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Sent 6y: �art!i Consultants A25 74G 0060; 06/79/02 4:57PM;JCtFex �563;Pave 3 <br /> Panattoni Development E-1D134 <br /> June 19, 2002 Page 2 <br /> infiltration Evnluation <br /> Wc underst�nd it is planned to infiltrato roof downspout stormwater from the <br /> proposed development at each buildmg location. As part of this ovaluation, we <br /> conducted an intiitration evaluation to determine the feasibility of infiitratinq <br /> stormwater and roof runoi( at the site. At the time of our study, we were provided <br /> with :� general location for the proposed iniiltration areas. O�r infiltration evaluation <br /> consisted of ihe following: <br /> • Excavating eight test pits at the proposed infiltration areas; <br /> • A textural analysis of representative soils from the infiltration areas; and <br /> • Intcrpreting thc iir.ld data and laboratory ans,lyses in order to provide infiltration <br /> rates for thc: proposed infiitration areas. <br /> Textural Analysis <br /> Subsurface conditions wer�: evaluatc�d by excavatinc� elght test pits within the <br /> proposed infiltration locatior�s. I est pit logs are presented in Appendix A. Grain size <br /> analy,es were conducted on representative soils. Based on our yrain slze analyses, <br /> the proposed infiltration areas in the vicinity of Test Pits TP-1 through Tes[ Pit TP-6 <br /> are underlain by coarse sands. 7he proposed infiltration areas in ihe vicinity oF Test <br /> Pit TP-7 is underlain by fine sandy IoanL and Test Pit TP-8 is underlain by <br /> approximately five (eet of coarse sand overiying tine sandy loam. No gruundwater <br /> sr_epaye was encountered at the time of tF�e field work (Jui?a, 20021. <br /> The soil conditions encountered at the site are consistent with c�eologic mans for this <br /> vicinity. Soils in the proposed development are mapped as advance placiAl outwash, <br /> consisting primarily ot puorly sor[ed sands with variable gravel content underlyiny <br /> silty sand with qravel glacial till. <br /> Infiltratioiy Recommendaiions <br /> Uased on the results of thc ficld exploration and tc�xtural analyses, it is ECI's opinion <br /> that infiltration of stormwater and roof runoif should be feasible in the proposed <br /> � development areas in the vieinity of T � rts TP-1 through Test Pit TP-6. For design, <br /> � an ultim�te infiltration rate of twenty (20 inches per hour can be used. Infiltration in <br /> the vicinity o( 7est Pit -1 P 7, below fiv eeT, and Test Plt TP-B will not be feasible. <br /> nb Comuttanq, Inc. n �2 <br /> D��h«���� ��m� , <br />