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HomeMy WebLinkAboutSEPA EPIC-27-88 - RADOVICH JOHN - FORT DENT II OFFICE BUILDINGSFORT DENT TWO & THREE TWO OFFICE BUILDING DEVELOPMENTS WITH PAVING & LANDSCAPING 6840 SOUTHCENTER BLVD. ( #2) 6860 SOUTHCENTER BLVD. ( #3) EPIC 27 -88 June 13, 1989 Moira Bradshaw City of Tukwila 6300 Southcenter Blvd. Tukwila, WA 98188 Subject: FORT -- -DENT TWO & THREE Amendment to Environmental Checklist Filed 8/25/88 RECEIVED CITY OF UKWI ,A JUN 13 198 BUILDING tSEFvF. Dear Moira: The following is updated information applicable to the environmental checklist previously filed on this project. Page 3, 11, Project Description; Development consisting of two class A, multi- tenant buildings. Building. Two will be 60,000 sf, Building Three will be 40,000 sf. Page 16, f, Trips Generated; As the buildings have decreased slightly in size, so does the parking generated. Building Two will generate approximately 1,062 daily trips. Building Three will generate approximately 708 daily trips. The peak percentages will not change. Page 12, i, Number of People; The proposed buildings are slightly smaller in size, therefore completed Building Two will be occupied by approximately 510 people, Building Three; 340 people. Page 13, Aesthetics a; Building height for both buildings, Two and Three, has been reduced to 39'6 ". Page 15, Transportation c; The basement parking at Building Two has -been eliminated. The total project parking is now 409 stalls which is one stall per 244 sf. Page 4, g, Impervious Surface; 152,556 sf /69%. (Both Buildings) Please contact me if you have any questions. _ o Cord ally, Katie Greif Development Manager 301111CeRadlOVith Development Company 2000 -124th Ave. N.E. B -103 Bellevue, WA 98005 (206) 454 - 6060`• • November 10, 1988 • f T.9 VV / if. '%1\1 �T / j � f 11 Mr. Ross Earnst /� 2 1 ` Public Works Department ea v City of f T k 1 a �} / �1* 6300 Southcenter Blvd. 'C Tukwila, WA 98188 � ��� 3 �iv� Ba�r�' �� /- � Subject: Fort Dent Dear Ross: Enclosed you -/w�1 ort Dent Burin eport fuller r regarding stability. o 2/ �L � U Z vises rr dSantud sJ�99c.nior t � s grns and\. �"the re p Two /and rem s to ail e th� depa .t? and Please cont Cordially, CP"ri imti�e�i ely i jyoi�l ave' ai 6( Katie Greif Development enclosure cfss " '>6 („ °/,c(c <>0..e9°6 1� r r 2000 - 124th Ave. N.E. B yMopment Company Bellevue, WA 98005 i . 454 -6060 0 Vol 1//r)/ PREPARED BY: Keith Litchfie Staff Engineer u-k Charles L. Vita, Ph.D., P. E. Senior Project Manager A REPORT PREPARED FOR JOHN C. RADOVICH DEVELOPMENT CORPORATION SUPPLEMENTAL GEOTECHNICAL ENGINEERING STUDY FORT DENT 2 SOUTHCENTER BOULEVARD TUKWILA, WASHINGTON E- 3007 -4 November 8, 1988 Earth Consultants, Inc. 1805 - 136th Place Northeast Suite 101 Bellevue, Washington 98005 (206) 643 -3780 4 Ltttye. ,WC ia's Earth Consultants Inc. Geotechnical Engineers, Geologists & Environmental Scientists November 8, 1988 E- 3007 -4 John C. Radovich Development Corporation 2000 - 124th Northeast #B -103 Bellevue, Washington 98005 Attention: Ms. Katie Greif - Kulczyk Subject: Reference: Consultation River Bank Stabilization Fort Dent Phase II Tukwila, Washington Earth Consultants, Inc. Geotechnical Engineering Study E- 3007 -2, November 2, 1987 Dear Ms. Greif - Kulczyk: We are pleased to submit herewith our report titled "Supplemental Geotechnical Engineering Study, River Bank Proposed Fort Dent -2 Office Building, Tukwila, Washington." This report presents the results of our field exploration, laboratory tests, and engineering analysis for the property located on Plate 1. The purpose and scope of our study is outlined in our September 13, 1988 proposal. We previously submitted a general geotechnical study for this site in the report titled "Geotechnical Engineering Study, Melin Parcel 2," dated November 2, 1987, and a preliminary report titled "Fort Dent Phase II," dated October 5, 1988. This report supercedes the later reports. 1805 - 136th Place N.E., Suite 101, Bellevue, Washington 98005 Bellevue (206) 643 -3780 Seattle (206) 464 -1584 222 E. 26th Street, Suite 103, P.O. Box 111744, Tacoma, Washington 98411 -9998 Tacoma (206) 272 -6608 John C. Radovich Development Corporation November 8, 1988. E- 3007 -4 Page 2 The results of our study indicate that the existing river bank is at least marginally stable under present site conditions. The river adjacent to the site is in an active depositional mode. Up to two feet of loose sand has been deposited on the banks adjacent to the site. These deposits overlie a riprap armor previously placed to inhibit erosion. Higher stream flows during rainy . periods will result in erosion of these recent sand deposits. Earth Consultants, Inc. (ECI) recommends that the existing vegetation covering the lower bank be retained to help minimize the erodability of these loose surficial sands. SITE CONDITIONS Surface - The lower river bank has slopes of 2:1 (Horizontal:Vertical) to 1H:1V. A cover of grasses, blackberry bushes, and vines blanket much of the river bank and reduce accessbility as well as obscure the riprap which protects the slope. At the time of our study, the river was at low flow and approximately twenty -five (25) feet (vertically) of the river bank was exposed. Subsurface The river bank was explored by hand - excavating six bore holes at two locations (HA -1, 2) shown on Plate 2. Please refer to the test hole logs, Table A, for a detailed description of the conditions encountered at each location explored. The following is a description of the subsurface conditions encountered: (1) the bank has had up to two feet of loose fine to medium sands deposited over the spalls during periods of high river flow; (2) the river bank has an apparently continuous cover of quarry spalls four to ten inches in size and larger; and (3) the quarry spalls are underlain by fine silty sands. Earth Consultants, Inc. John C. Radovich Development Corporation November 8, 1988 E- 3007 -4 Page 3 Groundwater Previous groundwater measurements (by others) indicate that the groundwater level corresponds roughly with the elevation of the river. Clearly, the groundwater level is not static. Thus one should expect fluctuations depending on the river level, season, rainfall, and other factors. Generally, the water level is higher in the wetter winter months. Changes in groundwater levels probably lag changes in river level by a significant time interval. This characteristic has been accounted for in the slope stability evaluation. DISCUSSION AND RECOMMENDATIONS Bank Slope Stability A slope cross section (Mithun Partners dated 9- 12 -88) and soil information from borings (ECI report E- 3007 -2) were used to assess the riverbank stability. Two slope configurations (Plate 4) were evaluated: 1) Existing Configuration: The riverbank unchanged at about 1H:1V. 2) Proposed Configuration: The riverbank is reshaped with a fourteen (14) foot wide bench excavated at Elevation 18.4, then sloped back at 2H:1V to the existing graound surface, as shown on Plate 4. Conventional analytical methods and computer program PCSTABL4 (Purdue University, 1975) were used to calculate a slope stability factor of safety (FS). The estimated factor of safety of the proposed design was estimated as follows: 1. The effective angle of internal friction for the silty sands was conservatively estimated to be 30 degrees, based on SPT blow counts and soil texture. 2. The minimum value of effective cohesion required . to just maintain stability of the existing slope configuration (FS =1) was back - calculated. An estimated cohesion of 100 psf was obtained. Earth Consultants, Inc. John C. Radovich Development Corporation November 8, 1988 E- 3007 -4 Page 4 3. FS for the proposed slope configuration (Plate 4) was calculated using an effective angle of internal friction of 30 degrees and an effective cohesion of 100 psf. Using the above design constraints and soil parameters, three slope configurations were assessed for slope stability. The letters (A,. B, C, D) correspond to points or the slope (Plate 4). The slope sections and estimated factor of safety are as follows: o Existing ground surface (ABD): FS =1.0 (selected reference value). o Slope below Elevation 18.4 (AB): FS =1.1 o Proposed bench and slope below Elevation 18.4 (ABC): FS = 1.3 o Proposed cut below Elevation 24.0 (A, B, C, D): FS = 1.7 These factors of safety are approximations of actual conditions. Under extreme drawdown conditions, local instabilities will occur; these may require remedial repair from time to time. Bank Slope Stabilization We believe, after interpreting our slope stability analyses and field observations, and based on apparent past performance and current conditions, that the river bank below the proposed bench is currently stable under normal river flow conditions. An average flow velocity of five feet per second (fps) was reported by the Corp of Engineers (telephone conversation with J. Lenconie, April, 1986 regarding ECI report 2720 -1). ECI then assumed a maximum high flow velocity of ten fps (twice the average flow velocity) for this reach of the river in evaluating stability and estimating a riprap size of approximately six inches by the tractive force method. The ten (10) fps flow velocity and resulting erosion potential was also evaluated by the U. S. Bureau of Reclamation Method (also Tractive Force Method). Riprap sizes were slightly larger. Earth Consultants, Inc. John C. Radovich Development Corporation November 8, 1988 E- 3007 -4 Page 5 Extreme flows in excess of ten (10) fps (up to fifteen [15] fps) would require riprap sizes to sixteen (16) inches. However, these extreme flow conditions are considered to be unlikely, infrequent events. Properly placed six to eight inch sized riprap is expected to provide adequate protection, though with a lower margin, of safety. Modifications to the river bank will be made by the John C. Radovich Development Company. These alterations will take the form of a fourteen (14) foot wide bench constructed at Elevation 18.4. Above this bench, a 2H:1V slope will be constructed to the top of the bank. The bank cuts made during the proposed development will be armored with riprap. ECI recommends that the proposed river bank improvements include the following: 1. The erosion control for high velocity flow should consist of a basal blanket of three -inch rock underlying six to eight -inch (minimum dimension) riprap. The riprap cover will secure the smaller rock and help further stabilize the river bank against erosion (see Figure 1A). Emplacement of a geotextile blanket between the silty bank and riprap is optional, but not required on the low energy side = of the river. Riprap placed on any river bank excavations should be hard, sound, durable, free of seams and cracks and should be broken into near - cubical shapes. The three -inch rock to be used as a wearing course and a filter material and the riprap rock should have a minimum density of one hundred sixty -five (165) pounds per cubic foot (pcf). The size distribution for the riprap should consist of particles no less than six inches in least dimension, 45 to 60 percent should be eight inches, and 35 percent or more should exceed eight inches in least Earth Consultants, Inc. John C. Radovich Development Corporation November 8, 1988 E- 3007 -4 Page 6 dimension. The average size (D50) for the total riprap gradation should equal or exceed eight inches. Riprap should be placed in a single lift and nested for maximum resistance to stream action. 2. A combined wearing surface . and erosion surface control for vehicular traffic where necessary. The wear surface may be achieved by providing a cover of up to . four inches of three -inch rock (minimum dimension) over the riprap (see Figure 1B). Usual, seasonal fluctuation of the river will result in sporadic deposition and erosion of the loose surficial sands. As long as these surface deposits are underlain by bank armor, damage should not occur to the banks. The previous owner has been reported to have placed riprap on the existing river bank in accordance with King County rquirements. If bank maintenance and aesthetics require removal of vegetation, care must be taken to replace disturbed riprap to maintain bank protection. In order to decrease development costs, the earthwork contractor may want to screen the river bank material excavated to construct the bench to retrieve the existing riprap. The screen should have the necessary dimensions to ensure that the material meets the specifications stated above. After the modifications are made to the river bank, the bank should be monitored. If areas of erosion are observed, additional riprap should be selectively placed in these areas. Earth Consultants, Inc. John C. Radovich Development Corporation November 8, 1988 FIELD EXPLORATION AND LABORATORY TESTING E- 3007 -4 Page 7 Our field exploration was performed in September, 1988. Subsurface conditions at the site were explored by hand- excavating six borings to a maximum depth of one and one -half feet below the existing grade. The borings were hand - excavated due to access problems and to minimize the potential for erosion on the slope. The locations of the bore holes were determined approximately by- pacing from assumed property corners. Elevations of bore holes were determined by hand level measurements. The locations and elevations of the bore holes should be considered accurate only to the degree implied by the method used. The locations are shown on the Exploration Location Plan, Plate 2. The field exploration was performed by a soils engineer from our firm who classified the soils encountered, logged each test hole, obtained representative samples, and observed pertinent site features. Due to the proximity of the riprap to the surface, relatively shallow bore holes were achieved with the hand equipment. All samples were visually classified in accordance with the Unified Soil Classification System which is presented on Plate 3, Legend. Logs of the bore holes are presented on Table A. Representative soil samples were placed in closed containers and returned to our laboratory for further examination and testing. Visual classifications were supplemented by index tests such as sieve analyses on representative samples. LIMITATIONS Our recommendations and conclusions are based on the site materials observed, selective laboratory testing and engineering analyses. The conclusions and recommendations are professional opinions derived in accordance with that level 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. Earth Consultants, Inc. John C. Radovich Development Corporation November 8, 1988 E- 3007 -4 Page 8 The recommendations submitted in this report are based upon the data obtained from the explorations. Soil and groundwater conditions between explorations may vary from those encountered by the explorations. The nature and extent of variations between explorations may not become evident until construction. If variations then appear, ECI should be requested to reevaluate the recommendations of this report prior to proceeding with the construction. Additional Services It is recommended that ECI provide 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. It is also recommended that ECI be retained to provide geotechnical services during construction. Because of the nature of this project, we do not accept responsibility for the performance of the earthwork unless we are retained to review the construction drawings and specifications, and to provide construction observation and testing services. 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. Earth Consultants, Inc. John C. Radovich Development Corporation November 8, 1988 The following table and plates are attached and complete this report: Table A Hand Auger Hole Logs Plate 1 Vicinity Map Plate 2 Exploration Location Map Plate 3 Unified Soil Classification Plate 4 Slope Stability Cross Section Appendix Slope Stabilization and Erosion Control Respectfully submitted, EARTH CONSULTANTS, INC. Keith Litchfield Geotechnical Engineer Charles L. Vita, Ph.D., P.E. Senior Project Manager KAL /RJB /CLV /kml Earth Consultants, Inc. E- 3007 -4 Page 9 TABLE A HAND AUGER HOLES E- 3007 -4 BORE HOLE DEPTH NUMBER (FEET) DESCRIPTION HA -1 (slope top) 0 -1.0 Very " stiff silt (slope middle) 0 -0.25. Loose silty sand 0.25 Spalls (slope toe) 0 -0.25 " Loose silty sand 0.25 -1.5 Dense sand HA -2 (slope top) 0 -1.5 Very dense silt with gravel slope middle)_ 0 -1.0 Medium dense silty sand 1.0 Spalls (slope toe) 0 -0.75 Loose silty sand 0.75 -1.5 Loose sandy silt 1.5 Spalls Earth Consultants, Inc. ••'-' •:',•-■rN,Ttc2 • p•v„,t_azoo, .T I ''•!'-'" '1. .1,P kt • Te vams, .;•;•,•.•:;IM.::.; ' • 'I t i 51P--- ago 5 R ST 517 VAIllY GH0ENtliApett Earth Consultants Inc. Geoteritnical Engineering and Geology - 41 MTN RV Reference King County / Mcp 41 By Thomas Brothers Maps Dated 1988 Vicinity Map Fort Dent 2 Tukwila, Washington Pro'. No. 3007-4 I Date Oct. '88 I Plate 1 Not - To - Scale LEGEND ♦ HA-1 Approximate Location of ECI Hand Auger Hole, Proj. No. E-3007-4, Sept. 1988. S B-1 Approximate Location of ECI Boring , Proj. No. E-3007-2 , Oct. 1987 7P-I Approximate Location of ECI Test Pit, Proj. Na E- 3007 -2 , Oct. 1987 Approximate Limits of !� Fi I I Approximate Area of Proposed Building Reference : Plat Map Received From Client Undated Earth Consultant Inc. GMtectuaieal Engineering ad Geology Boring and Test Pit Location Plan Fort Dent 2 Tukwila, Washington 3007-4 Oct. [Date 138 'Plate 2 • • MAJOR DIVISIONS GRAPH SYMBOL LETTER SYMBOL TYPICAL DESCRIPTION Coarse Grained Soils More Than 50% Material Larger Than No. 200 Sieve Size Gravel And Gravelly Soils More Than 50% Coarse Fraction Retained On No. 4 Sieve Clean Gravels (little or no fines) a 'o °a : o °; ° o vv. o••o• ° '......... •o,o GW gw Well- Graded Gravels, Gravel -Sand Mixtures, Little Or No Fines . :0: :•: :•:: • • IF • • • GP gp Poorly - Graded Gravels,Gravel - Sand Mixtures, Little Or No Fines Gravels With Fines ( appreciable amount of fines) b, I GM gm Silty Gravels, Gravel -Sand- Silt Mixtures , r/ GC gC Clayey Gravels, Gravel- Sand - Clay Mixtures Sand And Sandy Soils More Than 50% Coarse Fraction Passing No.4 Sieve Clean Sand (little or no fines) *0°00 ; o o °OO °o o °o° o p0 0 SW SW Well- Graded Sands, Gravelly Sands, Little Or No Fines ,;! 9.....•t. :': ' •'- :' :: SP Sp Poorly- Graded Sands, Gravelly Sands, Little Or No Fines Sands With Fines (appreciablery amount of fines) /t e:1, ! .:j;1:j: {; ;; • ij� •�;i:;l SM Sn1 • Silty Sands, Sand Silt Mixtures SC SC Clayey Sands; Sand Clay Mixtures Fine Grained Soils More Than 50°/ Material Smaller Than No. 200 Sieve Size Silts Liquid Limit And Less Than 50 Clays I ML ml Very , .r,y- Clayey Inorganic Fine Silts Sands: 8 Clayey Fine Silts Sands w/ Rock Slight FloltPlasticitySilt CL CI Inorganic Clays Of Low To Medium Plasticity, Gravelly Clays, Sandy Clays, Silty Clays, Lean' OL Organic Silts And Organic Silty Clays Of Low Plasticity Silts And Liquid Limit Clays Greater Than 50 ;x: MH mh Inorganic Silts, Micaceous Or 'Diatomaceous Fine Sand Or Silty Soils CH C Inorganic Clays Of High Plasticity, Fat Clays. oh Organic Clays Of Medium To High Plasticity, Organic Silts Highly Organic Soils y == -< - ` ' PT pt Peat, Humus, Swamp Soils With High Organic Contents Topsoil Fill Humus And Duff Layer . Highly 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 Notes : Dual symbols are used to indicate borderline soil classification. Upper case letter symbols designate sample classifications based upon lab- oratory testing; lower case letter symbols designate classifications not verified by laboratory testing. I • 2 "0.D. SPLIT SPOON SAMPLER TT 2.4" I.D. RING SAMPLER OR 11 SHELBY TUBE SAMPLER P SAMPLER PUSHED SAMPLE NOT RECOVERED 2 WATER LEVEL (DATE) aWATER OBSERVATION WELL C TORVANE READING, tsf qu PENETROMETER READING, tsf W MOISTURE, percent of dry weight pcf DRY DENSITY, pounds per cubic ft. LL LIQUID LIMIT, percent PI PLASTIC INDEX Earth Consultants Inc. Geottechnlcal Engineering and Geology LEGEND Proj. No. 300'7 -4 Date Oct' 88' IP1te .3 BORING B-I E- 3007-2 9/15/87 ML ML /SM SM SM /SP 20 — 0— -10 — -20 SILT SILTY SAND WATER TABLE Horizontal Scale 0 5 10 20ft. Vertical Scale 0 5 10 20ft. PROPOSED CUT —` Elev. 22//2000 CFS WATER TABLE EXISTING GROUND SURFACE Elev. 18.4/9000 CFS 1 GREEN RIVER 0 30 —20 — 10 0 ° w - -10 — -20 Earth Consultants Inc. G.ot.chnical Engineering and G.oiogy Slope Stability Cross Section 'Fort Dent 2 Tukwila, Washington Proj. No. 3007-4 I Date Nov 88 ,Plate F.IC -aVRC 1: PrioPOSED faro e O s \0 N 5TAB1 L 1ZATION C01-4'CROL_ (.NOT To SLAL E� EROSIt.a C01,1-1- Rv 1_. O = zz.L\ -}aTT• APPROsIMIN -T - Loc- AcctoN of j�R0 L-T ExiS-1NNCa GROUND 4 S‘..eceace.• —�'— — EL. ZZ /z000 CFS 2:1 wAL_E TRA1`. �o�� �r F-q-S. H R FASS _ G 2 Av ■44n1U CovNiTY MA►ts+TaN ANVC 'Cg W y k e■l &'1 Su E cz os t v N . C'o nn r., 0 L. 2/o ■ A \ rl A 0 tfl Su va MAW I fa el dy 7 F� o;� 0 m 0 } Imo 0 c- m 0 -4 z 0 W 0 0 fi A8 83)IJ3H3 A8 831f1d104O3 r m v k I 3 Copies Technical and Quality Review by: R. J. Bielefeld Project Manager DISTRIBUTION E- 3007 -4 John C. Radovich Development Corp. 2000 - 124th Northeast, #B -103 Bellevue, Washington 98005 Attention: Ms. Katie Greif - Kulczyk Earth Consultants, Inc. Christine Gregoire NROMMAWK4XXxx Director STATE OF WASHINGTON DEPARTMENT OF ECOLOGY • Mail Stop PV -11 • Olympia, Washington 98504 -8711 • (206) 459 -6000. _ October 27, 1988 Mr. Rick Beeler City of Tukwila 6200 Southcenter Blvd. Tukwila, WA 98188 Dear Mr. Beeler: OCT 2,j 1988 Thank you for the opportunity to comment on the determination of nonsignificance for the construction of two office build- ings by Mr. John Radovitch (EPIC- 27 -88). We reviewed the en- vironmental checklist and have the following comments. The proposed project must be consistent with all applicable policies and other provisions of the Shoreline Management Act, its rules, and the city shoreline master program. This includes, but is not limited to, those provisions pertaining to commercial development, landfill, parking, utilities, con- servation, and public access. We would encourage the city to insure that there will be ad- equate storm water control, landscaping, and public access trail facilities along the shoreline. The area excavated for additional flood water capacity along the top of the bank should be revegetated with native riparian plant species that will protect against erosion and enhance fish and wildlife habitat. If you have any questions, please call Mr. Bruce Smith of the Shorelands Program at (206) 459 -6762. Sincerely, Barbara J. 12itchie Environmental Review Section BJR: cc: Linda Rankin, Shorelands *METRO Municipality of Metropolitan Seattle Exchange Building • 821 Second Ave. • Seattle, WA 98104 -1598 October 24, 1988 Rick Beeler, Planning Director City of Tukwila 6200 Southcenter Blvd. Tukwila, Washington 98188 Determination of Non-Significance File No.: EPIC- 27 -8g John C. Radovich Dear Mr. Beeler: 179 f I °CT 26 1988 Metro staff has reviewed this proposal and anticipates no significant impacts to its wastewater facilities. Public Transportation Metro recommends that a transportation management plan be developed for this site. The plan should identify the following: o A performance standard (% trip reduction or mode split goals). o Site design considerations, such as, pedestrian amenities, placement of parking. o Distribution of transit /rideshare information. f------ 4e- o Commuter Information Center. o Assignment of an employee transportation coordinator. o Preferential parking for High Occupancy Vehicles. o Flexible working hours program. o Transit or vanpool subsidies for employees. o Guaranteed ride home program. o Conduct of surveys /monitoring in cooperation with the jurisdiction and Metro. The developer should contact Bob Flor, Metro market Development Planner at 684 -1611 about the TMP. Thank you for the opportunity to review and comment. Sincerely, Gregory M. Bush, Manager Environmental Planning Division GMB:pig> cc: Bob Flor AFFI•AVIT OF DISTRIOJTION 1, JOANNE JOHNSON hereby declare that: O Notice of Public Hearing 0 Determination of Nonsignificance [[ Notice of Public Meeting [[ Board of Adjustment Agenda Packet [[ Board of Appeals Agenda Packet [[ Planning Commission Agenda Packet [[ Short Subdivision Agenda Packet X X1 X Mitigated Determination of Non - significance O Determination of Significance and Scoping Notice O Notice of Action [[ Official Notice [[ Notice of Application for [[ Other Shoreline Management Permit [[ Shoreline Management Permit Other AA was mailed to each of the following addresses on TUESDAY. OCTOBFR 11, 19RR (SEE ATTACHED) Name of Project FT DENT TWO File Number EPIC� 27 ='88 WASH ST OFF OF ARCHAEOLOGY • DNS (MITIGATED) AND HISTORIC PRESERVATION FT DENT TWO 111 WEST 21ST STREET, KL -11 10/11/88 OLYMPIA, WA 98504 WASHINGTON STATE DEPT FISHERIES JOHN C RADOVICH 115 GENERAL ADMIN BUILDING OLYMPIA, WA 98504 2000 -124TH AVENUE NE #B -103 BELLEVUE, WA 98005 WASHINGTON NATURAL GAS ATTN: WILLIAM FRY P.O. BOX 1869 SEATTLE, WA 98111 GROUP W CABLE (TCI) P.O. BOX C96029 BELLEVUE, WA 98009 STATE OF WASHINGTON DEPARTMENT OF ECOLOGY ENVIRONMENTAL REVIEW SHORELANDS DIVISION MAIL STOP PV -11 OLYMPIA, WA 98504 ATTN: KAREN BEATTY STATE OF WASHINGTON DEPARTMENT OF ECOLOGY ENVIRONMENTAL REVIEW MAIL STOP PV -11 OLYMPIA, WA 98504 ATTN: KAREN BEATTY PUGET SOUND POWER & LIGHT CO ATTN: RENVIRONMENTAL REVIEW 10608 N.E. 4TH STREET BELLEVUE, WA 98004 METRO ENVIRONMENTAL PLANNING DIVISION ATTN: MANAGER MS 92 - 821 SECOND AVENUE SEATTLE, WA 98104 DUWAMISH TRIBE 15616 - 1ST AVENUE S. SEATTLE, WA 98148 ATTN: CECILE MAXWELL, CHAIR. VALLEY DAILY NEWS 212 WELLS AVENUE RENTON, WA 98055 • CHECKLIST: ENVIRONMENTAL REVIEW MAILINGS U.S. Army Corps of Engineers ) Federal Highway Administration FEDERAL AGENCIES ( )U.S. Environmental Protection Agency ( )U.S. Department of H.U.D. (Region X) WASHINGTON STATE AGENCIES ( Office of Archaeology ( ) Transportation Department ) Department of Fisheries ( ) Office of the Governor ( ) Planning & Community Affairs Agency ( )Dept. of Social and Health Services (!><1Dept. of Ecology, Shorelands Division )Dept. of Ecology, SEPA Division * ( )Department of Game ( )Office of Attorney General * Send checklist with all determinations KING COUNTY AGENCIES ) Dept. of Planning & Community Devel. ) Fire District 18 ) Boundary Review Board ) Health Department ( ) South Central School District ( ) Tukwila Library ( ) Renton Library ( ) Kent Library ( ) Pacific Northwest Bell Telephone ( ) Seattle City Light Washington Natural Gas Water District 75 ) Seattle Water Department ) Group W Cable ( ) Kent Planning Department ( ) Tukwila Board of Adjustment ( ) Tukwila Mayor Tukwila City Departments: ( ) - Public Works ( ) - Parks and Recreation ( ) - Police ( ) - Fire ( ) - Finance ( ) - Planning /Building ( )Fire District 1 ( )Fire District 24 ( )Building & Land Development Division SEPA Information Center SCHOOLS /LIBRARIES ( )Highline School District ( )King County Public Library ( )Seattle Municipal Reference Library UTILITIES '44puget Sound Power & Light ( )Val -Vue Sewer District ( )Water District 20 ( )Water District_ ). ( )Water ( )Union P, rt i Sr ±-`°1 -Nod CITY AGENCIES ( )Renton Planning Department ( )Tukwila Planning Commission Tukwila City Council Members: ( )- Edgar Bauch ( )- Marilyn Stoknes ( )- Joe Duffie ( )- Mabel Harris ( )- Charlie Simpson ( )- Jim McKenna ( )- Wendy Morgan OTHER LOCAL AGENCIES ( ) Puget Sound Council of Government(PSCOG) ( ) Puget Sound Air Pollution Control Agency ( ) Tukwila /Sea -Tac Chamber of Commerce Daily Journal of Commerce Renton Record Chronicle )METRO Environmental Planning Division Office/Industrial-10,000 gsf or more Residential 50 units or more Retail 100,000 gsf or more MEDIA ( )Highline Times ( )Seattle Times w . ° £.inc v- hers 0)--) C cc) Le i S. Co I (p 1 Ave_ LM- 9 g/y? V \c ia.R_4P WAC 197 -11 -970 • • MITIGATED DETERMINATION OF NONSIGNIFICANCE Description of Proposal DEVELOPMENT OF APPROXIMATELY 111,065 SQUARE FEET IN TWO OFFICE BUILDINGS WITH ACCESSORY PAVING AND LANDSCAPING ALONG SHORELINE OF THE GREEN RIVER. Proponent JOHN C. RADOVICH Location of Proposal, including street address, if any LOTS 1 AND 2 TUKWILA SHORT PLAT 79 -7 -SS; 6840 AND 6860 SOUTHCENTER BLVD. Lead Agency: City of Tukwila File No. EPIC -27 -88 The lead agency for this proposal has determined that it does not have a probable significant adverse impact on the environment. An environmental impact statement (EIS) is not required under RCW 43.21C.030(2)(c). This decision was made after review of a completed environmental checklist and other information on file with the lead agency. This information is available to the public on request. There is no comment period for this DNS This DNS is issued under 197 -11- 340(2). Comments must be submitted by OCTOBER 25, 1988 . The lead agency will not act on this proposal for 15 days from the date below. Responsible Official Rick Beeler Position /Title Address Date Planning Director 6200 Southcenter Boulevard, Tukw; Signature Phone 433 -1846 .A40/0/511,11 You may appeal this determination to the City Clerk at City Hall, 6200 Southcenter Boulevard, Tukwila, WA 98188 no later than 10 days from the above date by written appeal stating the basis of the appeal for specific factual objections. You may be required to bear some of the expenses for an appeal. Copies of the procedures for SEPA appeals are available with the City Clerk and Planning Department. FM.DNS City of Tukwila PLANNING DEPARTMENT 6200 Southcenter Boulevard Tukwila, Washington 98188 (206) 433 -1849 MITIGATION MEASURES DNS for FORT DENT TWO EPIC 27 -88 1. If artifacts are revealed during earthwork, all excavation, grading, and fill must be stopped and the Department of Community Development, Office of Archeology and Historic Preservation contacted at 753 -4011, Robert Whitlam, State Archaeologist. An historic marker or archeological display will be required if documentation of historic note is discovered or per substantive comments of Duwamish Tribe during comment period, to be reviewed and approved by Planning Department. 2. Construct recreational trail per City standards. 3. Dedicate any additional necessary area for public recreational trail and riverbank maintenance easements. 4. Riverbank excavation shall be revegetated with native materials to be reviewed and approved by Washington State Department of Fisheries. • City of Tukwila 6200 Southcenter Boulevard Tukwila Washington 98188 (206) 433 -1800 Gary L. VanDusen, Mayor Sepember 30, 1988 Ms. Katie Greif John C. Radovich Development Co. 2000 - 124th Avenue N.E., B -103 Bellevue, Washington 98005 Subject: FORT DENT 2 AND 3 Dear Katie: We have reviewed your submittal for Fort Dent 2 and 3. Our comments and questions follow. The two easements must be recorded prior to building permit issuance. 1. Recreational Trail Easement to Tukwila The Tukwila Parks and Recreation Department has reviewed the Fort Dent 2 cross section dated 09/07/88, and requests a 20 -foot easement from the top of the bank/dike or the 24 -foot elevation landward. The improvements to this area should be to our standards. The easement form will be forwarded to you in the near future; we are currently updating. 2. Riverbank Improvement/Maintenance Easement to Tukwila The Tukwila Public Works Department agrees with the above cross section subject to a riverbank stability study to verify the acceptability of the 2:1 slope. This study must be completed prior to issuance of the Shoreline Permit. 3. The above maintenance easement.should cover the area from the landward edge of the requested trail easement waterward to the edge of your property line (please see enclosed easement form). 4. The need for additional detention on -site will depend on hydraulic calculations to be determined by you, prior to issuance of utility permits. 5. The Planning Department notes six handicap stalls will be required per the Washington Barrier -Free Code. 6. Where will the approximate 6,000 cubic feet of fill be disposed of from the Fort Dent Two building? Please respond by October 5, 1988. 7. An engineering study addressing the methane gas and compliance with Seattle /King County Department of Public Health standards will be required prior to issuance of building permit (please see enclosed regulations). Ms. Katie Greif September 30, 1988 Page 2 8. The proposed boundary line adjustment must be reviewed and recorded prior to building permit issuance. 9. The two -way aisle dimension between 90° stalls which are 8.5 feet in width is 25 feet, not 24 feet. Please make corrections to your site plan. 10. The Tukwila Fire Department notes that the cul -de -sac in front of Fort Dent Three does not meet their turning radius requirement and that they will not allow a path into oncoming traffic. Please contact Nick Olivas and make appropriate changes. 11. The elevation of the screen wall in Phase II is needed for both the shoreline and BAR reviews. 12. Per our conversation, BAR approval is needed for issuance of a Shoreline Permit for Phase II of your proposal. Finally, I have not begun design review at this point, but will get back to you if any issues arise. Yours truly, Moira Carr Bradshaw Associate Planner MB /sjn TO: FROM: DATE: SUBJECT: • City of Tukwila 6200 Southcenter Boulevard Tukwila Washington 98188 (206) 433 -1800 Gary L. VanDusen, Mayor MEMORANDUM 07424/774//?a/e4rS //0/%QA- AWLS/MW. 9Q v 67)°7 --iii g of4 )/f) Pfie f7 4eedx9 64J/ �A, / ),liy %i;� jeiv l cJ (10 /T2.MEMO) g2P g �S • Nothing in this letter is meant or should be interpreted to establish final Uniform Building Code requirements that will be addressed through the normal plan check procedure when application is made for building permit. CITY OF TUKWILA CENTRAL PERMIT SYSTEM ENVIRONMENTAL REVIEW ROUTING FORM TO: BLDG PLNG /i1161/51 P.W. PROJECT /),- f/ Th�ry Iasi CN EPIC 27-83 FILE gg PO -Jr-ff FIRE n POLICE J P & R LOCATION 5 • e.:i t. 6O FILE NO. DATE TRANSMITTED 9//i2!5ty' STAFF COORDINATOR j bete _ /z c RESPONSE REQUESTED BY 9/2 2/25 `6 RESPONSE RECEIVED THE ATTACHED ENVIRONMENTAL CHECKLIST WAS RECEIVED REGARDING THIS PROJECT. PLEASE REVIEW AND COMMENT BELOW TO ADVISE THE RESPONSIBLE OFFICIAL REGARDING THE THRESHOLD DETERMINATION. THE ENVIRONMENTAL REVIEW FILE IS AVAILABLE IN THE PLANNING DEPART- MENT THROUGH THE ABOVE STAFF COORDINATOR. COMMENTS REGARDING THE PROJECT YOU WISH CARRIED TO THE PLANNING COMMISSION, BOARD OF ADJUSTMENT, AND CITY COUNCIL SHOULD BE MADE ON THE ATTACHED CENTRAL PERMIT SYSTEM ROUTING FORM. ITEM COMMENT , A RokiL'ik._ 13t\--N IC/ID ► ICS `OILS si / 31�(T -f STufYi w I t ez*. 1 t) L AS i\fl OF T 11E FL& o col :31 -0AmL. P,3 I0 O IN pe2M C�' PRIJC IISS PsPPN -ovtt ) ?No Po.S D Acc Ss UTI l_iT`1 EA 'v1 )TS )' 30( 1.-IT A Ada 1.m u rti cR0s5.1 N 4rS o v L+!. LOTS r aTI(0. P61.'J P & ri "1 v fLt_uw Fvll\-. A- (3CDUA1 -7 PCB S `fi I TI I_nh IS Co111140 n�S F-()1 souTH III • 01 rzc-y- INN► Oflea -u u c er -c..0 o rt mss,1 r t LJ 0‘-,1 FTc Mh ALs o hn tA■ (-I1h ins. 'i) 'Pitov I O . I �' vaN MtKAT l.tK.A c &t STEINN CAN IT 1.) Ao0 -'tom D l( y7. . Fu S . Pak-n-1 IS cr f- I C IL L_LT3 DATE q /2 /eg COMMENTS PREPARED BY C.P.S. Form 11 ITY OF TUKWILA 1 CENTRAL PERMIT SYSTEM — ROUTING FORM TO: [[ BLDG. PLNG. [j P.W. [11 FIRE [[ POLICE J P. & R. PROJECT tO .T DENT IWO -- cues ADDRESS (oso OJf Lem t -61v'4 DATE TRANSMITTED �(� yy RESPONSE REQUESTED BY WI. kvAi q122-( 00 C.P.S. STAFF COORDINATOR Re bec c& Fox RESPONSE RECEIVED JAh PERMIT NUMBER CONTROL NUMBER PLEASE REVIEW THE ATTACHED PROJECT PLANS AND RESPOND WITH APPROPRIATE COMMENTS IN THE SPACE BELOW. INDICATE CRUCIAL CONCERNS BY CHECKING THE BOX NEXT TO THE LINE(S) ON WHICH THAT CONCERN IS NOTED: N,R• 0,2 04t,ve re,6�w Q Q Q 0 Q 0 0 Q Q 0 0 / O '-- .›. --ga. � 4:2 --- v-... 5 �- - - - �- f D.R.C. REVIEW REQUESTED 0 PLAN CHECK DATE PLAN SUBMITTAL REQUESTED J`r, COMMENTS PREPARED BY /�0►1_— �_-- PLAN APPROVED 0 C.P.S. FORM 2 23% Var1.42.4ion rn Pro re. L: n t IOC ":o ri 1 os 4 'C6�F -° El- lxa• 1 y. 4. �,� � ��� ��� r' Q`0 I ti 026 1 ,,, a f .v t‘. ail . lope 4. e • -` C°. A ll' 7 M,6-/C-b g 7' get / /8 7€7 ASbgavNED •1: r S lope CITY OF TUKWILA CENTRAL PERMIT SYSTEM ENVIRONMENTAL REVIEW ROUTING FORM TO: n BLDG n PLNG P.W. [j FIRE n POLICE [ P & R EPIC 27-88 FILE gg -7/-4e 9Q -3 -✓yam PROJECT F',-f 2 'nf- 7i- c11.; eV %yam LOCATION f'�)ix�r,.,k% /./.',11 q'"46O ""gam'-FILE NO. .Si�l DATE TRANSMITTED Vg RESPONSE REQUESTED BY V. /2 2- STAFF COORDINATOR - bec.-". RESPONSE RECEIVED THE ATTACHED ENVIRONMENTAL CHECKLIST WAS RECEIVED REGARDING THIS PROJECT. PLEASE REVIEW AND COMMENT BELOW TO ADVISE THE RESPONSIBLE OFFICIAL REGARDING THE THRESHOLD DETERMINATION. THE ENVIRONMENTAL REVIEW FILE IS AVAILABLE IN THE PLANNING DEPART- MENT THROUGH THE ABOVE STAFF COORDINATOR. COMMENTS REGARDING THE PROJECT YOU WISH CARRIED TO THE PLANNING COMMISSION, BOARD OF ADJUSTMENT, AND CITY COUNCIL SHOULD BE MADE ON THE ATTACHED CENTRAL PERMIT SYSTEM ROUTING FORM. ITEM COMMENT DATE �� -3�� COMMENTS PREPARED BY C.P.S. Form 11 ENVIRONMENTAL REVIEW ROUTING FORM TO: [BLDG jn PLNG P.W. n FIRE n POLICE n P & R PROJECT T Fu'-/- 2 '� � ? 4/777/t.,2- • CN EPIC 27-88 FILE Sg - / / -Le PO - 3 -j>yp LOCATION 6 l`1k0 / /g/i V4.10 e'`'/Si'/�'`'•L`�-FILE NO. �� DATE TRANSMITTED //1361 STAFF COORDINATOR RESPONSE REQUESTED BY 9/2.2-/.` ect'- fin RESPONSE RECEIVED THE ATTACHED ENVIRONMENTAL CHECKLIST WAS RECEIVED REGARDING THIS PROJECT. PLEASE REVIEW AND COMMENT BELOW TO ADVISE THE RESPONSIBLE OFFICIAL REGARDING THE THRESHOLD DETERMINATION. THE ENVIRONMENTAL REVIEW FILE IS AVAILABLE IN THE PLANNING DEPART- MENT THROUGH THE ABOVE STAFF COORDINATOR. COMMENTS REGARDING THE PROJECT YOU WISH CARRIED TO THE PLANNING COMMISSION, BOARD OF ADJUSTMENT, AND CITY COUNCIL SHOULD BE MADE ON THE ATTACHED CENTRAL PERMIT SYSTEM ROUTING FORM. ITEM COMMENT 16;s eyo jecl robed; ?y falIN (uilLi Ica lo(,L /I awl- 0 / a/a4r, 4 c 3 t 1 e g u e m , fi y lie Di ke. _ 0 1 f / r /MD 44710 TO S ?fig igrn QrO CA:rn e T 1CPLit. -we-Slated 44. L koke CVe, ( oyi iiC w yociS i) OCc: fen? 6U7' 1 9')eiiee iicaykp 'S 240 40e41 1(15.4 of eykiL)iya, v 41 0.4pr /4- ?roxle 4 el/ PeYir/ f a.11,ro4 y kce pt,ied ; ce gzy I)Ike oacf 46 5-de � wh; woulct So115 e Otte y 01411 pin,416 Sht ®c4 1 le%pcDrcoty t toe! o fkdot. Irak Q DATE 7-4- COMMENTS PREPARED BY C.P.S. Form 11 'OF TUKWILA CENTRAL PERMIT SYSTEM ENVIRONMENTAL REVIEW ROUTING FORM i TO: F-71 BLDG n PLNG 1 P.W. ET FIRE n POLICE n P & R PROJECT Fo✓& ?'✓i /- T «T4.r,a-- • CN EPIC FILE 27 -88 89 -g-4e Re- 3 -syt LOCATION 6$ #O soa/ c' f3/ve f G /6o 0.4',,cer FILE NO. DATE TRANSMITTED 04,03i? RESPONSE REQUESTED BY- 9 /2z-l$ e STAFF COORDINATOR , ztecea. 7 x RESPONSE RECEIVED THE ATTACHED ENVIRONMENTAL CHECKLIST WAS RECEIVED REGARDING THIS PROJECT. PLEASE REVIEW AND COMMENT BELOW TO ADVISE THE RESPONSIBLE OFFICIAL REGARDING THE THRESHOLD DETERMINATION. THE ENVIRONMENTAL REVIEW FILE IS AVAILABLE IN THE PLANNING DEPART- MENT THROUGH THE ABOVE STAFF COORDINATOR. COMMENTS REGARDING THE PROJECT YOU WISH CARRIED TO THE PLANNING COMMISSION, BOARD OF ADJUSTMENT, AND CITY COUNCIL SHOULD BE MADE ON THE ATTACHED. CENTRAL PERMIT SYSTEM ROUTING FORM. ITEM COMMENT ,4 hoo4G q(o t°!Ir1574Vl OUJQ /(. yS e. 7 le NAM g46 11 /V d�s.� d ha,��,r_ C'tJ'Y1,5fric , ,ors /►.kd /OA. p •i 3 000-r. -ekt/afibn .+vm,tir1044 Aug Qink.v(vic .foxl (ad..us rn,� 4. DATE COMMENTS PREPARED BY C.P.S. Form 11 • • • ENVIRONMENTAL CHECKLIST Conal No. Epic—File No. �'1- ' Fee $100.00 Receipt No. A. BACKGROUND 1. Name of proposed project, if applicable: Fort Dent Two and Three 2. Name of applicant: John C. Radovich 3. Address and phone number of applicant and contact person: John Radovich /Katie Greif 2000 124th Ave. NE, B -103, Bellevue, WA, 98005 4. Date checklist prepared: August25, 1988 5. Agency requesting Checklist: City of Tukwila 6. Proposed timing or schedule (including phasing, if applicable): Obtain all necessary permits for Fort Dent Two and start construction March 1989. Fort Dent Three to be constructed in approximately three years. 7. Do you have any plans for future additions, expansion, or further activity related to or connected with this proposal? If yes, explain. Once buildings Two and Three are constructed the project will be completed. 8. List any environmental information you know about that has been prepared, or will be prepared, directly related to this proposal. A geotechnical study was per- formed in November of 1987 . by Earth Consultants. 9. Do you know whether applications are pending for governmental approvals of other proposals directly affecting the property covered by your proposal? If yes, explain. To the best of our knowledge there are no government actinns pending that will affect the proposal. • • 10. List any government approvals or permits that will be needed for your proposal. Board of Architectural Review approval, Shoreline Use Permits, Flood Zone Control Permits, all City Utility Permits, Building Permits and Occupancy Permits, for building shell, building permits and occupancy permits for tenant spaces, Fisheries Permit. 11. Give brief, complete description of your proposal, including the proposed use and the size of the project and site. There are several questions later in thi . checklist that ask you to describe certain aspects of your proposal. You do no . need to repeat those answers on this page. Section E requires a complete description of the objectives and alternatives of your proposal and should not be summarized here. To develop two Class A, multi- tenant office buildings on approximateljfive acres of land within the City of Tukwila. Building Two will be_05,065' sq. ft. Building Three: 46,000 sq. ft. 12. Location of the proposal. Give sufficient information for a person to understand the precise location of your proposed project, including a street address, if any, and section, township, and range, if known. If a proposal would occur over a range of area, provide the range or boundaries of the site(s). Provide a legal description, site plan, vicinity map, and topographic map, if reasonably available. While you should submit any plans required by the agency, you are not required to duplicate maps or detailed plans submitted with any permit applica- tions related to this checklist. Lots 1 and 2 of Short Plat No. 79 -7 -55 according to the Short Plat Surve recorded under King County recording No. 7908210370; City of Tukwila. Keg County., Washington. The y roperty is located at the entrance to Fort Den. Park northeast_ of Interurban. The address for building two is: 6840 SouthcenLer BIvd., and building three is: 6860 Southcenter Blvd. 13. Does the proposal lie within an area designated on the City's Comprehensive Land Use Policy Plan Map as environmentally sensitive? Yes, the Green River borders the property,on the northwest, m rth -and northeast.. TOL'BE COMPLETED BY APPL ICI B. ENVIRONMENTAL ELEMENTS 1. Earth a. General description of the site (circle one): rolling, hilly, steep slopes, mountainous, •Evaluation for Agency Use Only b. What is the steepest slope on the site (approximate percent slope)? Parcel 1; 50 %, Parcel 2: 08% c. What general types of soils are found on the site (for example, clay, sand, gravel, peat, muck)? If you know the classification of agricultural soils, specify them and note any prime farmland. Gray and brownish silt of loose to medium density. For addi- tional information, see attached soils report. d. Are there surface indications or history of unstable soils in the immediate vicinity? If so, describe. No, however preloading of the building site on Fort Dent One to the south was required to insure minimal building settlement. e. Describe the purpose, type, and approximate quanti- ties of any filling or grading proposed. Indicate source of fill. Approximately 2,200 cubic yards of structural fill will be used under the building area. All other grading will be to balance the site and to facilitate a planned building elevation. f.. Could erosion occur as a result of clearing, construction, or use? If so, generally describe. ;Minimal erosion could occur during clearing and grading, however, erosion control methods in accordance with City of Tukwila standards will be observed. g. About what percent of the site will be covered with impervious surfaces after project construction (for example, asphalt or buildings)? 68% impervious surface • 0 Evaluation for Agency Use Only h. Proposed measures to reduce or control erosion, or other impacts to the earth, if any: All appropriate erosion control measures will be taken to minimize runoff. 2. Air a. What types of emissions to the air would result from the proposal (i.e., dust, automobile odors, industrial wood smoke) during construction and when the project is completed? If any, generally describe and give approximate quantities if known. Dust from earthwork and vehicle emissions during construction, vehicle emissions only after completion. b. Are there any off -site sources of emissions or odor that may affect your proposal? If so, generally describe. No c. Proposed measures to reduce or control emissions or other impacts to air, if any: None 3. Water a. Surface: 1) Is there any surface water body on or in the immediate vicinity of the site (including year - round and seasonal streams, saltwater, lakes, ponds, wetlands)? If yes, describe type and provide names. If appropriate, state what stream or river it flows into. The Green River borders the property to the north and west. 0 Evaluation for Agency Use Only 2) Will the project require any work over, in, or adjacent to (within 200 feet) the described waters? If yes, please describe and attach available plans. Portions of the building, land- scaping and parking will be constructed within 200 feet of the Green River. In addition, the river bank adjacent to the project site will be excavated to create a 2:1 slope and 1.6 foot bench area to allow for additional storm water runoff. 3) Estimate the amount of fill and dredge material that would be placed in or removed from surface water or wetlands and indicate the area of the site that would be affected. Indicate the source of fill material. An estimated 1800 cubic yards of earth material will be removed from the river bank along the entire river frontage. 4) Will the proposal require surface water withdrawals or diversions? Give general description, purpose, and approximate quan- tities, if known. No withdrawals are required. Surface storm water will be channeled and collected by means of a storm water drainage system. 5) Does the proposal lie within a 100 -year floodplain? If so, note location on the site plan. No 6) Does the proposal involve any discharges of waste materials to surface waters? If so, describe the type of waste and anticipated volume of discharge. Only normal passenger automobile related pollutants should enter surface waters from the parking areas. Runoff from basement parking will enter the sanitary sewer system and runoff from on grade parking will pass through grass lined swales before entering the river. • Evaluation for Agency Use Only b. Ground: 1) Will ground water be withdrawn, or will water be discharged to ground water? Give general description, purpose, and approximate quan- tities, if known. No 2) Describe waste materials that will be discharged into the ground from septic tanks or other sour- ces, if any (for example: Domestic sewage; industrial, containing the following chemicals...; agricultural; etc.) Describe the general size of the system, the number of such systems, the number of houses to be served (if applicable), or the number of animals or humans the system(s) are expected to serve. Not Applicable c. Water Runoff (including storm water): 1) Describe the source of runoff (including storm water) and method of collection and disposal, if any (include quantities, if known). Where will this water flow? Will this water flow into other waters? If so, describe. Storm water will be collected by an approved drainage collection system including catch basins, pipes and grass linedLzales. Water will then be outleted into a c4.tch basin _at Southcenter Blvd. and channeled to the Green River. Expected storm quantity will. be'approximattlx 9 cubic feet per second. Evaluation for Agency Use Only 2) Could waste materials enter ground or surface waters? If so, generally describe. Some auto- mobile related pollutants may enter the storm system from the parking areas. Oil /water separators will be installed as well as the implementation of grassy swales within the landscaped area. d. Proposed measures to reduce or control surface, ground, and runoff water impacts, if any: See above, page six — 6 and page eight — 2 4. Plants a. Check or circle types of vegetation found on the site: deciduous tree: alder, maple, aspen, other evergreen tree: fir, cedar, pine, other shrubs x grass pasture _ crop or grain wet soil plants: cattail, buttercup, bullrush, skunk cabbage, other water plants: water lily, eelgrass, milfoil, other x other types of vegetation b. What kind and amount of vegetation will be removed or altered? All existing vegetation will be removed. c. List threatened or endangered species known to be on or near the site. None Aft Evaluation for ler Agency Use Only d. Proposed landscaping, use of native plants, or other measures to preserve or enhance vegetation on the site, if any: A much improved landscape environment will result from the comp[eted project. Shrubs: Otto - Luyken Laurel, New Zealand Flax Rhododendron Snow Lady, White Flowering Potentilla. Trees: Norway Maple, Sweet Gum, Washington Thorn, Kousa Dogwood. Groundcover: Sod. 5. Animals a. Circle any birds and animals which have been observed on or near the site or are known to be on or near the site: birds: hawk, heron, eagle, songbirds, crows, finches, sparrows, robins mammals: deer, bear, elk, beaver, other: None fish: bass, salmon trout, herring, shellfish, other: b. List any threatened or endangered species known to be on or near the site. None c. Is the site part of a migration route? If so, explain. The Green River may be a migration route for salmon and trout. d. Proposed measures to preserve or enhance wildlife, if any: None 0 Evaluation for Agency Use Only 6. Energy and Natural Resources a. What kinds of energy (electric, natural gas, oil, wood stove, solor) will be used to meet the completed project's energy needs? Describe whether it will be used for heating, manufacturing, etc. Electric heating and air conditioning units will be installed. b. Would your project affect the potential use of solar energy by adjacent properties? If so, generally describe. No c. What kinds of energy conservation features are included in the plans of this proposal? List other proposed measures to reduce or control energy impacts, if any: Construction will include insulated roof, foundation, walls and windows. The rooftop air conditioning equipment will feature a variable speed controller and an economizer to utilize fresh outdoor air when temperatures are at acceptable levels. 7. Environmental Health a. Are there any environmental health hazards, including exposure to toxic chemicals, risk of fire and explosion, spill, or hazardous waste, that could occur as a result of this proposal? If so, describe. No 1) Describe special emergency services that might be required. Not Applicable 2) Proposed measures to reduce or control environ- mental health hazards, if any: Not Applicable .1 • 0 Evaluation for Agency Use Only b. Noise 1) What types of noise exist in the area which may affect your project (for example: traffic, equipment, operation, other)? Some traffic noise exists but will not affect the project. 2) What types and levels of noise would be created by or associated with the project on a short - term or a long -term basis (for example: traf- fic, construction, operation, other)? Indicate what hours noise would come from the site. Short term construction noise resulting from excavation equipment and trucks may occur during some parts of construction. • 3) Proposed measures to reduce or control noise impacts, if any: Construction will be limited to daylight hours only. 8. Land and Shoreline Use a. What is the current use of the site and adjacent properties? The project site is currently vacant land. The Green River and Fort Dent Park lie to the north and west. Fort Dent One Office Building is located to the south. State Farm Insurance Co. plans to develop an office building on property which is currently vacant to the east. b. Has the site been used for agriculture? If so, describe. Yes, more than 25 years ago the property was used for farming. It is not know what type of crops were planted. c. Describe any structures on the site. None •Evaluation for Agency Use Only d. Will any structures be demolished? If so, what? No e. What is the current zoning classification of the site? C -2 f. What is the current comprehensive plan designation of the site? Commercial g. If applicable, what is the current shoreline master program designation of the site? Urban h. Has any part of the site been classified as an "environmentally sensitive" area? If so, specify. The Shoreline Master Program has designated a por- tion of the site as environmentally sensitive due to the close proximity of the Green River. i. Approximately how many people would reside or work in the completed project? Using the building_depart- ments ratio of 1 employee _per 100 sq. ft., the project will include 550 people at Building Two and 390 people at Building Three. These numbers are based upon net j. Approximately how many people would the completed useable area and in reality project displace? None are quite high. k. Proposed measures to avoid or reduce displacement impacts, if any: None 1. Proposed measures to ensure the proposal is com- patible with existing and projected land uses and plans, if any: The property will be developed in accordance witfiTukwila C -2 zoning and other applirahle laws. • Evaluation for Agency Use Only 9. Housing a. Approximately how many units would be provided, if any? Indicate whether high, middle, or low- income housing? None b. Approximately how many units, if any, would be eli- minated? Indicate whether high, middle, or low - income housing. None c. Proposed measures to reduce or control housing impacts, if any: None 10. Aesthetics a. What is the tallest height of any proposed structure(s), not including antennas; what is the principal exterior building material(s) proposed? Building height for Building Two is approx. 43 feet exclusive of air conditioning equipment and parapet. - uil.ding Three will be near the same height. The principal building materials include painted concrete panels, glass, and metal panel accents. b. What views in the immediate vicinity would be altered or obstructed? None c. Proposed measures to reduce or control aesthetic impacts, if any: Attractive architectural and landscape designs are planned which will require review by and approval of the Architectural Review Board. ilo Evaluation for Agency Use Only 11. Light and Glare a. What type of light or glare will the proposal produce? What time of day would it mainly occur? The site will be "illuminated by low glare lights on 10 -20 foot standards throughout the parking area and landscaping. The exterior glass selection wi1T be of a type not to exceed the reflectivity standards for the City of Tukwila. b. Could light or glare from the finished project be a safety hazard or interfere with views? No c. What existing off -site sources of light or glare may affect your proposal? None d. Proposed measures to reduce or control light and glare impacts, if any: By use of low glare perimeter lighting and meeting reflectivity requirements. 12. Recreation a. What designed and informal recreational oppor- tunities are in the immediate vicinity? Fort Dent Park and in the near future, the Green River Recreational Trail will be developed within the River Bend area. b. Would the proposed project displace any existing . recreational uses? If so, describe. No c. Proposed measures to reduce or control impacts on recreation, including recreation opportunities to be provided by the project or applicant, if any: The Green River Recreation Trail borders both phases of the proposed development. . Evaluation for Agency Use Only 13. Historic and Cultural Preservation a. Are there any places or objects listed on, or pro- posed for, national, state, or local preservation registers known to be on or next to the site? If so, generally describe. Historic Fort Dent Park is located across the river northwest of the site. b. Generally describe any landmarks or evidence of historic, archaeological, scientific, or cultural importance known to be on or next to the site. Fort Dent Park c. Proposed measures to reduce or control impacts, if any: None 14. Transportation a. Identify public streets and highways serving the site, and describe proposed accss to the existing street system. Show on site plans, if any. Interurban Avenue South and Southcenter Boulevard serve the sub- ject property. Access to these streets is from a 20 foot ingress /egress easement on the southeasterly property line. b. Is the site currently served by public transit? If not, what is the approximate distance to the nearest transit stop? Not directly, although there is a bus route along Interurban Avenue South. c. How many parking spaces would the completed project have? How many would the project eliminate? The completed project will include approx. 48 basement parking stalls at Building Two, 49 under cover sur- face stalls at Building Three and 271 regular surface stalls. Total parking will be approximately 365 stalls. None will be eliminated. • •Evaluation for Agency Use Only d. Will the proposal require any new roads or streets, or improvements to existing roads or streets, not including driveways? If so, generally describe (indicate whether public or private). Sidewalks, curb.. and gutter will be installed along the street frontage. e. Will the project use (or occur in the immediate vicinity of) water, rail, or air transportation? If so, generally describe. No f. How many vehicular trips per day would be generated by the completed project? If known, indicate when peak volumes would occur. According to the International Traffic Engineers Trip Generation Manual, general office — type uses generate approx. 17.7 trips per 1000 sq. ft. of gross building area. Building Two will generate approx. 1,150 daily trips and Building Three will generate approx. 814 daily trips. Approx. 12% of these trips will occur during the a.m. peak hour and 13.6% during g. Proposed measures to reduce or control transpor- the p.m. peak hour. tation impacts, if any: The buildings are being constructed in phases. Use of public transportation and flexible working hours will be suggested to tenants. 15. Public Services a. Would the project result in an increased need for public services (for example: fire protection, police protection, health care, schools, other)? If so, generally describe. The completed projects could marginally add to the need for police and fire protection. b. Proposed measures to reduce or control direct impacts on public services, if any. None other than payment of City taxes. Evaluation for Agency Use Only 16. Utilities a. Circle utilities currently av lable at the site: electricity, natural gall_ water refuse service, telephone, sane ary ewer septic system, other. b. Describe the utilities that are proposed for the project, the utility providing the service, and the general construction activities on the site or in the immediate vicinity which might be needed. Presently, sewer and water are available to the site and are serviced by the City of Tukwila. Electricity and phone service will be required and provided by Puget Power and Pacific Northwest Bell. Actual construction requirements to connect to utilities are not known at this time. C. Signature The above answers are true and complete to the best of my knowledge. I understand that the lead agency is relying on them to m4g it decision. r Signature: Date Submitted: PLEASE CONTINUE TO THE NEXT PAGE. G �.�,TQ,. .BE COMPLETED BY APPL IC• 0 Evaluation for Agency Use Only E. SUPPLEMENTAL SHEET FOR ALL PROJECT AND NON PROJECT PROPOSALS The objectives and the alternative means of reaching the objectives for a proposal will be helpful in reviewing the aforegoing items of the Environmental Checklist. This information provides a general overall perspective of the proposed action in the context of the environmental infor- mation provided and the submitted plans, documents, suppor- tive information, studies, etc. 1. What are the objective(s) of the proposal? To develop an office project of quality design and construction which will promote future business growth in the City of Tukwila and to fulfill a need for office space in an easily accessible location. 2. What are the alternative means of accomplishing these objectives? None 3. Please compare the alternative means and indicate the preferred course of action: Number One • • Evaluation for Agency Use Only 4. Does the proposal conflict with policies of the Tukwila Comprehensive land Use Policy Plan? If so, what poli- cies of the Plan? No Proposed measures to avoid or reduce the conflict(s) are: Not Applicable -23- Af* 00 tooZ7c9 0 GEOTECIEIN I CAL ENGINEERING STUDY PLIEL1N PARCEL 2 • SOUTHCENTER BOULEVARD TUKWILA , WASHINGTON • E-3007-2 FOR JOHN C RADOVI CH • DEVELOPMENT COMPANY 0.00..4k •=. .•■0136,1.w., r N,tr.k . "t"'*--•,•r • • •••• • • •,'•;-.V. ksft-0,1_ •3=-JA•t•4te Earth Consultants Inc. Geotechnical Engineers, Geologists t! Environmental Scientists November 2, 1987 E- 3007 -2 John C. Radovich Development Company 2000 - 124th Avenue Northeast, B -103 Bellevue, Washington 98005 Attention: Ms. Katie Greif Kulczyk Gentlemen: We are pleased to submit herewith our report entitled "Geotechnical Engineering Study, Melin Parcel 2, Southcenter Boulevard, Tukwila, Washington ". This report presents the results of our field explora- tion, laboratory tests, and engineering analyses. The purpose and scope of our study was outlined in our proposal dated July 28, 1987. The site is underlain by non - plastic silt and sand to the maximum depth explored, forty -nine (49) feet. The existing fill pile south of the proposed building area consists of wet, non - plastic to low plasticity, silt and construction debris. This material may be used as structural fill provided that the construction debris is removed and the soil can be adequately dried or stabilized for proper compaction. The use of this material as structural fill will be difficult if construction is done during wet weather. The proposed building can be supported on conventional footings bearing on at least two feet of structural fill. This report has been prepared for specific application to this project in accordance with generally accepted geotechnical engineer- ing practices for the exclusive use of John C. Radovich Development Company and their representatives. No other warranty, expressed or implied, is made. We recommend that this report, in its entirety, be included in the project contract documents. The following sections of this report describe our study and contain recommenda- tions regarding foundation design criteria, earthwork considera- tions, and site drainage. PROJECT DESCRIPTION The site is located north of the cul -de -sac at the terminus of Southcenter Boulevard. This four -acre, nearly rectangular site is bordered on the northwest and northeast by the Green River, by the Fort Dent access road on the southwest, and undeveloped land to the southeast. The site location is shown on the Vicinity Map, Plate 1. 1805 - 136th Place N.E., Suite 101, Bellevue, Washington 98005 222 E. 26th Street, Suite 103, P.O. Box 111744, Tacoma, Washington 98411 -9998 Bellevue (206) 643 -3780 Seattle (206) 464 -1584 Tacoma (206) 272 -6608 John C. Radovich Development Company November 2, 1987 E- 3007 -2 Page 2 We understand the proposed structure is to be similar to the building under construction southwest of this site. The building is anticipated to be two -story masonry with the bottom floor slab -on- grade. Centered on the property, the building footprint is an- ticipated to be rectangular and cover . approximately twenty -five thousand (25,000) square feet. The approximate building location is shown on the Boring and Test Pit Location Plan, Plate 2. The maximum column loads are anticipated to be one hundred twenty - five (125) kips with perimeter wall loads of two kips per lineal foot (kif). Slab loads are expected not to exceed one hundred fifty (150) pounds per square foot (psf). We anticipate that finished surface and floor elevations will be approximately equal to the existing surface elevations. If any of the above design criteria change, we should be consulted to review the recommendations contained in this report. In any case, it is recommended that Earth Consultants, Inc. (ECI) provide a general review of the final design. SITE CONDITIONS Surface The northeastern two - thirds of the site is covered with up to five feet of fill. Topographic relief at the edge of the fill is approximately three feet. A large fill pile approximately twenty (20) feet high exists from the cul -de -sac to approximately fifty (50) feet south of the proposed building footprint. The edge of fill and the large fill pile are depicted on Plate 2. Where the property is bordered by the Green River, the land slopes to the river's edge at an approximate inclination of 1.5:1 (Horizon - tal:Vertical). The elevation drop from the top of the slope to the river's edge is approximately twenty (20) feet. Vegetation consisting of a thick covering of grasses exists along the riverbank and on the southwestern third of the property. Trees, approximately twenty (20) feet high and eight (8) inches in diamet- er, exist along the riverbank and within fifteen (15) feet of the northern edge of the fill pile. Subsurface The site is overlain by as much as five feet of uncontrolled fill. This fill was excavated from the property immediately southwest of Earth Consultants, Inc. John C. Radovich Development Company November 2, 1987 E- 3007 -2 Page 3 this site and consists of fine - grained soils. A loose to medium dense silt exists below the fill and extends to approximately ten feet below the surface. Underlying the silt, a silty sand exists to the maximum depth explored of forty -nine (49) feet. This silty sand is medium dense and becomes dense to very dense at approximately forty -two (42) feet below the surface. Groundwater The groundwater levels observed while drilling were at twenty -two and one -half (22 -1/2) and twenty -seven and one -half (27 -1/2) feet below the surface. Slotted standpipes were installed in the borings to allow subsequent measurement of the groundwater level. Readings taken two days after completion of the borings are shown on the boring logs. The groundwater seepage level is not static and fluctuations in the level will occur depending on the amount of rainfall, surface water runoff, and other factors. Generally, the water level is higher during the wetter winter months. DISCUSSION AND RECOMMENDATIONS General Relatively recent fills cover most of the surface area of this site. These fills are anticipated to consolidate under the loads imposed by the proposed structure. On the adjacent site, native soils similar to those below the recent fills have demonstrated settle- ments of up to thirteen (13) inches under soil fill depths of about seven (7) to eight (8) feet. Settlement magnitudes will not be uniform across the site and differential settlements are expected to exceed tolerable limits for the structure. Based on these con- siderations, it is prudent in our opinion to surcharge the building area to reduce potential settlement magnitudes. In lieu of surcharging, structural loads can be supported on deep foundations extending below the compressible soil layers. This latter alternative does not provide for support of the floor slabs, entry way slabs or utilities. Further, we believe that deep foundations will be a more costly procedure if project scheduling can accommodate the time required for surcharge loading. The existing site soils are fine grained and will be difficult to properly compact if their moisture content is above optimum at the time of construction. These soils may be used as structural fill provided that they can be compacted to the specified percent density. The material in the large fill pile south of the site is wet and contains construction debris consisting of lumber, filter fabric and metal. Mineral soils in the fill pile must be cleaned of Earth Consultants, Inc. John C. Radovich Development Company November 2, 1987 E- 3007 -2 Page 4 construction debris and dried to near optimum moisture before being used as structural fill. Site Preparation and General Earthwork The building and pavement areas should be stripped and cleared of trees, existing utilities, surface vegetation, organic matter and other deleterious material. It is anticipated that a stripping depth of four inches or more will be required. Stripped materials should not be mixed with any materials to be used as structural fill. Structural fill is defined as any fill placed under buil- dings, roadways, slabs, pavements, or any other load bearing areas. Following the stripping operation, the ground surface where struc- tural fill, foundations, or slabs are to be placed should be proofrolled. All proofrolling should be performed under the observation of a representative of ECI. Soil in any loose or soft areas should be removed and replaced with structural fill to a depth that will provide a stable base beneath the general structural fill. Structural fill under floor slabs and footings should be placed in horizontal lifts and compacted to a minimum 95 percent of the maximum dry density 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. On -site soils at the time of our exploration were above the optimum moisture content. These soils may be used as structural fill provided that they can be compacted to the appropriate density designated above and are free of organic matter and construction debris. The on -site soils have a significant amount of fines. Thus, compaction and grading will be difficult if the soil moisture is above the optimum moisture content at the time of construction. To compact the site soils to the proper density, the moisture content needs to be reduced to near the optimum moisture content. Unless the moisture content can be reduced, it may be necessary to use imported granular soil as structural fill. The moisture content can be reduced by aeration in dry weather, or by using lime or cement stabilization. Ideally, structural fill which is to be placed in wet weather should consist of a granular material with a maximum size of three inches and no more than 5 percent fines passing the No. 200 sieve. During dry weather, any compactible non - organic soil can be used as structural fill. Earth Consultants, Inc. John C. Radovich Development Company November 2, 1987 Surcharge Program E- 3007 -2 Page 5 We recommend that the building area be pre- loaded with a minimum of three feet of surcharge fill. The purpose of the surcharge fill is to induce as much settlement in the building area as possible prior to construction. This fill is in addition to any structural fill materials required to achieve design finish grades; thus, the top of the surcharge should be three feet above finish grade and should extend a minimum of five feet beyond the building perimeter or exterior footing line. If future expansion is anticipated, the surcharge should extend at least fifteen (15) feet in the direction of the future addition. The extra surcharge area is to reduce the possibility of differential settlement from future building or surcharge loads. Also, no fill for landscaping purposes should be placed near the building since any additional fill could induce further settlement. The side slopes of the surcharge fill should be inclined no steeper than 1H:1V. We estimate that the surcharge fill will need to remain in place approximately two to three weeks to permit primary settlements to be completed, after which building construction may be started. Before placing the surcharge fill, structural fill should be placed six inches above finish grade to allow for anticipated settlement. Depending on site grades, it may be necessary to overexcavate soil to provide the required thickness of structural fill below footings and slabs. Alternatively, footing excavations can be done after removal of the surcharge fill. The surcharge fill does not have to meet any specific requirements except that it should have a minimum in -place total density of one hundred twenty (120) pounds per cubic feet (pcf). However, if the surcharge fill is to be used later as fill on another part of the site, we recommend it meet the requirements for structural fill. Structural fill to be placed in wet weather should contain no more than 5 percent fines passing the No. 200 sieve. Prior to placement of the surcharge fill, we recommend installation of at least four settlement markers within the surcharge area. These markers should be protected from disturbance by construction equipment. In addition, these markers should be surveyed by ECI personnel or a licensed surveyor daily during fill and surcharge placement and at intervals of 2, 4, 8, 16 (so forth) days after completion of the surcharge fill placement. The initial reading should show the natural ground elevation, and readings taken during surcharge placement should show surcharge thickness. The surcharge may be removed when the required settlement has been reached. The subgrade should be proofrolled and any unstable pockets should be overexcavated and replaced by structural fill. Earth Consultants, Inc. • John C. Radovich Development Company November 2, 1987 Foundations E- 3007 -2 Page 6 After removal of the surcharge loads, the proposed structure may be supported on conventional continuous and spread footings bearing on at least two feet of structural fill. Overexcavation of soil below the footing will be required. Fill placed under footings should extend outward from the edge of the footings for a distance equal to its depth. Exterior footings may be bottomed at a minimum depth of twelve (12) inches below the lowest adjacent outside finish grade. Interior footings may be at a depth of twelve (12) inches below the top of the slab. Footings bearing on structural fill should be designed for a bearing pressure of twenty -five hundred (2500) psf. Continuous and individual spread footings should have minimum widths of twelve (12) and eighteen (18) inches, respectively. A one -third increase in the above bearing pressures may be used when considering short term wind or seismic loads. For the above design criteria, it is anticipated that total post - construction settlement of footings will be about one inch with differential settlements of about one -half inch. If any continuous footings are located partially in cut and partially in fill, we recommend that consideration be given to additional reinforcement in the footings and footing walls near the cut -fill transition line to reduce the possibility of structural damage due to differential settlement. Lateral loads due to wind or seismic forces may be resisted by friction between the foundation and the supporting compacted fill subgrade or by passive earth pressure on the foundations. For the latter, the foundations must be poured "neat" against the existing soil or backfilled with a compacted fill meeting the requirements of structural fill. A coefficient of friction of 0.35 may be used between the structural foundation concrete and the supporting subgrade. The passive resistance of undisturbed natural soils and well- compacted fill may be taken as equal to the pressure of a fluid having a density of two hundred fifty (250) pcf. We''recommend that drains be placed around all perimeter footings. The drains should be constructed with a four -inch diameter per- forated pipe bedded and covered with free - draining gravel. The drains should have a positive gradient towards suitable discharge facilities. The roof drainage system should not be tied into the footing drainage system. The footing excavation should be back - filled with granular soil except for the top foot which should be backfilled with a relatively impermeable soil such as silt, clay or topsoil. Alternatively, the surface can be sealed with asphalt or concrete pavements. Earth Consultants, Inc. • • John C. Radovich Development Company November 2, 1987 Slab -on -Grade Floors E- 3007 -2 Page 7 Slab -on -grade floors may be supported on the compacted site soils or on imported structural fill. Any disturbed site soils must be recompacted or replaced with structural fill. A minimum of four inches of free - draining sand or gravel should be placed between the slab and subgrade as a capillary break. We also recommend that a vapor barrier such as a 6 mil plastic membrane be placed between the slab and capillary break to reduce water vapor transmission through the slab. Two inches of sand may be placed over the membrane for protection during construction and to aid in curing of the concrete. Excavations and Slopes In no case should excavation slopes be greater than the limits specified in local, state and national government safety regula- tions. Temporary cuts greater than four feet in height should have an inclination no steeper than 1.5H:1V. As an alternate to open cuts, temporary shoring can be used in conjunction with vertical cuts. Detailed criteria for shoring systems can be developed, if needed. All permanent cut and fill slopes should be inclined no steeper than 2H:1V. We recommend that all excavations be examined by ECI to verify that conditions are as anticipated. Supplementary recommen- dations can then be developed, if needed, to improve stability, including flattening of slopes and installation of surface and subsurface drains. In any case, water should not be allowed to flow uncontrolled over the top of any excavation 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 Groundwater was encountered in our borings at depths of twenty -two and one -half (22 -1/2) and twenty -seven and one -half (27 -1/2) feet. However, it has been our experience that groundwater levels change significantly due to changes in rainfall amounts, surface drainage or other factors. If seepage is encountered in the excavation, the water should be drained away from the site by use of drainage -ditches, perforated pipes or French drains, or by pumping from sumps interconnected by shallow connector trenches at the bottom of the excavation. Earth Consultants, Inc. John C. Radovich Development Company November 2, 1987 E- 3007 -2 Page 8 We suggest that appropriate locations of subsurface drains, if needed, be established during grading operations by a representative of ECI, at which time the seepage areas, if present, may be more clearly defined. The excavation and site should be graded so that surface water is directed off the site. Water should be not allowed to stand in any area where buildings, slabs, or pavements are to be constructed. During construction, loose surfaces should be sealed at night by compacting the surface soils to reduce the infiltration of rain into the soils. Final site grades should allow for drainage away from the building foundations. We suggest that the ground be sloped 3 percent for a distance of at least ten feet away from the buildings except in areas that are to be paved. Pavement Areas All parking and roadway areas may be supported on the existing soils provided that those soils can be compacted to 95 percent density and are stable at the time of construction. Structural fill and /or fabric may be needed to stabilize soft, wet or unstable areas. In most instances twelve (12) inches of granular fill will stabilize the subgrade except for very soft areas where greater thicknesses may be required. The upper twelve (12) inches of pavement subgrade should be compacted to at least 95 percent of the maximum density. Below this level, a compactive effort of 90 percent would be ade- quate. The pavement section for lightly loaded traffic and parking areas should consist of two inches of Asphalt Concrete (AC) over four inches of Crushed Rock Base (CRB) or three inches of Asphalt Treated Base (ATB). Heavier loaded areas will require thicker sections. We will be pleased to assist you in developing ap- propriate pavement sections or specifications for heavy traffic zones, if needed. Methane Concentrations Methane gas concentrations were measured in the soil samples taken from the borings and test pits. The concentrations were measured using a "Gastechtor" device calibrated for toluene gas. The appropriate conversion factor was then used to convert the actual readings to parts per million (ppm) methane which is reported on the boring logs at the appropriate sample locations. The readings taken in the field indicated concentrations of methane gas between 40 and 450 ppm. These concentrations are less than one percent of the Lower Explosive Limit (LEL) of 50,000 ppm for methane Earth Consultants, Inc. • • John C. Radovich Development Company November 2, 1987 E- 3007 -2 Page 9 and are not considered to be an environmental or safety hazard at the measured concentration. The concentrations of methane gas are probably a result of decaying organic matter in the soils. FIELD EXPLORATION AND LABORATORY TESTING Our field exploration was performed on September 15, 16 and 17, 1987. Subsurface conditions at the site were explored by drilling two borings to a maximum depth of forty -nine (49) feet below the existing grade and by excavating seven test pits to a maximum depth of eleven (11) feet. The borings were drilled by Associated Drilling, Inc. using a truck - mounted drill rig. Continuous flight, hollow stem augers were used to advance and support the boreholes during sampling. The approximate locations of the borings and test pits were determined using a nylon tape. Approximate elevations of borings were determined using a hand level. The locations and elevations of the borings should be considered accurate only to the degree implied by the method used. These locations are shown on the Boring and Test Pit Location Plan, Plate 2. The field exploration was continuously monitored by an engineering geologist from our firm who classified the soils encountered and maintained a log of each boring and test pit, obtained representa- tive samples, measured groundwater levels, and observed pertinent site features. Slotted standpipes were installed in Borings B -1 and B -2 to monitor groundwater levels. All samples were visually classified in accordance with the Unified Soil Classification System which is presented on Plate 3, Legend. Logs of the borings and test pits are presented on Plates 4 through 9. The final logs represent our interpretations of the field logs and the results of the laboratory examination and tests of field samples. The stratifica- tion lines on the logs represent the approximate boundary between soil types. In actuality, the transition may be gradual. In each boring, Standard Penetration Tests (SPT) were performed at selected intervals in accordance with ASTM Test Designation D -1586. The split spoon sampler was driven with a one hundred forty (140) pound hammer falling thirty (30) inches. The consistency of the soil in the test pits was estimated based on the effort required to excavate the soil, the stability of the trench walls and other factors. Representative soil samples were placed in closed containers and returned to our laboratory for further examination and testing. Visual classifications were supplemented by index tests such as sieve analyses and Atterberg Limits on representative samples. Earth Consultants, Inc. John C. Radovich Development Company November 2, 1987 E- 3007 -2 Page 10 Moisture determinations were performed on all samples. Results of moisture determinations, together with classifications, are shown on the boring and test pit logs included in this report. LIMITATIONS Our recommendations and conclusions are based on the site materials observed, selective laboratory testing and engineering analyses. The conclusions and recommendations are professional opinions derived in accordance with current standards of practice. No warranty is expressed or implied. The recommendations submitted in this report are based upon the data obtained from the borings and test pits. Soil and groundwater conditions between borings and test pits may vary from those encountered by the borings and test pits. The nature and extent of variations between borings and test pits may not become evident until construction. If variations then appear, ECI should be allowed to reevaluate the recommendations of this report prior to proceeding with the construction. Additional Services It is recommended that ECI provide a general review of the final design and specifications to verify that the earthwork and founda- tion recommendations have been properly interpreted and implemented in the design and in the construction specifications. It is also recommended that ECI be retained to provide geotechnical services during construction. Because of the nature of this project, 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 bonstruc- tion observation and testing services. This is to observe com- pliance 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. Earth Consultants, Inc. John C. Radovich Development Company November 2, 1987 E- 3007 -2 Page 11 The following plates are attached and complete this report: Plate 1 Plate 2 Vicinity Map Boring and Test Pit Location Plan Plate 3 Legend Plates 4 through 9 Boring and Test Pit Logs Respectfully submitted, EARTH CONSULTANTS, INC. f/d4- Sheldon T. Lynne Staff Engineer ohn J. Moran roject Manager STL /JJM /cac /kml Earth Consultants, Inc. • • Reference : King County / Map 41 By Thomas Brothers Maps Dated 1988 Earth Consultants Inc. Vicinity Map Melin Parcel 2 Tukwila, Washington Prof. No. 3007-2 I Date Oct. '87 I Plate I Property Line 7P-3 PARCEL 2 tIC B 2 B-1 b,1 f5i ,#1P4 .'--4 PARCEL / A 7P-2 PARCEL 3 _ — TP-7 \49-14P-6 Large Fill Pile . . • , • c''‘N Not - To - Soole LEGEND S B-1 Approximate Location of ECI Boring, Proj. No. E-3007-2, Oct. 1987 1P-I Approximate Location of ECI Test Pit, Proj. No. E30072, Oct. 1987 •y"-- Approximate Limits of Fill r Approximate Area of Proposed Building Reference : Plat Map Received From Client Undated Boring and Test Pit Location Plan Melin Parcel 2 Tukwib, Washington Proj. No. 3007-2 'Date Oct. '87 'Plate 2 MAJOR DIVISIONS GRAPH SYMBOL LETTER SYMBOL TYPICAL DESCRIPTION Coarse Grained Soils More Than 50% Material Larger Than No. 200 Sieve Size Gravel And Gravelly Soils More Than 50% Coarse Fraction Retained On No.4 Sieve Clean Gravels (little or no fines) ..t .a.• .:: ;�Gw • r..� >•: =Y:O•• • • gw Well- Graded Gravels, Gravel -Sand Mixtures, Little Or No Fines �- - :0::0::0 :: .. • .. • ' .. 0. GP gp Poorly-Graded Gravels, Gravel - Sand Mixtures. Little Or No Fines. Gravels With Fines( appreciable amount of fines) GM gm Silty Gravels, Gravel - Sand- Silt Mixtures 4 GC gc Clayey Gravels. Gravel - Sand - Clay Mixtures And Sandy Soils More Than 5004 Coarse Fraction Passing No. 4 Clean Sand ( little or no fines) '00 °00 00 0° 000 0 O 0 000• 0°00°0 °000• SWj j SW Well-Graded Sands, Gravelly Sands, Little Or No Fines •••.-.;..•••-•#. •. :•.:•.;:•:• SP Sp Poorly-Graded Sands, Gravelly Sands, Little Or No Fines Sands With Fines (appreciable amount of lined • : ::!•1•:: `''''''''' , : l : , i S(N Sm Silty Sands. Sand - Silt Mixtures y yyyy prSC Clayey Sands, Sand Clay Mixtures Fine Grained Soils • More Than 50% Material Smaller Than No. 200 Sieve Size Silts Liquid Limit And Less Than 50 Clays ML ml Inorganic Silts 8 Very Fine Sands, Rock Flour,Silty- Clayey Fine Sands; Clayey Silts w/ Slight Plasticity /%� / / CL / __ CI Inorganic Clays Of Low To Medium Plasticity, Gravelly Clays Sandy Clays. Silty Clays. Lean I I <, I I r QL i /� OI Organic Sdts And Organs Silty Clays Of Low Plasticity Silts Liquid Limit And Greater Than 50 Clays MH mh Inorganic Sills Micaceous Or Diatomaceous Fine Sand Or Silty Soils CH Ch Inorganic Clays Of High Plasticity. Fat Clays / j'oH --- Oh Organic Clays Ot Medum To High Plasticity, Organic Silts Highly Organic Soils — ` PT pt Peat, Humus. Swamp Sods With High Organic Contents Topsoil Fill Humus And Duff Layer Highly 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 Notes : Dual symbols are used to indicate borderline soil classification. Upper case letter symbols designate sample classifications based upon lab- oratory testing; lower case letter symbols designate classifications not verified by laboratory testing. I 2 "0.D. SPLIT SPOON SAMPLER Tr 2.4" I.D. RING SAMPLER OR 11 SHELBY TUBE SAMPLER P SAMPLER PUSHED * SAMPLE NOT RECOVERED Si WATER LEVEL (DATE) aWATER OBSERVATION WELL C TORVANE READING, tsf qu PENETROMETER READING, tsf W MOISTURE, percent of dry weight pcf DRY DENSITY, pounds per cubic ft. LL LIQUID LIMIT, percent P1 PLASTIC INDEX Earth Consultants Inc. GEOTECHNICAL ENGINEERING & GEOLOGY LEGEND Proj. No. 3007 -1 Date Oct' 87 11'iate 3 Logged Date w BORING By STL • NO. -4.7'± ELEV. 9/15/87 Graph CS Soil Description I (efptlh Sample (N) Blows Ft. (W) - 1 16 15 ML Tan SILT, damp, medium dense - I 6 23 100 ppm* i ml/ sm Brown interlayered silty SAND and sandy SILT, moist, medium dense - 5 - 15 37 300 ppm <' t ___ = I 13 6 ,Z; :, •;; ; sm Brown silty fine SAND, moist, medium dense 10 - I 9 9 50 ppm - 1 9 5 50 ppm ,: 15 � .�. # <f Z 13 6 • •' Wet below 22.5' —20 Q ;.�;•; ` sm/ 9 -17 -87 Dark brown, 22.5 to 32.5' : - 11 28 200 ppm i.�, ::...� sp —25 ` 17 Dark gray /black, 32.5 to 49' 13 32 ••; •_ 35 = 16 29 —40 • Very dense at 42.5' � 55 12 :• -45 •.;:: Dense at 47.5' - f ''. - T 40 22 *ppm = parts per million methane Boring terminated at 49 feet below existing grade. Groundwater encountered at 22.5 feet during drilling. 3/4" PVC standpipe installed to bottom of boring. Lower 10 feet slotted. Boring backfilled with cuttings. Subsurface ca ndMbrr depicted represent our obeawiar at the time and location of dr..Rploreary hole. modified by engineering tests, anayde, end judgement. They are not necessarily npn.awrite d other times and Imams Not centl weep responsibly kw the use or iMapwlaion by others of information presented w this lag. BORING LOG (i � Earth Consultants Inc. - MELIN PARCEL 2 .TUKWILA, WASHINGTON • Geotechnical Engineering and Geology , Proj. No.3007 -2 1 Date oct' 87 (Plate 4 Logged Date BORING By STL w NO. ____2____ ELEV. -1.7'± 9/15/87 Graph CS Soil Description Defpt)h Sample (N) Blows Ft. ( %) •�H�•�o• � (1/2" topsoil) - 15 19 '''°'°". ml Fill: Tan SILT, damp, medium dense r- 200 ppm ML Gray SILT, moist, medium dense I 10 27 300 ppm — — 5 LL -36 — ml Brown SILT with rootlets, moist, loose - I 9 PI =9 ' With scattered organic matter at 7' 6 450 ppm �':•: sm Brown silty SAND, moist, medium dense - 10 I 12 10 350 ppm y :., :• - I 9 5 120 ppm —15 • = I 6 6 :,. 20 I 9 7 420 ppm '∎ sm /. sp Wet below 27.5' — 24Z 9/17/87 I 14 --30 Dark gray/black silty fine to coarse = 9 26 SAND, wet, loose to dense 35 250 ppm I24 . 27 250 ppm .:: — 40 Dense below 42.5' 150 ppm With gravel at 42.5' _ 31 27 — 45 4 T 37 17 Boring terminated at 49 feet below existing grade. Groundwater encountered at 27.5 feet during drilling. 3/4" PVC standpipe installed to bottom of boring. Lower 10 feet slotted. Boring backfilled with cuttings. Subnrleas condidar depicted represent our ob.arvalwe ■ the time and location at this .rplonlory hole. moaned by engineering test.. map., and payment. They an na necessarily representative oh other dross and locat ion.. We cannot accept rwpono iIy ex the use or inewpretation by others of inhorm.tion presented on We lop. BORING LOG 11 MELIN PARCEL 2 . Earth ;'' Consultants Inc. TUKWILA, WASHINGTON Geeteehnical Engineering and Geology Proj. No. 3007 -2 I Date oct' 87 IPlate 5 Logged By Date 9/16/87 Depth (ft.) USCS 0 5 10 15 0 5 10 MEI r ml • TEST PIT NO. A. Soil Description Elev. = W 1961 Fill: Tan SILT, damp, loose, with concrete rubble sm/ ml Tan silty SAND and sandy SILT, moist, loose 7 2 40 ppm Test pit terminated at 7 feet below existing grade. No groundwater seepage encountered during excavation. Logged Dace 9/16/87 STL_ TEST PIT E lev. -1-71 Fill: Brown sandy GRAVEL, moist,, loose S sm/ ml Brown silty SAND to sandy SILT, damp, loose Corregated plastic pipe at 4.5' Test pit terminated at 5 feet below existing grade. No groundwater seepage encountered during excavation. 15 srarrroe cmdwoes depicted rpr..ea our m.wv.tbns r the dine and location or dee ea lanaory hole. modified by engineering Maac analysis. end ludgrn.m. Thai age not n.a..ray represents** oI other time and locaio e. W. cannot scow reeporu'bility for the use as inierpreielion by other. of Yrlor.etion presorted on this b► Earth Consultants Inc. GEOTECHNICAL ENGINEERING & GEOLOGY TEST PIT LOGS MELIN.PARCEL 2 TUKWILA, WASHINGTON Proj. No. 3007 -2' Dsa Oct' 87 1PM* 6 By STL D 9/16/87 Depth (h,) USCS 0 5 10 15 0 5 10 ., owl TEST PIT NO. L.3 Soil Description Elev._ W (96) 12" crushed rock ballast ml Fill: Tan SILT with gravel and a boulder, moist, medium dense ml Brown sandy SILT, moist, loose to medium dense 13 12 Test pit terminated at 6 feet below existing grade. 'No groundwater seepage encountered during excavation. Logged By STL DaW 9/16/87 TEST PIT NO. Elev. -2.0± Fill: Tan SILT, moist, loose, with tree limbs and other organic debris Old topsoil r ml Gray SILT, moist, loose ml mai Light and dark brown SILT with scattered organic matter ml Brown sandy SILT, moist, loose 15 33 18 Test pit terminated at 11 feet below existing grade. No groundwater seepage encountered during excavation. 15 8ub.urtscs conditions depicted Pigment our obw.etiera r the time and location of this av orslory hole, modified ty •naM«ww tests, sn.yeis, and judgement. Thaw ass not noe«orily rspnasrtaYve of other times and locations. Ws cannot accept responsibility for the um «intermission bothers d Information mssertsd on Ws log. Earth Consultants Ins. GEOTECHNICAL ENGINEERING • GEOLOGY TEST PIT LOGS MELIN PARCEL 2 TUKWILA, WASHINGTON Proj. No. 3007 -2' D>di Oct' 87 Fate 7 Depth (ft.) 0 5 10 15 0 5 10 15 Loggod By STL Dab 9/16/87 USCS TEST PIT NO. _..5. Soil Description EIev. w (%) r INN MEI OWN ml Tan sandy SILT, damp, loose 14 Test pit terminated at 4.5 feet below existing grade. No groundwater seepage encountered during excavation. Looped By STL_ Date 9/16/87 TEST PIT NO. S_ E lev. -1'71 Fill: Tan sandy GRAVEL, damp, loose to medium dense 4 4 150 ppm 200 ppm Test pit terminated at 4 feet below existing grade. No groundwater seepage encountered during excavation. Subsurface conditions depicted we're our obeervrions st the time and location of this aippallory Hob, moaMd by prpireerinp lets, anaemia, and jtrdpernaa. They are no necessarily representable al other times and locations. Ws cannot accept responsibility ter the use or ir1nprutaYon by others al information preesrrsd an this los. Earth 410 4) Ori Consultants Inc. GCOTECHNICAL ENGINEERING • GEOLOGY TEST PIT LOGS MELIN PARCEL 2 TUKWILA, WASHINGTON Proj. No.3007 -2 I Date oct r 87 ,Prate 8 Depth (ft.) 0 5 Logged By Date 9/17/R7 uscs TEST PIT NO. .Z_ Soil Description Elev. -4.71 W (96) ml Fill: tan sandy GRAVEL, damp, loose to medium dense Gray clayey SILT, moist, soft 24 25 320 ppm ,350 ppm Test pit terminated at 4 feet below existing grade. No groundwater seepage encountered during excavation. 10={ 15 OEM Subeurlaoa conditions depicted moment our abeervalions at the bine and location of this wobblier/ hole. meddled W engineering teal., anieele. and judgement. They w not necessarily representative al other tines and locations. We cannot accept rs.ponsibiWY for dte use ar interpretation by of irdormalion prsursed on this low Earth 4) ;1°1 Consultants Inc. GEOTECHNICAL ENGINEERING & GEOLOGY TEST PIT LOGS MELIN'PARCEL 2 TUKWILA, WASHINGTON Proj. No. 3007 -21 Dmi Oct' 87 Fats 9 ABANDONED LANDFILL STUDY IN KING COUNTY SEATTLE-KING COUNTY DEPARTMENT OF PUBLIC HEALTH APRIL 30, 1985 RENTON JUNCTION • RENTON JUNCTION ABANDONED LANDFILL • • RENTON JUNCTION (MONSTER ROAD) King County operated a refuse disposal site at the Renton Junction near Longacres from approximately 1946 to about 1961. It operated on land leased from the Northern Pacific Railway Company described as: "Those portions of Lots 31 and 32 of Interurban Addition to Seattle, according to the recorded plat thereof, lying northeasterly of a line parallel with and distant 36 feet northeasterly, measured at right angles, from the center line of the most northeasterly main track as now constructed across said lots; together with the southwesterly one -half of the original channel of the White River which attached thereto when the channel of said river was relocated and constructed along the southwesterly side of the Railway Company's. tracks." Additional land was obtained from Mr. Fred Nelson of Renton for the operation described as: "that portion of government Lot 6, Section 24, Township 23N, Range 4EWM, lying between the westerly right of way line of the Steel Hill County road No. 24- 23 -4 -1 and the centerline of the old channel of the Green River." PAST AND PRESENT USE As noted by the legal description, part of this property was once the old river channel whicn became part of the Northern Pacific Railway right of way and private rural property. After its operation as a sanitary landfill the land was surplused and in 1979 purchased for commercial use. The site is currently used by a decorative rock company and is used for storage of crushed rock and gravel associated with that operation. Across the Green River lies Fort Dent Park, southwest of the site is the Riverview Nursery and to the east is the Metro Secondary Sewage Treatment Plant. SITE /ENGINEERING INFORMATION AND WASTE DISPOSAL PRACTICES No specific geological or hydrological information was found regarding the site other than it was part of the old river channel. It may be surmised that the • • base soil is clay, sand and gravel overlain by fill forty to fifty feet deep and topped off with a relatively impermeable layer and topsoil. Once the landfill operation started there are records showing numerous complaints regarding the site. Nuisance conditions prevailed in the warm weather. Fire and smoke were reported night and day. Inadequate fill dirt for the cover of the operation was noted, as were problems of dumping sewage and oils on site. The County had a contract for the maintenance of this dump with a private concern in effect until December 31, 1957. This contract called for bulldozing and compaction twice weekly with the top side being covered with eighteen inches of dirt. It also required that the garbage be deposited in lifts or layers not to exceed twelve feet in depth after initial compaction. There was no earth available on the site and all cover material had to be brought in by trucks. The only earth available within hauling distance had been of a hardpan type with a heavy clay concentration. The site was used not only by the County, but according to copies of agreements, also by the City of Renton to dispose of a portion of their garbage and refuse. The seriousness of the fires at the south end'of the dump operations in 1950 prompted correspondence between the King County Fire Marshal and the Health and Sanitation Department, who ran the landfill, to confine burning to the north area of the landfill. The landfill was closed effective December 27, 1957 with directions for refuse to be taken instead to either the Bow Lake Fill at South 188th and Military or the landfill at South 352nd Street about one -half mile east of the Puyallup cut off highway, both still in operation at that time. However, the Health Department was requested to continue filling operations as plans to discontinue the fill were described as leaving the fill in an unusable • • condition. The fill waF reopened, using County equipment to conduct operations, which continued for about two years. SUSPECTED PROBLEMS Due to the proximity of the old landfill site to the Green River, it is conceivable that leachate may reach the river. The site is recorded on the EPA 'RRIS list. The site's proximity to several industries in South King County make it possible that some potentially hazardous materials, including oil, were dumped at the site during its years of operation. FIELD RESULTS The Renton Junction Abandoned Landfill was tested for methane and trace gas emissions on January 10, 1985. These data are presented in Table XXXVI. Methane gas levels were observed ranging between 17% and 33% from test holes located at the northerly half of the former fill. Lower levels of methane gas (3% to 5 %) were observed within the southerly section. Trace gas levels were observed ranging between -4.8 ppm to 0 ppm relative to the ambient air. A surface water sample was retrieved along the shoreline of the Green River immediately adjacent to the former landfill. Leachate contamination was not indicated (Table XXXVII). • • FIGURE 2C RENTON JUNCTION ABA";DONEI LANDFILL Ammar Monster Road • TABLE XXXVII METHANE AND TRACE GAS CONCENTRATIONS RENTON JUNCTION ABANDONED LANDFILL Site Methane (° =) Trace Gas (ppm) 1 33 -2.7 2 30 -4.6 3 17 -4.8 4 4 0 5 3 0 6 3 0 7 5 0 (1) Trace•gas measurements made with 11.2 eV HNU probe (2) Reading represents change from ambient air level • • TABLE XXXVIII SURFACE WATER PARAMETERS RENTON JUNCTION ABANDONED LANDFILL Site (A) (1) pH 5.6 Temperature 5.2 Dissolved 9.8 Oxygen (PPm) Electrolytic 0.2 Conductivity my /cm Turbidity 1 (PPm) (1) Green River surface water • • CONCLUSIONS AND RECOMMENDATIONS RENTON JUNCTION ABANDONED LANDFILL This site demonstrated relatively high levels of methane off - gasing with five of the seven test holes being within or above the explosive range. No evidence of non - specific organic /inorganic gases were observed exceeding background levels. It is recommended: 1. That all existing building construction be properly vented and periodically monitored to insure that methane is not accumulating in any substructures. 2. That no further building construction take place over the former landfill site until it has been stabilized. I -5 High ,17 BOY LAKE ABANDONED LANDFILL Steep Downhill Embankment Steep Downhill Embankmen' -Not to scale 1985 1 I vi/C, Y 1 GEpri2AL 1 C. ATro I, SECTION 3. CONSTRUCTION STANDARDS. A. APPLICABILITY. This construction restriction applies to all construction activities on /or within one thousand feet of an active, closed or abandoned landfill that has been documented by the health officer to be generating levels of methane gas on-site at the lower explosive limits or greater levels. The distance shall be calculated from the location of the proposed structure to the nearest property line of the active or former landfill site. 8. REQUIREMENTS. All enclosed structures to be built within the one - thousand foot landfill zone must be protected from potential methane migration. The method for insuring a structure's protection from methane shall be addressed in • report submitted by • licensed civil engineer to the local building departarent for approval. Such a report shall contain a description of the investigation end recommendation(s) for preventing the accumulation of explosive concentrations of methane gas within or under enclosed portions of s building or structure. At the time of final inspection, the civil engineer shall furnish a signed statement attesting that the building or structure has been constructed in accordance with his /her recommendations for addressing methane gas migration. SECTION 10. EFFECTIVE DATE. These Rules and Regulations shall take effect on January 1, 1987. Passed this , 19 , NAY of December . 1986. RING COUNTY BOARD OF HEALTH RING COUNTY, WASHINGTON ATTEST: Secretary i°„ed., rldxli. 0 I 1 •f PUBLIC WORKS DEPT. FIRE TRUCK TURNING RADII 3 1 F u RIVER IMPROVEMENT EASEMENT This indenture, made this day of 19 between Kaiser Gateway Associates, Grantors, and the City of Tukwila, its successors or assigns, Grantee: WITNESSETH, that first party in consideration of Mutual Benefits and the benefits which will accrue to the land of Grantor by the exercise of the rights herein granted to hereby remise, release and forever quit -claim unto the Grantee, its assignee, an easement and right -of -way for the purposes hereinafter stated along the westerly bank of the Duwamish River. A riverbank improvement easement over a 30.00 foot wide strip in Lot 4 of Tukwila Short Plat No. 85- 32 -SS, recorded in Book 52 of Surveys at Page 113, under A.F. #8611179001, records of King County Washington, and being more particularly described as follows: BEGINNING at a point on the westerly line of said Lot 4, distant thereon NO °41'14 "W 309.53 feet from an angle point in said Lot 4 (said angle point being at the intersection of the two courses shown as N60 °32'46 "E'g7.13 feet and N0 °41'14 "W 352.00 feet); thence from said POINT OF BEGINNING, along said westerly line of Lot 4,'N0 °41'14 "W 30.85 feet; thence leaving said westerly line N75 °48'04 "E 79.44 feet; thence 77'22'27" E 27.90 feet; thence N74 °28'54" E 53.39 feet; thence N87 °57'42 "E 44.41 feet; thence S79 °18'02 "E 46.43 feet; thence N77 °16' 11" E 34.14 feet; thence N89 °14'54 "E 61.39 feet; thence S77 °00' 29 "E 143.53 feet; thence S60 °59'45 "E 79.84 feet; thence S50 °18'13 "E 61.75 feet; thence S47 °10'35 "E 69.43 feet; thence S42 °48'46 "E 74.82 feet; thence S26 °36'41 "E 155.18 feet; thence S2 °11'55 "E 59.81 feet; thence S5 °05'51 "W 158.78 feet; thence S5 °46'43 "E 91.24 feet; thence S8 °01'36 "E 110.51 feet; thence S2 °14'21 "E 30.95 feet thence S71 °21'58 "E 12.28 feet to a point on the southeasterly line of said Lot 4;thence along said southeasterly line S41 °46'16 "W 32.62 feet, thence leaving said southeasterly line N71 °21'58:W 20.13 feet; thence N2 °14'21'W 50.10 feet; thence N8 °01'36 "W 109.59 feet; thence N5 °46'43 "W 94.68 feet; thence N5 °05'51 "E 159.72 feet; thence N2 °11'55 "W 51.41 feet; thence N26 °36'41 "W 144.42 feet; thence N42 °48'46 "W 69.40 feet; thence N47 °10'35 "W 67.47 feet; thence N50 °18'13 "W 58.12 feet; thence N60 °59'45 "W 72.81 feet; thence N77 °00'29 "W 136.09 feet; thence N89 °14'54 "W 54.63 feet; thence S77 °16'11 "W 36.82 feet; thence N79 °18'02 "W 49.30 feet; thence S87 °57'42 "W.37.51 feet; thence S74 °28'54 "W 57.36 feet; thence N77 °22'27 "W 28.26 feet; thence S75 °48 04 "W 79.49 feet to the POINT OF BEGINNING. Containing 41,588 square feet, more or less. • Said easement and right -of -way are for the following purposes: The right to enter upon the above described land to construct„ reconstruct, maintain and repair a river channel and /or other flood control works, including all appurtenances thereto, together with any enlargement or reconstruction thereof, and to trim, cut, fell and remove all such trees, brush and other natural growth and obstructions as are necessary to provide adequate clearance and to eliminate interference with or hazards to the structures; and included as an appurtenance to said easement is a reasonable right to access thereto over any other land owned by the Grantor. The consideration above mentioned, is accepted as full compensation to the exercise of the rights above granted. To have and to hold, all and singular, the said easement and right -of -way together with appurtenances, unto Grantee, its successors and assigns. IN WITNESS WHEREOF Grantor hereunto set his hand, the day and year above written. KAISER GATEWAY ASSOCIATES CAL F D E TERPRISES By: By: General Partner KAISER DEVELOPMENT COMPANY By: / :•tic.± .( -� Jl �L s1 ,rn.�t.v7 k / Qeneral Pattner STATE OF CALIFORNIA ss. COUNTY OF San Francisco THIS IS TO CERTIFY that on this 4th day of April , 19 88 , before me, the undersigned, a notary public in and for the State of Washington, duly commissioned and sworn, personally appeared ROBERT M. KAGAN AND RICHARD DEFABIO to me known to be the Vice President's ofCAL FED ENTERPRISES, a General Partner of Kaiser Gateway Associates, a California partnership, that executed the within and foregoing instrument, and acknowledged the said instrument to be the free and voluntary act and deed of said partnership for the uses and purposes herein mentioned, and on oath stated thatTheyeauthorized to execute said instrument. WITNESS my hand and official seal the day and year in this certificate first above written. STATE OF COUNTY OF ) ss. No ary Pfiblic in and for the State of CALIFORNIA residing at San Francisco My commission expires 4/8/88 THIS IS TO CERTIFY THAT ON THIS day of , 19 , before me, the undersigned, a notary public in and for the State of Washington, duly commissioned and sworn, personally appeared to me know to be the of , a General Partner of Kaiser Gateway Associates, a California partnership, that executed the within and foregoing instrument, and acknowledged the said instrument to be the free and voluntary act and deed of said partnership for the uses and purposes herein mentioned, and on oath stated that he was authorized to execute said instrument. WITNESS my hand and official seal the day and year in this certificate first above written. Notary Public in and for the State of residing at My commission expires STATE OF ;./')/`1V7 COUNTY OF i I i'-/ r ss. THIS IS TO CERTIFY that on this // day of(,CJ�ii , 19 , before me, the' undersigned, a notary public in and for the State of Washington, duly - commissioned and sworn, personally appeared !_-1 . 2 f;! 'C ) �11(/) ). ,� R___ ` to , me kngw to be the 1..'i l./ of t �:'.t'G /i7.4 f/�ci 1(C' , a General Partner of Kaiser Gateway Associates, a California partnership, that executed the within and foregoing instrument, and acknowledged the said instrument to be the free and voluntary act and deed of said partnership for the uses and purposes herein mentioned, and on oath stated that he was authorized to execute said,instrument. WITNESS my had and official seal the day and certification first above written. Nota Publi State, of in this occi Residing at Ate`, c /_ My commission e • ires ,i'-Z//,;9/ APPENDIX E UNIVERSITY OF WASHINGTON SEATTLE, WASHINGTON 98195 28 May, 1982 Institute for Environmental Studies Office of Public Archaeology Engineering Annex, FM -12 (206) 543 -8359 Thomas E. Moore, Project Manager Construction Division Evergreen Management Company 1721 132 Avenue N.E. Bellevue, Washington 98005 DEC 1 -_ %v• LS -AM. ii: C Re: Archaeological reconnaissance of the 16 acre Tukwila Bend Project Dear Mr. Moore: The following report, in letter format, details the findings of the Office of Public Archaeology's recent assessment of the proposed Tukwila Bend office complex. Assessment procedures included archival research and field investi- gation. Assessment activities were conducted by Mr. Guy F. Moura and Mr. Stephen Elmore on 7, 10 and 11, May, 1982. The Project Area The project is located on the west bank of the Green River, just north of the Interstate 405 and SR 181 junction, in the town of Tukwila, King County, Washington. The project is more specifically located on the western boundary of the NW and SW 1 /4s of Sec. 24, T23N, R4E (Figures 1 and 2). The project area now forms a rectangular peninsula on the Green River. This peninsula was created when a river bow was truncated by the Great Northern Railroad some time prior to 1949 (U.S.G.S. 1949). Immediately west of the site is a 150 foot bluff; to the north, east, and south lies the floodplain of the Green River Valley. An isolated hill rises 150 feet above the flood - plain, on the east side of the river, northeast of the proposed office com- plex. During on -site inspection, it was discovered that river sediments had been removed from the site and /or bulldozed into several mounds. Except for a narrow band of sands, retained by rip -rap around the periphery, the site is now composed of pebble to boulder sized rocks in a fine grained matrix which is presumably of glacial origin. When the river sediments were removed is unknown; it could have occurred when the road to the Fort Dent Athletic Com- plex was built (it now transects the site), or during railroad or highway construction. 0 Recycled Paper 93 T. E. Moore 28 May, 1982 Page Two Brush growth on the dozer mounds and a small, established marsh in the cen- ter of the peninsula indicate that sediment removal occurred at least sev- eral years prior to this survey. Vegetation on the site consist of a ring of mature trees along the bank, with brambles, brush, grass and marsh vege- tation over the remainder of the site. Archival Research Archival research revealed that the project area had good potential for cul- tural resources because of: 1. its proximity to known prehistoric sites; 2. the ethnographic evidence. This area of the green river is known to have been heavily utilized by the Duwamish Indians; and 3. the historic evidence. Some of the earliest EuroAmerican settlers in what is now Washington State lived along the waters of the Green River; and Fort Dent was erected just north of the project properties, on the east side of the river, in 1856. A more detailed cultural resource overview of the region is presented in Dalan, et al. (1981). Prehistorically, the Green River was part of a drainage complex which formed a highway for canoe passage between Puget Sound and the interior prairies and mountains. Besides temporary camps and fishing sites, major Indian villages were located along the river courses. Prehistoric archaeological sites are common in the vicinity. Three such sites, 45 -KI -6, 45 -KI -51 and 45- KI -59, are located within a kilometer of the project, along existing and extinct river banks. Ethnographically, the area was within the territory controlled by the Duwamish Indians (Haeberlin and Gunther 1930:10; Smith 1940:16; Spier 1936 :38 and 42). Evidence of the Duwamish peoples' familiarity with the area is provided by the following place -names excerpted from T. T. Waterman (ca. 1920). These places are readily identified on modern topographic maps. 200. Where black river enters White river, Squoa'l -qo, "meeting of the rivers," a village. 201. The level land below the mouth of Black river at Renton Junction, on the E. bank, T3awe'dJtc, "river duck." 202. An isolated knoll. There were "piles" of snakes there (apparently water- snakes). An informant found three piles, each of them a yard high when he was a boy. This place would not submit to transformation, so it is a part of the "old" world, as it was before the Transformer came. 94 T. E. Moore 28 May, 1982 Page Three 203. A sandy point, now occupied by the picnic- grounds at Renton Junction, Cuhu'dutugwEl, "burning each other;" (hud, "to burn "). Snakes who land here after swimming across the river, in the summer time, get burned by the sand and die. 203a. A place on the W. bank of the river, BIs /g3a'ka, "where there are crows." 203b. Number not used. 203c. A bluff overhanging the river on its W. side, Bsts/ xEbe'dats, "place of ironwood." People used to go there for ironwood, tsE1x"b .Ld. (Waterman, ca. 1920:31 and 32). Two historically documented villages (Dalan et al. 1981 and Hedlund 1981) are within a kilometer downstream of the project. These villages are distinct from the prehistoric sites mentioned earlier. The green river was settled by EuroAmericans early in the history of the Pacific Northwest. The property on which the cultural resource reconnais- sance was conducted may have first been claimed by William H. Gilliam be- tween 1850 and 1855. It is known that at the time of his claim, Gilliam was a single man who had not been in the territory prior to 1850. Gilliam claimed 160 acres in portions of Sections 23 and 24, for which he later re- ceived title under the provisions of the Donation Claim Land Law. Although residence and cultivation were required to receive title for the land, General Land Office plat maps (1861 and 1863) do not depict structures or farmed lands; nor do they even locate Gilliams' claim, which was patented in 1866 (Shackleford 1940). During the Indian Wars of 1855-56, the local settlers constructed Fort Dent for protection against raids by the hostiles. It was built across the river from the project area, and today an historic marker indicates the former location (Dalan et al. 1981). Field Reconnaissance As stated earlier, upon arriving at the site it became apparent that consider- able surface sediment removal had occurred several years ago. The entire site was surveyed in 10 meter intervals and 14 core and 8 shovel test holes were placed to determine the limits of disturbance and to look for cultural re- sources. Because of this disturbance, and the small marsh, -core locations and shovel tests were not systematically placed. Virtually all of the site, except for a narrow strip along the bank, was disturbed. It appears the site was bulldozed and several mounds of earth remain on the grounds to attest to this theory. No cultural resources were located during this survey. Recommendations While archival research indicated a high potential for discovery of cultural material, the disturbance to the site would have eradicated any such materials. We therefore recommend that this project be allowed to proceed. However, in 95 T. E. Moore 28 May, 1982 Page Four the event that cultural material is unearthed during construction, even in the dozer mounds, work should stop immediately in that area and the Office of Archaeology and Historic Preservation should be notified forthwith. A professional archaeologist should then assess the significance of the find prior to any further disturbance. The possibly intact peripheral strip of sediments is, at this time, protected on the river side by riprap and on the site by the. mandatory .40 foot from high water. setback. This report should not be considered to be permission to proceed with the project in question. It contains professional opinions on cultural resources which might be affected by the project. This report should be submitted to the appropriate review agencies for their comments prior to the commencement of any ground disturbing activities. Sincerely, Guy F. Moura, Staff Archaeologist GFM:ALL Encl. 96 • • FIGURE 2. Project location is circled and blacked out. 98 Additional mitigating measures should include continuing the existing street tree landscaping concept throughout the site. This concept presently is in place through the site on the north side of Southcenter Boulevard and into Fort Dent Park. Also, driveways north of Southcenter Boulevard should be located to avoid the existing trees. During design review for building permits, the city should consider limiting or requiring screening of rooftop structures since residents in the apartments on the hillside west of the site will be able to look down on the site. ARCHAEOLOGY /HISTORY The Green River Valley was one of the earliest areas in the Northwest to be settled by Euro- Americans. The project site was first claimed between 1850 and 1855. During the Indian Wars of 1855 -56, Fort Dent was constructed across the river from the site. Railroads were first built through the valley in the 1880s. The site is adjacent to the former right -of -way of the Interurban Railway, once an important transportation link between Seattle and Tacoma. ENVIRONMENTAL IMPACT The site was investigated by the University of Washington Office of Public Archaeology to identify the potential for historical or archaeological resources on the site. (See Appendix D.) Since the site was filled and graded many years ago, any potential cultural remains have been covered by several feet of fill. Construction of the project will occur entirely on previous fill, and will not cause any additional impact to potential cultural resources on the site. MITIGATING MEASURES As a mitigating measure to the previous filling of the site, an interpretive display describing local history could be constructed along the river trail. RECREATION The site is privately owned, and is not presently used for recreation. However, Fort Dent Regional Park is adjacent, and its sole access is through the site. The publicly owned riverbank along the site is lightly used for recreation. The project would have no significant adverse impacts to recreation on the site. Access to the publicly owned riverbank would be improved. The land for a trail and benches along much of the riverfront would be deeded to the city as part of the project. The 53 C?' _ ',-,PAC-TECH . =m: c m ENGINEERING, INC �6 11170 BOOTH BTN OTREET, SUITE 20,1 N - reeore, weenlNOtoN BB•oe • (200/30S -44111. p 3721 NITOA• WAY. SUITE • 1l' BRE0ERTON, WASHINGTON • 120111S77 ..2033 • 023 70736. .0)0 0AROOR :/B1 -2022 CLIENT io N 4 %2.400✓ /GA, 2000 /24TH A ✓E NE B t'E BG R ✓2jE;. WA'. 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