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Rcid Middlc�un & Associ;tics <br /> Septemher 2, 1992 <br /> Pagc S <br /> conJitiuns,and uur experience wilh similar prujetix. In general, we conclude that site cunditions <br /> nre suitahle for the pond expansion providui a continuous impermeahle liner is conswcted as the <br /> pond bottom. Detailed recommendations ti�r �:onstruction of this liner and our evniva�ic,n of thc <br /> ezisting earth dam arc presenteJ hclow. <br /> EARTH DAM <br /> The re,euhs of the IicIJ and lahuratory tests on samples of soils in the horings indicate <br /> medium dense silty sand thruughout lhe depth of the emhankment. The gradation test results uf <br /> 34 percent or more of malerial finer than thc U.S. No. 200 sieve and the ahsence o(any seepage <br /> in the borings suggesl no scepage through the dam. Also, the results of denxity le.ats on thc <br /> samples indicale relative densities equal to or greater than the minimum density specified for <br /> constructinn. Tlierefore, it is our opinion that the earth dam was conswcted as designed ucing <br /> suitable materials anJ constructiun melhods, and we find no evidence of degradation of fill <br /> material �hat might compromise the swclurnl integrity of�he dam. We feel thnt the condition <br /> of the d•am is adequate for the prn��uxcd pund expansiun, given that thc design w.iicr surl'ace <br /> elevatinns are to he unchanged. <br /> PQND EXPANSION <br /> Wilhin the anlicipatecl arca ol'dden�iun pund cxpansiun. �hc rclatively perviuus native snils <br /> are similar to the native suils underl}'ing ihe exisling pond liner. In order to contain water for <br /> the proposed permanent pond expansion, we recummend that the imperviuus soil liner that exists <br /> under the present pond he extendul. We recommend thal criterie similar lo Ihose used (or design <br /> and consiruc�ion uf the ezisting lincr, which are presentul in our supplemental report dateJ <br /> July 9, 1984, he usu! tiir Jesign and construction of the expanda� pnnd. 'Ihese criteria include <br /> the fhlluwing ilcros: <br /> �. The liner should he cunstructed using nn-site we,�thered nr unweathercd �ill material with <br /> a tines conlem of et least 20 percem. 7'his m.iterial shnuld he I'ree of si�nilicam urganir <br /> and other deleterious malerial. We recummenJ a represema�ivc liam �wr �um hr ,m si�c <br /> lu atisist in identifying suitaMe horn�w sources. <br /> 2. The liner shuulJ have a minimum comp:ictul thickness uf 2 feet. <br /> 3. Tlic new liner should he made tuminunus wiih the existing liner hy sc;uilying. ihun�uph <br /> mixing and cumpacling th� �ill m:ucrial with a minimum ovcrlap wid�h u( q {i�� ,�i ili�• <br /> juncture Hith the existing liner. <br /> 4. 7he liner zhuuld extend at Ie;�st 3 (eet ahuve thc marimum ezpected water xurf�ce elevatiun <br /> in thc permanent ponJ. <br /> c i o c � p i n . , r > <br /> i Ilc N��. nl?U I5�1 RIO <br />