11632 EVERGREEN WAY BASE FILE 2018-01-01 MF Import

- 7-1443 �i Proposed Retail Dcvelopment February 26,2004 1]2'h Shcct and Hwy 99 Page 7 � / Evered,Washington \ � Layers of organics and peat were encountered in test pits TP-1,TP-7, and TP-8 dwing the i Octobcr 2002 Limited Phase II Environmental Assessment as well as in borings B-11, B-24, and i B-30 completed as pari of this evaluation. The soft peat varied in thiclmess from 1 to 6'/s feet and ., was covered with 3 to 6%: feet of undocumented fill. 'fhe peat appears to occur randomly across � !he sitc and should be expected in areas ttiat were not disclosed during our evaluations. The i mterpreted thickness of peat and undocumented fill is presented on , Figure 1, the 3ite and , � Lxploratin Plan. ' i During the October 2002 Limited Phase II evaluation, hydrocarbon odors •.vere noticed � during the excavation oFtest pits TP-7,TP-9, and TP-17. Laboratory test results indicated that the Total Petroleum Hydrocarbon concentrations varied&om 140 ppm to 660 ppm,below the MTCA � Mcthod A cleanup standards. lmpacted soil may be encountered during earthwork-related phases of the project. The impactcd soi] observed in test pil'�'P-9 (October 2002 evaluation) appears lo � be within the proposed stream realignment. I Access Road Alignmcnt � Borings B-I, B-2, and B-33 were completed along the proposed alignment off of 112'� � Street. A majority of the alignment was covered with grass with smaller azeas covered with brush i and trecs. The subsmface conditions encountered consisted of 2 to 3 fcet of loose silty sand with some grave( interpreted to be fill. In the topograplucallY hiBher portion of the access road r.ear I 112'� Street, boring B-I encountered a 6-incl� thick relic topsoil layer that cor,sisted of silty sand � below 2'/� feet of undocumented fill. In boring B-33, 2 feet of loose soil was encountered that � was also intecpreted to be Gll. Beneath the fill materials, medium dense grading to very dense soils were encountcred. In general,the dense soils were interpreted to be glacial till. Proposed Stream Realignmcnt I Borings B-18 through B-21 were completed along the proposed stream realignment. Surface cover varicd between grass, asphalt and baze soil. Where grass was present, the topsoiUraot zone varied between 4 and 6 inches thick. We interpreted the subsurface condirions to consist of 4%z to S'/z feet of loose to medium dense silty sand and gravelly silty sand that was interprctcd as probable structu�•.1 fill. Beneath the fill,very loose lo loose,silty sand and gravelly silty sand with varying amounts of woody debris (roots) was encountered to depths of 9 to 14'/z bclow grade. Below the ver�loose to loosc soils,a variety of soils consisting of inedium dense to very dense gravclly sandy silt, gravelly silty sand and sand with some silt and gravel was encountered to the full depths explored. Proposed Building Pad Borings B-3 through B-15 wcre completcd within the proposed building pad. In 7 of the 13 borings,undocumented Fill material consisting of very loose to mediutn dense, crushed gravel, quarry spalls, silty sand, and silty sand with some gravel was encountercd and varied in thickness form approximately 4 inches lo as much as 9'/x fect. The deepeet fills were encountered in borings B-6, B-7, R-11, and B-12, with respcctive depths of 9'h, 7, 5, and 4'/:feet. In boring B- C11, approximately 6'/: fect of very soR to soft peat was encoun[ered bcneath the 5 feet of quazry J-1443,022604 1 '