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intercepted by temporary drainage measures and routed to the sediment ponds, from which the flow is ultimately evaporated or discharged to the North or South Creeks. As mentioned previously, the LFGTE facility will occupy 0.41 acres of the 744-acre Forward Landfill site. The development will result in approximately 0.27 acres (11,700 square feet) of new impervious area. The LFGTE facility will be graded to allow storm water runoff to sheet drain to the south to match existing conditions. Currently runoff from this area is captured in a borrow area (refer to SWT Engineering Figure 2 in Appendix C), which acts as a detention and infiltration basin. When Phase 8 of Forward Landfill is constructed (refer to BAS & Associates Sheet 5 in Appendix C), runoff from the LFGTE facility area will be conveyed via a perimeter channel which runs along the east side of Phase 8 and Phase 9 and the south side of Phase 1, into Retention Basin #2 which discharges to the South Fork of Little Johns Creek (refer to BAS & Associates Sheet 9 in Appendix Q. According to the Joint Technical Document(JTD) dated May 2002, storm water drainage control facilities at Forward Landfill were sized using the Rational Method and the design criteria in 27 California Code of Regulations (CCR), Section 20320. For Class II waste management units, 27 CCR Section 20320 requires that permanent storm water runoff and drainage control facilities be designed to carry the peak discharge resulting from a 1,000-year 24-hour storm event. The runoff and coefficient and rainfall data used were based on criteria in the County of San Joaquin Hydrology Manual. Utilizing the method presented in the JTD, the proposed new impervious area of 11,700 square feet is calculated to increase the subarea runoff rate from 23.23-cfs to 23.28-cfs (see calculations in Appendix Q. This increase in runoff rate into downstream perimeter channels and retention/sedimentation basins is negligible. In accordance with State Water Resources Control Board Requirements,Ameresco will apply for coverage under the General Permit (GP) for Discharges of Storm Water Associated with Construction Activity (if necessary) and the GP for Discharges of Storm Water Associated with Industrial Activity. As required by the latter, a Storm Water Pollution Prevention Plan (SWPPP) will be prepared for the LFGTE facility. C:\Doc=ents and Sctongsyesmcasees\Desktoff orwerd LFGTE-Project Description.doc CORNERSTONE 4-4 Orevp.LLC LEWIS ENGINEERING Evvixvv mavlal