �{ � �'' • �' ir• y . _ C6 tiCitgr+Y . N jt � :•�� �ri i ia' �;.Yi ;% � t..r:.`''..,�. X5,1,. e r :i�', 9 &iiip leeward. # s+ .. 1 ,3 Caa+�l{ ka�M.• : >y. �s ; i tJ k �'� r+y�N ter' r r. 0 Park j' 11 I� n 1 j eat. F t!Newcastle_'j:i4_ t '� '' 9n!-'hton"`�° a. • '�1- } it�3 ` < rb �o i r :. "��iie � R , , r •. iC1s i .��• . r ti's , •!-,. r A101�ileln t:i 'i1U6 ,,yh+mr�i -Il � t ". 'fit < 4i '. - t •k wr•, h' ia'.rta.i. y . - 1 t'` r - � stfi" -,:'�' . Z" SITE h - - x �1 K.=„ !.w•:' ... 984 qtr ` ".;'Riflierth�ety� �r�xs'�{a'.;�;.r kr+ �� {k ti��� �3tis' � 'A R `f`�"� fi:kk.�•�f�,y-°�� c t� t.� � , �� a, 3u1� 31c + r l��l� -:r. -- � t - 3 � c iJ � � �- • . " Rd {ill �I'"- r a- l� �,---.•,s-.1E ,�fi 1261h Si - srr+r=Ba1 R9nto1!5��1 - 4, 'ti Y _ a.F ♦ r 1 i„ f� i + c e 1s r Highlands , - � y t � 1` �.fj,;+ � �.- _-�-.r:--.h, 'p,� L ` . 1 +:f SY--h � e w - � ♦ - — t��..+��+:�I� �a;, mb P1 �,,.�+ i1 �4, 'r � ld l -- .� 1 : icy,♦ f\�� 1 \I � s � .. � � ..� S it "t _ if 1l � rfi�}4'V•sj# y i �,� l� �` _ �� ` -1:y� f�hr 1 l •]r'��5�,', �_ -vY3: -- � - {ti +.. - i s ,'S i l±,,f�rsif �� . r'„R�� �Y ;Z;licW11B t + 1i� 'i,.� ","`.,,7,'{:yi i� i '� � i � i66 1ARPXr'IVPPd Gwf� -- ..tn_• -1 SF. d .�", ' Li u i zEmF'ic'f.` r Rli 189 ' k 7 , �, J_� f -",rFY 'y�l „ f '�' f; �� � �I.,,� ,� , ti „x'71 � +-+1'� A�y+' } L,{'c. .• y� . �., .- - , y}� 4� F,',- "7- i s_ i I .,ri�la� a v 4'` iso{ l er'•- 4• 3 Map1n '�`� { � . ��,:�•p, � ,, +t?,3 iCassada � iwvnd;� ��Fke4wopd dap FEaipqllls•[.aka � ;t ,� t' (��'o✓' :t - e7J� ��Fp+ , ' ,'• i ,, � ...� RQ4. landCqunvyGwb- Psalie...� �� 16 A nal! + r 3 ��: } i -�! I� '=T..' -90 Sevsrd „�i _ 8ro 1r } i8 t i � tr _ v '�'•.: � �a 6 Palk r �? + '�, µ if.� 11 r} — j ,-- j�h.., ; �'t- �' � Y i:�aa ,..,. ,I [. ';• " ,.• ;xtYapdel,"®an3Qoo�le- Figure I S&EE Site Location Map IN OAV spuourPI 9 C 19 S cm m Irl m , 0 0 w C m a V, IT r 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 OI O O M Ignore top two feet Passive Earth Pressure = 300 pcf acting over 2 Ole diameters Soldier Pile with Lagging Notes: } Surcharge -Induced lateral load C'A must be added in the design. av The magnitude can be estimated using equations shown in Figura 5. H r,.�. (NOT -TO -SCALE) Lateral Earth Pressure above base of excavation: = 40 pcf acting over pile spacing Lateral Earth Pressure below base of excavation = 40(H) psf acting over one pile diameter Notes: 1) Traffic and storage surcharges can be accounted for by Increasing the effective height of the wall by 2 feet 2) Slope surcharge can be accounted for by increasing the effective height of the wall by 1/2 (one-half) of the slope height, 3) Passive pressure includes a safety factor of 1.5. 4) Allowable vertical pile capacity: Skin Friction = 1,000 psf; End Bearing = 15,000 psf (salty factors = at least 2.0) 5) Subgrade reaction modulus = 200 pci (pounds per cubic inch) 5&E15 Jab no. to 10 Piguru 4 Latieml Earth Pressures Cantilever Wall Shoring System 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 C 0.2 0.4 0.8 111 4 y 0.8 a 01 VALUE OF TH ( HL} LINE LAAO QL X �mli FOR m 0.4- aH(UL) (0.15+n Z Z=nH PH': 0.5.5QL L H FOR M)0.4: dH (7 1.2a m2 n R VL {m2 i-nz)2 RESULTANT PH 0.osa OL 2+I ) PRESSURES FROM LINELDAO QL (BOUSSINESO EQUATION MODIFIED BY EXPERIMENT) Reference: Foundations and Earth Structures, pesipn Manual 7.2, Department of the Navy, May 1982 ■ 04 ■moi' MEN ME FAREl MINE a 01 VALUE OF TH ( HL} LINE LAAO QL X �mli FOR m 0.4- aH(UL) (0.15+n Z Z=nH PH': 0.5.5QL L H FOR M)0.4: dH (7 1.2a m2 n R VL {m2 i-nz)2 RESULTANT PH 0.osa OL 2+I ) PRESSURES FROM LINELDAO QL (BOUSSINESO EQUATION MODIFIED BY EXPERIMENT) Reference: Foundations and Earth Structures, pesipn Manual 7.2, Department of the Navy, May 1982 • ,5 1.0 2 H i.7 VALUE OF T () POINT i.DAD Op Q I X --MHP Z=nH PH LL cr H H R FOR m� 0,4- H2 O.28n2 T (7 {016 —in rJ-37 FOR m )O.a. (�}1? 1. 1.77m2n2 H Up (fn2+n2)3 al z 0-H fA52 (I.18 ) Q Q S. X-n'1H SECTION A -A PRESSURES FROM POINT LOAD Op (BOUSSINESQ EQUATION MODIFIED BY EXPERIMENT) Calculation of Surcharge loads on Subsurface Walls Figure 5 ■ ■moi' MEN ME MINE • ,5 1.0 2 H i.7 VALUE OF T () POINT i.DAD Op Q I X --MHP Z=nH PH LL cr H H R FOR m� 0,4- H2 O.28n2 T (7 {016 —in rJ-37 FOR m )O.a. (�}1? 1. 1.77m2n2 H Up (fn2+n2)3 al z 0-H fA52 (I.18 ) Q Q S. X-n'1H SECTION A -A PRESSURES FROM POINT LOAD Op (BOUSSINESQ EQUATION MODIFIED BY EXPERIMENT) Calculation of Surcharge loads on Subsurface Walls Figure 5 SLAB /_ Vapor Barrier 411 BLANKET DRAIN (free -draining crushed rock) 5" Min. P a ° ° o ° o ° ° 311Min. 0G0aRQ°0°°o o ° ° ° ° ° o 12" Min. (NOT -TO -SCALE) GENERAL MOTES: 1. DRAIN PIPE SHOULD BE CAPPED AT THE BEGINNING OF LINE. 2. INSTALL ADEQUADE NUMBER OF CLEANOUT FOR FUTURE MAINTENANCE, 3. DO NOT WRAP DRAIN PIPE WrrH FILTER FABRIC, 4" DIA, PVC, PERFORATED DRAIN PIPE BACKFILL TRENCH WITH 1" DRAIN GRAVEL. SEE UNDER SLAIN DRAINS Figure 6 (NST TO SCALE) APPENDIX A FIELD EXPLORATION AND LOGS ' The soil conditions underlying the site were explored by the excavation of 6 test pits, TP -1 through TP -6 on August 27, 2010 and the drilling of 2 soil test borings, i3-1 and T3-2 on October 28, 2010. The ' approximate locations of these explorations are shown on Figure 2 which is included at the end of this report. The test pits were excavated with a Kubota 080 excavator.. A representative from S&EL was ' present throughout the exploration to excavate the pits and log the subsurface soil conditions. 'rhe soil test borings were advanced using a track -mounted drill rig. A representative from S&EE was present ' throughout the exploration to observe the drilling operations, log subsurface soil conditions, obtain soil samples, and to prepare descriptive geologic logs of the exploration. Soil samples were taken at 2.5- and 5 -foot intervals from the borings with procedures in accordance with ASTM D-1586, "Standard Method ' for Penetration `fest and Split-13arral Sampling of Soils" (1.4" I.D. sampler). 'fhe penetration test involves driving the samplers 18 inches into the ground at the bottom of the borehole with a 140 pounds ' hammer dropping 30 inches. Tho numbers of blows needed for the samplers to penetrate each 6 inches are recorded and are presented on the boring logs. The sum of the number of blows required for the ' second and third 6 inches of penetration is termed the "standard penetration resistance" or the "N -value". In cases where 50 blows are insufficient to advance it through a 6 inches interval the penetration after 50 blows is recorded. The blow count provides an indication of the densi of the subsoil, and it is used in ' many empirical geotechnical engineering formulae. ' All test pits were backfilled with the excavated soils which were placed in 2 -foot thick lifts and compacted with the excavator's bucket. Plcase note that if these test pits are located at the future footing locations, the top 4 rect of the backfill in the test pits should be removed, and the pits be backfilled with structural fill. 1 All boreholes were backfilled with bentonite chips. The exploration logs are presented in this appendix. A chart showing the Unified Soil Classification System ' is included at the end of this appendix. 1 10101pt S&FT I I I� soil Descrrpdon SMI Topsoil with grass roots sM park brown silty send with bricks (dry)(loose)(fiil) TEST PIT TP -1 I Brown, light brown and gray silty very fine sand, trace fine to coarse gravel, trace cobbles:(dry)(loose to medium dense) -a pocket of brown fine to medium sand at 3.5 to 4.5 feet gM IGray and dark gray silty fine to coarse sand with fine to coarse gravel, trace cobbles (moistXdense to very dense)(camen ted)(gloci al till) very dense and difficult digging below 6 feet Excavation terminated at a depth of 6.5 feet. No caving occured during excavation. No groundwater encountered. Ghent: Renton Housing Authority Exploration Method: Kubota 080 Ex"vator Explorailon sato: August 27. 1010 Figure A-1 , 0 Proposed Development at Edmonds Ave NE and Glennwood Ave NE 1 1 I� y1 Z.g+ $; , ' i I ' III III IC! 7.11: SMI Topsoil with grass roots sM park brown silty send with bricks (dry)(loose)(fiil) TEST PIT TP -1 I Brown, light brown and gray silty very fine sand, trace fine to coarse gravel, trace cobbles:(dry)(loose to medium dense) -a pocket of brown fine to medium sand at 3.5 to 4.5 feet gM IGray and dark gray silty fine to coarse sand with fine to coarse gravel, trace cobbles (moistXdense to very dense)(camen ted)(gloci al till) very dense and difficult digging below 6 feet Excavation terminated at a depth of 6.5 feet. No caving occured during excavation. No groundwater encountered. Ghent: Renton Housing Authority Exploration Method: Kubota 080 Ex"vator Explorailon sato: August 27. 1010 Figure A-1 , 0 Proposed Development at Edmonds Ave NE and Glennwood Ave NE 1 1� 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 I I l Y 18 , I i 1 I 1 at I I I Sol! Description TEST PIT TP -2 Brown and gray silty fine sand with trace fine to coarse gravel (dry)(mediam dense) Gray and dark gray silty fine to medium sand with fine to coarse gravel (moist)(dense to very dense)(cemented)(glacial till) - sandy below 10 feet F,xcavation terminated at a depth of 12 feet. No groundwater, no caving encountered during excavation. C[lent: Renton Housing Authority Exploration Method: Kubota 080 Excavator Exploration pate: August 27, 1010 Figure A-2 SUE proposed Development at Edmonds Ave NE and Glennwood Ave NE 1 1 , , I 1 I I l Y 18 , I i 1 I 1 at I I I Sol! Description TEST PIT TP -2 Brown and gray silty fine sand with trace fine to coarse gravel (dry)(mediam dense) Gray and dark gray silty fine to medium sand with fine to coarse gravel (moist)(dense to very dense)(cemented)(glacial till) - sandy below 10 feet F,xcavation terminated at a depth of 12 feet. No groundwater, no caving encountered during excavation. C[lent: Renton Housing Authority Exploration Method: Kubota 080 Excavator Exploration pate: August 27, 1010 Figure A-2 SUE proposed Development at Edmonds Ave NE and Glennwood Ave NE TEST PIT TP -3 Soil DescripUon Topsoil with roots'an h (silty send with gravel and trace brlcks) Brown and gray silty fine sand, sandy slit and thin lenses of fine sand (dry)(medium dense) Gray and dark gray silty fine to medlum sand with fine to coarse gravel (molst)(dense to very dense)(cemented)(glaciat till) sPrl Brown slightly silty fine sand with thin lenses of hard silt 5M (slightly cemented)(moist to damp)(dense) - groundwater seepage (about 11100 gpm) at 10 feet Excavation terminated at a depth of 12 feet. No caving encountered during excavation. Groundwater seepage encountered at 10 feet. Client: Renton Housing Authority Exploration Method: Kubota 080 Excavator Exploratlon Date: August 27, 1010 Figure A-3 SM. &E� Proposed Development at Edmonds Ave NE and Glennwood Ave NE 1 1 ' , I• , I 16 + 1 241-- 8 t I II� 1 ' 1 TEST PIT TP -3 Soil DescripUon Topsoil with roots'an h (silty send with gravel and trace brlcks) Brown and gray silty fine sand, sandy slit and thin lenses of fine sand (dry)(medium dense) Gray and dark gray silty fine to medlum sand with fine to coarse gravel (molst)(dense to very dense)(cemented)(glaciat till) sPrl Brown slightly silty fine sand with thin lenses of hard silt 5M (slightly cemented)(moist to damp)(dense) - groundwater seepage (about 11100 gpm) at 10 feet Excavation terminated at a depth of 12 feet. No caving encountered during excavation. Groundwater seepage encountered at 10 feet. Client: Renton Housing Authority Exploration Method: Kubota 080 Excavator Exploratlon Date: August 27, 1010 Figure A-3 SM. &E� Proposed Development at Edmonds Ave NE and Glennwood Ave NE 10 , 16 + 1 241-- TEST PIT TP -3 Soil DescripUon Topsoil with roots'an h (silty send with gravel and trace brlcks) Brown and gray silty fine sand, sandy slit and thin lenses of fine sand (dry)(medium dense) Gray and dark gray silty fine to medlum sand with fine to coarse gravel (molst)(dense to very dense)(cemented)(glaciat till) sPrl Brown slightly silty fine sand with thin lenses of hard silt 5M (slightly cemented)(moist to damp)(dense) - groundwater seepage (about 11100 gpm) at 10 feet Excavation terminated at a depth of 12 feet. No caving encountered during excavation. Groundwater seepage encountered at 10 feet. Client: Renton Housing Authority Exploration Method: Kubota 080 Excavator Exploratlon Date: August 27, 1010 Figure A-3 SM. &E� Proposed Development at Edmonds Ave NE and Glennwood Ave NE 1 1 1 1 1 1 1 I at �. a 1 a � a � Soff DescrfpUon MTV F ioosoil with ro TEST PIT TP -4 Brown and gray silty fine sand and sandy silt (dry)(medium dense) Light gray to gray silty fine sand with fine to medium gravel (dry to moist)(dense to very dense)(cemented)(glecial iiil) -very dense and difficult digging below feet E=xoavatlon terminated at a depth of 8 feet. No groundwater, no caving encountered during excavation. Client: Renton Housing Authority Exploration Method: Kubota 080 E=xcavator Exploration Date: August 27, 1010 Figure A-4 $&EE Ab Proposed Development at Edmonds Ave NE and Glennwood Ave NE TEST PIT TP -5 ' Soil Descrfpffon Topsoil with rlwith r, Brown and gray silty fine sand with some fine gravel (dry)(loose to medium dense) Gray and dark gray silty fine to medium sand with fine to medium gravel, occasional cobbles (dry to moist)(dense to very dense)(cemented)(glacial till) - one boulder at 5 feet -very dense and difficult digging below feet Excavation terminated at a depth at 12 feet. No groundwater, no caving encountered during excavation, client: Renton Housing Authority Exploration Method: Kubota 080 Excavator Exploration Date: August 27, 1010 Figure A-5 SUE Proposed Development at Edmonds Ave NE and Giennwood Ave NE I 1 ' 1 1 I 1 I + I 1 I I I 1 1 1 1 �II TEST PIT TP -5 ' Soil Descrfpffon Topsoil with rlwith r, Brown and gray silty fine sand with some fine gravel (dry)(loose to medium dense) Gray and dark gray silty fine to medium sand with fine to medium gravel, occasional cobbles (dry to moist)(dense to very dense)(cemented)(glacial till) - one boulder at 5 feet -very dense and difficult digging below feet Excavation terminated at a depth at 12 feet. No groundwater, no caving encountered during excavation, client: Renton Housing Authority Exploration Method: Kubota 080 Excavator Exploration Date: August 27, 1010 Figure A-5 SUE Proposed Development at Edmonds Ave NE and Giennwood Ave NE 1 1 1 1 1 1 1 1 SO Descnprfan arK orown slay s TEST PIT TP -6 e ,3m Brown, Ight brown and gray silty very fines and, trace fine to coarse gravel, trace cobbles (dry)(loose to medium dense) sin Gray and dark gray silty fine to coarse sand with fine to coarse gravel, trace cobbles (mo€st)(dense to very dense)(cemented)(g€anal till) Excavation terminated at a depth of 6 feet. No caving occured during excavation. No groundwater encountered. Client. Renton Housing Authority Exploration Method: Kubota 080 Excavator Expiambon Date: ' August 27, 1010 Figure A-6 SHE Proposed Development at Edmonds Ave NE and Glennwood Ave NE • I , , 1 2,et I 1 I ' I ' 1 t ' I ' 111 1 ' 111 f , I ,I 1 O SO Descnprfan arK orown slay s TEST PIT TP -6 e ,3m Brown, Ight brown and gray silty very fines and, trace fine to coarse gravel, trace cobbles (dry)(loose to medium dense) sin Gray and dark gray silty fine to coarse sand with fine to coarse gravel, trace cobbles (mo€st)(dense to very dense)(cemented)(g€anal till) Excavation terminated at a depth of 6 feet. No caving occured during excavation. No groundwater encountered. Client. Renton Housing Authority Exploration Method: Kubota 080 Excavator Expiambon Date: ' August 27, 1010 Figure A-6 SHE Proposed Development at Edmonds Ave NE and Glennwood Ave NE —a Sof! Descrfpflon S13 1 BORING B-1 I sM Brown and gray silty fine send, sandy silt and thin lenses of fine sand (darnp)(medlum dense) SMI Gray silty fine sand with some fine to medium gravel (damp)(very dense)(glaeial till) wet at 15 feet Mi_ Brown silt with lenses of fine sand (very stift)(moist) (Boring log continues on Figure A -7b) client: Renton Housing Authority Drilling Wthod: r-10 HSA advanced by track -mount Diedrich D-50 Drill Rig Semple Method: SPT sampler driven by t404b auto hemmer Drill Contractor; October 28, 2010 Drill Date: Holocene Drilling Figure A -7a SUE Proposed Develpment at Edmonds Ave and Glennwood Ave Jab No. 1{0 101 1 1 I I 1111 1 24 I 19 22 14 ' 1 { 23' 1 I I 1 1 Sof! Descrfpflon S13 1 BORING B-1 I sM Brown and gray silty fine send, sandy silt and thin lenses of fine sand (darnp)(medlum dense) SMI Gray silty fine sand with some fine to medium gravel (damp)(very dense)(glaeial till) wet at 15 feet Mi_ Brown silt with lenses of fine sand (very stift)(moist) (Boring log continues on Figure A -7b) client: Renton Housing Authority Drilling Wthod: r-10 HSA advanced by track -mount Diedrich D-50 Drill Rig Semple Method: SPT sampler driven by t404b auto hemmer Drill Contractor; October 28, 2010 Drill Date: Holocene Drilling Figure A -7a SUE Proposed Develpment at Edmonds Ave and Glennwood Ave Jab No. 1{0 BORING B-1 (Continued) y Soil Descdpffon 20 1 t� SM Gray silty fine sand with some tine to medium gravel (damp)(very deriso)(glacial tilt) ' 1 1 I I 1I ! till 1 bb —28 I 1 1 I W 15 I 1 � 1 III , I 4 'I 30 1 550,.1 s ® Boring terminated ata depth of 30 feet. ! 1 No groundwater encountered during drilling. 1 951 1 1 ! I I 40:_ Client: Renton Housing Authority Drbling Method: W-11) HSA advanced by track -mount Diedrich D-50 Drill Rig Sample Method: SPT sampler driven by 140.1b auto hammer Drill Contractor: October 26, 2010 Drill nate: Holocene Drilling Figure A -7b SUE Proposed Develpment at Edmonds Ave and Glannwood Ave Job No. 110 1 1 BORING B-2 1 j Snit DescripBon Sly J Topsoil with roots sM I Brown and gray silty fine sand with trace One gravel (damp)(medlum dense to dense) sM I Gray silty fine sand with some fine to medium gravel (damp)(very dense)(gleclal till) ML I Brown sandy silt with lenses of wet fine sand (stff )(moist) (Boring log continues on Figure A -8b) Client: Renton Housing Authority DrOling Method: W -ID HSA advanced by track -mount Diedrich 0-50 Drill Rig Sample Method: SPT sampler driven by 140 -Ib auto hammer Drill Contractor October 28, 2010 Drill Data: Holocene Drilling Figure A -8a SUE Proposed Develpment at Edmonds Ave and Glennwood Ave .rob No. 1010 1 1 A BORING B-2 I (Continued) ' G G Soil Descrfpflon 20 1e ; ie ML Brown sandy silt (molst)(very stiff) 1a ; I ' 26 ; 17 12 ; SM Gray silty fine sand with some fine to medium gravel (damp)(very dense)(glacial till) :51V ' 5 sw 5 ;® , Boring terminated at a depth of 30 feet. during drilling. No groundwater encountered 1 I 1 , I as l_ Cuent: Renton Housing Authority Drilling Method: T-lD HSA advanced by track -mount Diedrich D-50 Drill Rig ' Sample Method: SPT sampler driven by 140 -Ib auto hammer Drill Contractor: October 28, 2010 Drill Date: Holocene DrlllIng Figure A -8b ' S&EE Proposed � ro osed Devel meat at Edmonds Ave and Glennwood Ave Job No. W10 UNIFIED SOIL CLASSIFICATION SYSTEM 12 8 z Cf w j IH z _o i KEY TO SAMPLES SZ DEPTH OF GROUNDWATER DURING DRILLING ® INDICATE.SDEPTHOFSTANDMI)PENETHATION TF•ST SOIL CLASSIFICATION CHART AND KEY TO BORING LOG I]ESCRIPTIOE� MAJOR DIVISIONS N J GW WELL -GRADED GRAVELS OR GRAVEL -SAND MIXTURES, GLEAN LITTLE OR NO FINES � y � GP POORLY -GRADED GRAVELS OR GRAVEL -SAND MIXTURES, GRAVELS w � $� O � LITTLE OR NO FINES No FINES) 7 SILTY GRAVELS, GRAVEL-SANQ-51LT GRAVELS N GM MIXTURES WITH FINS �v' CLEAN w Im CLAYEY GRAVELS, GRAVEL -SAND -CLAY {AppR�GABLE�� z � cc MlxrlaREs µlour�T of FINES) � WELL -GRADED SAND OR GRAVELLY SANDS, SW LITTLE OR NO FINER $p,j�jEa;; $ z Y (p POORLY -GRADED SANDS OR GRAVELLY SANDS. (urrLsoR tlG � 5P LITTLE DR NO FINES No FlNES) Z 0 � SM SILTY SANDS, SAND»811.7 MIXTURES SANDS ¢ � HIM � U ! I I WITH FINE=S SANDS, SA D -CLAY MIXTURES [APPft5 to ECIAeLE; Q� SC CLAYEY N AMOUNT OF FINES) ML INORGANIC SILTS, VERY FINE SANDS, ROCK FLOUR, SILTY OR CLAYEY FINE SANDS OR CLAYEY SILTS WITH SLIGHT PLASTICITY V1 � CL INORGANIC CLAYS OF LOW TO MEDIUM PLASTICITY, GRAVELLY SILTS & CLAYS p CLAYS, SANDY CLAYS, SILTY CLAYS, LEAN CLAYS LIauIDUMITLESS THAN 6o (n � .. OL ORGANIC SILTS AND ORGANIC SILT -CLAYS OF LOW � I PLASTICITY FL Z � INORGANIC SILTS, MICACEOUS OR DIATOMACEOUS FINE MH SANDY OR SILTY solLs, ELASTIC SILTS � CH INORGANIC CLAYS OF HIGH PLASTICITY, FAT SILTS &CLAYS � CLAYS � LIOUIDLIµRGREAT FRTHAN 56 OH ORGANIC CLAYS OF MEDIUM TO HIGH PLASTICITY, ORGANIC SILTS PT PEAT AND OTHER HIGHLY ORGANIC SOILS HIGHLY ORGANIC SOILS S&EE 8 z Cf w j IH z _o i KEY TO SAMPLES SZ DEPTH OF GROUNDWATER DURING DRILLING ® INDICATE.SDEPTHOFSTANDMI)PENETHATION TF•ST SOIL CLASSIFICATION CHART AND KEY TO BORING LOG I]ESCRIPTIOE� MAJOR DIVISIONS N J GW WELL -GRADED GRAVELS OR GRAVEL -SAND MIXTURES, GLEAN LITTLE OR NO FINES � y � GP POORLY -GRADED GRAVELS OR GRAVEL -SAND MIXTURES, GRAVELS w � $� O � LITTLE OR NO FINES No FINES) 7 SILTY GRAVELS, GRAVEL-SANQ-51LT GRAVELS N GM MIXTURES WITH FINS �v' CLEAN w Im CLAYEY GRAVELS, GRAVEL -SAND -CLAY {AppR�GABLE�� z � cc MlxrlaREs µlour�T of FINES) � WELL -GRADED SAND OR GRAVELLY SANDS, SW LITTLE OR NO FINER $p,j�jEa;; $ z Y (p POORLY -GRADED SANDS OR GRAVELLY SANDS. (urrLsoR tlG � 5P LITTLE DR NO FINES No FlNES) Z 0 � SM SILTY SANDS, SAND»811.7 MIXTURES SANDS ¢ � HIM � U ! I I WITH FINE=S SANDS, SA D -CLAY MIXTURES [APPft5 to ECIAeLE; Q� SC CLAYEY N AMOUNT OF FINES) ML INORGANIC SILTS, VERY FINE SANDS, ROCK FLOUR, SILTY OR CLAYEY FINE SANDS OR CLAYEY SILTS WITH SLIGHT PLASTICITY V1 � CL INORGANIC CLAYS OF LOW TO MEDIUM PLASTICITY, GRAVELLY SILTS & CLAYS p CLAYS, SANDY CLAYS, SILTY CLAYS, LEAN CLAYS LIauIDUMITLESS THAN 6o (n � .. OL ORGANIC SILTS AND ORGANIC SILT -CLAYS OF LOW � I PLASTICITY FL Z � INORGANIC SILTS, MICACEOUS OR DIATOMACEOUS FINE MH SANDY OR SILTY solLs, ELASTIC SILTS � CH INORGANIC CLAYS OF HIGH PLASTICITY, FAT SILTS &CLAYS � CLAYS � LIOUIDLIµRGREAT FRTHAN 56 OH ORGANIC CLAYS OF MEDIUM TO HIGH PLASTICITY, ORGANIC SILTS PT PEAT AND OTHER HIGHLY ORGANIC SOILS HIGHLY ORGANIC SOILS S&EE 21 C c