3003 W CASINO RD 1992 SITE DEV 2018-01-01 MF Import

RciJ MidJic(nn & Acuoci,ucs Septemhcr 2. 1992 Pagc 4 Suhsurl;uc nmdilions wi�hin and undcrlying thc c;inh �;im �mlianki»�m and in Ihc vicinity ol lhc delenliun punJ nrc Jiscusscd in separntc sectiuns hclnw. Earth Dam The carth dnm was cunslruc�ul uf lill Jerivul fium glacial till. '1'he fill generally consists of silty sand with occasional gravel, cohhle,e and ��rgnnic matter. Lahoratnry tests indicate that the fine�s content (the amount of soil matcrial passing the U.S. no. 200 sieve) ranges Gom approximalely 34 to 37 percent. Dasu1 on continuous Mow count dala from the three borings, the fill is uniformly meclium dense. Native soilx underlying the fill comprise advance glacial outwash. These soils generelly conxist of mulium dense tn very dense interheclded sand and gravel with variahle amnunts of silt. No ground water seepagc w;is cncuunlcrcJ in th� d;un fill ur underlying n�itive soils at the time of our lield explorati�ms. Detention Pond Suils in the vicinity uf ihe proposu� detentiun punJ �x�rmsiun incluJe gl�ici�il lill underlain hy advance oWwash. The till, consisting ol' mulium Jeme tu ��cry dense siliy sAnd with occasional gravel, cobhle,e and boulders, wax observecl in explorations on the west ravine slope down to an clevation of approximately 4G3 fcet. 7he till is underlain by medium dense to vcry dense interbeddeci sand, gravel, silty sand and silt extending to the completion depths o(the �est pits. 'Ihese outwash materi:ds are relalively pervious. In 7'P-I and TP-5, IocateJ on the bouom uf the ravine, we encour.tereci a thickness uf 0.5 tu 2.5 feet o1'till overlying native outwash soils. The fill consists of loose lo dense silty sand and mrdiwn uiff sili with ncc;isionel FfBVI'I. l'I�III�ICS and organic mnttcr. Ground Water Conditions No gruimd water sec��agc �eas uhscrvrd in �m� uf uur huring.� ur �est pil expluratiuns completeci on August 24 anJ 25, 1992. A perchul gwunJ water condi�inn typic�lly occurs within rclelively impenncahlc zuncs uf glaci:d till. Ilccause the till c:qi was unly cncounter�l abnvc I:levation 4G3, it is unlikely �hat signilicant groimJ watcr will he encuumeral during grading 1'ur Ihe ponJ expansion. Conversely, it is impunant that a cnminuous. impermcahle liner he cunstructuJ ti�r �he pond hnttum tu cuntrol seep:�ge through �he suhsiui:�cr sanJ �md �!ravrl suils. 'lliix reeuntmendation is discussul in detail in [he liilluwing seclion. CONCLUSIONS AND RECOMMENDATIONS GENERAL Our conclusinns and recommenJAtiuns are h.ised un nhservatiuns made durinb uriginal cunstructinn of Ihe eanh dam anJ detention p�tind. the results nf our present evalu.ilion uf the sile (i c u G n E i n e a r F File Nn.0120-150�R10