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' l�eccmber 15. 1992 4 9?3-1184 <br />feel in TP-3 attained a maximum Ihickness o( 9.8 (ect in TP-4. l'he inferrcd <br />' thickness o( thc pcal is shown on I�igurc �. <br />, • Clayey Silt - During our 1987 subsurface invesli�alion, (inc-grained soil was <br />� encounlered in hvo lest pils localed ivilhin the central porlion of Uie site. 7'he <br />fine �rained soil consisted of sofl, li�hl rcddish brown Io lighl blue-groy, clayey <br />I silt and silly clay wilh a Irace of organics. This soil tvas encountered at deplhs <br />of 2(cel and 7.5 (ecl tvilh lhicknesses o( G fcet and 3 fcet, respeclively. In <br />�;cncr:il lhc clayry silt was ovcrlain by fill and pcal and undcrlain by nalivc lill. <br />Wealhercd 'I'ill - Wealhercd lill tvas encountercd at the surface along the <br />weslem, clevaled porlion of the sitc in lest pils TP-1, TP-2, and TP-7. Thc <br />weathered lill mnsisled of loose lo compacl, moderale brotvn, (ine lo medium <br />sand tvith sonte silt and lillle lo some gravel and Iraces of rools and organics. <br />'ihc wcalhered IiU exlended lo a maximunt deplh and ihickness o( 4.1 (ect in <br />TP-7. <br />'I'ill - Till was cncounlerccl brnealh Ihe �vcalhercd lill along Ihe weslcrn sidr of <br />Ihc silc, al lhc surfacc in TP-10 localed in lhe easl-cenlral porlion o( thc sile, <br />and bencalh Ihc fill and ��cat Ihroul;hout Ihe remaindcr o( lhe properly. The <br />till ronsisted of densc lo vcry dense, li�lil olivc gray to mcdiinn gray, finc lo <br />medium sand and gravel tvilh some sill and lrace cobbles. The till exlended lo <br />Ihc full deplh of our exploralions in all of the tesl pits exccpt T'P-12 �nd �'P-13, <br />whcrc it was undcrlain by an ouhvash deposit. <br />Ouhvnsli - Ouhvash dc��osils wcrc cncoun�crcd in lesl pils 71'-12 and 'I P-11 <br />located within the south-cenlral porlion o( lhe sile The oulwash tvas <br />encounlcred at deplhs of 8.8 (cel and fiA fcet, and extended to lhe full depth.o( <br />bolh explorations. In'fP-12 lhe oultvash was ovcrlain Uy Ihe fill, pcat, and till <br />sequcncc tvhcreas in TP-13 only fill and pcat were observed lo overlic Ihe <br />oul�vash. The outwash consisled of dcnsc, light olivc gray lo med n gr�y, <br />sUalificd, finc sand wilh IitUc �ravcl nnd a trace silL Slight to m� �Ic iron <br />slaining was obscrved �vhere gruundwaler �vas present. <br />4.2 Groundwalcr and Surfacc Walcr <br />At Ihc lime of our ficld invesli�;ation on Novembcr 25, 19')2, �roundwaler secpa�c was <br />encoimlered in all a( Ihe lesl pils except l'P-7,'I'P-8,'IP-10 and 7'P-11. Durin�; our previous <br />Invesllg�llolt conducled In Oclobe� o( 1987, ground�valer was enmuntered in 4 0( Ihe 9 tesl <br />pil excavalions. Thc deplh lo groundHalcr ranred from 3.5 fcrl in TP-2 to 11A fecl in TP-12. <br />Ground�vater was obscrved lo bc randuinly present in all lhc soil unils encoimtcrcd at Uic <br />sile. Waler conlained within Il:e loosc fill an� pcal yicl�led widcly varying tlo�v rales <br />indicaling ll�e polenlial (or localized regions ol Ira����ed ground�vater wilhin a given soil <br />horizon. In somc of the tesl ��ils, moJerale �cepagc w�s naled in fill Iying direclly on top of <br />thc till and �vithin thc upper ��urtion o( Ilic tilL Tlic pri�nary sourcc of �roundwalcr wilhin <br />Ihc fill and peal is assuined to bc sin'(acc infillralion. Duc lo thc random appcarance of <br />ground�valcr in Ihc nali��c till il is assumc�l Ihat ha�vJ� scc�,arc �vill only oo_ur in sandy, morc <br />Golder Associales <br />