Loading...
HomeMy WebLinkAboutLUA-06-023_MiscJune 3, 2005 DRAFT HEATHER DOWNS PARK PUBLIC MEETING #1 Location: Highlands Neighborhood Center. JUNE 1,2005 MEETING NOTES Prepared by: J.A. Brennan Associates j.a. br~~.~ ~ Landscape Mcbitects & Planners 100 S. King Street, Suite 200, Seattle, WA 98104 t. 206.583-0620 f. 206.583.0623 www.jabrennan.com J.A. Brennan presented a PowerPoint Show that introduced the project team and gave an overview of the project. The slide show included sIte images, an Issues and Opportunities Plan, potential programming elements and landscape characters. After fhe slide show, attendees brought up the following discussion points: I •. • An attendee noted that alot of children use NE 3rd Court as an informal play area. Access to the site for Parking may not be appropriate for this street. • It was noted fhat the comer of3rd and Union is a children's bus stop. • Another person commented that NE 3rd Court is a high traffic street. • One person commented that the existing ornamental shrubs and fruit trees form the previous home site should be preserved. • If the park retains the name Heather Downs park, an individual requested that heafher plantings be installed. • Another person asked where the dog park could go, as it could potentially bring more surveillance to the site. • There was a recommendation that leashed dogs should be permitted in the new park. • Someone asked what the park's hours of operation would be. The City answered that the proposed park hours would be sunrise to sunset. • Another person asked whether there was a need for a ball park here, as there are five other ballfields nearby. • A preference for non-ordered/informal playfield with minimal backstop was made. • A grass in-field was proposed. • An attendee said that the new park should encourage walking MEETING NOTES j.a.brennan associates, pile • One person said the park should be designed for multi-generational users. • There was a comment that a multi-use field would accommodate different sports. • Another person commented that trails should have different surfaces, both soft and hard surfaces in different areas. • One person noted that traffic on Union travels at high speeds. The City responded that ideas to reduce speed could be considered. Potential traffic calming enhancements include bulb-outs and a controlled traffic crossing on union just south of NE 2nd Place. • There was a recommendation that a smaller parking area providing ADA access should be considered off Union. In general, the recommendation was that the park should provide parking for 10 cars or only the minimum required for ADA access. • Someone asked ifthe electrical infrastructure on the site could be placed underground. The City responded that undergrounding utilities is very expensive and would probably be more than the budget for the park. • There was a request for a more rustic gathering space as opposed to a concrete gathering plaza. • There was a recommendation to provide the parking area off the existing house driveway and to utilize the existing plumbing utilities from the previous home for the new restroom. • A discussion about park safety included the recommendation of security lighting, fencing, and a permeable planting buffer that allows people to see into the park. • Someone commented that the park should give teenagers good things to do. • There was a comment that black chain link fencing should be used for fencing. • Another person preferred that a rustic wood-rail fence be used. • An attendee requested that a range of climbing boulder structures be incorporated into the park. • A request was made to name the park after the Barfield family, former residents of the site and Pioneers to the City of Renton as a Memorial to the family. • There was a comment that there should be a separation of users by age in the children's play area. • One person recommended a pea-patch garden for the site. • Another attendee would like bike racks/parking facility on the site. • Attendees were encouraged to sign up for a neighborhood group to help voice their concerns in the community .. • There was a request to bring a traffic representative to the next meeting. • Someone asked about barrier/fencing at the street edges of the park. • There was a discussion about staging construction. • There was a request to provide crosswalks with white stripes at intersections (NE 1st and NE 3rd Court), as well as flashing lights at crosswalks. The meeting was adjourned at 8:50pm. The next public meeting will be held to introduce park design alternatives and will take place on Tuesday June 28 th , 2005 at 7pm at the Highlands Neighborhood Center. Comments received on the Programming Questionnaires include: • There should only be 5 spaces for handicapped parking. No other parking lot. • Dog friendly park, on leash ok. • Only provide ADA parking • Environmental restoration is important. native vegetation should remain, only use natives, create a rustic feel park with benches. • Save existing flowering trees and shrubs (spring/early summer blooming) • Consider play areas for age groups 0-4, 5-11, 12-6 MEETING NOTES 2 j.a.brennan associates, pile • Avoid creating areas which could encourage crime, drug activities, through lights and clearing existing vegetation. Encourage pedestrian use for multi-generational "children and older population" Gathering spaces or small courtyards. • Avoid physical fences, they are elements which are reminders of the sense oflimit, borders, segregation. Instead use landscape elements to buffer areas between park and existing homes. • As a resident facing the park site on NE 3rd, I would prefer to have a park that will be quiet, community oriented park. I would like to see trails and paths where people could enjoy the natural foliage and passive play areas for picnics. I do not want a parking lot across the street from my home. There is already too much traffic going too fast on my street to add a parking lot. • Desires no organized little league, but informal ball play area. • No on street parking, prefers on site. • Parking would be acceptab13e if the entrance to the parking lot is off of Union. The entrance to the parking lot should not be off ofNE 3rd Ct. Lots of children are crossing NE 3rd Ct. throughout the day. • Create a drop off area for cars to unload and then go park on the street. • Try to keep areas will in view to prevent unwanted and unsafe activity (like Lake Boren Park) for areas nearest the young children's area. • Provide resting benches • Park signs on Union and Children/Slow signs • Buttons across Union in tow or three locations • Noise and kids area on North and West side, where most kids live, Natural Area !Wildlife habitat on south and southwest side where the older people live. • Entrance on SE side of park is not acceptable • Entrance should be from comer, Union • Need to preserve the privacy of houses on SE border of park, fence all the way to Union, • Must have parking area • For safety of neighbors, park should close at dusk. • Provide no more than eight parking stalls. • A climbing structure, especially a good quality custom solution, could cater to a broad range of ages, qualify as I % for the arts and more. And not a vertical or top rope climbing structure. A "bouldering" structure can be versatile, very low maintenance, and even easily moveable. MEETING NOTES 3 j.a.brennan associates, pUc Heather Downs Park Development Public Meeting No.2 June 28,2005 City of Renton Community Services j.d. br~nl1al1~ , .. ,. ""'" Heather Downs Park Development Park Context • Neighborhood with Single-Family and Multi-family housing • Diverse culture • Dense population • Bike and pedestrian access Ci ty of Renton Community Serv ices j .. l. br~llIuJ1~ Heather Downs Park Development Renton Parks Map Cit y of Renton Community Services CITY OF RENTON PARKS . SCHOOLS AND TRAILS :::::c:=::I OP,VRI.OPEf) PA k KS _ OPEN SPACES -__ I"EOI!STKIAN OWL.. Y T1IAILS ---MIXED USE TltAIl. ---RlUIIOtm:(SItARE[) ROAOWAy) ~SoCHOOLS (,.,TY LIMITS * TIIAII . Acx,'t,S.$ P"()II''T e '-~ ~,~-, -- """".WoJIlMQ'IOoI I " r' . -i . '-. di ;'::~:" .~. 1 \ ,G'<'?~'; F~ .. ~. ; N,E;WC ASTLJ! .-" , . .!,i·:W.;:: ~.; '.. ; '. ~ \"_ . ._! 1·-· ~,:~ ; .. ~'~ '/ r j: -:-' ..... " ,-" ,~ ,.:,;.~ '-. /"~ ... ; ,".\ Heather Downs Park Development \ 'v--' I ; J I. I 1 i , . --1 II D l) 1"\ \" It\er- -, L 'AkTjlv.rr'(_ i-I . .' -, ' ; I . I .. , I /1 I I 'I -...... '~r', t \ I I : ,' .. I --------~:;~r)1 ,~.!~ ~I -' t---.~------- ANALYSIS PLAN LEGEND ~\snHq-rrrr-t-nJ C-~IH4"~ I I ,-:1 r'P~ rII--S-..--' ~,.J I , -1 'T" -"1 ,' . ..... , '\ ~.:, PDI-'\~Irle;, ~ t>.L-TIVIT'\ ~ E.X\S\IN{;f' fOR~ ! I _:1··.0'0 · ~~'!"I"-'"::""=' .. o ~ ~ HEATHER DOWNS PARK MASTER PLAN ~a.br~~ -..:!!~:.!!: Heather Downs Park Development Neighborhood context City of Renton Community Services j,a . br e nnan~ ,,',,' ' Heather Downs Park Development - ,-4~. ,. -.- Slope challenges Sidewalk on Union City of Renton Community Services j.a . br ~J~nall" ., .. , , Heather Downs Park Development Protecting site resources City of Renton Community Services j.a . brel1l1al1~ """ .. ," ,;., , Heather Down s Park Development Vision Statement Create a neighborhood park that meets the neighborhood's active and passive recreation needs, while being sensitive to significant environmental features and adjacent property ownership_ City of Renton Community Services j.a. br e llllall~ ... , ... , ..... . Heather Downs Park Development Park Goals Park Integration • Link park to surrounding neig h borhood • Buffer parking lot views • Encourage pedestrian access • Create neighborhood entries • Enable views to the site to enhance park safety • Work with CPTED (Crime Prevention Through Environmental Design) ideas to remove illegal activity on site City of Renton Community Services .-.-;-.~',: " j.a,brelUlall • "'Q," "C-'-'-'-'; Heather Downs Park Development Park Goals Recreation • Create multi-use recreational facilities • Develop facilities that respond to the neig h borhood""""",,"'fIl<1fd' "","",,~: d • Provide recreation appropriate to the site • Provide active and passive recreation activities~. ," ,. • Provide summer youth programming opportunitiEis>j Environmental Stewardship • Enhance native vegetation • Preserve existing significant trees. . > • Eliminate on-site dumping City of Renton Community Services j.a. br~nnan'" ,., ". ,.,,, ,,',. Heather Downs Park Development Park Goals Neighborhood Enrichment • Consider neighborhood gathering areas • Create sense of neighborhood ownership· • Consider adopt a park opportunities (Volunteer plantings and maintenance) Aesthetics • Enhance existing vegetation. • Utilize naturalistic landforms • Improve the visual quality into the • Enhance or maintain framed views ~d~ •. _ •.• ,.,.. Maintenance' /)) • Balance park improvements with maihten'$ncetr~?9,~m City of Renton Community Services . ." . :'"t\ :,1, .,~~( ""~ ~. "it j.a. brennan. ,.,~. , .. " -.-,,: Number of attendees Heather Downs Park '/9Rme'ij ranking this rogram lement Yes No Maybe elemen. Ranking of Program Elements City of Renton Community Services li'o":!Ioll • "'-1 iiJl<.'lTop ten yes items Top ten Ranked itemj·a.hr~p.r!lfI.~1 Heather Downs Park Development Final Park Programming Elements • Children's Playground • Children's Climbing Boulder Play Area • Informal ball field • Multi-use Playfield • Basketball (Half Courts) • Running Trail - pedestrian/bike trails • Volleyball Court • Individual Family Picnic Areas • Picnic Shelter City of Renton Community Services • Passive Lawn Area • Barbeque(s) • Soft Surface Trails (nature trails) • Hard Surface Trails • Park Signage • Sculptural Elements • Forested Areas • Understory Planting • Restrooms • Parking j.a. brClljlan. ,-, .. ",', . [ Arter~ativr !. -.~-- 'f ( ) I I. , ,-- !~ Q II{ 11 '~i ./ I) I I I ,'1 h /1 ri I JL I r~. I:~j '1 ,J'r - i--j '--~ TI ~l r, 1/ ,-,1,-f! .~)I·~ rJ City of Renton Community Services " . , , , : _____ :_~:ir~ ___ _ j TACOMAF\ .~ ~,--Ll :~~~--~------------: " ,-' \1 .1 ~ : . ~ " .' " .. " !'. _.1 -, / \ ALTERNATIVE CONCEPT ONE LEGEND A . Picnic Shelter B . Restroom C. Parking Area (5 ears with one load unload) D . Playground (Ages 2-5) E. Playground (Ages 5-12) F. Rock Climbing Stru cture G . Half Court Basketball H . Informal Vo ll eyball I. Picnic Plaza J . Picnic Meadow K. Primary Path (Hard Surface) L Secondary Path (Soft Surface) M . Traffic Bulb-Out N . Existing Significant Tree s O. Guardra il 1 _1'·:1(1'0' ,-._-,--. ~ ~ HEATHER DOWNS PARK MASTER PLAN CITY OF RENTON COMMUNITY SERVICES j,aJu<. "g,q1_~ '" OATE : 6-27-05 FIGURE: i.a.lJr~nn ."l\~ ca N ca -c.. (.) .-t: ........ (.) .-c: c.. <D E Q) Q t: 0 0 -<D Q) (f) :::,. <1> <l> > <..> .-> a +oJ '-ca <1> ~ t: (/) ~ >- ctl Q) --Q +oJ C :=l C/) < E c: E ~ 0 0 u a c 0 --"-c <D <1> ...c: 0::: ....... '+- ctl 0 <D >- :t:: ."!:::: U Heather Downs Park Developmen t Alternative One: Path with planter strip on Union Ave. I , ~ I "lor =-.,------.--::......,,---.~ .. ----II ::'~. f ", )BlYE" .. _ ...... ,;;. • _ -'.~ ,_ .. _-------. ·--.--,,:::.:r_-.::=--.. L -l1~ , . / --. -. I .,-..);-T' '., . ., ! _ I I . , City of Renton Commun ity Services j.a. b r e r ~n a n~ ... , .. ~ternatj~~ 1 'I I' ) 1 [' ! II \\ I t·.11 l> ,'. --.~ H UJ,) If .. '; /t I" . 'J J I'_I . J J( " :J.·~I L,._ ,1/ D ~~) I '" , .q h II ~i j. \. I City of Renton Community Services u.~ '1/, ',_J [~J --:-fAG~i ' .-; ~ ~ r 1. 1 ., r ,~ ,';" ", \ } i : --.. --~/ , , ......,J I ~·-". -.. " J' -.•.• ' I' 1 16 --;.\ i.~ 1 roo:-_.1 . Ii "Il , s lrilLE FAMILY RESIDENTIAL II ~, I \ ;;--~J: ._1 1 .~ ! f -+~ , \ 11 \ , ~ ALTERNATIVE CONCEPT TWO LEGEND A. Picni c Shelter B . Restroom C . Parking Area (5 Cars with one load unload) D. Playground (Ages 2·5) E . Playground (Ages 5-12) F Rock Cl imbing S tructure G . Half Court Basketball H I nfom)al VOlleyball I. Picnic Plaza J Small Entry Pl aza K. low Plantings L. Pi cnic Meadow M . Primary Path (Hard Surface) N . Secondary Path (Sofl Surface) O . Traffic Bulb-Oul Q. Exis ting Significant Trees 1 _1'_60'''' /,,"'-'--.........,: , ~ ~ HEATHER DOWNS PARK MASTER PLAN CITY OF RENTON COMMUNITY SERVICES w<J DATE: 6·27-05 I FIGURE: j.a. br e l1l1 a ll~ ... ,,',," ;". co N co -n. (,) .-s:::: (,) .-n. ........ c: 0 <J) E ~ Q.. I- 0 Q) -> <J) ::::. .-..... <J) CO a s:::: ~ ~ Q) ..... <U -a.. <C C/) c: ~ 0 a ~ <J) ..c: ........ <U <J) :r: .' . '--.::---.- i " '---.../\ u.}, ) / -/ ~: gi ~; .!O ., Cf) Q) <..) > '-Q) U) >--+-' c ~ E E 0 0 c 0 ....... c Q) 0:::: '+- 0 >-.~ 0 Heather Downs Park Development Alternative Two: Traffic Bulb Out 3rd Court and Union --1'1 l:~~<~~:!Y '~ I~ :r ~ _"'I , .,., . . ... , . , r . , ~ I.. I.~ .. ~ ~." <c )~n •• ·.. 'I ~r ""'~~ I . y; ~ r "" " L '-.. '," ':>-.. '. II< I, c .. '?"""\ ./" ... -~ I~. ~ '.,' ..--~ ..... ~... -" ---=--------, -'---r--",1,:; .. ,_ 11 , -.... -- • 1 , J ~ City of Renton Commun ity Services ~~',;, .: I.~~ '''-,; < ....';'. j"l. bet'nn ,an. August 15,2005 CITY OF RENTON HEATHER DOWNS PARK Public Meeting #3 Location: Highlands Neighborhood Center, July 26, 2005 Meeting Notes Prepared by: l.A. Brennan Associates Attendees Name Organization Leslie Betlach City of Renton Community Services Bill Rasmussen City of Renton Community Services Tanja Wilcox JA Brennan Associates Drew Coombs JA Brennan Associates j.a. br~~.~ ~ Landscape Architects & Planners 100 S. King Street, Suite 200, Seatde, WA 98104 t 206.583-0620 f. 206.583.0623 www.jabrennan.com Phone E-mail 425-430-6619 lhetiachra)d. renton. l~'a. us 425-430-6617 brllsmussen(ai,s;.i,renfon. wa.us 206-583-0620 tanja@jabrennan.com 206-583-0620 drew@jabrennan.com Approximately 20 ll1embers of the public attended the meeting Comments Introduction • Leslie Betlach introduced the status of the project and reviewed the process that has been utilized to date. • JA Brennan Associates presented the Draft Master Plan graphic and accompanying site section boards to the attending public. Handouts • Handouts: 8 Y, x 11 master concept plans Public Input and Comments Following the presentation of the Draft Master Plan, the meeting was opened up for comments and questions. MEETING NOTES 1 Heather Downs Park plio General o Use existing water meters, but replace old utility lines ... potential reuse? Larger water line required for fire hydrant and new sewer line to minimize future maintenance o Guardrail-low wooden 8"x8" timber, 36" from ground to top of timber Paths o ADA accessibility throughout path o Like: meandering sidewalk/path along Union Site Lighting o Leslie Betlach noted to the attendees that the City Council requested Lighting from dusk until approximately 10pm along paths o A few attendees though lights were fine. o General response from attendees was to tum off lights at 8:30 or 9pm? Parking o The participants indicated they wanted the park closed similar to other parks in the system. o With a potential locking gate and locking restroom. Traffic o Like: traffic calming on Union o Bulb-outs and lighting a priority ... Public works to assist with bulbs Picnic Plaza o An individual questioned the distance from the proposed planter bed seat wall to the parking area? A setback of 10-12' between parking curb and bed was requested. o Drew Coombs noted that the East side of the bed may be curb and the west side a seating wall. o The attendees were interested having BBQs included as part of the Picnic Plaza o The Picnic Shelter will have summer reservations similar to other shelters in the park system Planned Project Schedule One attendee asked what the planned schedule was for the project. Leslie Betlach provided the following tentative schedule o Construction schedule: Bid October Preconstruction JanlFeb cleaning and chipping Earthwork March! April Open end of summer 2006 Maintenance An attendee was interested to know how emergency and maintenance vehicles will access the site? o Service vehicles will be able to use the hard surface asphalt path, AC ... useable for maintenance and emergency vehicles, a bollard will probably be located at the path from the parking lot to allow for controlled vehicle access. Park Naming Leslie Betlach presented the current park names that have been submitted to date. Decision is still to be made MEETING NOTES 2 Heather Downs Park plk • The name Heather Downs comes from a housing development at the end of Union Avenue Ideas: Heritage Park Barfield Community Park (Parks bought property from Barfield family Barfield Neighborhood Park A name for consideration will be presented to the Parks Board with a recommendation made to City Council for final consideration and adoption, Parks Board has not made recommendation for name Further naming suggestions please should be e-mailed to Bill and Leslie. Artl Education • I % for the arts? YES, Arts Commission to assist • Attendees liked the idea of Y. mile markers--{)n soft and hard trails • It was suggested to include a Map oftrails or an interpretive or art element • One individual expressed an interest in identifying Tree age as an interpretive art! educational element .... (example at another park -50-75 years at Jones Park ... elms for educational interest) • The Barfield family will be donating a bench. An attendee also wondered about incorporating some of the family history into art for the park Planting An individual asked the number of proposed trees to be installed. At this Master Plan level of design the number of trees to be installed is unknown. This will come later in the construction design phase. • New trees can be added later, maybe for Arbor Days, etc. • Want: open views into park • An individual inquired about shoring up west side of park, and is this going to happen? Bill Rasmussen responded that the area will be avoided to avoid disturbance, and no major park elements will be installed in this area to avoid encouraging use • An individual inquired if the existing lilacs will be saved. Due to the short lifespan and nature of the site work required they may not be retained, but efforts will be made to save the plants. They could possibly be replaced if they can't be saved. • Wetland (Class 3) to be filled in doesn't require mitigation. Depression due to human activity, very seasonal, potential mosquito problem also Project Budget One individual asked what the project budget is for the project. • Budget: $1, 250,000.00 (Design and Construction) Will try to incorporate all design elements Add alts: Smaller curbing at playground area Phased development Phase I-park lighting and traffic calming elements City Council has the option to appropriate additional funding (if needed) • The public expressed ideas for elements that could be phased in, these include the picnic shelter informal baseball field, and basketball half-court. • It was noted the baseball field area would be graded and seeded as open space lawn as part of the overall project and the participants agreed. MEETING NOTES 3 Heather Downs Park pile Property Ownership • Northwest parcel belongs to Water Department and south parcel also to P.B and P.W. There is potential for future a future water tower on the N.W. parce\. Other • Include scattered picnic tables at site • Email info updates regarding phasing or not • Everyone is excited to be getting a new park' • Email the City Council meeting time for public to attend and support park Next meetings September 13, 2005 4:30pm, Park Board Meeting (Confirm) September 26, 2005 7:30pm, City Hall Council Meeting (Confirm) MEETING NOTES 4 Heather Downs Park pUc SHANNON &WILSON. INC. ~ "" -{. Geotechnical Report Heather Downs Park Development Renton, Washington October 1 0, 2005 ~~~N/NG MAR-22006 RECEIVED 'x 'c -~;I:~':~Jr:;'Lf~7¥~~~~-~~'H N leA L II N 0 ENVI ~;~{f~~:~~< c'~~~~~~;~~s":' Submitted To: Mr. Jim Brennan JA Brennan Associates, PLLC 100 South King Street, Suite 200 Seattle, Washington 98104 By Shannon & Wilson, Inc. 400 N 34'" Street, Suite 100 Seattle, Washington 98103 21-1-20373-001 SHANNON &W1LSON,INC. TABLE OF CONTENTS Page 1.0 INTRODUCTION ................................................................................................................. 1 1.1 Purpose ....................................................................................................................... 1 1.2 Scope of Work ............................................................................................................ 1 2.0 SITE AND PROJECT DESCRIPTION ................................................................................. 1 3.0 SUBSURFACE EXPLORATION PROGRAM .................................................................... 2 4.0 GEOLOGY AND SUBSURFACE CONDITIONS .............................................................. 2 4.1 Regional Geology ....................................................................................................... 2 4.2 Subsurface Conditions ............................................................................................... 3 4.3 Groundwater Conditions ............................................................................................ 3 5.0 ENGINEERING CONCLUSIONS AND RECOMMENDATIONS ................................... .4 5.1 General ................................................. : ..................................................................... 4 5.2 Foundation Design ..................................................................................................... 4 5.3 Estimated Settlement.. ................................................................................................ 4 5.4 Lateral Earth Pressures ............................................................................................... 5 5.5 Lateral Resistance ...................................................................................................... 5 5.6 Floor Slabs ................................................................................................................. 6 5.7 Drainage ..................................................................................................................... 6 5.8 Earthwork ................................................................................................................... 7 5.8.1 Site Preparation and General Excavation .................................................... 7 5.8.2 Temporary Groundwater Control ................................................................ 7 5.8.3 Fill Placement, Compaction, and Use of On-site Soils ............................... 8 5.8.4 Wet Weather Earthwork .............................................................................. 9 5.8.5 Erosion Control ............................................................... : .......................... 10 6.0 CONSTRUCTION CONSIDERATIONS ........................................................................... 10 6.1 Obstructions ............................................................................................................. 1 0 6.2 Loose Test Pit Backfill ............................................................................................. 10 7 .0 LIMITATIONS ................................................................................................................... 1 0 8.0 REFERENCES ..................................................................................................................... 13 21.1-20373-001-RJlwplLKDLORJ OOHERTY 21-1-20373-001 l TABLE OF CONTENTS (con!.) SHANNON &W1LSON,INC. LIST OF FIGURES Figure No. I Vicinity Map . 2 Site and Exploration Plan LIST OF APPENDICES Appendix A Field Explorations B Important Information About Your Geotechnical Report 21-1-20373-OOI-R IIwplLKD 2\-\-20373-001 11 SHANNON &WILSON.INC. 1.1 Purpose GEOTECHNICAL REpORT HEATHER DOWNS PARK DEVELOPMENT RENTON,.WASHINGTON 1.0 INTRODUCTION This report presents the results of subsurface explorations and geotechnical engineering studies for the Heather Downs Park Development site located inRenton, Washington. The purpose of our geotechnical studies was to evaluate subsurface conditions in order to formulate engineering recommendations for use in the design and construction of the proposed project. Our services were provided in accordance with our proposal, dated May 31, 2005, and authorized by Mr. James A. Brennan at J.A. Brennan Associates, Inc. on July 19, 2005. 1.2 Scope of Work Our scope of work for this project included the following: ~ Identifying and reviewing existing subsurface information in the general vicinity. ~ Overseeing and sampling excavation of three test pits. ~ Performing laboratory tests. ~ Preparing a site and exploration plan and logs oftest pits. ~ Conducting engineering analyses. ~ Summarizing our conclusions and recommendations in this report. 2.0 SITE AND PROJECT DESCRIPTION The proposed Heather Downs Park Development project, as shown in the Vicinity Map, Figure I, is situated southwest of the intersection ofNE 3rd Court and Union Avenue in the City of Renton. We understand that the site was formerly residential property and the majority of the site is currently overgrown with trees and brush, including dense thickets of blackberries. Based on the proposed site plan surveyed by Penhallegon Associates Consulting Engineers, Inc. (PACE), on September 13, 2005, the area of concern at the site measures about 250 feet by 300 feet. In general, the ground surface across the site slopes gently from elevation 414 feet on 21.1-2037J-OOI-Rl/wplLKDLORIOOHERTY 21-1-20373-001 SHANNON &WILSON.INC. the south end to about elevaaon 408 feet on the north end. These elevations are in terms of the . North American Vertical Datum of 1988 (NAVD88). The proposed developed area of the park will cover about 75,000 square feet. The buildings at the site include a restroom facility and a picnic shelter. We understand that these structures will be constructed on slabs-on-grade with shallow perimeter footings. The site will also include paved parking lots, playground areas, and planters and landscape areas, as shown on the Site and Exploration Plan, Figure 2. 3.0 SUBSURFACE EXPLORATION PROGRAM To generally characterize subsurface conditions in the vicinity of the proposed structures, three test pits were excavated and sampled at the approximate locations shown in Figure 2. The test pits are designated TP-I through TP-3. A description of the methods and procedures used for locating, excavating, and sampling the test pits is included in Appendix A. The logs of the test pits are also included in Appendix A as Figures A-2 through A-4. 4.0 GEOLOGY AND SUBSURFACE CONDITIONS 4.1 Regional Geology The project site is located in the central portion of the Puget Lowland, an elongated topographic and structural depression bordered by the Cascade Mountains on the east and the Olympic mountains on the west. Low-rolling relief, with some deeply cut ravines and broad valleys, characterizes this lowland. In general, the ground surface elevation of the project site is within 410 feet above sea level. Geologists generally agree that the Puget Sound area was subjected to six or more major glaciations during the Pleistocene Epoch (2 million years ago to about 10,000 years ago), which filled the Puget Lowland to significant depths with a complex sequence of glacial and non- glacial sediments. Ice for these glacial events originated in the coastal mountains of the Vancouver Range of British Columbia. The maximum southward advance of the ice was about halfway between Olympia and Centralia (about 80 miles south of Seattle). During the most recent ice coverage of the central Puget Lowland (Vashon Stade of Fraser Glaciation), the 21-1-20J73-00I-R I/wpllKD 21-1-20373-001 2 SHANNON &W1LSON.INC. thickness of ice is estimated to have been about 3,000 feet in the project area. The last ice covering the project area receded about 13,500 years ago. The distribution of sediments in the Puget Lowland is complex, because each glacial advance deposited new sediments and partially eroded previous sediments. During the intervening interglacial episodes, the complete or partial erosion or the reworking of some deposits, as well as the local deposition of other sediments, further complicated the geologic setting. 4.2 Subsurface Conditions The results of our subsurface explorations, TP-I through TP-3, indicate the general subsurface conditions across the proposed park site are underlain by a varying thickness of fill material overlying native glacial till. Fill was not encountered in TP-3. The fill material, to a depth of 2 to 3Y> feet, generally consists ofloose to medium dense, slightly gravelly, silty sands. The test pit locations were deliberately chosen to avoid excavating within future building footprints and adjacent to the site of the demolished former residence. Demolition debris was not encountered in the fill layer during excavation, but may be encountered during earthwork activities. Large concentrations of demolition debris were not encountered during exploration. However, due to the history ofthe site, which includes two residences that were demolished, it is likely that debris concentrations in the fill may be encountered across the site. The debris may include abandoned foundations, concrete and asphalt rubble, metal, bricks, wood, tree stumps, and other organic and construction debris: Underlying this surficial fill layer, the soils consist ofloose to medium dense, slightly gravelly, silty sand (weathered glacial till) approximately 2 to 3 feet thick overlying a dense to very dense, concrete-like mixture of silt, gravel, sand, and clay (glacial till). Cobbles and up to 3-foot-diameter boulders are commonly included in the matrix ofthe glacial till, though none were encountered during our explorations. 4.3 Groundwater Conditions Groundwater was not observed in the test pits during excavation. However, we observed iron oxide stains on partings and lenses, which suggest fluctuating groundwater conditions. Therefore, we anticipate that seasonal perched groundwater conditions may be present. 21-1-203 73-OO1-R I/wplLKD 21-1-20373-001 3 SHANNON &WILSON.INC. 5.0 ENGINEERING CONCLUSIONS AND RECOMMENDATIONS 5.1 General Based on our current understanding of the proposed park development project as described previously, and on the results of our geotechnical studies, we developed the following recommendations for foundation design. The following sections describe these recommendations and provide additional recommendations for site preparation, excavation, fill placement and compaction, use of on-site soil, and wet weather earthwork. 5.2 Foundation Design In our opinion, the proposed structures could be supported on conventional spread footings or on slab-on-grades with thickened edges. However, because of the depth of relatively loose soils that underlie the proposed structures, we recommend the foundation areas be overexcavated to competent soil (up to about 2 feet) and replaced with compacted structural fill. For footings bearing on densely compacted structural fill or dense, unweathered, native soil, we recommend using an allowable bearing pressure of 2,000 pounds per square foot (pst). Continuous wall footings should have a minimum width of 18 inches and column footings should have a minimum width of 24 inches. All footings should be embedded at least 18 inches below the lowest adjacent exterior grade. The allowable bearing pressure may be increased by one-third for short-term wind or seismic loads We recommend that each footinglslab excavation be evaluated by a qualified geotechnical engineer or representative during construction to confirm the presence of competent bearing soil and to determine that all unsuitable fill and organic material have been removed. 5.3 Estimated Settlement Foundations designed and constructed as recommended in this report are estimated to undergo total settlement ofless than Y, inch. Owing to the variation of footing loads and soil conditions, differential settlements are estimated to be about one-half of the total settlements between heavily loaded and lightly loaded footings or along a continuous footing for a distance of approximately 20 feet. It is anticipated that the majority of the estimated settlements would occur simultaneously as the loads are applied. 21-[-20373-001-R l/wp/I.KD 21-1-20373-001 4 SHANNON &WILSON,INC. 5.4 ; Lateral Earth Pressures' The lateral pressures against a buried wall are dependent upon many factors, including method of backfill placement and degree of compaction, backfill slope, surcharges, the type of backfill soil and native soils, drainage, and whether or not the wall can yield or deflect laterally or rotate at the top after or during placement of backfill. If the wall is free to yield at the top an amount equal to approximately 0.001 times the height of the wall, the soil pressures will be less (active case) than if this amount of movement is not allowed due to stiffness or resistance of the wall (at-rest condition). Rigid, buried walls should be designed to resist an "at-rest" lateral earth pressure based on an equivalent fluid unit weight of 55 pounds per cubic foot (pcf). Walls allowed to deflect laterally or rotate at the top should be designed using an active lateral pressure equivalent to a fluid unit weight of35 pcf. These values should be increased by I pcffor each degree of upward inclination of the backslope above the wall. The above pressures are for permanent walls and assume that proper drainage is provided behind the walls so there is no buildup of hydrostatic pressures. Backfill should not be placed behind a wall until the wall is capable of supporting lateral pressures. 5.5 Lateral Resistance Lateral loads, due to unbalanced lateral earth pressures, wind, or seismic forces, would be resisted by base friction and passive earth pressure against buried portions ofthe structure. We recommend passive earth pressures in dense, silty, gravelly sands or compacted structural fill be determined using an equivalent fluid density of 200 pcf. This value assumes that footings are founded at least 18 inches below the lowest adjacent grade and placed within neat excavations. The a,bove value includes a factor-of-safety of 1.5. We recommend that a coefficient of friction between mass concrete and dense native ground and structural fill of 0.40 be used, with an appropriate factor-of-safety to calculate the resistance to sliding. 21-1-20373-001-RI/wplLKD 21-1-20373-001 5 SHANNON &WILSON.INC. 5.6 Floor Slabs We recommend that all floor slabs be supported be densely compacted structural fill or dense native soil. If unanticipated loose. soft, or unsuitable soil is encountered in the floor sub grade preparation, it should be overexcavated and replaced with compacted structural fill. We recommend placing a capillary break consisting of at least 4 inches of washed pea gravel or 'I.-inch minus crushed gravel beneath the floor slabs. The washed pea gravel will provide positive leveling and a more uniform surface than the native soil or structural fill and will also act as a capillary break. For heated spaces or spaces with floor coverings, a vapor barrier consisting of plastic sheeting or equivalent should be plaeed on top of the washed pea gravel. As an alternative, the capillary break may consist of a 2-inch layer of washed gravel beneath a 2-ineh layer of erushed rock. The crushed rock should be compacted with a vibrating plate compactor to provide a working surface for concrete placement. We recommend using a modulus of subgrade reaction, k, of 250 pounds per cubic inch (pci) for designing floor slabs-on-grade. This design recommendation assumes that slabs-on-grade are constructed in accordance with the above recommendations. 5.7 Drainage Groundwater was not encountered in the subsurface explorations performed at the site. Therefore, the proposed structures will not require a permanent subdrain system. To control surface water, provisions should be made to direct it away from structures and prevent it from seeping into the ground adjacent to structures or excavations. The ground surface should be sloped away, and surface and downspout water should not be introduced into site backfill. Surface water should be collected in catch basins and along with downspout water, should be conveyed in a non-perforated pipe (tightline) into an approved discharge point. Except as otherwise designed and/or specifically covered in the contract, the Contractor should be made responsible for control of all ground and surface water encountered during construction. In this regard, sloping, ditching, pumping from sumps, providing trench drains, dewatering, and other measures should be employed as necessary to permit proper completion of the work. 21-1-2037J-001-RllwplLKD 21-1-20373-001 6 SHANNON &WILSON.INC. 5.8 Earthwork 5.8.1 Site Preparation and General Excavation Site preparation for excavation and fill placemerit should commence by collecting and diverting an sources of surface water flow into temporary storm drainage facilities. Each building site should be cleared of all trees, brush, and other vegetation, and should then be grubbed oflarge roots and stripped of surficial soil containing significant amounts of roots or other objectionable debris (see Section 4.2) and organic material. The material should not be mixed with soil that may be used as structural fill. Abandoned utility pipes should be plugged or removed so they do not provide a conduit for water that could cause saturation and stability problems. Based on the subsurface conditions encountered in the explorations, we anticipate that the excavations at the site could be made using conventional excavating equipment such as dozers, front-end loaders, rubber-tired backhoes, or tracked hydraulic excavators. Cobbles and possibly boulders could be encountered in dense glacial soil, and the Contractor should anticipate their presence. We recommend that all loose fill soil in the building footprint be removed. Native ground should be encountered from Y:z to 2 feet below existing ground surface. Where fins are made on a slope, the native ground upon which the fin is placed should be terraced to key the fin into the slope. We recommend that the height of each terrace not exceed 2 feet. Following stripping, grubbing, and excavation to obtain desired grades or exposed native . ground, a geotechnical engineer or engineer's representative should evaluate the density of the exposed surface. Should the presence of loose zones be revealed, they should either be removed and replaced with structural fin, or dried or moistened as required (including scarifying, mixing, and/or aeration), reworked, and adequately compacted until a dense, unyielding soil mass is produced. 5.8.2 Temporary Groundwater Control Groundwater was not encountered in the explorations performed at the site. If the earthwork occurs during the wet season, perched groundwater could be encountered. In our opinion, perched groundwater that may seep into the excavation and rainwater that fans into the 21-1-20373-00I-Rl/wplLKD 21-1-20373-001 7 SHANNON &WILSON.INC. excavation· could be controlled by means of sumps and pumps installed in the bottom of the , excavations. 5.8,3 Fill Placement, Compaction, and Use of On-site Soils All fill material placed behind walls and beneath structures or other areas where settlements are to be reduced should consist of structural fill. In general, we expect that most of the on-site soil to be excavated should be suitable for reuse as structural fill, provided the soil is free from organics, debris, and other deleterious material. The on-site soils contain significant quantities of silt and fines, such that an unstable mixture is produced under wet weather conditions; therefore, it should only be used as structural fill during dry weather. If the structural fill material is imported, it should consist of a reasonably well-graded mixture of sand and gravel that is free of organics, debris, rubbish, and other deleterious material. Structural fill material should contain not more than 20 percent fines (material passing the No. 200 mesh sieve, based on the minus %-inch fraction) for dry weather construction; the fines should be non-plastic; and the moisture content of the soil within plus or minus 2 percent of its optimum at the time of compaction. All structural fill material should have a maximum particle size of 3 inches. If earthwork takes place in wet weather or wet conditions, no matter what time of the year, the structural fill material should contain no more than 5 percent fines (see Wet Weather Considerations). Fines should be non-plastic. Except for the 5 percent fines content limit, this soil should otherwise conform to the quality and gradation characteristics of Gravel Borrow as defined in Section 9-03.14(1) (Gravel Borrow) of the current Washington State Department of Transportation! American Public Works Association (WSDOTI APW A) Standard Specifications. Prior to the placement of structural fill, any ponding water should be drained from the area. A geotechnical engineer or the engineer's representative should observe the subgrade to evaluate ifit is suitable for placing structural fill. Structural fill should be placed in uniform lifts and compacted to a dense and unyielding condition, and to at least 95 percent of the Modified Proctor maximum dry density (American Society for Testing and Materials [ASTM) D 1557). The thickness of soil layers before compaction should not exceed 8 inches for heavy equipment compactors or 4 inches for hand-operated mechanical compactors. 21-1-20]7]-OOI-RllwplLKD 21-1-20373-001 8 · '. SHANNON &WILSON.INC. 5.8.4 Wet Weather Earthwork Wet weather generally begins about mid-October and continues through about May, although rainy periods may occur at any time of year. Some of the soil at the. site contains sufficient silts and fines to produce an unstable mixture when wet. Such soils are susceptible to changes in water content, and they tend to become unstable and difficult or impossible to compact if their moisture content significantly exceeds the optimum. If earthwork at the site continues into the wet season, or if wet conditions are encountered, we recommend the following: ~ The ground surface in and surrounding the construction area should be sloped as much as possible to promote runoff of precipitation away from work areas and to prevent ponding of water. ~ Work areas or slopes should be covered with plastic. The use of sloping, ditching, sumps, dewatering, and other measures should be employed as necessary to permit proper completion of the work. ~ Earthwork should be accomplished in small sections to minimize exposure to wet conditions. That is, each section should be small enough so that the removal of unsuitable soils and placement and compaction of clean structural fill can be accomplished on the same day. The size of construction equipment may have to be limited to prevent soil disturbance. It may be necessary to excavate soils with a backhoe, or equivalent, located so that equipment does not traffic over the excavated area. Thus, subgrade disturbance caused by equipment traffic will be minimized. ~ Fill material should consist of clean, well-graded, pit-run sand and gravel soils, of which not more than 5 percent fines by dry weight passes the No. 200 mesh sieve, based on wet- sieving the fraction passing the Y<-inch mesh sieve: The gravel content should range from between 20 to 60 percent retained on a No.4 mesh sieve. The fines 'should be nonplastic. ~ No soil should be left uncompacted and exposed to moisture. A smooth-drum vibratory roller, or equivalent, should roll the surface to seal out as much water as possible. ~ In-place soils or fill soils that become wet and unstable and/or too wet to suitably compact should be removed and replaced with clean, granular soil (see part 4). ~ Excavation and placement of structural fill material should be observed on a full-time basis by a geotechnical engineer (or representative) experienced in earthwork to determine that all work is being accomplished in accordance with the project specifications and our recommendations. ~ Grading and earthwork should not be accomplished during periods of heavy, continuous rainfall. .21-1-20J73-OO1-Rl/wp/LKD 21-1-20373-001 9 SHANNON &WILSON.INC. We suggest that these recommendations for wet weather earthwork be 'included in the contract specifications. 5.S.5 Erosion Control The Contractor should employ proper erosion control measures during construction. especially if construction takes place during wet weather. Covering work areas, soil stockpiles, or slopes with plastic, sandbags, sumps, and other measures should be employed as necessary to permit proper completion of the work. Bales of straw, geotextile silt fences, and drain inlet sediment screens/collection systems should be appropriately located to control soil movement and erosion. 6.0 CONSTRUCTION CONSIDERATIONS 6.1 Obstructions Unanticipated conditions are commonly encountered and cannot be fully determined by merely taking soil samples or making explorations. Although not encountered in the explorations, cobbles and boulders are commonly found in glacial soils and should be anticipated at the site. These obstructions would impact excavations. Such unexpected conditions frequently require that additional expenditures be made to achieve a properly constructed project. Some contingency fund is recommended to accommodate such potential extra costs. 6.2 Loose Test Pit Backfill Test pits dug to explore the site were loosely backfilled. If a test pit falls in an area that will not be overexcavated below the boitom of the test pit, the loose soil should be removed dunng construction and replaced with compacted structural fill. 7.0 LIMITATIONS This report was prepared for the exclusive use of l.A. Brennan Associates, Inc. and other members of their design team to assist in the design and construction of the Heather Downs Park 21-1-20373-00I-Rl/wplLKD 21-1-20373-001 10 SHANNON &WJLSON.INC. Development project. The analyses, conclusions, and recommendations contained in this report are based on site conditions as they presently exist and on the site and project descriptions as presented herein. We should be notified if differences are identified. We assume that the exploratory test borings and retrieved samples are representative of the subsurface conditions throughout the site; i.e., the subsurface conditions everywhere are not significantly different from those disclosed by the explorations. During construction, if subsurface conditions different from those described in this report are observed or appear to be present during construction, we should be advised at once so that we can review these conditions and reconsider our recommendations, where necessary. If conditions have changed due to natural causes or construction operations at or adjacent to the site, it is recommended that this report be reviewed to determine the applicability of the conclusions and recommendations considering the changed conditions and time lapse. Within the limitations of the scope, schedule, and budget, the analyses, conclusions, and recommendations presented in this report were prepared in accordance with generally accepted professional geotechnical engineering principlcs and practice in this area at the time this report was prepared. We make no other warranty, either express or implied. These conclusions and recommendations were based on our understanding of the project as described in this report and on site conditions as observed at the time of the exploration. The scope of our services for this project did not include any environmental assessment or evaluation regarding the presence or absence of wetlands or hazardous or toxic materials in the soil, surface water, groundwater, or air, on or below or around the site, or for the evaluation or disposal of contaminated soils or groundwater, should any be encountered. However, we will be glad to provide such services on request. 21-1-20J73-00I-Rl/wp/lKD 21-1-20373-001 1 1 SHANNON &WILSON.INC . . Shannon & Wilson has prepared and included in Appendix B, "Important Information About Your Geotechnical Report," to assist you and others rn understanding the use and limitations of our reports. SHANNON & WILSON, INC. Thomas M. Gurtowski, P.E. Vice President JXM:TMG/met 21.1-2037J-OOI-RJlwpfLKD 21-1-20373-001 12 .' I M ~AI!}~.~ S~iety for TeSting and Materials (ASTM), 20<J4f ,o\ruiltia1 book of standards, .g61!1Struction"v. 4.08, Soil and rock (I): D 420 -Conshohocken, Pa. Stat!} Department of Transportation and 'Anim~ ,Standard specifications for road, bridge, arid mp;ijI-pi ' ~blic Works Association, 20<14, ¢cOrjl;tiuction (M41-1 0) •. o I 1/4 I 112 I Scale in Miles NOTE Reproduced with permission granted by THOMAS BROS. MAPS®. This map is copyrighted by THOMAS BROS. MAPS®. It is unlawful to copy or reproduce all or any part thereof, whether for personal use or resale, without permission. All rights reserved. Heather Downs Park Development City of Renton Renton, Washington VICINITY MAP' J N I File: J:\211\20373-001\21-1-20373-001 TPs,dwg Date: 10-05-2005 Author: SAC SHANNON & WILSON, INC. JOB NO: 21-1-20373-001 DATE: 9-29-2005 LOCATION: See Site and Exploration Plan Geotechnical and Environmental Consultants LOG OF TEST PIT TP-2 PROJECT: Heather Downs Park Development, City of Renton ~-U) u: Sketch of East Pit Side Surface Elevation: Approx. 411 Ft. "C ~ '" c: '" c: '" -'" c. ~ SOIL DESCRIPTION :0-Ol-E 0'" ~ § -Horizontal Distance in Feet c. c'3~ Ol '" *U (f) 0 0 1 2 3 4 5 6 CD Medium dense, brown, slightly fine o • U~ )~J)l(~)~~~~ffi)·l(hz)~J)J4)~jUA~)~jU~) gravelly, silty, fine to coarse SAND; dry: occasional rootlets; (Fill) SM. "C 16~pvc Drain Pipe '" CD Loose to med'ium dense. rust c: '" U) orange, slightly fine gravelly, silty .0 CD fine SAND; moist; occasional 0 ,1 f-cl .' . '" rootlets; (Weathered Till) SM. c: ,1",:::.,_/"",.:>,/'>:--" . 0 ~ z i I I Medium dense to dense. light gray , 10 I I to tan. slightly Silty. slightly gravelly, I , fine SAND; moist; becomes more S-1 2 moist with depth; (Glacial Till) SP-SM. 3 CD ... NOTE Bottom of Test Pit at 8 feet. S-2 4 I--5 -. . . "T'I G'l Ii > 0 W S-3 6 . I File: J:\211120373-001121-1-20373-001 TPs.dwg Date: 10-05-2005 Author. SAC SHANNON & WILSON, INC. Geotechnical and Environmental Consultants JOB NO: 21-1-20373-001 DATE: 9-29-2005 LOCATION: See Site and Exploration Plan LOG OF TEST PIT TP-3 PROJECT: Heather Downs Park Development, City of Renton "O,-Q>c '" Ii Sketch of East Pit Side Surface Elevation: Approx. 408 Ft. Q) I§Srn~ Q. ~ SOIL DESCRIPTION e ~ ~ § E Horizontal Distance in Feet '" Q) 5 6 (!) ;::;g 0 en Cl 0 1 3 4 0 \ CD Very loose to loose, tan to light I~ brown. silty fine SAND: dry: occasional organics: (Weathered "0 Q) Till). i:: I~ Q) CD '" Very dense, light gray to tan, .0 0 slightly gravelly, slightly silty, fine Q) I (I SAND; dry; (Glacial Till) SP-SM. c 0 Z , ' I· / ! . '. , \ ! / \ Tree and Blackberry Roots S-1 2 3 CD S-2 I 4 5 I ." G') > J,.,I I S-3 , 6 AP~ENDIXA FIELD EXPLORATIONS TABLE OF CONTENTS SHANNON &W1LSON.INC. Page A.I GENERAL.. ..................................................................................................................... A-I A.2 TEST PITS ....................................................................................................................... A-I LIST OF FIGURES Figure No. A-I Unified Soil Classification and Log Key (2 sheets) A-2 Log of Test Pit TP-I A-3 Log of Test Pit TP-2 A-4 Log of Test Pit TP-3 21-1-20373-001 -R I-ANwplLKD 21-1-20373-001 A-i SHANNON &W1LSON.INC. APPENDIX A, FIELD EXPLORATIONS A.l GENERAL The field explorations were accomplished to obtain subsurface information for our geotechnical studies for the proposed park development project at 233 Union Avenue NE in Renton, Washington. Field explorations perfoffiled for this project consisted of excavating and sampling three test pits at the site. The test pit locations were selected based on our understanding of the site layout of the proposed buildings. The approximate locations of the explorations are shown in the Site and Exploration Plan (Figure 2) in the main text of the report. The test pits were located in areas accessible to the equipment adjacent to where future structures are anticipated. The approximate locations and elevations of the three test pits were determined by field measuring from existing site features and estimating elevations from a topographic survey provided by I.A. Brennan Associates, Inc. These locations and elevations should be considered approximate. All the test pit locations and elevations should be considered accurate to the degree implied by the method used. A.2 TEST PITS Three test pits, designated TP-I through TP-3, were excavated adjacent to the proposed building locations using a rubber-tired backhoe provided and operated by the City of Renton Parks Department. The test pits were excavated on September 29, 2005. The test pits depths ranged from 4 to 8 feet below existing ground surface. A geologist from our finn observed the excavation of the test pits, estimated soil density, obtained representative soil samples, and prepared a descriptive log of each test pit in the field. Each soil sample was classified according to a modified version of the Unified Soil Classification System (USCS), which is presented on the Soil Classification and Log Key (Figure A-I). The relative soil densities or consistencies orthe exposed soils were estimated based on probing the sides and bottom of the test pits with a Y2-inch-diameter, steel T-bar, where practical, and by evaluating the relative ease or difficulty of the excavation. The relative densities are included in the descriptions shqwn on the test pit logs, presented in this appendix as Figures A-2 through 21-1-20373-OO1-R I-ANwp/lKD 21-1-20373-001 A-I l SHANNON &W1LSON.INC. A-4. After completion of excavating and sampling, all test pits were100sely backfilled with excavated S6il and nominally compacted with the excavator bucket.' Where observed, groundwater seepage into the tcst pit was noted during excavation. The quantity of groundwater seepage into the test pit during the excavation was based on a visual estimate. The test pit logs for the proposed project are presented as Figures A-2 through A-4 in this appendix. A test pit log is a written record of the subsurface conditions encountered. It graphically illustrates the soil units (layers) encountered in the test pit. Other information shown on the test pit logs includes groundwater seepage, groundwater level (if any), types and depths of sampling, and potential obstructions. 21-1-20373·001-RI-AAiwp/LKD 21-1-20373-001 A-2 Shannon & Wilson, Inc. (S& W), uses a soil GRAIN SIZE DEFINITION classification system modified from the Unified DESCRIPTION SIEVE NUMBER AND/OR SIZE Soil Classification System (USCS). Elements of Ihe USCS and other definitions are provided on ,FINES < #200 (0.08 mm) this and the following page. Soil descriptions , are based on visual-manual procedures (ASTM SAND' o 2488-93) unless otherwise noted. -Fine #200 to #40 (0.08 to 0.4 mm) -Medium #40 to #10 (0.4 to 2 mm) -Coarse #10 to #4 (2 to 5 mm) S&W CLASSIFICATION GRAVEL' OF SOIL CONSTITUENTS -Fine #4 to 3/4 inch (5 to 19 mm) • MAJOR constituents compose more than 50 -Coarse 314 to 3 inches (19 to 76 mm) percent, by weight, of the soil. Major consituents are capitalized (i.e., SAND). COBBLES 3 to 12 inches (76 to 305 mm) • Minor constituents compose 12 to 50 percent BOULDERS > 12 inches (305 mm) of the soil and precede the major constituents (Le., silty SAND). Minor constituents • Unless othel'1Nise noted, sand and gravel, when preceded by "slightly" compose 5 to 12 present, range from fine to coarse in grain size. percent of the soil (i.e., slightly silty SAND). • Trace constituents compose 0 to 5 percent of RELATIVE DENSllY I CONSISTENCY the soil (i.e., slightly silty SAND, trace of gravel). COARSE-GRAINED SOILS FINE-GRAINED SOilS N, SPT, RELATIVE N, SPT, RELATIVE MOISTURE CONTENT DEFINITIONS BLOWS/FT. DENSllY BLOWSIFT. CONSISTENCY Dry Absence of moisture, dusty, dry 0-4 Very loose Under 2 Very soli to the touch 4 -10 Loose 2-4 Soli 10 -30 Medium dense 4-8 Medium stiff Moist Damp but no visible water 30 -50 Dense 8 -15 Stiff Wet Visible free water I from below Over 50 Very dense 15 -30 Very stiff water table Over 30 Hard ABBREVIATIONS WELL AND OTHER SYMBOLS ATD At Time of Drilling ~ Bent. Cement Grout E~~~ Surface Cement Elev. Elevation Seal II feet D Bentonite Grout -Asphalt or Cap FeO Iron Oxide 1m t:.~?1 MgO Magnesium Oxide Bentonite Chips Slough HSA Hollow Stem Auger D Silica Sand ~ Bedrock ID Inside Diameter in inches rn::J PVC Screen Ibs poundS rn Mon. Monument cover Vibrating Wire N Blows for last two 6-inch increments NA Not applicable or not available NP Non plastic 00 Outside diameter ~ OVA Organic vapor analyzer " 0 PID Photo-ionization detector § ~ ppm parts per million 0 " PVC Polyvinyl Chloride ~ Heather Downs Park Development w SS Split spoon sampl'er Renton, Washington ~ 00 SPT Standard penetration test ~ " USC Unified soil classification ,.; ~ WLI Water level indicato'r SOIL CLASSIFICATION ~ 0 ":"! AND LOG KEY ;; ;;; 00 ~ October 2005 21-1-20373-001 " " SHANNON & WILSON, INC. I FIG. A·1 z " Geotechnical eM Environmental ConsUltants Sheel1 of 2 0 m ::l S u COARSE- GRAINED SOILS (more than 50% retained on No. 200 sieve) UNIFIED SOIL CLASSIFICATION SYSTEM (USCS) (From ASTM D 2487·98 &2488-93) 'I' GW Clean Gravels .~ , 1Tr-'''AL ",un Well-llraded oravels, oravels, graveTlsand rt"tlxlures,liHle or no fines (less than 5% :l ~ ~, Poorly graded gravels, gravel·sand" mixtures, little or no fines Gravels lines) GP {l)~~ (more than 50% ,-_____ + ___ H .. u;ii;,r+-____________ ----j of coarse t" fraction retained on NO.4 sieve) Gravels with GM Silty gravels, gravel-sand-silt mixtures Fines l---i~,.tt-------------j (more than 12% I fines) GC SW v...... Cl,ayey gravels, gravel-sand-clay ~ mixtures ::::::::: Well.graded sands, gravelly sands, :::::;::: little or no fines . ',: .-:,: Clean Sands (less than 5% fines) Poorly graded sand, gravelly sands, little or no fines Sands SP (.'.::,:.: (50% or more of 1--------l----J:".>iT''F.II---------------J coarse fraction passes the NO.4 sieve) Silts and Clays (liquid limit less than SO) Sands with r~S:M~l·~' ~~rS~il:ty:s:a~nd:s:,:s~a:nd:-~si:lt:m:ixt:ur:e:s::_l Fines ", (more than 12% fmes) SC Clayey sands. sand-clay mixtures ML Inorganic CL ~~~ 'If~~i.' ;~~~~;YI~l . ~ silts, or clayeY-sills -;J;;Tti slight Inorganic clays of low to medium plasticity, gravelly clays, sandy clays, silty clays,-Iean clays FINE·GRAINED l ______ L~o::rg~a:n:ic~JL~o~L:...-~I-~~ -·2 -~o:r~ga~n~ic~s~i:lts~a=n=d-o=r=ga=n-ic=s=i~lty~c=la=ys~o_fj SOILS low plasticity (50% or more passes the No. 200 sieve) HIGHLY- ORGANIC SOILS Silts and Clays (liquid limit 50 or more) Inorganic Organic Primarily organic matter, dark in color. and organic odor NOTE: No.4 size::; 5 mm; No. 200 size = 0.075 mm MH CH OH PT 1. Dual symbols (symbols separated by a hyphen, i.e., SP·SM, s/ighlly silty fine SAND) are used for soils with between 5% and 12% fines or when the liquid limit and plasticity index values plot in the CL-ML area of the plasticity chart. . Inorganic silts, micaceous or diatomaceous fine sands or silty soils. elastic silt Inorganic cla~ or medium to high plastiCity, saridy fat clay, or gravelly (at clay .- Organic clays of medium 10 high plasticity, organic silts - Heather Downs Park Development Renton, Washington SQIL CLASSIFICATION AND LOG KEY October 2005 21-1-20373-001 ~ SHANNON & WILSON, INC. FIG. A·1 O Geotechnical and Environmental Consullants S I 2 2. Borderline symbols (symbols separated by a slash, i.e., CUML silty CIA Y/clayey SILT; GWISW, sandy GRA VEUgravelly SAND) indicate that the soil may fall into one of two possible basic groups. mL. ________________________________________________________ L-__________________________ ~~~~~t~2~O~ __ --' File: J:\211\20373-001\21·1·20373..(J01 TPs.dwg Date: 10"()7·2005 Author. SAC SHANNON & WILSON, INC. Geotechnical and Environmental Consultanm LOG OF TEST PIT TP-1 ~-'" 'C ~ .l!l <::: ., I <::: ., ~~ c. SOIL DESCRIPTION =>-E c3~ 0 '" c!.u rn CD Medium dense, rust brown, slightly gravelly, silly, fine 10 medium SAND; dry to moist; (Fill) SM. ijJ ® Loose to medium dense. gray. ~ ., '" round gravel; dry; (Fill) GPo .c 0 0 Medium dense to ~ery dense. light Q) <::: brown to gray, slightly gravelly, 0 Z slightly silly SAND; moist; (Weathered Till) SM. CD Dense, light gray, slightly silly. slightly gravelly, fine to ooarse I S-l SAND; moist; (Glacial Till) SP-SMo S-2 ." ~ l> NI I S-3 , " ' JOB'NO: 21-1-20373-001 DATE: 9-29-2005 LOCATION: See Site and Exploration Plan PROJECT: Heather Downs Park Development, City of Renton U:I Sketch of ~ Q. ., OJQ 0 1 North Pit Side Surface Elevation: Approx, 413 Ft. Horizontal Distance in Feet 1 2 , ~')' (fA' )\ I~ l " , 'Rootlets' j .J . l. . . . . \ '--!I ' . 0 3 CD Ihcised Fill' o I i 6 b ., .. ~ . . . . .. 4 ----,---_'--.. __ n, __ •• _ ... _ ..... _-j-_ ~ .. _. ___ .... ___ _ . . .. 5' 8) 6 File; J:\211\20373-001\21.1·20373-001 TPs.dwg Date: 10·05.2005 Author: SAC __ SHANNON & WILSON, INC. Geotechnical and Environmental Con,ultanb LOG OF TEST PIT TP-2 G) o 0) I !! C') ~I SOIL DESCRIPTION Medium dense, brown, slightly fine gravelly, silty, fine to coarse SAND: dry: occasional rootlets: (Fill) SM. Loose to medium dense, rust orange, slightly fine gravelly, silty fine SAND: moist; 'occasional rootlets; (Weathered Till) SM. Medium dense to dense, light gray to tan, slightly silty, slightly gravelly, fine SAND; moist; becomes more moist with depth; (Glacial Till) SP-SM. NOTE Bottom of Test Pit at 8 fee!. 'O~ <= Q) :>-0~ '0 ~ Q) en .0 a Q) <= o Z ~­Q) <= caS ~ 5 *,u :g :a E ra en S-1 S-2 JOB NO: 21-1-20373-001 DATE: 9-29-2005 LOCATION: See Site and Exploration Plan PROJECT: Heather Downs Park Development,City of Renton ;i Sketch of East Pit Side Surface Elevation: Approx. 411 Ft. t ~ 10 1 2 Horizontal Distance in Feet 3 011' . : .. . . Rootlets . J .• \./. r/t<· )\ . I '~'k ).\... ..... ,'-', ... -PVC Drain Pipe G) 2 CD 41-··~·-· 5 I I I ® S-3 6 File: J;\211\20373-001121-1-20373-001 TPs.dwg Date: 10-05-2005 AulhQr: SAC .... SHANNON.·& WILSON, INC. Geotechnical and Environmental Consultants LOG OF TEST PIT TP-3 SOIL DESCRIPTION CD Very loose to loose, tan to light brown, silty fine SAND; dry; occasional organics; (Weathered Till). CD Very dense, light gray to tan, slightly gravelly, slightly silty, fine SAND; dry; (Glacial Till) SP-SM. I "T1 5 tl "0 ~ c: OJ ::J-~~ ~ Q) III .0 o Q) c: o Z ~-Q) c: -OJ "'-3: c: . 0 *,u III Q) a. E '" rJl JOB NO: 21-1-20373-001 DATE: 9-29-2005 LOCATION: See Site and Exploration Plan PROJECT: Heather Downs Park Development, City of Renton iii .c a. ~ 10 Sketch of 1:: ......... ~a~~ Pit Side Surface Elevation: Approx. 408 Ft. 1 \ Horizontal Dislance in Feet 2 3 4 i\ I Tree and Blackbeny Roots r;r 8-1 I 2 3 CD S-2 I 4,,···· 5 , , . I •.. S-3 6 6 DevaQPMe CITY oF~f:rt!/l4ING MAR -2 200s RECEIVED New Park at Northeast Third Court and Union Avenue Northeast Renton, Washington TECHNICAL INFORMATION REPORT 1 ----- d·',1 Consulting Engineers 1601 Fifth Avenue, Suite 1600 Seattle, WA 98101 Prepared by: Katie Herold KPFF Proiecf No. 105166. 10 February 27, 2006 New Pork at Northeast Third Court and Union Avenue Northeast Renton, Washington Technical Information Report TABLE OF CONTENTS Page SECTION 1-PROJECT OVERViEW .... . . .................................................... 1 Pre-developed Site Conditions .... . . ............................................................................... 1 Developed Site Conditions......... . ................................................................................ 1 SECTION 2 -CONDITIONS AND REQUIREMENTS SUMMARY .................................................. 2 Core Requirements ............. ............ . ........................................................................ 2 SECTION 3 -OFF-SITE ANALYSIS ..... ............................................................ 3 SECTION 4 -FLOW CONTROL AND WATER QUALITY FACILITY ANALYSIS AND DESIGN ........... 3 Part A -Existing Site Hydrology ..... Port B -Developed Site Hydrology. . ............................................................................. 3 . ........................................... 4 Part C -Performance Standards ........................................................................... . . ...... 5 Part D -Flow Control ............... . . .............................................................................. 5 SECTION 5 -CONVEYANCE SYSTEM ANALYSIS AND DESIGN ........................................... 5 SECTION 6 -SPECIAL REPORTS AND STUDIES. ..... .............................................................. 5 SECTION 7 -OTHER PERMITS....... .......... ... ...................................................................... 6 SECTION 8 -EROSION AND SEDIMENT CONTROL ANALYSIS AND DESIGN ............................ 6 SECTION 9 -BOND QUANTITIES, FACILITY SUMMARIES, AND DECLARATION OF COVENANT. 6 SECTION 10-OPERATIONS AND MAINTENANCE MANUAL .................................................... 6 KPFF Consulting Engineers February 28, 2006 New Pork at Northeast Third Court and Union Avenue Northeast Renton, Washington SECTION J -PROJECT OVERVIEW T echnicaJ Jnformation Report The new park at Northeast Third Court and Union Avenue Northeast is 0 proposed public park to include a play field, walking trail, basketball court, play structures, picnic facilities, public restroom, and parking for six vehicles. The site is 9.18 acres but the proposed project will only impact 6.38 acres of the site. The site address is 233 Union Avenue Northeast located in Renton, Washington. PRE-DEVELOPED SITE CONDITIONS The existing site is 100 percent pervious with forest and pasture groundcavers except for a small decomposed gravel road. The site is split up into three threshold drainage basins. The northwest basin sheet flows drainage to the north ond northwest. On the north side of the site, droinage sheet flows into the curbline of Northeast Third Court where it is collected in catch basins and conveyed westerly. Drainage also sheet flows across the site to the west and onto the adjacent property where it is collected in catch basins. The northeast basin sheet flows to the east and into the starm drainage system in Union Avenue Northeast where it continues northerly. The majority of the site is contained in the southwest basin which sheet flows in a westerly direction onto the adjoining property to the west where it is collected in catch basins. DEVELOPED SITE CONDITIONS The developed site will mostly consist of pervious surfaces with some new impervious surfaces consisting of new sidewalk and paved paths, a poved plaza, a small parking lot, and a restroom and picnic shelter. The new on-site improvements will cover approximately 6.38 acres. The developed condition drainage maintains the three pre-developed threshold basins. The northwest basin consists of grass, asphalt pathways, part of the sport field, and the unmodified forested area. The northwest basin sheet flaws to the northwest, same of the drainage entering the catch basins in Northeast Third Court and some of it sheet flowing to the property to the northwest and into catch basins in their parking lot. The northeast basin consists of grass, sidewalk, and the proposed parking lot. The drainage sheet flows into Union Avenue Northeast where it is collected and conveyed into catch basins in the street. The southwest basin contains the plaza area, sidewalks, playgrounds, half the sport fields, and the remaining pervious grass and existing forested areas. The plaza and playground drainage is collected in catch basins and tight-lined to the west where it term',nates in a flow dispersion trench that reintroduces the storm drainage into a sheet flow condition across the undisturbed forested area of the site. The remainder 01 the southwest basin sheet flows across the site before discharging on to the adjacent property to the southwest as in the pre-developed condition. KPFF ConsuJtlng Engineers February 28, 2006 New Park at Norlhea.st Third Court and Union Avenue Norlheo.st Renfon, Wa.shington SEQION 2 -CONDITIONS AND REQUIREMENTS SUMIvlARY CORE REQUIREMENTS o Core Requirement No.1 -Discharge at the Natural Location Technical information Report The manner in which drainage is discharged from the site is maintained from the pre-developed to the developed condition. Currently drainage is un-concentrated and sheet flows onto the adiacent properties and into the streets. The developed condition will also be un-concentrated discharge across the property line and into the streets. Drainage will not be significantly added to, or diverted from, the pre-developed threshold discharge areas. o Core Requirement No.2 -Off-Site Analysis The downstream conditions have been reviewed and determined to be stable. o Core Requirement No.3 -Flow Conlrol This proiect is exempt from implementing flow conlral using the exemptions listed in the 1990 King County Surface Water Design Manual (KCSWDM). o Core Requirement No.4 -Conveyance System The conveyance system was designed to meet the 2005 KCSWDM Core Requirements for new pipe systems. The system was designed to convey the 25-year storm without overtopping any catch basins. o Core Requirement No.5 -Erosion and Sediment Control The erosion and sediment control plan was designed per the requirements in Appendix D of the KCSWDM. • Care Requirement No.6 --Maintenance and Operations The City of Renton Community Services or their designee will maintain allan-site drainage facilities. The City of Renton Public Works will maintain drainage facilities in the right-of-way. o Core Requirement No.7 -Financial Guarantees and Liability Guarantees and liability issues will not be required, as the City of Renton Community Services owns the facility and will be maintaining it. o Core Requirement No.8 -Water Quality The proieel proposes to add less than 5,000 square feet of pollution generating impervious surfaces, thus will not require water quality treatment. o Special Requirements None of the five special requirements apply to this proposal. KPFF Con.sultlng EngIneers 2 February 28, 2006 New Park at Northeast Third Court and Union Avenue Northeost Renton, Washington SEalON 3 -OFF-SITE ANALYSIS T echn/callnformation Report The downstream conditions for the proposed new park development have been evaluated and determined to have no identifiable problems. The extent of the study extended downstream for 1 14-mile from the discharge points. The downstream was evaluated for the three primary discharge basins from the site. The small basin draining to Union Avenue Northeast is conveyed in underground pipe northward to Northeast Fourth Street. There are no known problems with this system as the conveyance system appears to be sized appropriately for the flows and there are no opportunities for erosion and no flooding problems. The northwest basin drains into an underground pipe storm drainage system and is conveyed westerly through the adjacent apartment complex over to the cemetery. The site storm woter discharges onto paved surfaces and then directly into catch basins and underground piping so there is no erosion opportunity. There are no known problems with this conveyance system and no flooding issues. The southwest bosin sheet flows onto the adiacent properly where it is immediately collected in catch basins and conveyed in underground pipes through the properly in a southwesterly direction. There are no known problems with this conveyance system, no erosion problems, and no flooding issues. SEalON 4 -FLOW CONTROL AND WATER QUALITY fACIUTY ANALYSIS AND DESIGN PART A -EXISTING SITE HYDROLOGY In its current condition, the site cover primarily consists of forest and pasture surfaces with two small gravel driveways. Currently the site can be divided into three different threshold discharge areas. The northwest basin consists 012.2 acres of pasture, forest, and a small amount 01 gravel sloping to Northeast Third Court and the adiacent property to the northwest. The slopes in this basin range from 1 to 25 percent. The southwest basin consists of 6.53 acres of pasture, forest, and gravel gently sloping to the southwest. The slopes range from 3 to 25 percent. The northeast basin consists of 0.46 acres of pasture, forest, and gravel, which slopes out to Union Avenue Northeast and is collected in existing catch basins. The slopes in this basin range from 1 to 16 percent generally in an easterly direction. See Appendix A, Figure 4 for an existing conditions map. There used to be a single-family residence on the central easterly quarter of the site. In that area, a layer of fill material, approximately 2 feet deep, has been placed. Underlying the fill, there is approximately 2 to 3 feet of weathered glacial till overlying non-weathered glacial till. Also in this area, there are two old gravel roads that have been weathered over time. The forest and pasture areas have an organic topsoil overlying the till layers. The Sail Conservation Service soils map shows the site as AgC, which is Alderwood gravely sandy loam with 6 to 15 percent slopes, (Appendix A, Figure 3). KPFF Consulting Engineers 3 February 28, 2006 New Park at Northeast Third Court and Union Avenue Northeast Renton, Washington The Pre-developed Basin Characteristics are as follows: Northeast Basin Gravel Road = 0,013 acres Pasture = 0.096 acres Forest = 0.346 acres Northwest Basin Gravel Road = 0.1 acres Pasture = 1.031 acres Forest = 1,065 acres Southwest Basin Gravel Road = 0,032 acres Pasture = 1 .88 acres Forest = 4.617 acres PAAT B -DEVELOPED SITE HYDROLOGY T echnicol'nformotion Report The developed site maintains the same three threshold basins as the exiting conditions. The northeast basin consists of the parking lot, grass areas, and some sidewalk that sheet flows into Union Avenue Northeast and into the existing storm drainage system. The northwest basin consists of grass, unmodified forested areas, and some sidewalk, which sheet flows to the existing storm drainage system in Northeast Third Court and the adjacent property to the northwest. The southwest basins consist of grass, unmodified forest, sidewalk, and plaza areas. The plaza area and play areas are being collected in new catch basins and conveyed to a flow dispersion trench to allow the drainage to flow un-concentrated through the forested area to match the existing drainage patterns. See Appendix A, Figure 5 for a developed conditions map and area breakdowns. The developed basin characteristics are as follows: Northeast Basin Impervious = 0.147 acres Grass = 0,364 acres Northwest Basin Impervious = 0.144 acres Grass = 1 .465 acres Forest = 0.855 acres Southwest Basin Impervious = 0.49 acres Grass = 3.65 acres Forest = 2.07acres KPFF Consulting Engineers 4 February 28, 2006 New Pork at Northeast Third Couri and Union Avenue Nor1heast Renton, Washington PART C -PERFORMANCE STANDARDS T echnicallnformotjon Report Per the City of Renton's direction, the site characteristics are to be evoluated to determine if flow control is required by reviewing the exemptions to flow control as described in the 1990 KCSWDM. The conveyance system has been designed to convey the 25-year storm without overtopping any structures. Water quality is not required because the project adds less than 5,000 square feet of pollution generating impervious surfaces. PART D -FLOW CONTROL Each basin was evaluated to determine if it met any of the exemptions to flow control as described in the 1990 KCSWDM. The manual states that if your increase in 100-year peak flow rate is less than 0.5 cfs from existing to developed conditions then flow control is not required. Each basin was under the 0.5 cfs increase in flow rate, thus meeting the flow control exemption. The basins were evaluated using Santa Barbara Urban Hydrograph method with StormShed. Please see Appendix B for a detailed basin analysis. The 1 OO-year peak flaw rates from pre-developed to developed is as follows: Northeast Basin Pre-developed = 0.12 cfs Developed = 0.19 cfs Northwest Basin Pre-developed = 0.34 cfs Developed = 0.51 cis Southwest Basin Pre-developed = 1 _ 1 cis Developed = 1 .37 cfs SECTION 5 -CONVEYANCE SYSTEM ANALYSIS AND DESIGN The new on-site conveyance system was sized using the backwater calculations spreadsheet. The conveyance system was sized to convey the 25-year storm without overtopping the catch basins. The conveyance and backwater calculations spreadsheet is provided in Appendix B. SECTION 6 -SPECIAL REPORTS AND STUDIES The geotechnical report is provided in Appendix C. KPFF Consulting Engineers 5 February 28, 2006 New Park at Northeast Third Court and Union Avenue Northeast Renton, Washington SECTION 7 -OTHER PERMITS Technical Information Report Washington State Department of Ecology National Pollutant Discharge Elimination System Permit, SECTION 8 -EROSION AND SEDIMENT CONTROL ANALYSIS AND DESIGN The erosion and sediment control plan was designed using Appendix D of the KCSWDM, The primary sediment control will be through filter fabric fence along the downhill sides of the perimeter, SECTION 9 -BOND QUANTITIES, FACILITY SUMw.RIES, AND DECLARATION OF COVENANT A bond quantities worksheet is not required, A storm water facility summary sheet does not apply since there are no flow control facilities or waler quality facilities, A declaration of covenant is not applicable. SECTION) 0 -OPERATIONS AND MAINTENANCE MANUAL The on-site drainage facilities will be maintained by the City of Renton, KPFF Consulting Engineers 6 February 28, 2006 Appendix A • TIR Worksheet • Vicinity Map • SCS soils Map • Existing Basins Map • Developed Basins Map King County Department of Development and. Environmental Services TECHNICAL INFORMATION REPORT (TIR) WORKSHEET Part 1 PROJECT OWNER AND PROJECT ENGINEER projec? Owner U'8 Q Rc:1lft,1\. Cnll!mu.nl~ $cYVIC.t..& Address I 0 5 5 S, 6~ IAI"M I Rell m .... IV/\ '1 ~ s:! Phon) ellS '130-# 17 Project EngineiJ,. f{tb.f:l~ He. ~ Company KPFF{"1\5"'~" Erhe'tfS Address/Phone ,/.0, 5t'\Av~ S ... • /600 Seo.Hf ..• wA "!'lrID' Part 3 TYPE OF PERMIT P APPLICATION Subdivison Short Subdivision @adinV Commercial Other Part 2 PROJECT LOCATION AND DESCRIPTION Project Name & .... &.k .... HIE 3.J. ColActQ.!lJ. IAoIIbv...Avc IV£ Location Township .23 N jJ; IJ~ o~ Range ~5l.!E,,-___ _ -Y.~!'!i . .of ... Section -'..'.=.6 ____ _ NS '/., art 4 OTHER REVIEWS AND PERMITS DFW HPA COE404 DOE Dam Safety FEMA Floodplain COE Wetlands Shoreline. Management Rockery Structural Vaults Other PartS SITE COMMUNITY AND DRAINAGE BASIN Community BIU:l.t~[\. I ; Wt.!..5 h /1) 3 to!\... Drainage Ba.:t. LI2l.I1~ ~, i: R; llf.~ Part 6 SITE CHARACTERISTICS River Stream __________ _ Critical Stream Reach Depressions/Swales Lake ___________ _ Steep Slopes Floodplain ________ _ " Wetlands 11m. "'"O...J. ... +-e.A Seeps/Springs High Groundwater Table Groundwater Recharge Other _________ _ Part7 SOILS Soil Type Slopes Erosion Potential Erosive Velcoties .tide l'I&I po J lI\II1\1e)y L (X)._)Y\. __ ",-6_-.:...1 5",--,--;t=-. ij rJ /. ol))-a..V(~ Additional Sheets Attached Part 8 DEVELOPMENT LIMITATIONS REFERENCE Ch. 4 -Downstream Analvsis Additional Sheets Attached Part 9 ESC REQUIREMENTS MINIMUM ESC REQUIREMENTS DURING CONSTRUCTION Sedimentation Facilities l\ Stabilized Construction Entrance 'I.. Perimeter Runoff Control X Clearing and Graing Restrictions X Cover Practices Construction Sequence Other LIMITATION/SITE CONSTRAINT Y1.OYl ~ MINIMUM ESC REQUIREMENTS AFTER CONSTRUCTION J< Stabilize Exposed Su rface X. Remove and Restore Temporary ESC Facilities J( Clean and Remove All Silt and Debris x.. Ensure Operation of Permanent Facilities Flag Limits of SAO and open space preservation areas Other Part 10 SURFACE WATER SYSTEM Grass Lined Tank Infiltration Method of Analysis Channel Vault Depression )(Pipe System Energy Dissapator )<. Flow Dispersal CompensationlMitigati on of Eliminated Site Open Channel Wetland Waiver Storage Dry Pond Stream Regional Wet Pond Detention Brief Description of System Operation Dre\'~ At" colic ~f .. J 11'1. ,,,1-c6 bo..s "II\S c::I\f\cl ~I~~ fo 4.. r/ow d's,eeys<t\ rrenck. I~to fi> Y6 feJ... MeA.... Facility Related Site Limitations Reference Facility Part 11 STRUCTURAL ANALYSIS Cast in Place Vault Retaining Wall Rockery > 4' High Structural on Steep Slope Other Limitation Part 12 EASEMENTStrRACTS Drainage Easement Access Easement Native Growth Protection Easement Tract Other Part 13 SIGNATURE OF PROFESSIONAL ENGINEER lor a civil engineer under my supervision my supervision have visited the s~e. Actual site cond~ions as observed were incorporated into this worksheet and the attachments. To the best of my knowledge the information provided here is accurate. Consulting Engineers 1601 Fifth Ave, Suite 1600 Seattle, WA 9810' (206) 622-5822 Fax (206) 622-8130 DAlE OWN. BY L--_______ L.-_" ___ ,_"' ___________ -L ___ ~_~ / , ..... . . r--_,'( EXISTING BASINS Basin Name Northeast Northwest Southwest Total Area (acres) 0.455 acres 2.196 acres 6.529 acres NE 3RD PLACE I NORTH~EST BASiN I i ;/ , j , . . \ ' I , r i \ \ Impervious Area (acres) 0.013 acres 0.100 acres 0.032 acres i \ Pervious Area (acres) 0.442 acres 2.096 acres 6.497 acres ,---" SCALE 1" = 100' am __ CITY OF RENTON NEW PARK AT NE 3RD COURT AND UNION AVENUE NE HICIf ,.. A_ :swer. ,«» .s.fUIr. ............ "'OI~ (20" &2:2-5122-r_ (ZtJII) ~.JD AT FIJU. SCALE IF" NaT ONE INCH SCN.£ """"""",,Y EXISTING BASINS 02/24/2000 - .J" " " DEVELOPED BASINS Basin Name Northeast Northwest Southwest 1iT:JU __ ,. ". A_ ~ NCO ------(»I) ~ F. (201:) ~:JO Total Area (acres) 0,5111 acres 2A640 acres 6,2070 acres Imperlious Area (acres) 0,1475 acres 0,1440 acres OA875 acres NE 3RD PLACE Pervious Area (acres) 0.3635 acres 2,3200 acres 5.7190 acres SCALE: 1" = 100' NEW PARK AT NE 3RD COURT AND UNION AVENUE NE DEVELOPED BASINS \ \ w z w > « z o Z => 02/2A/2003 -5 Appendix B • Pre-developed to Developed Basin Analysis for 100yr peaks, Flow Control Exemption • Conveyance Calculations Flow Control Exemption Pre-developed to Developed Basin Analysis for 1 OOyr peaks Northeast Basin Existing Stormwater Runoff Calculations: Precipitation: 2yr 24-hour: 2 in 10yr 24-hour: 2.9 in 25yr 24-hour: 3.4 in 50yr 24-hour: 3.4 in 1 OOyr 24-hour 3.9 in neexisting Event Summary: BasinlD Peak Q Peak T (cfs) (hrs) neexisting 0.12 8.00 Drainage Area: neexisting Hyd Method: SBUH Hyd Peak Factor: 484.00 Storm Our: 24.00 hrs Area CN Pervious 0.4420 ac 72.57 Impervious 0.0130 ac 95.00 Total 0.4550 ac Supporting Data: Pervious CN Data: Forest Pasture Impervious CN Data: gravel rd Pervious TC Data: Flow type: Description: Shallow Forest Sheet pasture area Impervious TC Data: Flow type: Description: Sheet gravel rd 73.00 71.00 95.00 Peak Vol Area Method Raintype Event (ac-It) ac ILoss 0.0562 0.45 SBUH/SCS TYPE1A 100 yr Loss Method: SCS CN Number SCS Abs: 0.20 Intv: 10.00 min TC 0.14hrs 0.03 hrs 0.3460 ac 0.0960 ac 0.0130 ac Length: Slope: Coell: Travel Time 50.00 ft 6.00% 3.0000 1.13min 50.00 It 2.00% 0.1500 7.12 min Length: Slope: Coeff: Travel Time 40.00 ft 4.00% 0.0500 1.87 min • Proposed Development Stormwater Runoff Calculations: Precipitation: 2yr 24-hour: 2 in 10yr 24-hour: 2.9 in 25yr 24-hour: 3.4 in 50yr 24-hour: 3.4 in 100yr 24-hour: 3.9 in NEdeveloped Event Summary: BasinlD Peak Q Peak T (cfs) (hrs) NEdeveloped 0.19 8.00 Drainage Area: NEdeveloped Hyd Method: SBUH Hyd Peak Factor: 484.00 Storm Dur: 24.00 hrs Area CN Pervious 0.3635 ac 74.00 Impervious 0.1475ac 98.00 Total 0.5110ac Supporting Data: Pervious CN Data: Grass lawn 74.00 Forest 73.00 Impervious CN Data: Plaza and Path 98.00 Pervious TC Data: Flow type: Description: Shallow Forest Sheet upper park area Impervious TC Data: Flow type: Description: Sheet across plaza Conclusion: Peak Vol (ac-It) 0.0912 Area ac 0.51 Method floss SBUH/SCS Raintype Event TYPE1A 100 yr loss Method: SCS CN Number SCSAbs: 0.20 Intv: 10.00 min TC 0.57 hrs 0.01 hrs 0.3635 ac 0.0000 ac 0.1475 ac length: Slope: Coeff: Travel Time 200.00 It 7.00% 30000 4.20 min 300.00 It 2.00% 0.1500 2985 min length: Slope: Coeff: Travel Time 40,00 It 2,00% 0,0110 0.74 min Using the 1990 King County Surface Water Design Manual, flow control is not required when there is less than a 0,5cfs increase from existing conditions to developed conditions for the 100yr peak 24-hour storm, The existing peak flow rate, Q, for the Northeast Basin is 0.12cfs, The proposed development would increase this flow rate to 0.19cfs; an increase of 0.07cfs. This increase is less than 0.5cfs which means Flow Control is not reguired for this basin. • Northwest Basin Existing Stormwater Runoff Calculations: Precipitation: 2yr 24-hour: 2 in 10yr 24-hour: 2.9 in 25yr 24-hour: 3.4 in 50yr 24-hour: 3.4 in 100yr 24-hour: 3.9 in nwexisting Event Summary: BasinlD Peak Q Peak T (cis) (hrs) nwexisting 0.34 8.50 Drainage Area: nwexisting Hyd Method SBUH Hyd Peak Factor: 484.00 Storm Dur: 24.00 hrs Pervious Impervious Total Area 2.0960 ac 0.0998 ac 2.1958 ac Supporting Data: Pervious CN Data: CN 72.02 95.00 Pasture 71.00 Forest 73.00 Impervious CN Data: gravel rd 95.00 Pervious TC Data: Flow type: Description: Sheet sheet in pasture area Shallow Through forest Impervious TC Data: Flow type: Description: Sheet gravel rd Peak Vol (ac-ft) 0.2707 Area Method ac fLoss 2.20 SBUH/SCS Raintype Event TYPE1A 100yr Loss Method: SCS CN Number SCS Abs: 0.20 Intv: 10.00 min TC 0.83 hrs 0.01 hrs 1.0310ac 1.0650 ac 0.0998 ac Length: 300.00 ft 300.00 It Length: 20.00 It Slope: Coell: 2.00% 0.2400 7.00% 3.0000 Slope: Coell: 4.00% 0.0110 Travel Time 43.47 min 6.30 min Travel Time 0.32 min Proposed Development Stormwater Runoff Calculations: Precipitation: 2yr 24-hour: 2 in 10yr 24-hour: 2.9 in 25yr 24-hour: 3.4 in 50yr 24-hour: 3.4 in 100yr 24-hour 3.9 in NWdeveloped Event Summary: BasinlD Peak Q Peak T Peak Vol Area ac 2.46 Method Raintype Event (cfs) (hrs) (ac-ft) NWdeveloped 0.51 800 0.3337 Drainage Area: NWdeveloped Hyd Method: SBUH Hyd Peak Factor: 484.00 Storm Dur: 24.00 hrs Area CN Pervious 2.3202 ac 73.63 Impervious 0.1440 ac 98.00 Total 2.4642 ac Supporting Data: Pervious eN Data: Grass Lawn Forest Impervious eN Data: Plaza and Path Pervious Te Data: Flow type: Description: Shallow Forest Sheet upper park area Impervious Te Data: Flow type: Description: Sheet across plaza Conclusion: 74.00 73.00 98.00 ILoss SBUHISCS TYPE1A 100 yr Loss Method: SCS CN Number SCS Abs: 0.20 Intv: 10.00 min TC 0.57 hrs 0.01 hrs 1.4650 ac 0.8552 ac 0.1440 ac Length: 200.00 It 300.00 It Length: 20.00 It Slope: Coeff: 7.00% 3.0000 2.00% 0.1500 Slope: Coeff: 2.00% 0.0110 Travel Time 4.20 min 29.85 min Travel Time 0.42 min Using the 1990 King County Surface Water Design Manual, flow control is not required when there is less than a 0.5cfs increase from existing conditions to developed conditions for the 100yr peak 24-hour storm. The existing peak flow rate, Q100, for the Northwest Basin is 0.34cfs. The proposed development would increase this flow rate to 0.51cfs; an increase of 0.17cfs. This increase is less than 0.5cfs which means Flow Control is not required for this basin. Southwest Basin Existing Stormwater Runoff Calculations: Precipitation: 2yr 24-hour: 2 in 10yr 24-hour 2.9 in 25yr 24-hour: 3.4 in 50yr 24-hour: 3.4 in 100yr 24-hour: 3.9 in swexisting Event Summary: BasinlD Peak Q Peak T (cfs) (hrs) swexisting 1.10 8.17 Drainage Area: swexisting Hyd Method: SBUH Hyd Peak Factor: 484.00 Storm Our: Pervious Impervious Total 24.00 hrs Area 6.4970 ac 0.0320 ac 6.5290 ac Supporting Data: Pervious CN Data: Pasture Forest Impervious CN Data: gravel rd Pervious TC Data: Flow type: Description: eN 72.42 9500 71.00 7300 95 00 Sheet sheet in pasture area Shallow Through forest Impervious TC Data: Flow type: Description: Sheet gravel rd Peak Vol (ac-ft) 0.7766 Area ac 6.53 Method Raintype Event ILoss SBUH/SCS TYPE1A 100 yf Loss Method: SCS CN Number SCS Abs: 0.20 Intv: TC 0.57 hrs 0.00 hrs 1.8800 ac 4.6170 ac 0.0320 ac Length: 300.00 It 300.00 It Length: 20.00 It 10.00 min Slope: Coeff: 6.00% 0.2400 8.00% 3.0000 Slope: Coeff: 6.00% 0.0110 Travel Time 28.01 min 5.89 min Travel Time 0.27 min Proposed Development Stormwater Runoff Calculations: Precipitation: 2yr 24-hour: 2 in 10yr 24-hour: 2.9 in 25yr 24-hour: 3.4 in 50yr 24-hour: 3.4 in 100yr 24-hour: 3.9 in SWdeveloped Event Summary: BasinlD Peak Q Peak T Peak Vol Area (cIs) (hrs) (ac-It) ac SWdeveloped 1.37 8.00 0.8632 6.21 Drainage Area: SWdeveloped Method ILoss SBUH/SCS Raintype Event TYPE1A 100 yr Hyd Method: SBUH Hyd Loss Method: SCS CN Number Peak Factor: 484.00 Storm Dur: 24.00 hrs Area CN Pervious 5.7190 ac 7364 Impervious 0.4875 ac 98.00 Total 6.2065 ac Supporting Data: Pervious eN Data: Grass Lawn 74.00 Forest 7300 Impervious CN Data: Plaza and Path 98.00 Pervious TC Data: Flow type: Description: Shallow Forest Sheet upper park area Impervious TC Data: Flow type: Description: Sheet across plaza Conclusion: SCS Abs: 0.20 Intv: TC 0.56 hrs 0.01 hrs 3.6500 ac 2.0690 ac 0.4875 ac Length: 200.00 It 300.00 It Length: 20.00 It 10.00 min Slope: Coeff: 8.00% 3.0000 2.00% 0.1500 Slope: Coeff: 2.00% 0.0110 Travel Time 3.93 min 29.85 min Travel Time 0.42 min Using the 1990 King County Surface Water Design Manual, flow control is not required when there is less than a 0.5cfs increase from existing conditions to developed conditions for the 1 OOyr peak 24-hour storm. The existing peak flow rate, Q100, for the Northwest Basin is 1.1 cfs. The proposed development would increase this flow rate to 1.37cfs; an increase of 0.27cfs. This increase is less than 0.5cfs which means Flow Control is not required for this basin. Conveyance Calculations • Conveyance Map • Basin Analysis for 25yr peak f10wrate • Conveyance and Backwater spreadsheet "1 I " ' '- f < , , \, .. , ,/ , 7 / "~: // " ; /' /' CITY OF RENTON NE 3RD PLACE' .' .-.- ",~---4! NEW PARK AT NE 3RD COURT AND UNION AVENUE NE CONVEYANCE LAYOUT ~; , ! w, Z w, > «: z g z ::> 02/24/2006 - "B01" Basin Precipitation: 2yr 24-hour: 2 in 10yr 24-hour: 2.9 in 25yr 24-hour: 3.4 in 801 Event Summary: BasinlD Peak Q (cIs) 801 0.14 Drainage Area: 801 Hyd Method: SBUH Hyd Peak Factor: 484.00 Storm Our: 24.00 hrs Area Pervious O. 1 722 ac Impervious 0,1288 ac Total 0,3010 ac Supporting Data: Pervious CN Data: Grass Lawn Playground Impervious CN Data: Plaza and Path Pervious TC Data: Flow type: Description: Sheet grass areas Sheet playground Impervious TC Data: Flow type: Description: Sheet across plaza Summary: Peak T (hrs) 7.83 CN 78.74 98.00 74.00 86.00 98.00 Peak Vol Area Method Raintype Event (ac-II) ac ILoss 0.0551 0,30 S8UHISCS TYPE1A 25 yr Loss Method: SCS CN Number SCS Abs: 0.20 Intv: 10,00 min TC 0,29 hrs 0,01 hrs 0.1042 ac 0.0680 ac 0.1288 ac Length: Slope: Coeff: Travel Time 30.00 II 2.00% 0.2400 6.89 min 30.00 It 200% 0.4100 10.57 min Length: Slope: Coeff: Travel Time 40.00 It 2.00% 0.0110 0.74 min The 25yr Peak Flow Rate is Q801= 0, 14cfs. "B02" Basin Precipitation: 2yr 24-hour: 2 in 10yr 24-hour: 2.9 in 25yr 24-hour: 3.4 in 802 Event Summary: BasinlO Peak Q (cIs) 802 0.07 Drainage Area: 802 Hyd Method: SBUH Hyd Peak Factor: 484.00 Storm Our: 24.00 hrs Area Pervious 0.0948 ac Impervious 0.0754 ac Total 0.1702 ac Supporting Data: Pervious eN Data: Grass lawn Playground Impervious eN Data: Plaza and Path Pervious Te Data: Flow type: Description: Sheet grass areas Sheet playground Impervious Te Data: Flow type: Description: Sheet across plaza Summary: Peak T (hrs) 7.83 CN 7400 98.00 74.00 86.00 9800 Peak Vol Area Method Raintype Event (ac-ft) ac floss 0.0291 0.17 SBUH/SCS TYPE1A 25 yr loss Method: SCS CN Number SCS Abs: 0.20 Intv: 10.00 min TC 0.34 hrs 0.02 hrs 0.0948 ac 0.0000 ac 0.0754 ac length: Slope: Coeff: Travel Time 45.00 It 2.00% 0.2400 9.53 min 30.00 It 2.00% 0.4100 10.57 min length: Slope: Coeff: Travel Time 65.00 ft 2.00% 0.0110 1.09 min The 25yr Peak Flow Rate is 0 802 = O.07cfs. "B03" Basin Precipitation: 2yr 24-hour: 2 in 10yr 24-hour: 2.9 in 25yr 24-hour: 3.4 in 803 Event Summary: BasinlD Peak Q (cts) B03 0.05 Drainage Area: 803 Hyd Method: SBUH Hyd Peak Factor: 484.00 Storm Dur: 24.00 hrs Area Pervious 0.1074 ac Impervious 0.0145 ac Total 0.1219 ac Supporting Data: Pervious CN Data: Grass Lawn Playground Impervious CN Data: Plaza and Path Pervious TC Data: Flow type: Description: Sheet grass areas Sheet playground Impervious TC Data: Flow type: Description: Peak T (hrs) 8.00 GN 84.50 9800 7400 86.00 98.00 Sheet across plaza 20.00 ft 2.00% Summary: Peak Vol Area Method Raintype Event (ac-tt) ac fLoss 0.0207 0.12 SBUH/SCS TYPE1A 25 yr Loss Method: SGS GN Number SGS Abs: 0.20 Intv: 10.00 min TG 0.32 hrs 0.01 hrs 0.0134 ac 0.0940 ac 0.0145 ac Length: Slope: Goeff: Travel Time 10.00 ft 4.00% 0.2400 2.17 min 55.00 ft 2.00% 0.4100 17.17 min Length: Slope: Goeff: Travel Time 00110 0.42 min The 25yr Peak Flow Rate is QB03= O.05cfs. Pipe Se ment from to Outfall WYE WYE CB3 WYE CB2 CB2 CB1 U!BI Backwater Calculations for 25yr 24-hour Design Storm Event per King County Surface Water Design Manual 1 2 3 4 5 6 Outlet Inlet Q Pipe Invert Invert desian QfuU Q/Qfull Length size 0 Elevation Elevation dID Ratio ef, ef, ft " II ft 0.26 1 712 0.15 229 8 0.012 402.06 405,96 0,26 0.05 1.6596 003 45 6 0.012 405.96 409,3 011 0.21 1.7086 0,12 79 , 0,012 405,96 4073 0.23 014 0,B494 016 36 6 0012 4073 408 0.27 2Syr Storm Main Backwater Ocatc,xls Prolec New Park In-Rento.Sheet Job # 1051660 lof By MOE IOate 7 , 9 10 ProportlO Barrel Tall oat V design Barret Barrel Velocity Water Velocitv V full ftls ttl, Area Velocity Head Elev «'2 ttl, ft II 0.72 490 3.51 0,349 074 001 402.56 043 B.45 3.60 0,196 0,24 000 406.21 0.67 4.B9 327 0.349 0.60 001 406.46 073 4.33 3.17 0.196 0.70 0.01 40763 02/24106 11 12 13 14 15 16 Entrance Outlet Inlet Friction Entrance Head Exit Head Control Control Control Loss HGL EL K, Loss Lass Elev HWfO Elev Elev ft Ii ft ft ft ft 0087 402.65 0.50 0.004 0008 402,66 0.1 40603 40603 o 003 40621 OSO 0000 0,001 40621 o 1 409.35 40935 0020 406.48 0,50 0,003 0,006 406,49 0.1 40737 40737 0018 407.65 0.50 0004 O.OOB 407.66 0.1 40805 408.05 17 18 19 Approach Velocity Bend Head Junction Head "" Loss " Head Loss ft ft ft 0240 0.00 0 0 0,0000 0270 0.40 0,00223518t 0.()'4B33486 0.0000 0,390 0.00 0 0 0.0000 0000 000 0 0 0.0000 20 Head Water Rim Elevation Elevation ft ft 405.79 406.96 409 08 411,1 406,98 4101 40B 05 409,B Rim EL to HGL ft 117 2.02 3.12 1.75 Req'd Clearance ft 0 0 0 0 OK' OK OK OK OK 212412006 Appendix C • Geotechnical Report Geotechnical Repor1 Heather Downs Park Development Renton, Washingto~ AI S!WIl//I!1I & Wi/lo}!. Oil! !!!i.\xio/I i.\ To !)(~ (/ {)rogrC,\,Ii\'f'. !I'e/!- and opfl/led l'(/111r \{'inICt'1 (Jur gou! is ro Jlcr/(I/"i!! (III)' ,1('I"I'ico' October 10, 200e Submitted To: Mr. Jim Brennan JA Brennan Associates, PLLC 100 South King Street, Suite 200 Seattle, Washington 98104 By: Shannon & Wilson, Inc. 400 N 34'h Street, Suite 100 Seattle, Washington 98103 21-1-20373-001 SHANNON &WILSON, INC. TABLE OF CONTENTS Page 1.0 INTRODUCTION ................................................................................................................. 1 1 .1 Purpose ....................................................................................................................... 1 1.2 Scope of Work ............................................................................................................ 1 2.0 SITE AND PROJECT DESCRIPTION ................................................................................. 1 3.0 SUBSURFACE EXPLORATION PROGRAM .................................................................... 2 4.0 GEOLOGY AND SUBSURFACE CONDITIONS .............................................................. 2 4.1 Regional Geology ....................................................................................................... 2 4.2 Subsurface Conditions ............................................................................................... 3 4.3 Groundwater Conditions ............................................................................................ 3 5.0 ENGINEERING CONCLUSIONS AND RECOMMENDATIONS ................................... .4 5.1 General.; ..................................................................................................................... 4 5.2 Foundation Design ..................................................................................................... 4 5.3 . Estimated Settlement.. ................................................................................................ 4 5.4 Lateral Earth Pressures ............................................................................................... 5 5.5 Lateral Resistance ...................................................................................................... 5 5.6 Floor Slabs ................................................................................................................. 6 5.7 Drainage ..................................................................................................................... 6 5.8 Earthwork ................................................................................................................... 7 5.8.1 Site Preparation and General Excavation .................................................... 7 5.8.2 Temporary Groundwater Control ................................................................ 7 5.8.3 Fill Placement, Compaction, and Use of On-site Soils ............................... 8 5.8.4 Wet Weather Earthwork .............................................................................. 9 5.8.5 Erosion Control .......................................................................................... 10 6.0 CONSTRUCTION CONSIDERATIONS ........................................................................... 1 0 6.1 Obstructions ............................................................................................................. 10 6.2 Loose Test Pit Backfill ............................................................................................. 1 0 7.0 LIMITATIONS .................................................................................................................... 10 8.0 REFERENCES ..................................................................................................................... 13 21-1.20373·00I·Rl/wplI.KDLORI DOHERTY 21-1-20373-001 TABLE OF CONTENTS (cont.) SHANNON &WlLSON.INC. LIST OF FIGURES Figure No. I Vicinity Map 2 Site and Exploration Plan LIST OF APPENDICES Appendix A Field Explorations B Important Information About Your Geotechnical Report 21·1-2037)-00 I-R l/wp/LKD 21-1-20373-001 11 SHANNON &WILSON.INC. 1.1 Purpose GEOTECHNICAL REpORT HEATHER DOWNS PARK DEVELOPMENT RENTON, WASHINGTON 1.0 INTRODUCTION This report presents the results of subsurface explorations and geotechnical engineering studies for the Heather Downs Park Development site located in Renton, Washington. The purpose of our geotechnical studies was to evaluate subsurface conditions in order to fonnulate engineering recommendations for use in the design and construction of the proposed project. Our services were provided in accordance with our proposal. dated May 31, 2005, and authorized by Mr. James A. Brennan at J.A. Brennan Associates, Inc. on July 19,2005. 1.2 Scope of Work OUf scope of work for this project included the following: • Identifying and reviewing existing subsurface infonnation in the general vicinity. • Overseeing and sampling excavation of three test pits. • Perfonning laboratory tests. • Preparing a site and exploration plan and logs of test pits. • Conducting engineering anal yses. • Summarizing our conclusions and recommendations in this report. 2.0 SITE AND PROJECT DESCRIPTION The proposed Heather Downs Park Development project, as shown in the Vicinity Map, Figure I, is situated southwest of the intersection ofNE 3'u Court and Union Avenue in the City of Renton. We understand that the site was fonnerly residential property and the majority of the site is currently overgrown with trees and brush, including dense thickets of blackberries. Based on the proposed site plan surveyed by Penhallegon Associates Consulting Engineers, Inc. (PACE), on September 13, 2005, the area of concern at the site measures about 250 feet by 300 feet. In general, the ground surface across the site slopes gently from elevation 414 feet on 21-1-2OJ73-00I-Rl/wplLKDLORI DOHERTY 21-1-20373-001 1 SHANNON &W1LSON, INC. the south end to about elevation 408 feet on the north end. These elevations are in terms of the North American Vertical Datum of 1988 (NAVD88). The proposed developed area of the park will cover about 75,000 square feet. The buildings at the site include a restroom facility and a picnic shelter. We understand that these structures will be constructed on slabs-on-grade with shallow perimeter footings. The site will also include paved parking lots, playground areas, and planters and landscape areas, as shown on the Site and Exploration Plan, Figure 2. 3,0 SUBSURFACE EXPLORATION PROGRAM To generally characterize subsurface conditions in the vicinity of the proposed structures, three test pits were excavated and sampled at the approximate locations shown in Figure 2. The test pits are designated TP-l through TP-3. A description of the methods and procedures used for locating, excavating, and sampling the test pits is included in Appendix A. The logs of the test pits are also included in Appendix A as Figures A-2 through A-4. 4.0 GEOLOGY AND SUBSURFACE CONDITIONS 4.1 Regional Geology The project site is located in the central portion of the Puget Lowland, an elongated topographic and structural depression bordered by the Cascade Mountains on the east and the Olympic. mountains on the west. Low-rolling relief, with some deeply cut ravines and broad valleys, characterizes this lowland. In general, the ground surface elevation of the project site is within 410 feet above sea level. Geologists generally agree that the Puget Sound area was SUbjected to six or more major glaciations during the Pleistocene Epoch (2 million years ago to about 10,000 years ago), which filled the Puget Lowland to significant depths with a complex sequence of glacial and non- glacial sediments. Ice for these glacial events originated in the coastal mountains of the Vancouver Range of British Columbia. The maximum southward advance of the ice was about halfway between Olympia and Centralia (about 80 miles south of Seattle). During the most recent ice coverage of the central Puget Lowland (Vashon Stade of Fraser Glaciation), the 21-1-20373 -00 I-Rl/wp/LKD 21-1-20373-001 2 SHANNON &WILSON, INC, thickness of ice is estimated to have been about 3,000 feet in the project area. The last ice covering the project area receded about 13,500 years ago. The distribution of sediments in the Puget Lowland is complex, because each glacial advance deposited new sediments and partially eroded previous sediments. During the intervening interglacial episodes, the complete or partial erosion or the reworking of some deposits, as well as the local deposition of other sediments, further complicated the geologic setting. 4.2 Subsurface Conditions The results of our subsurface explorations, TP-I through TP-3, indicate the general subsurface conditions across the proposed park site are underlain by a varying thickness of fill material overlying native glacial till. Fill was not encountered in TP-3. The fill material, to a depth of 2 to 3Y, feet, generally consists ofloose to medium dense, slightly gravelly, silty sands. The test pit Ibcations were deliberately chosen to avoid excavating within future building footprints and adjacent to the site of the demolished former residence. Demolition debris was not encountered in the fill layer during excavation, but may be encountered during earthwork activities. Large concentrations of demolition debris were not encountered during exploration. However, due to the history of the site, which includes two residences that were demolished, it is likely that debris concentrations in the fill may be encountered across the site. The debris may include abandoned foundations, concrete and asphalt rubble, metal, bricks, wood, tree stumps, and other organic and construction debris. Underlying this surficial fill layer, the soils consist of loose to medium dense, slightly gravelly, silty sand (weathered glacial till) approximately 2 to 3 feet thick overlying a dense to very dense, concrete-like mixture of silt, gravel, sand, and clay (glacial till). Cobbles and up to 3-foot-diameter boulders are commonly included in the matrix ofthe glacial till, though none were encountered during our explorations. 4.3 Groundwater Conditions Groundwater was not observed in the test pits during excavation. However, we observed iron oxide stains on partings and lenses, which suggest fluctuating groundwater conditions. Therefore, we anticipate that seasonal perched groundwater conditions may be present. 21·[ -20373.001-Rl/wp/LKD 21-1-20373-001 3 SHANNON &W1LSON.INC. 5.0 ENGINEERING CONCLUSIONS AND RECOMMENDATIONS 5.1 General Based on our current understanding of the proposed park development project as described previously, and on the results of our geotechnical studies, we developed the following recommendations for foundation design. The following sections describe these recommendations and provide additional recommendations for site preparation, excavation, fill placement and compaction, use of on-site soil, and wet weather earthwork. 5.2 Foundation Design In our opinion, the proposed structures could be supported on conventional spread footings or on slab-on-grades with thickened edges. However, because of the depth of relatively loose soils that underlie the proposed structures, we recommend the foundation areas be overexcavated to competent soil (up to about 2 feet) and replaced with compacted structural fill. For'footings bearing on densely compacted structural fill or dense, unweathered, native soil, we recommend using an allowable bearing pressure of 2,000 pounds per square foot (pst). Continuous wall footings should have a minimum width of 18 inches and column footings should have a minimum width of 24 inches. All footings should be embedded at least 18 inches below the 'lowest adjacent exterior grade. The allowable bearing pressure may be increased by one-third for short-term wind or seismic loads We recommend that each footing/slab excavation be evaluated by a qualified geotechnical engineer or representative during construction to confirm the presence of competent bearing soil and to determine that all unsuitable fill and organic material have been removed. 5.3 Estimated Settlement Foundations designed and constructed as recommended in this report are estimated to undergo total settlement ofless than Y, inch. Owing to the variation of footing loads and soil conditions, differential settlements are estimated to be about one-half of the total settlements between heavily loaded and lightly loaded footings or along a continuous footing for a distance of approximately 20 feet. It is anticipated that the majority of the estimated settlements would occur simultaneously as the loads are applied. 21-\-20373-00 I-Rl!wplLKD 21-1-20373-001 4 SHANNON &W1LSON.INC. 5.4 Lateral Earth Pressures The lateral pressures against a buried wall are dependent upon many factors, including method of backfill placement and degree of compaction, backfill slope, surcharges, the type of backfill soil and native soils, drainage, and whether or not the wall can yield or deflect laterally or rotate at the top after or during placement of backfill. If the wall is free to yield at the top an amount equal to approximately 0.001 times the height of the wall, the soil pressures will be less (active case) than if this amount of movement is not allowed due to stiffness or resistance of the wall (at-rest condition). Rigid, buried walls should be designed to resist an "at-rest" lateral earth pressure based on an equivalent fluid unit weight of 55 pounds per cubic foot (pcf). Walls allowed to deflect laterally or rotate at the top should be designed using an active lateral pressure equivalent to a fluid unit weight of35 pcf. These values should be increased by I pcffor each degree of upward inclination of the backslope above the wall. The above pressures are for permanent walls and assume that proper drainage is provided behind the walls so there is no buildup of hydrostatic pressures. Backfill should not be placed behind a wall until the wall is capable of supporting lateral pressures. 5.5 Lateral Resistance Lateral loads, due to unbalanced lateral earth pressures, wind, or seismic forces, would be resisted by base friction and passive earth pressure against buried portions of the structure. We recommend passive earth pressures in dense, silty, gravelly sands or compacted structural fill be determined using an equivalent fluid density of 200 pcf. This value assumes that footings are founded at least 18 inches below the lowest adjacent grade and placed within neat excavations. The above value includes a factor-of-safety of 1.5. We recommend that a coefficient of friction between mass concrete and dense native ground and structural fill of 0.40 be used, with an appropriate factor-of-safety to calculate the resistance to sliding. 21-1-20J73-00I-RllwplLKD 21-1-20373-00 I 5 " SHANNON &WILSON,INC. 5.6 Floor Slabs We recommend that all floor slabs be supported be densely compacted structural fill or dense native soil. If unanticipated loose, soft, or unsuitable soil is encountered in the floor subgrade preparation, it should be overexcavated and replaced with compacted structural fill. We recommend placing a capillary break consisting of at least 4 inches of washed pea gravel or Yo-inch minus crushed gravel beneath the floor slabs. The washed pea gravel will provide positive leveling and a more uniform surface than the native soil or structural fill and will also act as a capillary break. For heated spaces or spaces with floor coverings, a vapor barrier consisting of plastic sheeting or equivalent should be placed on top of the washed pea gravel. As an alternative, th.e capillary break may consist of a 2-inch layer of washed gravel beneath a 2-inch layer of crushed rock. The crushed rock should be compacted with a vibrating plate compactor to provide a working surface for concrete placement. We recommend using a modulus of subgrade reaction, k, of250 pounds per cubic inch (pci) for designing floor slabs-on-grade. This design recommendation assumes that slabs-on-grade are constructed in accordance with the above recommendations. 5.7 Drainage Groundwater was not encountered in the subsurface explorations performed at the site. Therefore, the proposed structures will not require a permanent subdrain system. To control surface water, provisions should be made to direct it away from structures and prevent it from seeping into the ground adjacent to structures or excavations. The ground surface should be sloped away, and surface and downspout water should not be introduced into site backfill. Surface water should be collected in catch basins and along with downspout water, should be conveyed in a non-perforated pipe (tightline) into an approved discharge point. Except as otherwise designed and/or specifically covered in the contract, the Contractor should be made responsible for control of all ground and surface water encountered during construction. In this regard, sloping, ditching, pumping from sumps, providing trench drains, dewatering, and other measures should be employed as necessary to permit proper completion of the work. 21-1-2037J-OOI-Rl/wpiLKD 21-1-20373-001 6 SHANNON bWILSON.INC. 5.8 Earthwork 5.8.1 Site Preparation and General Excavation Site preparation for excavation and fill placement should commence by collecting and diverting all sources of surface water flow into temporary storm drainage facilities. Each building site should be cleared of all trees, brush, and other vegetation, and should then be grubbed of large roots and stripped of surficial soil containing significant amounts of roots or other objectionable debris (see Section 4.2) and organic material. The material should not be mixed with soil that may be used as structural fill. Abandoned utility pipes should be plugged or removed so they do not provide a conduit for water that could cause saturation and stability problems. Based on the subsurface conditions encountered in the explorations, we anticipate that the excavations at the site could be made using conventional excavating equipment such as dozers, front-end loaders, r:ubber-tired backhoes, or tracked hydraulic excavators. Cobbles and possibly boulders could be encountered in dense glacial soil, and the Contractor should anticipate their presence. We recommend that all loose fill soil in the building footprint be removed. Native ground should be encountered from y, to 2 feet below existing ground surface. Where fills are made on a slope, the native ground upon which the fill is placed should be terraced to key the fill into the slope. We recommend that the height of each terrace not exceed 2 feet. -. Following stripping, grubbing, and excavation to obtain desired grades or exposed native ground, a geotechnical engineer or engineer's representative should evaluate the density ofthe exposed surface. Should the presence of loose zones be revealed, they should either be removed and replaced with structural fill, or dried or moistened as required (including scarifying, mixing, and/or aeration), reworked, and adequately compacted until a dense, unyielding soil mass is produced. 5.8.2 Temporary Groundwater Control Groundwater was not encountered in the explorations performed at the site. Ifthe earthwork occurs during the wet season, perched groundwater could be encountered. In our opinion, perched groundwater that may seep into the excavation and rainwater that falls into the 21-\ -2037] -00 loR \/wp/LK D 21-1-20373-001 7 SHANNON &WJLSON.INC. 5.8.4 Wet Weather Earthwork Wet weather generally begins about mid-October and continues through about May, although rainy periods may occur at any time of year. Some of the soil at the site contains sufficient silts and fines to produce an unstable mixture when wet. Such soils are susceptible to changes in water content, and they tend to become unstable and difficult or impossible to compact if their moisture content significantly exceeds the optimum. If earthwork at the site continues into the wet season, or if wet conditions are encountered, we recommend the fol1owing: • The ground surface in and surrounding the construction area should be sloped as much as possible to promote runoff of precipitation away from work areas and to prevent ponding of water. • Work areas or slopes should be covered with plastic. The use of sloping, ditching, sumps, dewatering, and olher measures should be employed as necessary to permit proper completion of the work. • Earthwork should be accomplished in small sections to minimize exposure to wet conditions. That is, each section should be small enough so that the removal of unsuitable soils and placement and compaction of clean structural fill can be accomplished on the same day. The size of construction equipment may have to be limited to prevent soil disturbance. It may be necessary to excavate soils with a backhoe, or equivalent, located so that equipment does not traffic over the excavated area. Thus, subgrade disturbance caused by equipment traffic will be minimized. • Fill material should consist of clean, well-graded, pit-run sand and gravel soils, of which not more than 5 percent fines by dry weight passes the No. 200 mesh sieve, based on wet- sieving the fraction passing the ~-inch mesh sieve. The gravel content should range from between 20 to 60 percent retained on a No.4 mesh sieve. The fines should be nonplastic. • No soil should be left uncompacted and exposed to moisture. A smooth-drum vibratory roUer, or equivalent, should roll the surface to seal out as much water as possible. • In-place soils or fiU soils that become wet and unstable and/or too wet to suitably compact should be removed and replaced with clean, granular soil (see part 4). • Excavation and placement of structural fill material should be observed on a full-time basis by a geotechnical engineer (or representative) experienced in earthwork to determine that al1 work is being accomplished in accordance with the project specifications and our recommendations. • Grading and earthwork should not be accomplished during periods of heavy, continuous rainfall. 21·1·20373-00 I-R I/wp/LKD 21-1-20373-001 9 SHANNON bWILSON.INC. We suggest that these recommendations for wet weather earthwork be included in the contract specifications. 5.8.5 Erosion Control . The Contractor should employ proper erosion control measures during construction, especially if construction takes place during wet weather. Covering work areas, soil stockpiles, or slopes with plastic, sandbags, sumps, and other measures should be employed as necessary to permit proper completion of the work. Bales of straw, geotextile silt fences, and drain inlet sediment screens/collection systems should be appropriately located to control soil movement and erosion. 6.0 CONSTRUCTION CONSIDERATIONS 6.1 Obstructions Unanticipated conditions are commonly encountered and cannot be fully determined by merely taking soil samples or making explorations. Although not encountered in the explorations, cobbles and boulders are commonly found in glacial soils and should be anticipated at the site. These obstructions would ilI!pact excavations. Such unexpected conditions frequently require that additional expenditures be made to achieve a properly constructed project. Some contingency fund is recommended to accommodate such potential extra costs. 6.2 Loose Test Pit Backfill '. Test pits dug to explore the site were loosely backfilled. If a test pit falls in an area that will not be overexcavated below the bottom of the test pit, the loose soil should be removed during construction and replaced with compacted structural fill. 7.0 LIMITATIONS This report was prepared for the exclusive use of J .A. Brennan Associates, Inc. and other members of their design team to assist in the design and construction of the Heather Downs Park 21-1-20373-00 1.RllwplLKD 21-1-20373-001 10 SHANNON &WILSON,INC. Development project. The analyses, conclusions, and recommendations contained in this report are based on site conditions as they presently exist and on the site and project descriptions as presented herein. We should be notified if differences are identified. We assume that the exploratory test borings and retrieved samples are representative of the subsurface conditions throughout the site; i.e., the subsurface conditions everywhere are not significantly different from those disclosed by the explorations. During construction, if subsurface conditions different from those described in this report are observed or appear to be present during construction, we should be advised at once so that we can review these conditions and reconsider our recommendations, where necessary. If conditions have changed due to natural causes or construction operations at or adjacent to the site, it is recommended that this report be reviewed to determine the applicability of the conclusions and recommendations considering the changed conditions and time lapse. Within the limitations of the scope, schedule, and budget, the analyses, conclusions, and recommendations presented in this report were prepared in accordance with generally accepted professional geotechnical engineering principles and practice in this area at the time this report was prepared. We make no other warranty, either express or implied. These conclusions and recommendations were based on our understanding of the project as described in this report and on site conditions as observed at the time of the exploration. The scope of our services for this project did not include any environmental assessment or evaluation regarding the presence or absence of wetlands or hazardous or toxic materials in the soil, surface water, groundwater, or air, on or below or around the site, or for the evaluation or disposal of contaminated soils or groundwater, should any be encountered. However, we will be glad to provide such services on request. 21-1-2037)"()(}J-Rllwp/LKD 21-1-20373-001 11 SHANNON &WILSON.INC. Shannon & Wilson has prepared and included in Appendix B, "Important Information About Your Geotechnical Report," to assist you and others in understanding the use and limitations of our reports. SHANNON & WILSON, INC. Thomas M. Gurtowski, P.E. Vice President JXM:TMG/met 21-1-20373-001-R Jlwp/LKD ---- 21-1-20373-001 12 SHANNON &WlLSON,INC. 8.0 REFERENCES American Society for Testing and Materials (ASTM), 2004, Annual book of standards, Construction, v. 4.08, Soil and rock (I): D 420-D 4914: West Conshohocken, Pa. Washington State Department of Transportation and American Public Works Association, 2004, Standard specifications for road, bridge, and municipal construction (M41 -1 0). -. 21.1-2037J-001.RllwplLKD 21-1-20373-001 13 ! !jl ';" ;; I ~ ~ ~ o I 1/4 I 1/2 I Scale in Miles NOTE 'r~~~' '4 .... r~... 0: .1' ~ \'~~~-:I~'~. l: '( ;WII' I'f.::; i.',r -.f ;o(ln,.Pl·~ ~ ,'J 1 I Reproduced with permission granted by THOMAS BROS. MAP~. This map is copyrighted by THOMAS BROS. MAPS 111>. It is unlawful to copy or reproduce all or any part thereof, whether for personal use or resale. without permission. All rights reserved. _I'I'~.:J .5' ~ '" ':!-..' ~, ~ "6. ~ " ~ 51 I _"'"~.~" i ~' Heather Downs Park Development City of Renton Renton, Washington VICINITY MAP ! I October 2005 21-1-20373-001 SHANNON & WILSON, INC. FIG. 1 Geotechnical 100 EnvIronmenbll ConIlitwlIll ~----------------------------------~--------------~------~ { N ... ... ~ 11 'T 1ij TP-1 ~ , : I , I I I ,,'I I , PARKING ~--.!..! Y I , ~ 'I' , , ,:- II II I I I !~)' '"I,' i I I :d I I , I ,1' LU I Z W > « Z ,0 Z ::> o 50 100 t:1 EH:::c::EH::::::r=l=1 =====31 LEGEND Test Pit Designation and Approximate Location Scale in Feet Heather Downs Park Development City of Renton Renton) Washington ! I SITE AND EXPLORATION PLAN ~_~ NOTE ~ Figure adapted from electronic flies, "survey.dwg", ~ "hdl-Jrading.dwg", and "hdp-site-layout-<ih2.dwg" October 2005 21-1-20373-001 -, provided by client 9-13-05. ,jj SHANNON & WILSON, INC. FIG. 2 ~L-______________________________________________ l.:G:k:':''*~':M~~:M:M:"m:~~~==::~L-~~~:--1 " ' APPENDIX A FIELD EXPLORATIONS SHANNON &WJLSON,INC. 21-1-20373-001 SHANNON &WJLSON.INC. APPENDIX A FIELD EXPLORATIONS TABLE 0 F CONTENTS Page A.I GENERAL. ...................................................................................................................... A-I A.2 TEST PITS ....................................................................................................................... A-I LIST OF FIGURES Figure No. A-I Unified Soil Classification and Log Key (2 sheets) A-2 Log of Test Pit TP-I A-3 Log ofTest Pit TP-2 A-4 Log ofTest Pit TP-3 21-1-20373-00 l-R I-AA/wp/LKD 21-1-20373-001 A-i SHANNON &WJLSON.INC. APPENDIX A FIELD EXPLORATIONS A.I GENERAL The field explorations were accomplished to obtain subsurface information for our geotechnical studies for the proposed park development project at 233 Union Avenue NE in Renton, Washington. Field explorations performed for this project consisted of excavating and sampling three test pits at the site. The test pit locations were selected based on our understanding of the site layout of the proposed buildings. The approximate locations of the explorations are shown in the ~ite and Exploration Plan (Figure 2) in the main text of the report. The tcst pits were located in areas accessible to the equipment adjacent to where future· structures are anticipated. The approximate locations and elevations of the three test pits were determined by field measuring from existing site features and estimating elevations from a topographic survey provided by I.A. Brennan Associates, Inc. These locations and elevations should be considered approximate. All the test pit locations and elevations should be considered accurate to the degree implied by the method used. A.2 TEST PITS Three test pits, designated TP-I through TP-3, were excavated adjacent to the proposed building locations using a rubber-tired backhoe provided and operated by the City of Renton Parks Department. The test pits were excavated on September 29,2005. The test pits depths ranged from 4 to 8 feet below existing ground surface. A geologist from our firm observed the excavation of the test pits, estimated soil density, obtained representative soil samples, and prepared a descriptive log of each test pit in the field. Each soil sample was classified according to a modified version of the Unified Soil Classification System (USCS), which is presented on the Soil Classification and Log Key (Figure A-I). The relative soil densities or consistencies of the exposed soils were estimated based on probing the sides and bottom of the test pits with a y,-inch-diameter, steel T-bar, where practical, and by evaluating the relative ease or difficulty of the excavation. The relative densities are included in the descriptions shown on the test pit logs, presented in this appendix as Figures A-2 through 21-1-20373-001-RI-AA/wp/LKD 21-1-20373-00 I A-I SHANNON &WlLSON.INC. A-4. After completion of excavating and sampling, all test pits were loosely backfilled with excavated soil and nominally compacted with the excavator bucket. Where observed, groundwater seepage into the test pit was noted during excavation. The quantity of groundwater seepage into the test pit during the excavation was based on a visual estimate. The test pit logs for the proposed project are presented as Figures A-2 through A-4 in this appendix. A test pit log is a written record of the subsurface conditions encountered. It graphically illustrates the soil units (layers) encountered in the test pit. Other information shown on the test pit logs includes groundwater seepage, groundwater level (if any), types and depths of sampling, and potential obstructions. '. 2 (-1-20J73-001-R I-ANwp/LKD 21-1-20373-001 A-2 ~ § ~ 0 " ~ ~ ~ ~ " M M 0 N N ~ ~ u " ~ g Shannon & Wilson, Inc. (S&III1, uses a soil classification system modified from the Unified Soil Classification System (USeS). Elements of the uses and other definitions are provided on this and the following page. Soil descriptions are based on visual-manual procedures (ASTM o 2488-93) unless otherwise noted. S&W CLASSIFICATION OF SOIL CONSTITUENTS • MAJOR constituents compose more than 50 percent, by weight, of the soil. Major consituents are capitalized (i.e .• SAND). • Minor constituents compose 12 to 50 percent of the soil and precede the major constituents (i.e., silty SAND). Minor constituents preceded by "slightly" compose 5 to 12 percent of the soil (I.e., slightly silty SAND). • Trace constituents compose 0 to 5 percent of the soil (I.e., slightly silty SAND, trace of gravel). MOISTURE CONTENT DEFINITIONS Dry Absence of moisture, dusty, dry to the touch Moist Damp but no visible water Wet Visible free water, from below water table ABBREVIATIONS . ATO At Time of Drilling Elev. Elevation ft feet FeO Iron Oxide MgO Magnesium Oxide HSA Hollow Stem Auger ID Inside Diameter in inches Ibs pounds Mon. Monument cover N Blows for last two 6-inch increments NA Not applicable or not available NP Non plastic aD Outside diameter OVA Organic vapor analyzer PID Photo-ionization detector ppm parts per million PVC Polyvinyl Chloride 55 Split spoon sampler SPT Standard penetration test USC Unified soil classification WLI Water level indicator GRAIN SIZE DEFINITION DESCRIPTION SIEVE NUMBER ANDIOR SIZE FINES < #200 (0.08 mm) SAND' -Fine #200 to #40 (0.08 to 0.4 mm) -Medium #40 to #10 (0.4 to 2 mm) -Coarse #10to #4 (2 to 5 mm) GRAVEL' -Fine #4 to 314 inch (5 to 19 mm) -Coarse 3/4 to 3 inches (19 to 76 mm) COBBLES 3 to 12 inches (76 to 305 mm) BOULDERS > 12 inches (305 mm) • Unless otherwise noted, sand and gravel, 'Nhen present, range from fine 10 coarse in grain size. RELATIVE DENSITY I CONSISTENCY COARSE-GRAINED SOILS FINE-GRAINED SOILS N,SPT, RELATIVE N,SPT, RELATIVE BLOWS/FT. DENSITY BLOWS/FT CONSISTENCY 0-4 Very loose Under 2 Very soft 4 -10 Loose 2"-4 Soft 10 -30 Medium dense 4-8 Medium stiff 30 -50 Dense B -15 Stiff Over 50 Very dense 15 -30 Very stiff Over 30 Hard WELL AND OTHER SYMBOLS g Bent. Cement Grout It~~~ Surface Cement Seal ~ Bentonite Grout -Asphalt or Cap 1m Bentonite Chips t;~~1 Slough " D Silica Sand ~ Bedrock rn:J PVC Screen rn Vibrating Wire Heather Downs Park Development Renton, Washington SOIL CLASSIFICATION AND LOG KEY October 2005 21·1·20373-001 SHANNON &. WILSON, INC, I FIG.A·1 Geotechnical and Enwoomenlal Consultants Sheel1 of 2 ~ ~ " ~ ~ N I;l S " I •. . ·<i.~.-.· (F~~~ ~~TMD 2ia~:~i1l!~~J~!rt"IQt'Q\ t====~~OR~~====~~~~HIC rrpl~ .' . COARSE- GRAINED SOILS (more than 50% retained on No. 200 sieve) FINE-GRAINED SOILS (50% or more passes the No. 200 sieve) HIGHLY· ORGANIC SOILS Gravels Clean Gravels (less than 5% fmes) 'IIUN ... I·, , • ..; Well-graded oravels, oravels, GW ~._-,_... gravel/sand mixtures, little or no fines GP ~ D~ Poorly graded gravels, gravel·sand -() '--mixtures, little or no fines (moffithan50% 1------------+------~w-1iUrt------------------------__1 of coarse r fraction retained on No.4 sieve) Gravels "With Fines (more than 12% fmes) GM GC Clean Sands In] SW Silty gravels, gravel·sand-sill mixtures CI.ayey gravels, gravel-sand-clay mixtures WeU·graded sands, gravelly sands, little or no fines (less than 5% Sands fines) sp 1(,: Poorly graded sand, gravelly sands, little or no fines (50% or more of I-----------i------hiir--------------------------j coarse fraction I passes the No. 4 sieve) Silts and Clays (liquid limit less than 50) Silts and Clays (liquid· limit 50 or more) Sands with Fines (more than 12% fines) Inorganic SM SC ML CL Silly sands, sancl·silt mixtures Clayey sands, sand-clay mixtures __ Inorganic clays of low to medium plasticity, gravelly clays, sandy clays, Silty clays, -lean clays I------t----l"'" Organic OL MH Inorganic CH :-........:_ = Organic silts and organic silty clays of --=-= low plasticity ~ Inorganic sills, micaceous or diatomaceous fine sands or silty soils, elastic silt clay ~ Inorganic days or medium to high plasucily, sandy fat clay, or gravelly fat f---o--rg-a-n-ic----f--O-H---f.j~ ::/?", Organic days of medium to high , / -:::' plasticity, organic silts color, and organic odor PT Peat, humus, swamp soils vvith h~ NOTE: No.4 size = 5 mm; No. 200 size = 0.075 mm 1. Dual sYmbols (symbols separated by a hyphen, i.e., SP-SM, slightly silty fine SAND) are used for soils with between 5% and 12% fines or when the liquid limit and plasticity index values plot in the CL-ML area of the plasticity chart. Heather Downs Park Development Renton. Washington SOIL CLASSIFICATION AND LOG KEY October 2005 21·1-20373-001 ~ SHANNON & WILSON, INC. FIG. A·1 Ir Geotechnical and Environmental Consultants 2 of 2 2. Border1ine symbols (symbols separated by a slash, i. e .. CUML, sifty CLA Y/c/ayey SIL T; GW/SW. sandy GRAVEUgravelly SAND) indicate that the soil may fall into one of two possible basic groups. ~L-____________________________________________________ .. ________________________ ~ __ ~S~~~~ __ ~ File: J:\211\20373-001\21·1·20373-Q01 TPs.dwg Date: 10"()7·2005 Author: SAC SHANNON & WILSON, INC. Geotechnical and EnvttonmanlaJ eons.n1I LOG OF TEST PIT TP-1 SOIL DESCRIPTION (/) -o~ ~-(I) (I) <: <: (I) -(I) a. ::>-Ol-E o Ol !:§ c'5!: Ol cf!.() C/) CD Medium dense, rust brown, slighUy gravelly, silty, fine to medium SAND; dry to moist; (Fill) SM. -0 0 Loose to medium dense, gray, ~ III (/) round gravel; dry; (Fill) GP. .0 0 CD Medium dense to very dense, light III <: 0 brown to gray, slightly gravelly, Z Slightly silty SAND; moist; (Weathered Till) SM. o Dense, light gray, slightly silty, I S-1 slightly gravelly, fine to coarse SAND; moist; (Glacial nil) SP-8M. S-2 " C5 > NI I S-3 , JOB NO: 21-1-20373-001 DATE: 9-29-2005 LOCATION: See Site and Exploration Plan PROJECT: Heather Downs Park Development, City of Renton ..; LL_ I Sketch of :; c. III North Pit Side Surface Elevation: Approx. 413 Ft. Horizontal Distance in Feet Cl 1 2 3 4 . \';' (IA~'\' I ~ 1 . . . Rootlets . J .J l. '" \ '-'I l. \~Jt 1 CD ->~) , , /-::;',.,',::-; <;1:i:'-c~;~';:';-;::<5:' 2 V r -, Concrete r -.-I'_':;-'r --'~-'r:>_../ ',--.../ • -" oy~/ -< , , l'::;-;"~ ~rain Pipe p<:;J:i5i-1J"'~~-{ ~ ;-~.~ ~ ::--:--:::::: .~ ';E"'~'< r~t'"" '/ ;"\",j' ::::-:----:-: WoOd ~ ""-. J..~'-:'W~=c/.,0 ,~,-;,--.-,. . A--r'if'U' :----.c~ '(_ \'1 ~ ~"i;:-YC , )..~,.\--.:-'..r-~ )---/~-\7'::17' i~ ;fL.;, f''''4\~' • i'(-~ I\..) ,~. • ", '_,j' .. __ -r, ~'( '~t f "-·/,..c~·C-r'-'~~~'-:-C:;T·._1~.,_-:_~_ f'3\ ,-~ ..... , .:>"''-'<."''-::(-'~;"""'-Y"~'t~-'T 1'--/ r-y \V 31Iq'~f '-, -:;~ ')'''';/ :-', . ~. ~'~"" .J" / \:'-" \ i '"'~ ,J" ~ J '--' -*-~-""' .. :l r~-i, f ..., _ <:: ..J-_, ___ ~ _.( ~~_/ -,,--,r'7--~;t~-:::'-~/~:J ::.-:' ';(.:::"i\_''",. ~I'-·o,,--_·~ -" ' '-InCised Fill ;<--.--\~--../. . :--y ,. , 4L . . .... _ .. n.. ... ~ 5' 0 6 File: J:\211\20373-001\21.1·20373-001 TPs.dwg Date: 1()..Q5-200S Author: SAC SHANNON & WILSON, INC. GeoteclNlical and Elwironmental CoosLManl5 LOG OF TEST PIT TP-2 G) CD o h "11 i5 ,. c:. SOIL DESCRIPTION Medium dense, brown. slighUy fine grav""IIy, silty. fine to coarse SAND; dry; occasional rootlets; (Fill) SM. Loose to medium dense, rust orange, slighUy fine gravelly, silty fine SAND; moist; occasional rDOUets; (Weathered Till) SM. Medium dense to dense, light gray to tan. slightly silty, slightly gravelly, fine SAND; moist; becomes more moist with depth; (Glacial Till) SP-SM. NOTE Bottom of Test Pit at 8 feel JOB NO: 21-1-20373-001 DATE: 9-29-2005 LOCATION: See Sije and Exploration Plan PROJECT: Heather Downs Park Development, City of Renton .... _ U> "0 ..... CDc: Q) Sketch of East Pit Side Surface Elevation: Approx. 411 Ft. §S (U.s c. e ~ 5: is ~ Horizontal Distance in Feet <.!l ;j1.U V> 1 2 3 4, 5 6 l II> U> .c a ., c: o Z S-1 S-2 S-3 J t(~)~~~~,;.U~)0J'U~)~JtD5S0JUlh) II ,J~..-:--~:.~~~ .. " ..... ...• 1~~,' ," pvc Orain Pipe ~~U;;..", .' . 1'<1 ·F"! ',' .' , :.::;::-<\ .,.i.'-:-/ G) 21 3 I ' CD 4-----f 51 --- J '" '0 - . . . I . ..... File: J:\211\20373-001\21-1-20373-001 TPs.dwg Oate: 10-05-2005 Author: SAC SHANNON & WILSON, INC. Geotechnical and Environmental Consultants LOG OF TEST PIT TP·3 SOIL DESCRIPTION CD Very loose to loose. tan to light brown, silty fine SAND; dry; occasional organics; (Weathered Till), ® ." !i' t Very dense, light gray to tan, slightly gravelly, slightly silty, fine SAND: dry: (Glacial Till) SP-5M. 'O~ " ., :>-~~ '0 ~ V> .c o ., c: o Z ~"E -., ~g ~u o JOB NO: 21-1-20373-001 DATE: 9-29-2005 LOCATION: See Site and Exploration Plan PROJECT: Heather Downs Park Development, City of Renton ., ., 0. E ., (IJ Ii ~ ., D 10 S-l I 2 3 S-2 I 4 -' 5 S-3 6 Sketch of East Pit Side Surface Elevation: Approx. 408 Ft. HOrizontal Distance in Feet 1 2 3 4 5 Tree and Blackberry Roots ® 6