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Rinkcr Materials <br /> July 23,2003 <br /> Page 5 <br /> SETTLEMENT MONITORING <br /> At thc complelion of the 2000 grading season four reference survey stakes were installed at <br /> thc ground surface for monitoring long-tertn setdement of the deep fill areas. The refercnce <br /> stazcs consistcd of a 2—toot long section of rebar. The stakes were dnven into the fill placed <br /> during 2000 bclwecn llie west edgc of Lot H and the cen(ral portion of Lot J. The sWctural fill in <br /> this arca is about 50 feet deep. <br /> '1'he survey stakcs were installcd on Ocrober 30, 2000 and wcrc monitored until Octobcr 8, <br /> 2001. Significant grading activities commcnced again on thc site around Junc 2001 and all of thc <br /> grading equipmcnt was staged around thc survcy stakes from aUout June through Octobcr 2001. <br /> Thercforc, a(ter the ]unc A, 2001 readings some of thc obscrvcd scttlemcnt may havc been <br /> induccd by thc hcary cquipment loads. I�ctwecn�OctoUcr 2000 and June 4,2001 onc survcy stake <br /> indicated no setticmcnt, two survcy stakcs scttled about 0.1 inchcs, and one about 0.4 �r�hcs. <br /> Although survcy measuremcnts continued to October 8, 2001, Ihc resulls of Li�c data may havc <br /> bcen influcnced Uy the hcavy cquipmcnt adjaccnt to the stakes. Ilowcver, evcn with possible <br /> sctticmcnt induccd by thc hcary cquipmcnt,the maximum total sctticmcnt oUscrved was less dian <br /> :�bovt 0.7 inches with di(Ccrcnlial scttlemcnt Icss than 0,4 inchcs ovcr approximately 200 fcet. <br /> L'ascd on our cvaluation of thc survcy data, to[al settlemcnt of the decp fill areas wzs less than <br /> '/.inchcs and diffcrcntial sctticmcnt ovcr approximatcly 200 fcet was Icss than 0.4 inchcs. Wc <br /> anticipate that settlement of the Gll undcr its own wcighl is substantially complete at this time and <br /> that future setticmcnt will bc less Uian 0.5 inches total and 025 inches differential. <br /> FSA DETENTIC�N POND <br /> During gcading in 2001, groundwa(cr sccpagc was obscrvcd emanating from ncar thc top of <br /> thz highwall cut Iceatcd on �ac Scaway Lot 8 property, immediately wcst of thc Pood Serviccs oC <br /> Amcrica (PSA) detu�tion pond. Thc top oC thc highwall was ]ocatcd about 5 to 10 fcct west oC <br /> t6c PSA properiy line. Thc secpagc was unusual io this area at the obscrved cicvation bccausc <br /> groundwatcr is]ocated bclow the bottom of the mincd piL The obscrved scopage was evidcnt as <br /> a wet spot on Au higLwall that was about 25 feet long and 10 fect high and at a�out tha samc <br /> elcvation as the PSA detcntion pond. Occasionally, frec tlowing water was observed emanating <br /> from thc highwall tivouglt mare parous layers within thc sand and gavcl outwash deposit. Thc <br /> scepagc was ty7�ically]css tlmn aboul%,gaflon per minutc. <br /> 12ic quantity of sccp:.ge appeared to incrcase and decrease in responsc to thc walcr Icvel in <br /> Uic PSA detention pond. I; is our opinion that thc obscrvcd secpage was the resull of detcntion <br /> pond watcr infiltntirg into the ouhrash soils and migraling to thc highwall. <br /> Ne rcconmicndcd to Rinkcr Matcrials that rSA Uc conlactcd to havc thc pond lincr <br /> (compacicd till fill) cvaluatcd for Ieals nnd/or to sec that it was reconswcted propedy. Wc <br /> understand that a lincr may nat have been consWctcd, cspccially on the wesl cnd •.vhcrc the <br /> outwash sand and gravel deposi�s �r�ere expcsed along the base of the pond. Accordingly, we <br /> recanmiended that the pond lincr be properly dcsigned and consWc!ed. <br /> 13ascd on our obscrvations, it is likcly lhat watcr scepagc froni dic PSA dcicntion pond will <br /> infilu,de into thc swctmal fill locatcd adj.aent to thc wcst of �he pond. Sccpage Gom the <br /> Geolin � i ncers PileNo. 619:-IX1J-07 ' �� I <br /> J / <br /> C � <br /> j <br />