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( p <br /> 65/24/2�02 15:37 5�32749351 FAFJAT744I DU�FMNT CO FA�E B1 <br /> Panattoni Development E-10134 <br /> June 19,2002 Page 2 <br /> � Inflitratlon Evaluetton <br /> We understand it (s lanned to infiltrate roof downspout stormwater from [he <br /> proposed development lat eech building location. As part of this evaluation, we <br /> conducted an infiltrati�n evaluation to determine the fe25ibility of infiltrating <br /> stormwater and roof ru off at the site. At the time of our study, we were provided <br /> with a general location�or the proposed infiltration ereas. Our infiltration evaluation <br /> consisted of the foliowi g: <br /> • Excavatin0 eight�est pits at the proposed inflltration areas; <br /> • A texturel analysi$ ot representative soils irom the infiltration areas; and <br /> • Interproting the fi I Id data and laboratory anelyses in order t� provide infiltration <br /> rates for the proposed infiltration areas. <br /> Textural AnalVsis <br /> Subsurtace conditions I ere evaluated by excavating eight test Nits within the <br /> proposed infiltration loc�tI�ions. Test pit logs are presented in Appendix A. Grain sizo <br /> analyses were conductetl c� representative soils. Besed on our grain size analy�es, <br /> the proposed in(iltration lareas in the vicinity of Test Pits TP-1 through Test Pi[ TP-6 <br /> are underlaln by coarse �Sands. 7he proposed intiltration areas in the vicinity o� Test <br /> Pit TP-7 ic undcrlain by fine sandy loam, and Test Pit TP-8 Is underlain by <br /> npproximataly five feot �f coarse sand overlyinp fine sandy loam. No grou�dwater <br /> _eepage wes encountere�i at tha time of the field work (June, 20021. <br /> The soil conditions enco I ntered at the site are consisten[ with yeologic maps for this <br /> vicinity. Soils in the pro�osed davelopmenl nre mapped as advance glacial autwash, <br /> cunsisting primarily af oorly sorted sands witi� variabfe grevel content underlyinq <br /> silty send with grevel glacial till. <br /> Inf�lYration Recommandal ions <br /> I <br /> 9ased on the results ot the field exploration and textural anelyses, it is ECPs opinion <br /> that infiltration of stormwater and roof runoff should ba feasible in the proposed <br /> development areas in the�vicinity of Test Pils TP•1 throuph Test Pit TP-6. For design, <br /> an ultimate infiltration rate of twanry (20) (nchea per hour can be used. Infiltra;ion in <br /> the viciniry of Test Pit TP-7, below five feet, and Test Pit TP-8 will not be teasihle. <br /> Eartn Comultems,inc. <br /> I <br /> I a/71 <br />