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Home My WebLink AboutSWP272224(1) �'Y., �V��'a��+,, a.� y4d�r r_y P''k+'}M-�t4 i�i�,grJ-`��t` �.� j" �`�'gy� ;�; .• � � ��'F �� Ar�' :? 'k±r '' t• °'" .. ,.,.w'a:+3Y #., ks�e'm`,4`P.::: s�'.. < f;. - 'tiJ11�� ,'Y^ t�9.P'�p s. f � ,, . "` fro �.'' �.zr'�¢ g,.gs $,�" ,�" "�' �^ `XY �•2�`�,S'��` "�^."X��`c."i'J'��ti.# ", d.�`/� we s Me ?;��"Y� 1 'Jr'�° *ti. r"��•'��f�. #�,y, :h�` ?" i ��Y,�+� ,�y �'�" i .�-1a�'�4 P :�Y F.:xr�%ti N �y Ilk Vill. 4 All ot� t ,yy T'�t +Y'+T � .a �` a+ f+°'S , ♦ t9^.,.�r tz� }yp '�' S r • r�1yJ ✓ 6_ ; X vy},v?. a PqM 4sYY �°- ti ._ d t �•� kygzi.. � I y ' '� Ta� •a.,, y �{.2, r�•��sg, y 'I �� . i } �? � 3� per_•` y"f a j.,�.` J - � .F�i v M7p 3F S ' ,a � � .��+�'•� "e +' 'i f bk •3Y.U: 4FiA1 '�.] .: . .. .� 1r`31'.v 'x � X fi Earth Consultants Inc. x 1 ^ t,'�, ' cmamfa Fnetr¢eis Ceobe��se Enmronmc++al stlm�Ls� j� y �yTb�', F "+ •"�" §�F 4'T�i� � p�'T�.a�. i+ �' '� 'v� ' ""•�i�y th�. +l�i r�'+�+'� { P ` i�. F � ,y �y�,xarppTFaIR�{,��tc✓, +°.€''1�� ,'`Rti+,� .��[[.;.' jr'lz��, r�� mob' ¢$pp »l ., � bX • �r �Y4'�' YY .T.Y R �& YX ��91gg._ .� }i� 4 rS '$�.a y y�fr ..Jp ' � � n.. s.`iP .f G`xS �• ...,r "'T,Y�`�$ a. •��s3G F:.'k�'�a trM,'du�SS Ab"` :ri. " +i � � }+. ",N taF '.sJ "y�.•t,�"�'+�''�" .� y � �� •X r`. r_,,1",4,r�. ' NOISING ONIC]IMS cm a L J-s ta3 A 1 3 O 3U N01M8 Jo wo GEOTECHNICAL ENGINEERING STUDY PROPOSED SEATTLE PACKAGING WAREHOUSE ' 34TH AVENUE SOUTHWEST AT SPRINGBROOK CREEK RENTON, WASHINGTON ' E-6955 August 22, 1995 ' PREPARED FOR ADVENTURE95 Raymond A. Coglas Staff Engineer /Z44_ /14691 ? ' Robert S. Levin Principal EBPIRFB 03/07/-1(rj Earth Consultants, Inc. ' 1805 - 136th Place Northeast, Suite 201 Bellevue, Washington 98005 (206) 643-3780 ' Earth Consultants Inc. GMechna'al 1n9h"ss.Gmlogisls&Knvironmenlal Snenllsis August 22, 1995 E-6955 Adventure 95 3701 South Norfolk Seattle, Washington 98118 ' Attention: Mr. Gordon Younger Dear Mr. Younger: ' We are pleased to submit our report titled "Geotechnical Engineering Study, proposed Seattle Packaging Warehouse, Renton, Washington." This report presents the results of our field exploration, selective laboratory tests, and engineering analyses. The purpose and scope of our study was outlined in our August 10, 1995 proposal. Based on the results of our study, it is our opinion the proposed development is geotechnically feasible. Our site exploration indicates the site is immediately underlain by approximately seven feet of medium dense to dense silty sand with gravel fill. The fill is ' underlain by approximately six feet to eight feet of organic silt with areas of extensive interbedded organics. In our opinion, the proposed building can be supported on conventional spread and continuous footings bearing on existing competent fill, provided a successful surcharge program is completed and the recommendations in this report are incorporated into the final design recommendations. ' We appreciate this opportunity to have been of service to you. If you have any questions, or if we can be of further assistance, please call. ' Respectfully submitted, ' EARTH CONSULTANTS, INC. kort S. Levinson, P.E. ' Principal -RACIRSLIk" 1805 -136th Place N.E., Suite 201, Bellevue, Washington 98005 Bellevue(206)643-3780 Seattle(206)464-1584 FAX(206)746 0860 Tacoma(206)272 6608 ' TABLE OF CONTENTS E-6955 ' PAGE INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Protect Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 SITE CONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 ' Surface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Subsurface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Fill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 ' Native . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Groundwater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Laboratory Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 DISCUSSION AND RECOMMENDATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 ' Site Preparation and General Earthwork 4 Surcharge Proara m 5 Foundations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 ' Dock-High Retaining Walls. . . . 7 Slab-on-Grade Floors 7 Seismic Design Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 ' Excavations and Slopes . . • . . . . . . . • . . . . . . . , . . , ' . . . . . . . . . . . . 9 . . . Site Drainage 9 Utility Support and Backfill . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 ' Pavement Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 LIMITATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 ' Additional Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 APPENDICES ' Appendix A Field Exploration ILLUSTRATIONS ' Plate 1 Vicinity Map Plate 2 Test Pit Location Plan Plate 3 Typical Footing Subdrain Detail Plate 4 Utility Trench Backfill Plate 5 Settlement Monitor Detail ' Plate Al Legend Plates A2 through A8 Test Pit Logs 1 ' Enrth Consultants, Inc. ' GEOTECHNICAL ENGINEERING STUDY PROPOSED SEATTLE PACKAGING WAREHOUSE 34TH AVENUE SOUTHWEST AT SPRINGBROOK CREEK RENTON, WASHINGTON E-6955 INTRODUCTION General ' This report presents the results of the geotechnical engineering study completed by Earth Consultants, Inc. (ECI) for the proposed Seattle Packaging Warehouse located along 34th ' Avenue Southwest at Springbrook Creek, in Renton Washington. The general location of the site is shown on the Vicinity Map, Plate 1 . The purpose of this study was to explore the subsurface conditions at the site and based on the conditions encountered to develop geotechnical recommendations for the proposed site development. At the time our study was performed, the building location, and our exploratory locations were approximately as shown on the Boring Location Plan, Plate 2. ' Project Description We understand it is planned to develop the site with a slab-on-grade "tilt-up" concrete structure with dock high fill. The remainder of the site will consist of asphalt pavement areas and landscaping. At the time this report was written, specific structural design information was not available. However, based on our experience with similar projects, we would anticipate the following structural: ' • Wall Loads 3 to 4 kips per lineal foot • Column Loads 75 to 125 kips • Slab Loads - 250 pounds per square foot ' If any of the above design criteria are incorrect or change, we should be consulted to review the recommendations contained in this report. In any case, ECI should be retained ' to perform a general review of the final design. Earth Conaultanta, Inc. ' GEOTECHNICAL ENGINEERING STUDY Adventure 95 E-6955 ' August 22, 1995 Page 2 SITE CONDITIONS ' Surface The subject site is located immediately to the west of Springbrook Creek along the south ' side of 34th Avenue Southwest in Renton Washington (see Plate 1, Vicinity Map). The property is rectangular in shape, extending about six hundred fifty (650) feet in the east- west direction and four hundred sixty (460) feet in the north-south direction. The site is ' bordered on the east and southeast by Springbrook Creek, on the north by 34th Avenue Southwest, and on the west by an existing warehouse. The property to the south of the site is undeveloped and is currently vegetated with trees and shrubs. The site vegetation ' consists mainly of grasses, and the site topography is relatively flat. Subsurface ' The site was explored by excavating seven test pits at the approximate locations shown on Plate 2. Please refer to the Test Pit Logs, Plates A2 through A8, for a more detailed description of the conditions encountered at each location explored. A description of the field exploration methods is included in Appendix A. The following is a generalized description of the subsurface conditions encountered. Fill ' Our test pits indicate that the grass sod is immediately underlain by approximately seven feet of fill. This soil unit was generally classified as medium dense to dense poorly graded sand with silt, and silty sand with gravel (Unified Classifications SP-SM and SM). Portions ' of the existing fill encountered during our exploration contained significant amounts of gravel and four to six inch cobbles. This soil unit may be suitable for support of foundation elements, slab-on-grade floors and pavements, provided the fill is prepared in ' accordance with the recommendations discussed in the "Site Preparation and General Earthwork" section of this report. ' Native Our exploration indicates the fill is generally underlain by approximately six feet to eight feet of loose organic silt with some areas that are highly organic and contain pockets of peat. Below this deposit, at approximately thirteen (13) to fifteen (15) feet below the ' existing surface, loose, water bearing poorly graded sand and silty sand were encountered. ' Earth Consultants, Inc- GEOTECHNICAL ENGINEERING STUDY Adventure 95 E-6955 August 22, 1995 Page 3 ' Groundwater Moderate to heavy seepage was encountered in our test pits at approximately six to seven feet below the existing surface. The location of the seepage is approximately at the contact between the existing fill and the native silt. Groundwater was observed in the ' sand and silty sand encountered below the silt deposit. Iron stains observed in the lower portions of the silt deposit suggest the groundwater level is not static. Therefore one may expect fluctuations in the level depending on the season, amount of rainfall, surface water ' runoff, and other factors. Generally, the water level is higher and seepage rate is greater in the wetter winter months (typically October through May). Laboratory Testing Laboratory tests were conducted on several representative soil samples to verify or modify ' the field soil classification and to evaluate the general physical properties and engineering characteristics of the soil encountered. Moisture content tests were performed on all samples. The results of laboratory tests performed on specific samples are provided at ' the appropriate sample depth on the individual test pit logs. It is important to note that these test results may not accurately represent the overall in-situ soil conditions. Our geotechnical recommendations are based on our interpretation of these test results and ' their use in guiding our engineering judgement. ECI cannot be responsible for the interpretation of these data by others. In accordance with our Standard Fee Schedule and General Conditions, the soil samples for this project will be discarded after a period of fifteen days following completion of this report unless we are otherwise directed in writing. DISCUSSION AND RECOMMENDATIONS ' General Based on the results of our study, it is our opinion that the proposed development can be constructed generally as planned provided the recommendations contained in this report are incorporated into the final design. The critical geotechnical aspects of the planned ' development are primarily associated with foundation support and reducing post construction settlements. To reduce post construction settlements a surcharge program should be completed. The purpose of the surcharge program is to induce the primary ' settlement of the underlying compressible soil, and reduce the amount of post- construction settlement. We estimate post construction total and differential settlements, after completion of the surcharge program, could be on the order of one and one-half ' inches and one inch, respectively. The proposed structure may then be supported by conventional spread and continuous footings bearing on at least two feet of structural fill. Recommendations for a surcharge program, and preparation and compaction of the ' existing fill, are presented in the following sections of this report. ' Earth Consultant., Inc. GEOTECHNICAL ENGINEERING STUDY Adventure 95 E-6955 August 22, 1995 Page 4 This report has been prepared for specific application to this project only and in a manner consistent with that level of care and skill ordinarily exercised by other members of the profession currently practicing under similar conditions in this area for the exclusive use of Seattle Packaging and their representatives. No warranty, expressed or implied, is made. This report, in its entirety, should be included in the project contract documents ' for the information of the contractor. Site Preparation and General Earthwork The building and pavement areas should be stripped and cleared of all organic matter, and any other deleterious material. In building areas where greater than two feet of fill is to ' be placed, and in paved areas with more than one foot of fill, the existing surface need not be stripped. In areas requiring stripping, we estimate a stripping depth of four to six inches. Stripped materials should not be mixed with any materials to be used as structural ' fill. Existing utility pipes to be abandoned should be plugged or removed so that they do not ' provide a conduit for water and cause soil saturation and stability problems. To reduce the potential for differential settlement, the existing storm water line should be abandoned and removed in areas where the pipe will be less than two feet from the bottom of ' foundation elements. The footing and slab foundation soil should be prepared in accordance with the ' requirements of structural fill, defined later in this section. For foundations bearing on competent existing fill, the upper one foot of fill should be removed, the lower one foot compacted in place, and the upper one foot replaced in accordance with structural fill ' requirements. Laboratory tests indicate the moisture content of the existing fill is at or near its optimum moisture content, indicating the existing fill is currently in a compactible condition. These circumstances, however, may be different at the time of site ' preparation. Due to the presence of some silt in the existing fill, the soil may degrade if exposed to excessive moisture, and compaction and grading will be difficult if the soil moisture increases significantly above its optimum condition. If areas of the existing fill are exposed to moisture and cannot be adequately compacted, ' then the unsuitable soil should be removed and replaced with a compactible structural fill. The unsuitable soil should be removed to a depth at which competent soil is encountered. Typically, overexcavation depths of twelve (12) to eighteen (18) inches are required; ' however, an ECI representative should observe the overexcavation to evaluate the competence of the overexcavated surface. During dry weather, any non-organic compactible soil can be used to replace the overexcavated soil. Fill for use during wet weather should consist of a fairly well graded granular material having a maximum size of three inches and no more than 5 percent fines passing the No. 200 sieve based on the minus 3/4-inch fraction. ' Earth Consultants, Inc. GEOTECHNICAL ENGINEERING STUDY Adventure 95 E-6955 August 22, 1995 Page 5 ' Structural fill is defined as any compacted fill placed under buildings, roadways, slabs, pavements, or any other load-bearing areas. Structural fill under floor slabs and footings should be placed in horizontal lifts not exceeding twelve 0 2) inches in loose thickness and compacted to a minimum of 90 percent of its laboratory maximum dry density, except for the top twelve (12) inches which should be compacted to 95 percent. The maximum dry ' density should be determined in accordance with ASTM Test Designation D-1557-78 (Modified Proctor). The fill materials should be placed at or near the optimum moisture content. Fill under pavements and walks should also be placed in horizontal lifts and ' compacted to 90 percent of maximum density except for the top twelve (12) inches which should be compacted to 95 percent of maximum density. ' Due to the large quantity of cobbles encountered in portions of the existing fill, compaction testing of prepared areas may be difficult. Therefore, we recommend the preparation of existing fill be observed by a representative from our office. ' Surcharge Program ' To help reduce post construction settlements, a two foot surcharge should be placed over the entire building area. The two feet of surcharge will be above the finished floor elevation. We estimate primary settlements induced by the surcharge will be complete in four to six weeks after the surcharge is placed. If a shorter time period is required, the surcharge program can be accelerated by increasing the thickness of surcharge. However, the actual surcharge time period will be dependent upon the rate and amount of settlement measured in the field. The surcharge should extend at least five feet beyond the perimeter of the buildings. The ' side slopes of the fill should not be inclined any steeper than 1 H:1 V. Surcharge till does not have to meet any specific requirements except that the material should have a unit weight of one hundred twenty (120) pcf. However, if the surcharge fill material is to be ' used for structural fill in other areas after completion of the surcharge program, it should meet the requirements for structural fill, The definition for structural fill can be found in the Site Preparation and General Earthwork section of-this report. In order to verify the magnitude of settlement, a monitoring program should be performed. The monitoring program should include setting settlement monitors on the existing site ' subgrade before any fill is placed, monitoring them through completion of fill placement, and continuing until settlements cease or are considered within the buildings tolerable ' limits. More specific details of this program are presented below: • Settlement markers should be placed on the native subgrade of each building pad ' before any fill is placed. A settlement monitor should be placed for every fifteen thousand (15,000) square feet of building area. ECI can supply and install these markers. (A typical detail is provided on Plate 5). Earth Consultants, Inc. GEOTECHNICAL ENGINEERING STUDY Adventure 95 E-6955 August 22, 1995 Page 6 ' • A baseline reading is obtained on each marker and is referenced to a temporary benchmark located on a feature that will be unaffected by the fill-induced settlements. ' • The surcharge fill is then placed. Settlement readings are taken at relatively short intervals during this process, since this phase generates relatively large and rapid settlements. ' Once the fill operation is complete, readings are obtained on a periodic basis, typically weekly, until the settlement ceases or is judged by the geotechnical engineer to be within tolerable limits. ' • Each set of settlement readings are plotted graphically against time to determine the magnitude and rate of settlement, and are matched against the predicted ' magnitudes and rates to verify the accuracy of earlier estimates and to make any appropriate modifications. ' ECI should be retained to acquire the settlement readings. If you prefer to use a surveyor to collect these readings, measurements should be provided to us as quickly after their acquisition as possible for plotting and interpretation. This will help avoid any ' misinterpretation or misunderstanding regarding the success of the surcharge program. In order to ensure the accuracy of the settlement readings, the settlement monitors must be maintained. In our experience, earthwork equipment (dozers and trucks) often demolish markers at a very high rate. This adds to the project costs in that they need to be replaced and it makes the information obtained less reliable. To avoid this, the project ' specifications should include a requirement that the earthwork contractor is required to immediately replace any damaged settlement marker and have the settlement readings re- obtained at his own cost. This requirement makes 'the earthwork contractor more ' conscious of the importance of the monitoring program and will aid in maintaining the integrity of the program. ' ' Foundations ' Assuming compliance with the recommendations outlined in the "Surcharge Program"and "Site Preparation and Genera/ Earthwork" sections of this report, it is our opinion the proposed building can be supported on a conventional spread and continuous footing ' foundation bearing on existing competent fill or newly placed structural fill. Exterior foundations elements should be placed a minimum depth of eighteen (18) inches below final exterior grade. Interior spread foundations can be placed at a minimum depth of ' twelve (12) inches below the top of slab, except in unheated areas, where interior foundation elements should be founded at a minimum depth of eighteen (18) inches. ' Earth Consultants, Inc. ' GEOTECHNICAL ENGINEERING STUDY Adventure 95 E-6955 August 22, 1995 Page 7 With foundation support obtained as described, for design, an allowable bearing capacity of two thousand five hundred (2,500) can be used. Continuous and individual spread footings should have minimum widths of eighteen (18) and twenty-four (24) inches, respectively. Loading of this magnitude would be provided with theoretical factor-of- safety in excess of three against actual shear failure. With structural loading as expected, ' total settlement in the range of one and one-half inches is anticipated with differential movement of about one inch. Most of the anticipated settlements should occur during construction as dead loads are applied. This is after successful completion of the ' surcharge program. For short-term dynamic loading conditions, a one-third increase in the above allowable bearing capacities can be used. ' The horizontal loads can be resisted by friction between the base of the foundation and the supporting soil and by passive soil pressure acting on the face of the buried portion of the foundation. For the latter, the foundation must be poured "neat" against the competent existing fill soils or backfilled with structural fill. For frictional capacity, a coefficient of 0.40 can be used. For passive earth pressure, the available resistance can be computed using an equivalent fluid pressure of three hundred (300) pcf. These lateral ' resistance values are allowable values, a factor-of-safety of 1 .5 has been included. As movement of the foundation element is required to mobilize full passive resistance, the passive resistance should be neglected if such movement is not acceptable. All footing excavations should be observed by a representative of ECI, prior to placing forms or rebar, to verify that conditions are as anticipated in this report. Dock-High Retaining Walls ' Dock-high retaining walls will be constructed along portions of the perimeter of the building. They should be designed to resist lateral earth pressures imposed by an equivalent fluid with a unit weight of thirty-five (35) pcf if they are allowed to rotate 0.002 times the height of the wall. If walls are prevented from rotating, we recommend that they be designed to resist-lateral loads of fifty (50) ,pcf.. These values are based on horizontal backfill and that surcharges due to hydrostatic pressures, traffic, structural loads or other surcharge loads Will not act on the wall. If such surcharges are to apply, they should be added to the above design lateral pressure. Slab-on-Grade Floors ' Slab-on-grade floors may be supported on existing or recompacted competent fill, or on new structural fill. Any disturbed subgrade soil must either be recompacted or replaced with structural fill. Slab-on-grade floors should be designed by the structural engineer based on the anticipated loading and the subgrade support characteristics. A modulus of vertical subgrade reaction of three hundred (300) pounds per cubic inch (pci) may be used for design. 1 Earth Cancultenm Inc. ' GEOTECHNICAL ENGINEERING STUDY Adventure 95 E-6955 August 22, 1995 Page 8 The slab should be provided with a minimum of four inches of free-draining sand or gravel. In areas where slab moisture is undesirable, a vapor barrier such as a 6-mil plastic ' membrane may be placed beneath the slab. Two inches of damp sand may be placed over the membrane for protection during construction and to aid in curing of the concrete. Seismic Design Considerations The Puget Lowland is classified as a Seismic Zone 3 by the Uniform Building Code (UBC). ' The largest earthquakes in the Puget Lowland are widespread and have been subcrustal events, ranging in depth from thirty (30) to fifty-five (55) miles. Such deep events have exhibited no surface faulting. Structures are subject to damage from earthquakes due to direct and indirect action. Direct action is represented by shaking. Indirect action is represented by foundation soil 1 failures and is typified by ground failure or liquefaction. The UBC Earthquake regulations contain a static force procedure and a dynamic force procedure for design base shear calculations. Based on the encountered soil conditions, it is our opinion that a site coefficient of S3 = 1 .5 should be used for the static force procedure as outlined in Section 1628 of the 1994 UBC. For the dynamic force procedure ' outlined in section 1929 of the 1994 UBC, the curve for rock or stiff clay (Soil Type 3) should be used for Figure 16-3, Normalized Response Spectra Shapes. Liquefaction is a phenomenon in which soils lose all shear strength for short periods of time during an earthquake. Groundshaking of sufficient duration results in the loss of grain to grain contact and rapid increase in pore water pressure, causing the soil to behave ' as a fluid. To have a potential for liquefaction, a soil must be cohesionless with a grain size distribution of a specified range (generally sands and silt); it must be loose to medium dense; it must be below the groundwater table; and it must be subject to sufficient ' magnitude and duration of groundshaking. The effects of. liquefaction may be large total and/or differential settlement for structures founded in the liquefying soils. ' It is our opinion the potential for widespread liquefaction over the site during a seismic event is low. Isolated areas may be subject to liquefaction, however, the effect on the planned building is anticipated to be minimal provided the recommendations contained in this report are followed. We estimate liquefaction induced settlement would be in the range of the post constructed settlements discussed earlier. ' Earth Consultants, Inc. GEOTECHNICAL ENGINEERING STUDY Adventure 95 E-6955 August 22, 1995 Page 9 Excavations and Slopes The following information is provided solely as a service to our client. Under no circumstances should this information be interpreted to mean that ECI is assuming responsibility for construction site safety or the Contractor's activities; such responsibility is not being implied and should not be inferred. ' In no case should excavation slopes be greater than the limits specified in local, state and Federal safety regulations. Based on the information obtained from our field exploration and laboratory testing, the site soils expected to be encountered in the upper six feet of the existing fill would be classified as Type B by OSHA, and as such, temporary cuts greater than four feet in height should be sloped at an inclination no steeper than 1 H:1 V. 1 Excavations in the lower native deposits should be sloped at an inclination no steeper than 1 .5H:1 V, meeting the requirements for a Type C soil. If slopes of these inclinations, or flatter, cannot be constructed, temporary shoring may be necessary. This shoring will 1 help protect against slope or excavation collapse, and will provide protection to workmen in the excavation. If temporary shoring is required, we will be available to provide shoring design criteria, if requested. All permanent cut and fill slopes should be inclined no steeper than 2H:1 V. All cut slopes should be observed by ECI during excavation to verify that conditions are as anticipated. Supplementary recommendations can then be developed, if needed, to improve stability, including flattening of slopes or installation of surface or subsurface drains. In any case, water should not be allowed to flow uncontrolled over the top of any slopes. ' All permanently-exposed slopes should be seeded with an appropriate species of vegetation to reduce erosion and improve stability of the surficial layer of soil. Site Drainage The site must be graded such that surface water is directed off the site. Water must not be allowed to stand in any area where buildings, slabs or pavements are to be I constructed. During construction, loose surfaces should be sealed at night by compacting the surface to reduce the potential for moisture infiltration into the soils. Final site grades must allow for drainage away from the building foundations. The ground should be sloped ' at a gradient of three percent for a distance of at least ten feet away from the buildings, except in paved areas, which can be sloped at a gradient of one percent. ' Earth Consultant., Inc. ' GEOTECHNICAL ENGINEERING STUDY Adventure 95 E-6955 August 22, 1995 Page 10 ' Perimeter footing drains should be installed around portions of the proposed warehouse not supported on dock high fill and having tile or carpet finishes that can be damaged by 1 water infiltration. The footing drain should be installed at or just below the invert of the footing, with a gradient sufficient to initiate flow. A typical detail is provided on Plate 3. Under no circumstances should roof downspout drain lines be connected to the footing ' drain system. All roof downspouts must be separately tightlined to discharge. Cleanouts should be installed at strategic locations to allow for periodic maintenance of the footing drain and downspout tightline systems. ' Utility Support and Backfill ' Based on the soil conditions encountered, utilities located in the upper six feet of the existing fill should be supported adequately by the fill. However, moderate to heavy seepage may be encountered in utility trenches deeper than approximately five feet below ' the existing surface elevation. In the event that utilities are located deeper in the upper portions of the native soils, remedial measures may be necessary in order to provide adequate support for utilities. This can be accomplished by overexcavating the unsuitable soil and replacing it with a suitable pipe bedding material such pea gravel. Utility trench backfill is a major concern in reducing the potential for settlement along utility alignments, particularly in pavement areas. It is important that each section of utility line be adequately supported in the bedding material. The material should be hand tamped to ensure support is provided around the pipe haunches. Fill should be carefully placed and hand tamped to about twelve inches above the crown of the pipe before any heavy compaction equipment is brought into use. The remainder of the trench backfill should be placed in lifts having a loose thickness of less than twelve inches. A typical trench backfill section and compaction requirements for load supporting and non-load supporting areas is presented on Plate 4. Pavement Areas 1 The adequacy of site pavements is related in part to the condition of the underlying subgrade. To provide a properly prepared subgrade for pavements, the subgrade should be treated and prepared as described in the "Site Preparation and Genera/ Earthwork" ' section of this report. This means at least the top twelve (12) inches of the subgrade should be compacted to 95 percent of the maximum dry density (per ASTM D-1557-78). It is possible that some localized areas of soft, wet or unstable subgrade may still exist after this process. Therefore, a greater thickness of structural fill or crushed rock may be needed to stabilize these localized areas. 1 Ewth Cnnsulte , Inc. ' GEOTECHNICAL ENGINEERING STUDY Adventure 95 E-6955 August 22, 1995 Page 11 ' The following pavement section for lightly-loaded areas can be used: ' • Two inches of asphalt concrete (AC) over four inches of crushed rock base (CRB) material, or • Two inches of AC over three inches of asphalt treated base (ATB) material. Heavier truck-traffic areas will require thicker sections depending upon site usage, pavement life and site traffic. As a general rule, the following sections can be considered for truck-trafficked areas: ' • Three inches of AC over six inches of CRB, or 1 • Three inches of AC over four inches of ATB. These pavement thicknesses may be modified based on anticipated traffic loads and ' frequency. Asphalt concrete (AC), asphalt treated base (ATB), and crushed rock base (CRB) materials ■ should conform to WSDOT specifications. All rock base should be compacted to at j least 5 percent of the ASTM D-1557-78 laboratory test standard. 1 LIMITATIONS Our recommendations and conclusions are based on the site materials observed, selective ' laboratory testing and engineering analyses, the design information provided to us by the you, and our experience and engineering judgement. The conclusions and recommendations are professional opinions derived in a manner consistent with that level I of care and skill ordinarily exercised by other members of the profession currently practicing under similar conditions in this area. No warranty is expressed or implied. ' The recommendations submitted in this report are based upon the data obtained from the borings. Soil and groundwater conditions between borings may vary from those encountered. The nature and extent of variations between our exploratory locations may not become evident until construction. If variations do appear, ECI should be requested to reevaluate the recommendations of this report and to modify or verify them in writing prior to proceeding with the construction. Earth C....[tanffi. Inc. GEOTECHNICAL ENGINEERING STUDY Adventure 95 E-6955 August 22, 1995 Page 12 ' Additional Services As the engineer of record, ECI should be retained to perform a general review of the final design and specifications to verify that the earthwork and foundation recommendations have been properly interpreted and implemented in the design and in the construction specifications. ECI should also be retained to provide geotechnical services during construction. This is to observe compliance with the design concepts, specifications or recommendations and to allow design changes in the event subsurface conditions differ from those anticipated ' prior to the start of construction. We do not accept responsibility for the performance of the foundation or earthwork unless we are retained to review the construction drawings and specifications, and to provide construction observation and testing services. t Earth Conauhenta, Inc. B 'A�...,I �I Y..�y 9� <'♦'♦♦ \ COP NORTHER O`t >5W >1 1515T ST 1 1 LJ > t t �Y2 ♦ - P 3• < 0 >ST y S 154YD 1 ST n < '� Na C I 231z t'/ sts n L ! >�. r A y <i 1 H T 1 cp rux PK n a i g a y S. T E,yT ;("c 1 7u ¢ A, aga es.'i ¢ ■CN G zz f_: ' I rn rgLy rqr I 7UKWILA 15a H sT zx; I W 21 T Lsr tsr" UT E fi 3 LA K �� SW 73 i1 T AKER - V IS z -I Y(1� 'A`' iT S ST y Y W .kO=BIC HrENN1A mL p 'O�(��/�� I Ij RE N T 1 � I I < Y PARK... / fl ' — 4 ¢ > s� T. "+ _< N L ¢ I �. S SW iTTFI a F♦ > aYF♦ y S 166TH$. N O }♦ O I H ST 15T WRECK R Z IHDU.fj. F 2 II < 1 C < I p 'P} _ t�rt Iuul w MTH ST l y = o S 1wr i m 26 z ` I `25I v I T I z I CHR/ST- = 1 3RN1 ST I < -I S .1 ENS£N I SW 31ST 1 I y L OREENBELT 2 sfy 33RD ITE E < ¢ C a DR N I I 2 Q I ST I I T al < aT II PL I CORP D RATE---- I I > - MINKLER B VDi OZI I ••••.•.- CHOMMUMTYfw_ �PIANO-BR — — .T — -- — EMERGENCY IcC 5 CENTER i y4� T MID A Qe i re" I o Sw a TH ST KKE I J f C t Y I ITI I < 1 7STH i '- SA%Di71 1DR I O W Al T T U y 5 179TH ST TRILANO OR I F ] Q s y y; T o aQPI IQ I I I " I ^ _ y M � I r n 3 I S 18DrH i T F ti SV� ^ g RD ST 3 SOD s y 1815T 5T - I 180TH w5 SEGAL rbAflRK6 a 1 >N I ST•>, ¢ I Yee ¢ = RIVERSIbE Spp< n --Rt-�—< '/� OT— 'Y- 5 — SPR%NGBRODKAl —I iT I <r >� l• GREENBELT 'FL4oDyg�*B� : t 36 1 I _ tiecTx sr �`' tiS I DLER CdRK � W ,glGus nEx y 'R y I 5 1a8'TH B; 4. S 1 TH ST 4 5 1a'TTH ' BRISCD b lI < C y I STD ^ MEPAR.. . .RK .<::..... _..<�^.. > Reference: u King County / Map 41 By Thomas Brothers Maps Dated 1990 Vicinity Map ' Fir' h COrisultmtS Inc. Proposed Warehouse GewHdmlml EnIDnrsls.Geoba�s a EnNroltrlenral ScienlWs Renton, Washington Proj. No. 6955 Drwn. GLS Date Aug. '95 Checked RC Date 8/23/95 Plate 1 ' S.W. 34th STREET i TP-1 e TP 5 ' TP-6 i ' TP-4 DTP-2 i TP-7 i I TP-3 ' LEGEND TP-1 -i- Approximate Location of ECI Test Pit, Proj. No. E-6955, Aug. 1995 Proposed Building Approximate Scale 0 50 100 200ft. ' Reference: Preload & Tesc Plan Sheet 2 of 5 By City of Renton Dated 6/16/95 Inc. est Pit Location Plan Earth Consultants Proposed Warehouse & ;OM�a��= Renton, Washington Prof. No. 6955 Drwn. GLS Date Aug. '95 Checked RC Date 8/23195 Plate 2 • o Slope To Drain r 6 inch min. ° f o , ! .o ;o, '�a.� i.';::e•'6' ° ° 18 inch min. 1 4 inch min. :, _• :.: ::;: ; •. ..:. a�.•' °. Diameter Perforated Pipe ': : •:°;;e ::o,;�:: - o. o Wrapped in Drainage » - •° ' Fabric ' 2 inch min. 2 inch min. / 4 inch max. 12 inch min. SCHEMATIC ONLY - NOT TO SCALE NOT A CONSTRUCTION DRAWING + Y LEGEND . o- Surface seal; native soil or other low permeability material. M Fine aggregate for Portland Cement Concrete; Section 9-03.1(2) of the WSDOT Specifications. I O Drain pipe; perforated or slotted rigid PVC pipe laid with perforations or slots facing down;tight jointed;with a positive gradient. Do not use flexible corrugated plastic pipe. Do not tie building downspout drains into footing lines. Wrap with Mirafi 140 Filter Fabric or equivalent. I Ealfrl CORSUItaI1tS Inc. TYPICAL FOOTING SUBDRAIN DETAIL Proposed Warehouse G[°1°fJrlp FnB. *s GeobgLais 6 Envlmuneidl SCY'nils+s Renton, Washington Proj. No, 6955 Drwn. GLS Date Aug. '95 Checked RC Date 8/23/95 Plate 3 1 Non-Load Supporting Floor Slab or Areas Roadway Areas . h «'C 4i .y'• Varies 9 0 0 ° a o 0 85 ' 95 1 Foot Minimum Backfill 80 j 90 Varies p PIPE o 0 0 Q° a°o °O oop eo 40.0 Bedding 6'4 .e o..!. ^ Varies o°�' oeO.C ,o. ei 8.•00• o Ooe O'. opo��((��o•;00'0004�O.o::p'?e. 'e'tT"e�D.O Q'o '(J-'•°0°.O.'b'•'O�'',oq.pe0 LEGEND: ' # Asphalt or Concrete Pavement or Concrete Floor Slab ° Base Material or Base Rock Backfill; Compacted On-Site Soil or Imported Select Fill Material as Described in the Site Preparation of the General Earthwork Section of the Attached Report Text. t 95 Minimum Percentage of Maximum Laboratory Dry Density as Determined by ASTM Test Method D 1557-78 (Modified Proctor), Unless Otherwise Specified in the Attached Report Text. Bedding Material; Material Type Depends on Type of Pipe and °0.b oo;p Laying Conditions. Bedding Should Conform to the Manufacturers Recommendations for the Type of Pipe Selected. ITYPICAL UTILITY TRENCH FILL 1 Earth Consultants Inc. Proposed Warehouse Renton, Washington Proj. No. 6955 Drwn. GLS Date Aug. '95 Checked RC Date 8/23/95 Plate 4 SCHEMATIC ONLY - NOT TO SCALE NOT A CONSTRUCTION DRAWING 1 1 >A pd 4k f Surcharge Surcharge or Preload FIII or Preload Fill t�Y H d i .. ki3 f ' ......:iN .':.:'. .. .:a: aXX ... -.:..... III-111 111= qF (11=111 111= ill 111= STANDARD NOTES 1) Base consists of 3/4 inch thick, 2 foot by 2 foot plywood with center drilled 5/8 inch diameter hole. 2) Bedding material, If required, should consist of Traction Sand. ' 3) Marker rod is 1/2 inch diameter steel rod threaded at both ends. 4) Marker rod is attached to base by nut and washer on each side of base. 5) Protective sleeve surrounding marker rod should consist of 2 inch diameter plastic tubing. Sleeve is NOT attached to rod or base. 6) Additional sections of steel rod can be connected with threaded couplings. 7) Additional sections of plastic sleeve can be connected with press-fit plastic couplings. ' 8) Steel marker rod should extend at least 6 inches above top of plastic sleeve. 9) Marker should extend at least 2 feet above top of fill surface. TYPICAL SETTLEMENT MARKER DETAIL ' Earth Consultants Inc. Proposed Warehouse Cedednlml Fnglrrsrs.CtObgWs F FnNmrc415ckmtas Renton, Washington Prof. No. 6955 Drwn. GLS Date Aug. '95 Checked RC Date 8/23/95 Plate 5 r � � � � � tAPPENDIX A ' FIELD EXPLORATION E-6955 ' Our field exploration was performed on August 15, 1995. Subsurface conditions at the ' site were explored by excavating seven test pits a maximum depth of seventeen and one-half feet below the existing grade. The test pits were excavated by Northwest Excavating & Trucking, subcontracted to ECI, using a track hoe. ' Approximate test pit locations were determined by taping from existing landmarks. The test pit locations should be considered accurate only to the degree implied by the method ' used. These approximate locations are shown on the Test Pit Location Plan, Plate 2. The field exploration was continuously monitored by an engineer from our firm who classified the soils encountered, maintained a log of each test pit, obtained representative samples, ' measured groundwater levels, and observed pertinent site features. All samples were visually classified in accordance with the Unified Soil Classification System which is presented on Plate Al, Legend. Logs of the test pits are presented on Plates A2 through A8. The final logs represent our ' interpretations of the field logs and the results of the laboratory examination and tests of field samples. The stratification lines on the logs represent the approximate boundaries between soil types. In actuality, the transitions may be more gradual. t ' E�h con.unmv, Ino. ' MAJOR DIVISIONS GRAPH LETTER TYPICAL DESCRIPTION SYMBOL SYMBOL ' 0 GW Well-Graded Gravels, Gravel-Sand Gravel a Clean Gravels Q Q 0 a 9W Mixtures, Little Or No Fines AndGravelly (little or no fines) r • GP Poorly-Graded Gravels,Gravel- Coarse Soils Grained ll gp Sand Mixtures, Little Or No Fines ' Soils More Than GM Silty Gravels,Gravel-Sand- 50% Coarse Gravels With gm Silt Mixtures Fraction Fines(appreciable Retained On amount of fines) GC Clayey Gravels,Gravel-Sand- No. 4 Sieve gC Clay Mixtures Sant o 'e SW Well-Graded Sands, Gravelly And d Clean Sand o u e^ o a SW Sands, Little Or No Fines Sandy (little or no fines) ,:g4I_ :•;.,+as More Than "�` a"Yn°'":" SP Poorly-Graded Sands, Gravelly Soils "` 'o:!%� Sp Sands, Little Or No Fines 50% Material ":$}�;':>;IN. ;.R ' Larger rSie More Than No.200 Sieve SM Silty Sands Sand-Silt Mixtures Size 50% Coarse Sands With ASm Fraction Fines(appreciable Sieving No 4 amount of fines) ' Clayey Sands, Sand-Clay Mixtures SC. SC ML Inorganic Silts&Very Fine Sands,Rock Flour,Silty- ml Clayey Fine Sands;Clayey Silts w/Slight Plasticity Fine Silts Liquid Limit CL Inorganic Clays Of Low To Medium Plasticity, Grained And Less Than 50 Cl Gravelly Clays, Sandy Clays, Silty Clays, Lean ' Soils Clays ill l l OL Organic Silts And Organic I I I I I I OI Silty Clays Of Low Plasticity MH Inorganic Silts, Micaceous Or Diatomaceous Fine ' More Then 50% Material MIT Sand Or Silty Soils Silts Liquid Limit Smaller Than And CH Inorganic Clays Of High No.200 Sieve Clays Greater Than 50 CI1 Plasticity, Fat Clays Size OH Organic Clays Of Medium To High Oh Plasticity, Organic Silts PT Peat, Humus, Swamp Soils Highly Organic Soils t 1/ t/ `r Pt With High Organic Contents ' Topsoil 'y y y y J Humus And Duff Layer ' Fill Hlyhly Variable Constituents The discussion in the text of this report is necessary for a proper understanding of the nature ' of the material presented in the attached logs. DUAL SYMBOLS are used to indicate bordedins soll classificatlon. ' C TORVANE READING,tsf I 2"O.D. SPLIT SPOON SAMPLER qu PENETROMETER READING,tat W MOISTURE,%dry weight II 24'I.D. RING OR SHELBY TUBE SAMPLER ' P SAMPLER PUSHED SAMPLE NOT RECOVERED + WATER OBSERVATION WELL pot DRY DENSITY,ibs.per cubic ft. LL LIQUID UNIT,% SL DEPTH OF ENCOUNTERED GROUNDWATER ' PI PLASTIC INDEX DURING EXCAVATION Z SUBSEQUENT GROUNDWATER LEVEL W/DATE ' Earth Consultants Inc. LEGEND i ' (ivxalx,k:Yl],aY„cp.(axxoakiaY Piwlnnnxnn,l5,.lnasrs tProj. No. 6955 Date Aug'95 Plate Al ' Test Pit Log ' Project Name: Sheet of Proposed Warehouse 1 1 Job No. Logged by: Date: Test Pit No.: 6955 1 RC 8 15 95 TP-1 ' Excavation Contactor: Ground Surface Elevation: Keith Wellard Notes: o y o Surface Conditions: 6"Sod W C a a u n ' (%) m y mLLa i L N 0 N N SP-SM Flat•Brown poorly graded fine to medium SAND with silt,gravel and cobbles,medium dense,moist 1 2 ' 5.5 3 SM BILL Gray silty fine to medium SAND with gravel 4 9.9 5 6 Q -seepage encountered at 6'-perched ' 7 OH Brown to black organic SILT with interbedded organics,loose,wet 119.4 /// 6 55.3 10 -less organics 11 " 12 $P Gray to black poorly graded Tine SAND,loose,water bearing 8.3 p e a 13 � a a e- u° 28.1 " 14 ' Test pit terminated at 14.5 feet below existing grade.Groundwater seepage encountered at 6 feet perched and 12'groundwater during excavation. 1 IN N 0 Test Pit Log Earth Consultants Inc. Proposed Warehouse ' aoftft m'Q'm"`"'' s<dftA" Renton,Washington J a Proj.No. 6955 Dwn. GLS Date Aug. '95 Checked RC Date 8/22/95 Plate A2 r Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by engineering tests, analysis and judgment. They are not necessarily representative of other times and locations. a cannot accept responsibility for the use or Interpretation by others of information presented on this log. Test Pit Log ' Project Name: Sheet of Proposed Warehouse 1 1 Job No. Logged by: Date: Test Pit No.: 6955 RC 8 15 95 TP-2 ' Excavation Contactor: Ground Surface Elevation: Keith Wellard Notes: ' U _ ° _ c y o Surface Conditions: 6"Sod W C 0 t a u a SP-SM DLL:Brown poorly graded fine to medium SAND with silt,gravel and cobbles,medium dense,moist 1 2 3.8 3 SM FILL;Gray silty fine to medium SAND with gravel,medium dense,moist 1 4 ' S 8 OH Brown organic SILT,loose,wet 44.9 /// 7 -wood debris-3"branch 8 212.0 g considerable organics 10 40.4 /// 11 -Interbedded organics and peat o a 13 SP Gray black poorly graded fine to medium SAND,loose,water bearing ' 33.8 c a e 4 0 14 Test pit terminated at 14.0 feet below existing grade.Groundwater seepage ' encountered at 12.5'during excavation. ' N N m Test Pit Log kn Earth Consultants Inc. Proposed Warehouse ccaka.aw Harem oewuen�sumne. � Renton,Washington J a Proj.No. 6955 Dwn. GLS Date Aug. '95 Checked RC Date 8/22/95 Plate A3 ' Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by engineering tests, analysis and judgment. They are not necessarily representative of other times and locations.we cannot accept responsibility for the use or Interpretation by others of Information presented on this log. ' Test Pit Log ' Project Name: Sheet of Proposed Warehouse 1 1 Job No. Logged by: Date: Test Pit No.: 6955 RC 8 15 95 TP-3 ' Excavation Contactor: Ground Surface Elevation: Keith Welland Notes: ' ° — o t � m o Surface Conditions: 6" Sod W = a u n i%j • ] Or u- ! J ] ' 0 N G W A SPSM FILL Brown poorly graded fine to medium SAND with silt,gravel and cobbles,loose, moist 1 ' 2 7.0 ' 3 severe to moderate caving -organics-3'branch 4 SM BLL-Gray silty fine to medium SAND,loose,moist ' 5 Q 5 OH Gray to brown organic SILT,loose,wet 8 ' 83.1 /// -Interbedded organics-peat 10 11 12 13 -considerable organics interbedded-peat 14 ' SP Black poorly graded fine SAND,loose,water bearing 15 Test pit terminated at 15.0 feet below existing grade.Groundwater seepage encountered at 5.5'perched and 14.5'groundwater during excavation. ' W P N N ' \ W Test Pit Log Earth COI1SUItaI1fS Inc. Proposed Warehouse P Gmldinl®IB,mneae.Ocob�e4PnNtmmerilal eCknasl8 Renton,Washington J F Proj.No. 6955 Dwn. GLS Date Aug. '95 Checked RC Date 8/22/95 Plate A4 Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by engineering tests, analysis and judgment. They are not necessarily representative of other times and locations. a cannot accept responsibility for the use or Interpretation by others of Informatlon presented on this log. Test Pit Log Project Name: Sheet of ' Proposed Warehouse 1 1 Job No. Logged by: Date: Test PitNo.: 6955 RC S 15 95 TP-4 ' Excavation Contactor: Ground Surface Elevation: Keith Wellard Notes: o L o y o Surface Conditions: 6"Sod L .2 a U a y y SP-SM FJLL Brown poorly graded fine to medium SAND with silt,gravel and cobbles,medium dense,moist 1 2 3 SM FILL:Gray silty fine to medium SAND with gravel and cobbles,dense,moist 4 ' 5 e 4 ' -heavy seepage-perched 7 CH Gray organic SILT,loose,moist 51.5 10 -interbedded organics-peat 11 12 57.8 /// 13 14 18 17 SP Gray black poorly graded tine to medium SAND,loose,water bearing Test pit terminated at 17.5 feet below existing grade.Groundwater seepage ' encountered at 6'perched and 17'groundwater during excavation. N P 0) Test Pit Log N Earth Consultants Inc. Proposed Warehouse Renton, Washington J Proj.No. 6955 Dwn. GLS Date Aug. '95 Checked RC Date 8/22/95 Plate A5 ' Subsurface conditions depleted represent our observations at the time and location of this exploratory hole,modified by engineering tests, analysis and judgment. They are not necessarily representative of other times and locations.We cannot accept responsibility for the use or Interpretation by others of information presented on this log. 1 Test Pit Log Project Name: Sheet of ' Proposed Warehouse 1 1 Job No. Logged by: Date: Test Pit No.: 6955 RC 8 15 95 TP-5 ' Excavation Contactor: Ground Surfaoe Elevation: Keith Wellard Notes: 1 0 — o L e rn Surface Conditions: 6" Sod _ o W r a *' a u a 1`M) e i • m i SP-SM FILL Brown poorly graded fine to medium SAND with silt,gravel and cobbles,medium dense,moist t 2 7.t -becomes dense ' 3 SM ELL Gray silty fine to medium SAND with gravel and cobbles,dense,moist 4 ' S 6 ' 4 -moderate seepage-perched 7 OH Gray organic SILT,loose,wet /// 6 ,u ' /// t 4 /// -interbedded organics-peat 9 Test pit terminated at 9.0 feet below existing grade.Groundwater seepage encountered at 6.5'perched during excavation. In n N ' m Test Pit Log Earth Consultants Inc. Proposed Warehouse ' OeO tlY GOYD° "40ry onnrn a StlC1tl�' Renton,Washington J a Proj.No. 6955 Dwn. GLS Date Aug. '95 Checked RC Date 8/22/95 Plate A6 Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by engineering tests, analysis and judgment. They are not necessarily representative of other times and locations.We cannot accept responsibility for the use or interpretation by others of information presented on this log. Test Pit Log Project Name: Sheet of ' Proposed Warehouse 1 1 Job No. Logged by: Date: Test Pit No.: 6955 RC 8 15 95 TP-6 t Excavation Contactor: Ground Surface Elevation: Keith Wellard Notes: ' ° — r _ o ° H Surface Conditions: 6"SOd W o L + • a u N SP-SM F]LL•Brown poorly graded fine to medium SAND with silt,gravel and cobbles,medium dense,moist 1 ' 2 ' 3 -becomes dense 3.7 4 SM FILL Gray silty fine to medium SAND with gravel,dense,moist ' 5 6 4 -slightseepage-perched 7 OH Brown gray organic SILT,loose,wet 71.8 /// 8 g -interbedded organics-peat 10 12 x SP Gray brown poorly graded fine SAND,loose,water bearing x e. 13 ' 27.2 a�. 14 a a;°a 15 Test pit terminated at 15.0 feet below existing grade.Groundwater seepage encountered at 6.5'perched and 12.5'groundwater during excavation. el P Test Pit Log N Earth COriSUltaritS Inc. Proposed Warehouse U GeatCrtlml GeWoylnb 4 eiM� Mw somame ' Renton,Washington J a Proj.No. 6955 Dwn. GLS Date Aug. '95 Checked RC Date 8/22/95 Plate A7 ' Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by engineering tests, analysis and judgment. They are not necessarily representative of other times and locations.we cannot accept responsibility for the use or Interpretation by others of Information presented on this log. Test Pit Log ' Project Name: Sheet of Proposed Warehouse 1 1 Job No. Logged by: Date: Test Pit No.: 6955 RC 8 15 95 TP-7 ' Excavation Contactor: Ground Surface Elevation: Keith Wellard Notes: ' L u _ ° _ y Surface Conditions: 6"Sod W o o a s a a u (%) • i • v. i i SP-SM f7LL,Brown poorly graded fine to medium SAND with silt,gravel and cobbles,medium dense,moist 1 ' 2 4.2 ' 3 -becomes dense 4 SP ML•Grades to poorly graded SAND ' S Q -heavy seepage-perched 6 ' 7 ON Brown gray organic SILT,loose,wet / ' 53.2 10 11 48.2 12 /// 13 27.1 /// 14 15 SM Gray silty fine SAND,loose,water bearing 16 Test pit terminated at 16.0 feet below existing grade.Groundwater seepage ' encountered at 5'perched and 15'groundwater during excavation. P m Test Pit Log Earth Consultants Inc. Proposed Warehouse 0`0 O �Mr4k "C`°'°° ` � Renton,Washington J a Pro).No. 6955 Dwn. GLS Data Aug. '95 Checked RC Date 8/22/95 Plate A8 r ' Subsurface conditions depicted represent our observations at the time and location of this exploratory hole,modified by engineering tests, analysis and judgment. They are not necessarily representative of other times and locations.We cannot accept responsibility for the use or Interpretation by others of information presented on this log. ' DISTRIBUTION E-6955 ' 4 Copies Adventure 95 3701 South Norfolk ' Seattle, Washington 98118 Attention: Mr. Gordon Younger ' 1 Copies Linardic Design Group Architects ' 1319 Dexter Avenue North, Suite 260 Seattle, Washington 98109 ' Attention: Mr. Ed Linardic 1 1 1 1 1 1 1 ' Earth Consuhants, Inc. wi?t w Fill' " IRV!R5 -At Ilk, AFT, 4.V t 44 "4T , Awl W 7z IV, 4 , WETLAND DETERMINATION ON THE ORILLIA BLOCK 8, LOT 4 SITE (Renton #8E Parcel) Renton. Washington Prepared For Lane Himmelman CMX Corporation 6601 S. Glacier Tuk%%ila, WA. 98188 G PCX0005 B) DAVID EVANS AND ASSOCIATES, INC. 415 118th Avenue SE Bellevue. Washington 98005 yy November 12, 1991 '�lj /�Fo o�yF< 0B Opp cryo FHrp tiNN1% i:� I AV", iPh iRi NITS(T> 0E\TIiTS REPORT PREFACE This report has been for the use of Lane Himmelman and the project consultants. In preparing this report David Evans and Associates. Inc. (DEA1 has used the site information and proposed de\elopment plans as referenced herein. Findings reported herein are based on information gathered in the field at the time of the im esti ation. DEA's understanding of the US Arm\ Corps of Engineers Triple Parameter Methodology. and DEA's understanding of federal. state. and local regulations go\erning m%etlands and stream areas. Prior to preliminan and final design or am construction. all appropriate regulator\ agencies should be contacted to verify the findings of this report. and to obtain appropriate approvals and pen-nits. The %cetland boundarc. %%etland and stream classification and recommended buffers are DEA's best professional opinion based on the circumstances and site conditions at the time of our study. The final N%etland boundary determination. classification of m%etlands and streams. and the required buffers and setbacks are made by the appropriate federal. state. and local jurisdictions. ii ` EXECUTIVE SUMMARY A field assessment for the presence and extent of%etlands on the Orillia Block 8. Lot 4 Site has been conducted be David Evans and Associates. Inc. tDEAt. The site is located south of South%est 34th Street. %%est of Sprin_brook Creek. north of South%'est 39th Street. and east of Oakesdale Avenue S.%k*. in the Cite of Renton. Washington. This approximately 9.28-acre site %'as investigated in September and October 1991. The site consists of herbaceous perennial grasses and fOrbs. annual herbs. and a fairly large forested component of coung to medium-aced cottonwoods and other shrubs. The site %%as legallc filled about twenty tears aao: hence. the topography is relativel\ flat. with small depressions and ruts forted b} head equipment as a result of the grading work. The wetland delineation used the 1987 US Arm\ Corps of Engineers Triple Parameter methodolog}. and resulted in the identification of three %'etlands located on-site. Total area of %'etlands identified %%ithin the boundaries of the site is 2.63 acres. The %'etlands range from 0.0- to 2.39 acres in size. T%o of the identified %'etlands %ould be classified according to the US Fish and Wildlife Service sNstem as palustrine. emergent %etlands. The southernmost wetland is a forested wetland % ith cottonwoods. %'illows and other %ith shrubs. and thus would be classified as palustrine. forested. Federal. state. and local agencies regulate activities in %etlands. This report can be used by these agencies to determine permit requirements associated %ith de\elopment plans. Preliminarn plat design for Orillia Block 8. Lot 4 Site has been completed. and potential %etland impacts are dentified in this report. iii TABLE OF CONTENTS Pale REPORTPREFACE.....................................................................................................ii EXECUTIVE SUMMARY.......................................................................I.................. iii INTRODUCTION.........................................................................................................I PURPOSE.......................................................................................................I...............I METHODOLOGY........................................................................................................I Preliminary Research............................................................................................3 Site-Specific Investigation.....................................................................................3 Wetland Determination ........................................................................................A Functional Value Assessment...............................................................................4 INVESTIGATION FINDINGS...................................................................................6 Vegetation..............................................................................................................6 Soils ......................................................................................................................9 Hydrolog} .............................................................................................................8 Wetland Determination..........................................................................................8 Functional Value Assessment...............................................................................9 REGULATORY REQUIREMENTS........................................................................10 IMPACT ASSESSMENT.....................................................................1.....................11 REFERENCES.............................................................................................................13 APPENDICES..............................................................................................................15 A. Plant Indicator Status Definitions..........................................................-16 B. Plants Occurring on the Subject Property................................................I C. Feld Data Sheets.....................................................................................18 List of Figures I. %'icinitc Map..............................................................................................2 2. Wetland and Data Plot Location Map........................................................ 3. Preliminan Impact Map..........................................................................12 List of Tables I. Triple Parameter Summary and Wetland Determination...........................8 INTRODUCTION On behalf of Lane Hinunelman, Dacid Esans and Associates. Inc. tDEAi conducted a wetland investigation of the Orillia Block 8. Lot 4 Site. Lot 4 is located west of Springbrook Creek. south of Southwest 34th Street. east of Oakesdale Avenue S.W.. and north of Southwest 39th Street in Renton. Washington (Figure 1). The 9.28-acre site is surrounded by undeseloped industriall%-zoned lands. The site consists of revegetated fill material placed approximately twenty )ears ago. Because the site is situated in the Green River floodplain. there is a need for a site-specific imestigation for the presence and extent of wetlands. Pursuant to the Clean Water Act. and through the Section 404 permitting process. the US Arm) Corps of Engineers (Corps) has been given the responsibility and authority to regulate the discharge of dredged and fill materials into waters and adjacent wetlands of the United States. The Corps defines wetlands as "those areas that are inundated or saturated hr surface or grtiunduater at a frequency and duration sufficient to support. and that under normal cirrunutanres do support. a prevalence of vegetation rs picalls• adapred fnr life in saturated soil conditiom." Wetlands generally include swamps. marshes. bogs. and similar areas. PURPOSE The purpose of this studs was to determine the presence and extent of wetlands on the subject propem. e\aluate the functional values of and wetland present. and based on the preliminary site plan Ia%out. identify potential wetland impacts due to site deg elopment plans. This report may be used bs local. state and federal agencies to determine am permit requirements associated with de\elopment plans. METHODOLOGY The analysis of wetlands conducted on this site was based on the methodology deceloped b\ the Corps ( 1987). commonly referred to as the Triple Parameter Method. for implementation of Section 40-4 of the Clean Water Act. The Triple Parameter Method requires that evidence of three 1 � i ro i TO i i o �r 5729•t 5• Z 51rE SIf..$Yr. > a I w 3 - 5 3 S.W.3Atn 5t V T 3 V J m 5s. ue e c _S ti Site Location I - u 1M5ET MAP Figure 1. Vicinity Map Rentm: Block 8, Lot 4 twe M�.a.ma parameters (a dominance of hydrophytic vegetation, hydric soils. and Hetland hydrology) be present for a Actland determination. T%%o levels of information ha%c been gathered for this analysis. These include: ( I ) preliminary site research. and (2) a site-specific imestisation for the presence of tietlands. The methodologies used in this approach are described beloH. Preliminary Research Review of existing information was conducted to develop background knowledge of physical features and to identify the potential for wetland occurrence on the subject property. Information related to topography. drainage, and water features was obtained from these information sources. The following resource documents were available for preliminary review of the site conditions: • Aerial photograph black-and-white (March 1985) and infrared (July 1988) at one inch = 400 feet scale,and natural color oblique view: • USDA Soil Conservation Service (SCS) 1973, Soil Suney of the King County Area. Renton Quadrangle: • USDI Fish and Wildlife Service (USFWS) National Wetland Imentory (NWI) Maps ( 1987): • USGS Geological Topographic Sun ey 1979, Renton Quadrangle: Site-Specific Investigation �'cectation Representati\e sample plots mere located in identified wetland plant communities and in the adjacent upland areas. Data plots. 11 .8-foot radius (0.01-acre). Mere established in areas of homogeneous megetation. Areas where more than 5017r of the dominant species present are hydrophytes (plant species adapted to saturated conditions) were generally considered to be inside the %%etland boundary, unless clear evidence of the absence of one or more of the other parameters was established. As per the methodology. hydrophytic vegetation was determined to be present if more than 5017c of the dominant plant species had an indicator status of facultative, facultative wetland, or obligate wetland. These and other plant indicator status definitions are presented in 3 Appendix A. In addition,all plant species observed on the site were identified. Appendix B Iists these species kith their wetland indicator statuses(per Reed 1988). Soils Soils on this site consist of fill material. Although the Corps Triple Parameter Methodology does not require that soils be addressed when vegetation is non-hydrophytic, a few soils pits were cursorily assessed in various areas on the site. Because the fill material has settled, compacted, and cemented over the years, soil pits could scarcely be excavated beyond six inches. Hydric soils are those that are saturated. flooded, or ponded long enough during the growing season to develop anaerobic conditions that favor the growth and regeneration of hydrophytic vegetation. Hydric indicators used in this study were limited to depressional areas that appeared to hold water long enough during the grow ina season to meet the hydtic soil criterion. Hvdrolow Observations of wetland hydrology were noted on data sheets, and included visual observations of inundation. soil saturation, clear evidence of areas that have ponded during the last wet season. water-borne sediment deposits, water-stained leaves, and aerial photograph analysis. Wetland Determination Analysis of all three parameters was conducted for the wetland determination. When one or more of the parameters were abseni, the area was determined to be non-wetland. Wetlands were flagged by DEA biologists and surveyed by Bush. Roed and Hitchings. Inc.. Seattle. and the wetland areas calculated by CAD. Functional Value Assessment Wetlands play important roles that pro\ide valuable benefits to society. Wetland habitat and functional values are numerous and \cried and have been described by several wetland investigators (WDOE 1988. Adamus et al. 1987. Reppert et al. 1979. Mitsch and Gosselink 1986). Wetlands often play dynamic roles in many ecosystems by performing functions of intrinsic ecological and social value. Important wetland functions include water quality protection. storm and flood flow alteration and storage, groundwater exchange, and biological support. 4 E%aluation of the assessment areas provides a context to the impact area evaluation and an understanding of the functions of the ,ite %%etlands in their present configuration. The evaluation of the impact areas describes the wetland values and areas directly affected b) the proposed development. Both evaluations are used to create a mitigation plan that provides for the replacement of any wetland area and \alues affected by the proposed development. Water Quality Protection One important %alue of wetlands is their ability to help maintain and improve the water quality of rivers. lakes, and other water bodies. Wetlands can function to naturally purify water by removing organic and mineral particulate matter. Large, densely vegetated wetlands can improve the processes of sediment and toxicant retention, ion exchange, chemical adsorption, and algal and bacterial degradation of pollutants. and ma) also moderate the effects of acid precipitation. Due to their position between upland and deep water, wetlands can intercept surface water runoff from land before it reaches open water. The) also can help filter nutrients. waste. and sediment from flood waters (EPA 1988). Key wetland predictors used to assess the level of water quality improvement are wetland type, its areal extent, vegetation density and geographic factors of its location (Reppen eta]. 1979). Storm- and flood-Water Storaoe and Alteration %Vetlan& modify the effects of storm- and flood-waters b) reducing floodpeaks, desynchronizing the floodpeaks of the various streams in a single watershed, providing flood water storage. slog+in flood waters. and increasing duration of flow. An) depression in the landscape has the potential to store water and thereby to plav a role in flood control. In general, wetlands not filled w ith water to capacit\ will perform a flood control function. Welland topography and vegetation dis.ipa(c the cnerg) and reduce the velocity of flood waters by providing surface roughness. The storage capaciq and the surface roughness of the wetlands are paramount in pro\iding this wetland function (Reppen et al. 19-9. Sather and Smith 1984). In watersheds where wetlands have been lost. flood peaks ma) increase by as much as 80% (Adamus and Stockwell 19&3). 5 Gmundwater F.\chanJe Groundwater exchange includes both recharge and discharge. These processes are not necessaril\ mutual]% exclusi\e as they are often dictated by seasonal conditions. During dry periods, surface water w II be absorbed into the ground and recharge may occur if the geomorphic conditions are suitable. As precipitation intensity increases during winter months and the water tables are replenished. water may discharge from a site. Groundwater exchange is a site-specific phenomena, which is dependent on wetland location in the watershed, soil permeability and drainage. and the h\drologic regime. Natural Bioloeical Support Attributes of this function are wildlife habitat, food chain production. and the potential for em ironmental studies, sanctuaries, and refuges. General habitat criteria used to assess the biological value are structural diversity of communities and species, diversity of adjacent upland areas. and the presence of biological support for game,commercial, or unique species. INVESTIGATION FL WNI GS Field imestigations for this study were conducted during September and October 1991. A DEA biologist located 18 data plots on the site (Figure 21. Vegvtatiun The National Weiland ln\entor% ( 1989) does not identif\ an% wetlands on the subject propert\. The on-site \egetation consists of an upland association and three wetland associations The upland association consists of an upland grass communit} dominated b\ bentorass (Agrn%(i% tenui� i and hairgrass (Aire rurr(Phrlleu) The wetland associations include two herbaceous and one shrub communit}. The herbaceous communities include small stands of reed canarygrass I Ph,rariN arun,fi+ai, ea). or a water foxtail (Alnre(urut genh ulutu%)-dominated communit\. The latter often contains \arcing amounts of soft rush (Junruc effiIsut), creeping ben(grass (A,,rfwi% vedonifera), or purslane speedwell (Veronica Peregrine). The wetland shrub community occurs in three wetland areas and consists of black cottonwood (Populus hulsmnifera) over sparse grasses and forbs. 6 i � N u 6 I A 3 F-G a p. F Y Wetland Area 0.05 0'9 Fv G37 "�_a 3 x •:es 9.28 acres �.: _..0 .. - P`iours 3. 5�st1aail anal 'Leta 1110t 1llap. Ran2on: Block 8, Lot 4 Soils A di>cu<xd pre%iously. the area has been tilled in the past. and the present soil conditions are difficult to assess. The area has been dri%en on. and the compaction. coupled with type and nature of the fill material and precipitation. has resulted in an extremely dense. hard. surface. It was not possible to adequately characterize the soil profile. Several pits were attempted and to the 6 inch depth, the soil displayed gravels and loams. The color was variable. but typically 75 YR 413. Hydrology Evidence of temporary inundation for some portions of the growing season characterized several areas on the subject property. The evidence included cracked mud surfaces. and microtopographic depressions (possibly due to vehicular traffic. poor grading procedures. and settling of the fill material during and after the fill operation). Wetland Deteruunation As described in the methodology. three wetland parameters must be evaluated for positive wetland identification. Criteria established by the Corps typically require that hydrology. hydrophytic vegetation. and hydric soils all be present for a positive wetland determination. Table 1 presents a summary of the three parameters used to make the wetland determinations. Table 1. Triple Parameter Sunman and Wetland Determination Plot Soil H�droIo2x Vc�!etation Detenninjtion I h%dric assumed hydrophytic %ketland non-hydric absent hydrophytic upland 3 hydric assumed hydrophytic wetland i hydric assumed h\drophvtic wetland 5 non-hydric absent hydrophytic upland soils were considered hydric is evidence of ponding was observed 8 Based on a dominance of h}drophytes. supporting hydric soils data. and evidence of positi%e wetland hydrology. three wetlands were identified on the subject property (Figure 21. The wetlands ranee from 0.05 to 2.39 acres in size. Two of the identified wetlands would 1r classified according to the US Fish and Wildlife Service system as palustrine. emergent marsh wetlands. The remaining would be classified as palustrine. forested wetland. Functional Value Assessment Water Quality Protection Densely vegetated grassy swales provide highly effective biofiltration. Swales 200 feet long can remo%a more than 80 percent of the lead and total suspended solids from influent. more than 60 percent of the copper and zinc. 5 to 85 percent of the phosphorous. 40 to 85 percent of the nitrate. and 67 to 93 percent of the oil and grease (Homer. 1988). This strongly suggests that a wet meadow. which is densely vegetated by grasses. such as the ones on the site can provide comparable biofiltration. The vegetation of the wetlands consists of low grasses so the surface roughness of the Welland is reduced. thereby reducing their ability to intercept pollutants. Tall grasses would be more capable of slowing surface water. and thus. causing sedimentation and absorption of pollutants. The larger forested wetland in the south-central portion of the property would channel flows and assist in sedimentation if p.dlutants entered the system The wetlands are curTently providing minimal to moderate water quality protection. They may be sequestering pollutants from adjacent sites, howeNcr due to the lack of drainage to off-site areas. any pollutants that mas be discharged to the site may remain on-site. Flckldflo\k alteration The subject wetlands low %alue for Iloodflow alteration. They are %en small wetlands (ranging from 0.0� to 2.39 acresi. Wetland F-G. due to its forested component and oaerall size does pros ide moderate water stonnWater retention function The wetlands. taken together mas assist in some floodflow stabilization due to the nature of their location in an old floodplain area. noW largely being used for industrial purposes. 9 Biological Support The wetlands on-site have low value for this function. Sightings over the last few years (DEA) have not yielded much specific information on animal species using these %%etlands. It could be assumed that during winter months when the wetlands pond. waterfowl use these areas for feeding or resting. However. again due to its size and multi-layer component, wetland F-G would probably rate moderate for biological support. Grounds%ater Exchange The wetlands on-site are not bounded by ditches and are almost completely surrounded by undeveloped upland areas. Therefore. virtually all of the edge of the wetlands can participate in groundwater recharge. Therefore. however minimal. groundwater recharge may be associated with the wetlands on-site. In summary, the wetlands probably have low to moderate value for groundwater recharge. This is a very qualitative assessment of groundwater recharge. A more definitive assessment would acquire a detailed. on-site hydrological investigation. REGULATORY REQUIREMENTS Pursuant to the Clean Water Act. and through the Section 404 permitting process, the LIS Army Corps of Engineers (Corpsl has been given the responsibility and authority to regulate the discharge of dredged and fill materials into waters of the United States including wetlands. The Corps(Federal Register. 1982) and the Environmental Protection Agency (Federal Register. 1980) jointly define wetlands as "thc»e arras that are intendated or sattn•ated by setrfare or grounclivater at a freyuenc.y and duration sins ient to support. and that under normal eireurn.ctanres do suhf1ort, a prevalence of vegetation typically adopted for life in satterated .coil eonclitiuns." Wetlands generally include swamps. marshes. bogs. and similar areas. Nationwide Permit 26 under Section 404 allows filling less than one acre of isolated cvetlands or adjacent wetlands located above the headwaters (defined as an average annual flow of 5 cfs). The Corps will be contacted to verify that %%etland fill less than one acre Nationwide Permit 26 is applicable. The State Environmental Protection Act (SEPA) is implemented by local agencies and provides a process to analyze the environmental impacts of development. During SEPA environmental review, various agencies have the opportunity to review and comment on the proponent's proposal. 10 For tilling wetland habitat. the CitN of Renton will most Iikeh require mitigation as a condition for SEPA appro%al. IMPACT ASSESSMENT The preliminan development proposed will result in una%oidable impacts from road and building construction in about 0.70 acres of wetland (Figure 3). In some areas the proposed buildings will be within 25 feet of the existing wetlands. These areas will not be lost to fill. however. they will be affected b% encroachment. The site plan has been prepared to aN oid wetland impacts and affects where feasible. The project was designed to impact wetlands of low value where impacts could not be a%oided and still allow reasonable use of the land. 11 REFERENCES Adanuts. Paul R. and L.T. Stockwell. 1983. A Method for Weiland Functional Assessment. ( nited States Department of Transportation. Federal Hi2hwa% Administration. Volumes and Il. Report Number FHWA-I P-82-23 and 24. Adamus. P.R.. E.J. Clairain. Jr.. R.D. Smith. and R.E. Young. 1987. "Wetland E�aluation Technique (WET)-. Volume II: Methodology." Operational Draft Technical Report Y-87. US Army Engineer Waterways Experiment Station. Vicksburg. Mississippi. Cowardin. L.M.. V. Carter, F.C. Golet. and E.T. LaToe. 1979. Classification of Wetlands and Deepwater Habitats of the United States. Office of Biological Serices. Fish and Wildlife Ser%ice. United States Department of the Interior. FWS'OBS-79131. Environmental Protection Agency (EPA). 1988. America's Wetlands: Our Vital Link Between Land and Water. Office of Wetlands Protection. Office of Water. Washington. D.C. OPA-8--016 Federal Register. Volume 45. Number 249. 1980. Environmental Protection Agency. Pan W. "Guidelines for Specification of Disposal Sites for Dredged or Fill Material." Greig-Smith. P. 1983. Quantitative Plant Ecology. University of California Press, Berkeley. Horner. R.R. 1988. Biofiltration Systems for Storm Runoff Water Quality Control. Prepared for the Municipality of Metropolitan Seattle. Seattle, Washington. King County Planning Division. 1982. King County Wetlands Inventor Notebook. 1litsch. W.J.. and J.G. JGosselink. 1986. Wetlands. Van Norstrand Reinhold Company. Inc. Reed. Jr.. P.B.. 1988. National List of Plant Species that Occur in Wetlands: 1988 Northwest Region 91. Biological Report 88(26.9). US Fish and Wildlife Serice, Inland Freshwater Ecolog% Section. St. Petersburg. Florida. Epp. 861. Rcpl)cn. Ri,hard T.. W. Sigleo. F. Stakhia. L. Messmnn. and C. Me%crs. 19-9. Wetland Values - Coniepts and Methods for Wetlands Esaluation. Research Report ,9-Rl . l'S Arm\ Coq), of Fngineers. Inaittue for Water Resources. Fort Bel%oir. Virginia. Sather. 1.H.. and R.D. Smith. 1984. An Oven iew of Major Wetland Functional Values.US Fish .and \1'ildlife Scricc. FWSOBS-8418. Sather. J.H and P.J.R. Stuher. tech. corrds. 1994. Proceedines of the .'rational Wetland Values Assessment Workshop. US Fish and Wildlife Sea ice. Weslem Fnerga and Land Use Team. FWS'OBS-84/12. United States Department of Agriculture, Soil Conseration Serice, 1973. Soil Surey, King County Area, Washington. Prepared in cooperation with Washington Agricultural Experiment Station. 13 United States Department of Agriculture. Soil Conser%ation Service. 1987, H,,dric Soils of the United States. National Technical Committee for H\dric Soils. I*nitcd States Department of the Ann%. 198—. Corps of Engineers Wetlands Delineation 1lanua' Environmental Laboratwn. Watensa\s Experimental Station. Vicksburg. Mississippi. United States Department of the Interior. Fish and Wildlife Service. 1987. National Wetlands Inventor\. Renton Quadrangle. United States Geological Survey. 1911. Renton Quadrangle. 7.5 Minute Series. scale 1:24000. United States Housing and Urban Development. Federal Emergency Management Agency. 1981. Federal Insurance Administration, National Flood Insurance Program. Flood Insurance Rate Map. Cit} of Aubum. Washington. Panel 1. Washington Department of Ecolog} tWDOEI. 1998. Wetland Regulations Guidebook. Publication Number 88-5. Weinmann. Fred. 1991. Personal communication. 14 APPE\-DICES 15 Appendix A. Plant Indicator Status Definitions Indicator Indicatorcateaorn Ssmbol Definition OBLIGATE OBL Plants that occur almost always(estimated WETLAND PLANTS probability >99°r) in wetlands under natural conditions. but which may also occur rarer• (estimated probability<1 t ) in non-wetlands. FACULTATIVE FACW Plants that occur usually (estimated probability WETLAND PLANTS 67% to 99"c t in wetlands. but also occur (estimated probability 117, to 33%) in non- uetlands. FACULTATIVE FAC Plants with a similar likelihood (estimated PLANTS probability 331-r to 67,C)of occurring in both wetlands and non-wetlands FACULTATIVE FACU Plants that occur sometimes (estimated UPLAND PLANTS probability It to<33%) in wetlands. but occur more often (estimated probability 67% to 99,%) in non-wetlands. OBLIGATE UPLAND UPL Plants that occur rarely (estimated probability PLANTS <1%) in wetlands under natural conditions. NO INDICATOR NI Plants which do not hate sufficient data available STATUS to estimate their probability of occurrence in wetlands 16 Appendix B. Plant species encountered during site-specific in, estigations kk etland Scientific Name Common Name Indicator Status Shrubs Census scoparius Scot's broom L'PL Populus haAamifera black cottonwood FAC Ruhua discolor Himalyan blackbern FACU Sahr hookeriana Hooker willow FAC Salir lasiandra Pacific willow FACNW+ Spraea douglasii Douglas' spirea F•ACNV Herbs Agrop-vron repen, quackgrass FACL Agrostis .rnlonifera creeping bentgrass FAC Agrostis tennis bentgrass FAC' Aira carsophsllea hairgrass LPL Aira proecar siher hairgrass LPL Alopecurus geniculatus water foXQ FACIA' Bromus trwllu bromegrass UPL Cesium anense Canada thistle FACU+ Dacnfis glrmerara orchardgrass FACU Dianthus armerta grass pink LPL Dwnthus deltotdes maiden pink UPL Eleocharo palustris creeping spike-rush OBL Festuca arurtdinaceu tall fescue FACU Gnaphalium palustre western marsh cudweed FAC Gnarhalium rurrureum cudweed LPL Hrdrus lunutus common selsetgrass FAC H%pr-ch errs ru.:.vra hain cat's ear LPL lunrue ,]. m:r.,Ca, taper-tip ruih ORL Jun, u, r:4.' •r.u, r�,ad rush luncue efus soft rush FACti1 j,.r haw kbil L PL thti:a Qr•mer_t;1 mountain tamed FACL r .r• ,•,r parerstu.cllia rAC( Phi Ljr.• .; .r .. :.:, r,r reed caner era>> F A(11 I nglish plantar F A( t - p,sjw,; r i:omnion plawa.r. FAC- p,.tr�r,:;, r.,, F.rntuck� hlurc-„- fk(A Rurrl<r. -.r:•,'r�` cur! dock F WV Srvru a.anr; hardstem hulr.>r OBL Srer�ulal,,: sp spurre\ S'r,r,;nthe r„m n✓y7;una ladies'tresses OBL Tr:jr ura r;rrn, "hire closer FA('( r,r)Ju iuq! Iru common cattail OBL t'enrntca peregruw purslane speedwell OBL ' note: personal communication with Fred Weinmann indicates that A. tenuis is now considered FAC 17 Appendix C. Field Data Sheets 18 YA]n aW. INTERXXDIATt-LEY,S!. ONBITE DETERMINATION XMIOD QUADRAT TRAXBECT AAXPLIN4 PROCEDU" (Vegetation Data) Field Invests ato;(a) ��^'RC�rClbl ✓ ,� � -- Data: Project/Site:��,g State: County: C r TransAppl cant/Owner: plot i - L __ Transect / ,Note : If a more detailed descript on is necessary, use the back of the data form or a field notebook. ••s*•i � �*��**•�»��r� ��♦*e�set�*�t��eftiii*��*feefteeta�*tee*ei�e�e*�t»>��• DOMINANT PLANT EPECIE8 Herbs (BrYODhYte'.!1 Status SaRl inns Status 1. - c A Cc Z_ 01 1. 2 . C. 2. 3 . -F- 3. L . Vi RC.1i Z.+ �2 LL,Zi��a 2 O ,. 4. L 5. nDIA ,: n v 5. 6. 7 CAL,) 6. r S . S. 9 . ' 10. 10. - li . 12 . 12. 13 . 13. Shrubs Trees 1 . 1. s .3 . 3. 4 . 4 ' S. 5. 6. 6. 7 . 7 . 8 . 8 . 9 . 9' 10. 10. 11 . 11. 12 . 12. 13 . 13 . Percent of dorinant species that are OBL, FACH and/or FAC Is the hydrophytic criterion met? YeSL No_ Is the hydric soils criterion met? Yes No_ Is the wetland hydrology criterion net? Yesk- No Is the vegetation unit or plot wetland? Yes No_ Rationale for jurisdictional decisions 1N is ,. IUTZRX1DIATt-L9VN.'j ORBIT! DETERXINATIOX XZ-XOD QUADRAT TRANSECT SAXPLIXO PROCEDURY (vegetation Data) Field Investigators) • Date: Project/Site: L`r)\ g State:_ L ___ County: C;r Applicant/owner: Transect f Plot f z Note: If a more detailed description is necessary, use the back of the data form or a field notebook. DOXINANT PLANT SPECIES Indic. 1• f teal go $ACus iaplinas Status 2. �. .� i Ei t 2. 3 . r�. .c \ 6.,4 . a Io OQL- 3. 4 . 4 . S, S. 6 . 6. 7. 7. 9. 9. 10. 10. _ 11 . 11. 12 . 12. 13 . 13 . Shrubs Trees 1 2 . 2. 3 . 3. 4 . 4 . S . S. 6 . 6 . 7 . 7. S . a . 9 . 9. 10. 10. 11 . il. 12 . 12 . 13 . 13 . Percent of dominant species that are OBL, FACN and/or FAC _ Is the hydrophytic criterion met? Yes No- Is the hydric soils criterion met? Yes_ NoL Is the wetland hydrology criterion met? Yes_ NOL. Is the vegetation unit or plot wetland? Yes_ No'� Rationale for jurisdictional decisions 1 INTLRKEDIATZ-LZVt& ONOM D=TEAJlIN71TI01I ME:>,OO QUADRAT TRANSECT DAMPLINQ PROCIDUR2 (vegetation Data) Fi . ld Invests ator(s) : `c "� e��`� Date: q State: county: L r Project/Site: Ll - Applicant/owner: plot ! 3 Transect 1 Note: If a more detailed description is necessary, use the back of the data form or a field notebook. •aaaaaaaaaria+aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa + �*�aa DOMINANT PLANT splelle Indic. Indic, �atua SaVI ims Status 1 MAO�a = 2 CLC`D( L'2 Ca Laai i-7 -r o 3• 3 . �r c-c the t Ov --a n Z _�- ,. GA. ., S S. 6. 7. 7. - 9. 9. 10. 10. 1 1. 11. 22. 122. 13. 13. Shrubs Trees 1. 1. 2. `. 3 3 . 1. S. 6. 6. 7. 7 . S. S . 9. 9. 10. 10. 11. il . 12. 12 . 13 . 13 . Percent of dominant species that are OBL, FACW and/or FAC '.S Is the hydrophytic criterion met? Yes No_ Is the hydric soils criterion met? Yes No Is the wetland hydrology criterion met? Yes No— la the vegetation unit or plot wetland? Yes No_ Rationale for jurisdictional decisions INSLRXEDIATE-LEFA!. OWBITZ DZTERXINATION XE:DOD QUADRAT TRANBECT SAMPLING PROCEDU" (vegetation Data) Fii Id Investsgatos (s) : ✓�I � Date:EL Project/site: State: County: ( r� AppIicant/Owner: ct t Plot Note: f Note: if a more detailed deacri t on ie necessary, use the back of the data form or a field notebook. * aiaaaaa�ata*fa*afftra�aiaaa!**a*aatffaa*a*tiif*aaa�aar*atitataf* aa*a�a :taat� DOMINANT PLAN'P BPECIEB Indic, Indic, Herbs (Brvophvtesl Status $aelines Status 1. �R 0' � ( u57 SSA 2 F� 2 . mAT(zrc- >rzra masz��n2 �o �) �F�� 2• 3 . -T AC . _ l . " a r I J6-L - 3. S. 5. 6. C, G PN ILAC] 7.1 ,Z,z r 1 FA- 6• - 7 . 7. 8 . 8. 9. 9. 10. 10. li. 11. 12. 12. 23 . 13. Shru1 . ��S?lasa 3Al '.Ol 2tcc2�r� 3 AL - 2. . 3 . 3. 4 4 . S. 5. 6 . 6. 7 . 7. 8 . 8 . 9 . 9. 10. 20. il . 11. 12 . 12 . 13 . 13 . Percent of dominant species that are OBL, FACW and/or FAC (00 Is the hydrophytic criterion met? Yes No_ Is the hydric soils criterion met? Yes4 No- la the wetland hydrology criterion met? Yes No Is the vegetation unit or plot wetland? Ye84 No 3 J_ Rationale for jurisdictional decisions IMTERMIDIATI-1XV&P ONeITI DITIRMINATIOM ME=EOD - QUADRAT TRANSICT &AMPLING PROCEDU" .� (Vegetation Data) Field Investiggator(s) : `�'� e�r� An- Date: Project/site: l. \ �'r State: County: L.r Applicant/owner: Transect 1 Plot 1 Kote: If a more detailed descript on is necessary, use the back of the data form or a field notebook. 1ff}fff} ffff}i}fftfffflfff!}f}}f}f}}!f!f}!}f}}1f}fffftfffff}f!}ffflffffttff� DOMIMWT PLAW 6PICII6 Indic• saplings Statu; 1. 2. 3 . , o UQL 3. 4 . 4 . S. S. 6. 6• 7 . 7. e . 8• - 9 . 9. 10. 10. 11. r 11. 22 . 12. 13 . 13. Shrubs Trees 1. 1. 2. 3 3 . 4 . 4 . 5. S. 6. 6. 7 . 7 . 8 . 8 . 9 . 9. 10. 10. 11 . 11. 12 . 12. 13 . 13. Percent of dominant species that are OBL, FACW and/or FAC Is the hydrophytic criterion met? Yes_ No_ Is the hydric soils criterion met? Yes_ Nox Is the wetland hydrology criterion met? Yes No� Is the vegetation unit or plot wetland? Yes` No�L 13 Rationale for jurisdictional decision: CRY OF RENTON i E C E I V EL JUN 2 3 T' i BUILDING DIVISI N 1 TECIINICAL INFORMATION REPORT CITY OF REWON f7E C E I V ED JUN 2 3 1095 BUILDING DIVISION Springbrook Warehouse BY • SITE DEVELOPMENT SERVICES 310 208TH ST SE BOTHELL 98012 481-9687 June 14, 1995 G. D O UC ASh/1 h �k rr '5i42 WS S�ONht� Ezl7CSS � rf+�1 TABLE OF CONTENTS SECTION NO. Project Overview I Preliminary Conditions Summary II (Not used) Off-Site Analysis III Retention/detention Design IV • Conveyance Systems Analysis and Design V (Swale Design) Special Reports and Studies VI (Not used) Basin and Community Planning Areas VII (Not used) Other Permits VIII (Not used) Erosion/Sedimentation Control Design IX Bond Quantities and Other Forms X (not used) Maintenance and Operations Manual XI (not used) • • SECTION I PROJECT OVERVIEW • PROJECT OVERVIEW This section summarizes all of the Core Requirements . Any applicable Special Requirements will also be discussed. The project consists of 6 . 72 acres and has no structures on it . The project will result in the creation of one building to be used as a warehouse and office . The parcel has been cleared and is covered with grasses . Because the site is next to Springbrook Creek, special water quality systems are provided in series with a bioswale . The system consists of one wetvault on each side of the building which drain to an open detention pond. The pond drains through a flow restrictor and into the bioswale . • • CORE REQUIREMENTS REQUIREMENT #1 : DISCHARGE AT NATURAL LOCATION Discharge from the site is to Springbrook Creek. The developed site discharges to the same location. REQUIREMENT # 2 : OFF-SITE ANALYSIS These issues are addressed in Section III . The downstream system consists of Springbrook Creek. REQUIREMENT # 3 : RUNOFF CONTROL As stated above, detention with a permanent pool is provided. REQUIREMENT # 4 : CONVEYANCE SYSTEM • Conveyance is accommodated by a piped storm drain system which drains into a wetvault . This then drains into a detention pond and then to a bioswale . The bioswale drains directly to Springbrook Creek. All roof runoff was diverted directly to the detention pond in order to minimize the flows entering the vaults, thus minimizing the required permanent pool . REQUIREMENT #5 : EROSION/SEDIMENTATION CONTROL Sediment runoff from the site will be controlled thru standard measures, including silt fences, a gravel construction entrance, and use of a two sediment ponds for sediment collection during construction. See Section IX for a complete design. • SPECIAL, REQUIREMENTS The only special requirement applicable to this project is Number 5 , and deals with special treatment due to the proximity of sensitive streams . The manner in which this issue was handled was discussed above . • SECTION III • Off-Site Analysis • OFF-SITE ANALYSIS Because of the simplicity of the downstream conditions, a detailed downstream analysis was not done. Runoff drains directly into Springbrook Creek, so no downstream systems are affected. No upstream areas drain onto the subject site, as the area is flat and what runoff occurs flows to the Creek. • • • SECTION IV DETENTION CALCULATIONS (WETVAULT DESIGN INCLUDED) O-S1' V. +o r Z �� ItoV 5r �oryy�S . f1� s1YS��un r�lLots`r �TI I�r�t�= �• 1 Zi�-c. tAs n o r < 6 4( t $ i-I J /�C- 0'4 r�rl W -22 Fv C. 90t V -� yf,e- Cd ..l N Ct fV j r r /� PO r �.�wiQ ©'t' GD 1.tce t.Jv C' rl'ur kA 'F-I.�c v-0 L. O-N (� 2S4F wt s (Ope o'F o. 170/0 . Oje - 'ram ��7 r ye. ( t)4J ._ 3 rtGb + 1 I ,j e2 I IM..c. l Oulna�� ✓U7v �! t �o Lf 0^�Ft� l4Gt�l �Gs(0 n C4!10 zoo [..k.- CV RtAel 4'(OA Ll < s0/ yQsSVw« ; (eaC(sc4--Prr ar -U = c, � I /4 � eh( = 86 i w ? p Y, Q 10 Vs Cti r t c,_ e- } 4 Aj q 'S V'G ss act V-- auC � / SWul2 � 5 � wt f u rs tl, 19 xxx N N N W W W NNN !' NOO �\ r nrr d� ua„e(o 0\,terlaws J�loW etc f ,l. !�r5 ULF - li' +�^ wce (9 r , roa(c Gv .a av�ct Z oa C_F swa(a G� / t0' prlJ r r WI�IT�`Ol SCY`VcZV I"�t 4/24/95 Site Development Services page 1 Spring-brook Warehouse . ----- BASIN SUMMARY BASIN ID: al NAME : 2 Year Predeveloped SBUH METHODOLOGY TOTAL AREA. . . . . . . : 6 . 72 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE . . . . : TYPElA PERVIOUS AREA PRECIPITATION. . . . : 2 . 00 inches AREA. . : 6 . 72 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 85 . 00 TIME OF CONC. . . . . : 84 . 18 min IMPERVIOUS AREA ABSTRACTION COEFF: 0 . 20 AREA. . : 0 . 00 Acres CN. . . . : 98 . 00 TcReach - Sheet L: 300 . 00 ns : 0 . 1300 p2yr: 2 . 00 s : 0 . 0019 TcReach - Shallow L: 375 . 00 ks :9 . 00 s : 0 . 0019 PEAK RATE: 0 .46 cfs VOL: 0 .45 Ac-ft TIME: 540 min BASIN ID: a2 NAME: 10 Year Predeveloped SBUH METHODOLOGY TOTAL AREA. . . . . . . : 6 . 72 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE . . . . : TYPEIA PERVIOUS AREA PRECIPITATION. . . . : 2 . 90 inches AREA. . : 6 . 72 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 85 . 00 TIME OF CONC. . . . . : 84 . 18 min IMPERVIOUS AREA • ABSTRACTION COEFF : 0 . 20 AREA. . : 0 . 00 Acres CN. . . . : 98 . 00 TcReach - Sheet L: 300 . 00 ns : 0 . 1300 p2yr: 2 . 00 s : 0 . 0019 TcReach - Shallow L: 375 . 00 ks :9 . 00 s : 0 . 0019 PEAK RATE : 0 . 98 cfs VOL: 0 . 84 Ac-ft TIME: 520 min BASIN ID: a3 NAME: 100 Year Predeveloped SBUH METHODOLOGY TOTAL AREA. . . . . . . : 6 . 72 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE . . . . : TYPElA PERVIOUS AREA PRECIPITATION. . . . : 3 . 90 inches AREA. . : 6 . 72 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . . 85 . 00 TIME OF CONC. . . . . : 84 . 18 min IMPERVIOUS AREA ABSTRACTION COEFF: 0 . 20 AREA. . : 0 . 00 Acres CN. . . . : 98 . 00 TcReach - Sheet L: 300 . 00 ns : 0 . 1300 p2yr: 2 . 00 s : 0 . 0019 TcReach - Shallow L: 375 . 00 ks : 9 . 00 s : 0 . 0019 PEAK RATE: 1 . 66 cfs VOL: 1 . 33 Ac-ft TIME: 510 min • 4/24/95 Site Development Services page 2 Springbrook Warehouse • BASIN SUMMARY=====_______________________ BASIN ID: bl NAME : 2 Year Postdeveloped SBUH METHODOLOGY TOTAL AREA. . . . . . . : 6 . 72 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE . . . . : TYPElA PERVIOUS AREA PRECIPITATION. . . . : 2 . 00 inches AREA. . : 1 . 11 Acres TIME INTERVAL . . . . : 10 . 00 min CN. . . . : 86 . 00 TIME OF CONC. . . . . : 9 . 01 min IMPERVIOUS AREA ABSTRACTION COEFF : 0 . 20 AREA. . : 5 . 61 Acres CN. . . . : 98 . 00 TcReach - Sheet L: 140 . 00 ns : 0 . 0110 p2yr: 2 . 00 s : 0 . 0100 TcReach - Channel L: 320 . 00 kc :21 . 00 s : 0 . 0050 TcReach - Channel L: 200 . 00 kc : 17 . 00 s :0 . 0050 PEAK RATE : 2 . 39 cfs VOL: 0 . 91 Ac-ft TIME : 460 min BASIN ID: b2 NAME: 10 Year Postdeveloped SBUH METHODOLOGY TOTAL AREA. . . . . . . : 6 . 72 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPEIA PERVIOUS AREA PRECIPITATION. . . . : 2 . 90 inches AREA. . : 1 . 11 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 86 . 00 TIME OF CONC. . . . . : 9 . 01 min IMPERVIOUS AREA • ABSTRACTION COEFF: 0 . 20 AREA. . : 5 . 61 Acres CN. . . . : 98 . 00 TcReach - Sheet L: 140 . 00 ns : 0 . 0110 p2yr: 2 . 00 s : 0 . 0100 TcReach - Channel L: 320 . 00 kc : 21 . 00 s : 0 . 0050 TcReach - Channel L: 200 . 00 kc : 17 . 00 s : 0 . 0050 PEAK RATE: 3 . 65 cfs VOL: 1 .39 Ac-ft TIME: 480 min BASIN ID: b3 NAME: 100 Year Postdeveloped SBUH METHODOLOGY TOTAL AREA. . . . . . . : 6 . 72 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPElA PERVIOUS AREA PRECIPITATION. . . . : 3 . 90 inches AREA. . : 1 . 11 Acres TIME INTERVAL. . . . : 10 . 00 min CN. . . . : 86 . 00 TIME OF CONC. . . . . : 9 . 01 min IMPERVIOUS AREA ABSTRACTION COEFF: 0 . 20 AREA. . : 5 . 61 Acres CN. . . . : 98 . 00 TcReach - Sheet L: 140 . 00 ns : 0 . 0110 p2yr: 2 . 00 s : 0 . 0100 TcReach - Channel L: 320 . 00 kc :21 . 00 s : 0 . 0050 TcReach - Channel L: 200 . 00 kc : 17 . 00 S : 0 . 0050 PEAK RATE : 5 . 06 cfs VOL: 1 . 94 Ac-ft TIME : 480 min • 6/12/95 Site Development Services page 1 Springbrook Warehouse HYDROGRAPH SUMMARY PEAK TIME VOLUME HYD RUNOFF OF OF Contrib NUM RATE PEAK HYDRO Area cfs min. cf-AcFt Acres 1 0 .462 540 _1.93.4_6--Qf 2 0 . 984 520 36703_ cf. �6_72 ION/r. F7ro-play 3 1 . 662 510 57780 cf 6 . 72 100,q - Fi'e -APB 4 2 .393 480 39554 cf 6 . 72 5 3 . 652 480 60701_cf 6 . 72 6 5 . 059 480 84538 cf 6 . 72 rod r 11 0 . 462 800 39554 cf 6 . 72 2 r 12 0 . 984 620 60701 cf 6 . 72 fa f K_� -a.5e. 13 1 . 662 560 84538 cf 6 . 72 co n o st • s �r • U( S t'�� r - S �c� JQc/ 5d �Vr JCJr'It e t c/a C(LtG� Ct/ t0�1 2 4 Ct�cI C�L.t S1 � l'C� Vc- Jl 'F VOI-J` T@ Cd I,..I�bl'K� SFCQC S1�0rt } GJr�Ft Gulp �1 Ge1ca�M�v�} . NNN (lz.sz-) NSS z, v to, og4 s187 764- lb� n¢S nAn 7 , 5 rl , (�G4 q;zs2 ¢) $S4 7 � goS u/'s� , !Ef• 'iZt'( l.�Y" •t-�,P In �tl N�' 6/12/95 Site Development Services page 1 Springbrook Warehouse Combined Detention System --------------------------------------------------------------------- STAGE STORAGE TABLE CUSTOM STORAGE ID No . det2 J4Il�s 4 170 Description: Combined Storage System STAGE o---STORAGE----> SAGE a----STORAGE----> STAGE -----STORAGE----> STAGS <----STORAGE----> (ft) ---cf--- --Ac-Ft- 1ft) ---cf--- --Ac-Ft- (ft) ---cf--- --Ac-Ft- (ft ---cf--- --Ac-Pt- 100.00 0.0000 0.0000 101.00 7641 0.1754 102.00 16045 0.3683 -03.:: 26552 0.6096 200.10 505.00 0.0116 101.10 8433 0.1936 102.10 17006 0.3904 =03.:: 27603 0.6337 100.20 1298 0.0298 101.20 9226 0.2118 102.20 17967 0.4125 -03.2: 28653 0.6578 100.30 2091 0.0480 101.30 10019 0.2300 102.30 18927 0.4345 CO3..: 29704 0.6819 100.40 2884 0.0662 1C1.40 10812 0.2482 102.40 19888 0.4566 -03.4: 30754 0.7060 100.50 3676 0.0844 IC1.50 11505 0.2664 102.60 20849 0.4786 -03.5: 31805 0.7301 100.60 4469 0.1026 1C1.60 12398 0.2846 102.60 21990 O.SO48 _03.5: 31805 0.7301 100.70 5262 0.1208 1C1.70 12190 0.3029 102.70 23130 0.5310 100.80 6055 0.1290 SC1.80 14119 0.3241 102.80 24271 0.5572 100.90 6948 0.1572 1C1.90 15082 0.3462 102.90 25411 0.5834 6/12/95 Site Development Services page 2 Springbrook Warehouse Combined Detention_System -------------------------------------------- STAGE DISCHARGE TABLE MULTIPLE ORIFICE ID No . rstrl Description: Flow Restrictor - Orifice Outlet Elev: 100 . 00 Elev: 98 . 00 ft Orifice Diameter: 3 . 5742 in. ' Elev: 101 . 90 ft Orifice 2 Diameter: 4 . 9922 in. 0r Ct't. ?4z Elev: 102 .40 ft Orifice 3 Diameter: 4 . 3359 in. 4 Or,' C{u '13 STAGE <--DISCHARGE---. STAGE <--DISCHAR.3E---> STAGS <--➢ISCHARGE---> STAGE <--DISCHARGE---> (fc) ---cfe-- ------- (ft) ---cfe-- ------- (ft) ---cfe-- ------- (ft) ---Cf--- ------- 100.00 0.0000 100.90 0.3289 101.80 0.4651 102.70 1.4540 100.10 0.1096 101.00 0.3467 101.90 0.4779 102.80 1.5444 100.20 0.1550 101.10 0.3636 102.00 0.7041 102.90 1.6274 100.30 0.1899 101.20 0.3798 102.10 0.8048 103.00 1.7050 100.40 0.2193 101.30 0.3953 102.20 0.8846 103.10 1.7781 100.50 0.24SI 101.40 0.4102 102.30 0.9535 103.20 1.8:76 100.60 0.2685 101.50 0.4246 102.40 1.0153 103.30 1.9:40 100.70 0.2901 101.60 0.4385 102.90 1.2333 103.40 1.9-77 100.90 0.3101 101.70 0.4520 102.60 1.3530 103.50 2.0391 • 6/12/95 Site Development Services page 3 Springbrook Warehouse Combined Detention System --------------------------------------------------------------- LEVEL POOL TABLE SUMMARY MATCH INFLOW -STO- -DIS- <-PEAK-> STORAGE ---------DESCRIPTION---------> (cfs) (cfs) --id- --id- <-STAGE> id VOL (cf) 2 Year Design ....... ........ . 0.46 2.39 det2 rstrl 101.78 11 13912.14 10 Year Design ...... ......... 0.98 3.66 det2 rstrl 102.35 12 29404.67 :00 Year Design ...... ....... . 1.66 5.06 det2 retrl 102.94 13 25912.27 s WETVAULT DESIGN • s • (/ viiv R.�UCG co 5 l 5 n VOInV �t.te 5FmVrw a/� o Y`VVf(7 pr' Oltot `Z., Y.aay^ S �-d V'Uit t-�r ['lam¢ • /tr«/. .SV y��1, rc� 1"0 �el.�t�cV lc�a- (-rr1a .(G � . r r�i g t5 C� ♦!o f v uti< p/t�` (/ S .'3 �'w1ctC �� S < ¢ ti�ti �r1�� jJrFaP.(P�f.V/I-t vrer }-O!' Y"4�i t.✓ei'1-.a V' f�1� \-(�^ W W W C1 IS t a/O v l^: 1 ^< GYWe� �"'4-� ✓�l FLS 1 '/ ��l'Q, xxx coo 1 f I oco YCtiv f C �� uv--Ews 4Jl` l �o -(cw '-�ry �-L_.� w ¢ Tvo al' "cc Oe°a L C V 0 f , "` {�trul�w� ✓�ao � � ctrac� 5 t�'r vf� • `O 1 ` �t��Wte NCI" )S�( v'4S /G r CNOT i>.t uvLFrd ��U�f dr�/Gl S4,0r4q � rr � 'c( Cut ) / r / a svv- �ls ` )c ( 8Z) �Z� • 4/26/95 Site Development Services page 1 Springbrook Warehouse --------------------------------------------------------------------- --------- ---------------------- BASIN SUMMARY BASIN ID : b4 NAME: 6 Month Postdevelop SBUH METHODOLOGY TOTAL AREA. . . . . . . : 4 . 65 Acres BASEFLOWS : 0 . 00 cfs RAINFALL TYPE. . . . : TYPElA PERVIOUS AREA PRECIPITATION. . . . : 0 . 67 inches AREA. . : 1 . 11 Acres TIME INTERVAL . . . . : 10 . 00 min CN. . . . : 66 . 00 TIME OF CONC. . . . . : 9 . 01 min IMPERVIOUS AREA ABSTRACTION COEFF : 0 . 20 AREA. . : 3 . 54 Acres CN. . . . : 98 . 00 TcReach - Sheet L : 140 . 00 ns : 0 . 0110 p2yr: 2 . 00 s : 0 . 0100 TcReach - Channel L : 320 . 00 kc: 21 . 00 s : 0 . 0050 TcReach - Channel L : 200 . 00 kc : 17 . 00 s : 0 . 0050 PEAK RATE : 0 . 38 cfs VOL: 0 . 15 Ac-ft TIME : 480 min r SECTION V BIOSWALE DESIGN • p • fFfddl cL ZrVO` lei pt��/n!) /0� . S �� y] ((. C- c cA, dmot-+t�'t1,OA S 5�-• L , Z--t.v tIGW [�S " FIOWLu14- Lv L., L--I K c. 0 L3.5 £r v m Y o .7,3 G GtnKu � (,cJl �� 'J' c. lt1 O i OWs 1l. 74 ` NNN F F F —era aaa H erA � Z-5-1v- V$wd t'vl.� T� a,d 49 �Cxtt7Vrl4rGaVSr C�a Zs l� �fgw' rr c� e10 W VS e �baff/ Pct i`S 4IW4)/'S a yew eQ' e(•� `p f-h -•-�.e. N {-(I a- ! o o�/v' c.v/n a u y t-ireo. �j o car t\ rw r• uS r y (oi� = l�l,e rL" i p ,V ( wcc'k ivoW� �vg7— de,�FP�oP�ci z7� C9 •0 f) A 3 S V (M E G = d . 9 J V� 4-z7 4tti i w 4 ( �r. c,S}} f cc ap l%j. . . Qzs _ C Yzr R C• Y�� 2. ZxG .7Z /tc� Trapezoidal Channel Analysis & Design . Open Channel - Uniform flow Worksheet Name : Springbrook Comment : Bioswale 2 Year Design Solve For Bottom Width Given Input Data : Left Side Slope. . 3 . 00 : 1 (H:V) Right Side Slope. 3 . 00 : 1 (H:V) Manning' s n. . . . . . 0 . 350 Channel Slope . . . . 0 . 0050 ft/ft Depth. . . . . . . . . . . . 0 . 33 ft ----C.40Y �Discharge . . . . . . . . 0 .46 cfs zYir 00 W Computed Results : Bottom Width. . . . 9 .41 ft - ----- t � �� Velocity. . . . . . . . . 0 . 13 fps < t. SAS Flow Area . . . . . . . . 3 .43 sf / Flow Top Width. . . 11 .39 ft Wetted Perimeter. 11 .49 ft Critical Depth. . . 0 . 04 ft Critical Slope . . . 5 . 1772 ft/ft Froude Number. . . . 0 . 04 (flow is Subcritical) b Open Channel Flow Module, Version 3 . 41 (c) 1991 Haestad Methods, Inc . * 37 Brookside Rd * Waterbury, Ct 06708 r ' U5t`�� [=�oc.✓i,uas �ov- ��iTaaµi'�� 1= 4, vw ��'otn� wt�� N=0�08 II r( J V (' US G cle � �� o Q �t� Ct �\ ot�) FVo 2rp mp yr NNN coo •.� sk`G estop e- 4T aea r i lV AA H H H • . Trapezoidal Channel Analysis & DeeiS open Channel - Uniform flow Worksheet Name: Springbrock Comment: 25 Year Plow Depth Solve For Depth Given Input Data: Bottom Width.... , 9.41 £t Left Side Slope. . 3.00:1 (H:V) Right Side Slope. 3.00:1 (H:V) Manning's n. .... . 0.080 Channel Slope. . . . 0.0050 ft/ft Discharge... .. . . . 13.30 cfe Computed Results: Depth............ 0.98 ft �• F p Velocity......... 1.11 fps f Flow Area........ 12.03 sf Plow Top Width... 15.26 ft Wetted Perimeter. 15.58 ft • Critical Depth.. . 0.38 ft Critical Slope. . . 0.1353 ft/ft Froude Number. . . . 0.22 (flow is Subc_itical) Open Channel Flow Module, Version 3.41 (c) 199: Haestad Methods. Inc. • 37 Brookside Rd • Wate-ury. Ct 06708 SECTION IX • Erosion/Sedimentation Control S c��t Ltd O ll�_l C' C91,• G� � t �'� � �i I VS -R �44--tl- ✓�f2N✓ h � ! 5GG\ • cal 4-, Q� � 2 . 4 ��s c ►cos-�dti��coPa� �,�o�� NNN ll 0 I�r. Z lJ O N O_O coo aaa SH- = ZO (V N(V C1 N iV ehV-0tJt,.el PC 'S! i ,A "n I Lh two oe r-fs U , �L o 51 �� O `2c' , cote , S � �2e�_�c.� Lei^ �• l W J 4_t.. e C 4-oQ cl� f)ot, J r2l'Se� fny :- orn cG_�C- V L'; .r f� �O v � 'G i; � r c � . ¢• � � Cc 1Ta GL�v C1� KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL Z FIGURE 4.4.7J RISER INFLOW CURVES / I` Weir Flow Orifice Flow ----- 700 :�., i r 36 33 30 g 27 N c U 24 s w U N 21 y i az N d � 18 E m o 15 o o 12 10 �:;• „ : 10 I , 1�4 0.1 0S, 1.0 1 0.0 HEAD IN FEET (measured from crest of riser) SOURCE: USDA-SCS OWIER = 9./39 D]i 2 QoRr-ICE = 3.782 D'Hirz O in cis, D and I- in feet '.4.7-10 1/90 r rr fin v c( (D e S l' Ca (e, ©V-�" A_ & Si -8-- -�-- Cn p- p q L rS 1'o v t-o LAA 0. U it o f o ,s A , <-z-t, __ 40 W W W 00o W4.ora A0 0Y-i� l-�'c� !'1 V`-O� NON V O V V l P G Cr� N H AAA f [ P Z f•� -2 �r z �F6a z x �•S� --�---