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' V N TRACY MATERIALS RECOVERY&TRANSFER FACILITY RFI AMENDMENT NO. 3 maintained on-site with approximately 1.4 feet of freeboard for a design volume of 17,000 cubic feet. (Memo from August 1, 2006 attached). Edgar& Associates, Inc., a the design review engineer, used the SCS TR-20 model to determine the design storm over 150,000 square feet, based a 100- year, 24-hour design storm event of 2.8 inches, the run-off amount totals 22,517 cubic feet, higher than the design storm of 17,000 cubic feet for the 90,000 square foot pad. The evaporation pond has adequate capacity to retain the run- off from the enlarge compost pad of 150,000 square feet. Engineer's Review: The drainage system is adequate to manage the run-off generated by the increase size of the compost pad of 150,000 square feet. The run-off from the wood waste processing pad drains to the retention basin that was designed to handle 223,025 square feet of service area including the area where the wood waste processing pad is located today. The current language on page 24 and page 25 is descriptive with the calculations in Appendix E. The only changes to the RFI on page 25 would to replace the last line of the first whole paragraph with the following below: "The evaporation pond is sized to retain up to 57,500 cubic feet of run-off without freeboard, and is adequate to retain the 100-year, 24-hour storm event over 150,000 square feet compost pad for a design storm of 22,517 cubic feet, leaving approximately 35,000 cubic feet of freeboard capacity." Appendix E can be supplemented by the current EBA memo, the Edgar Associates hydrological calculations, and the as-built plans. The additions to Appendix E are attached to this RFI Amendment. The pond has never filled in the 12 years of operations since the design is for the 100-year storm with two feet of freeboard. Therefore the contingency plan has not been exercised to date. However, the compost leachate has been tested. Attached is a set of lab results from compost leachate in the pond from early 2006 focusing on pesticides where it is mainly non-detect. We have researched compost leachate run-off from various studies where the strength of the compost leachate from green material feedstock is weak, coupled with large storm events that would further dilute the run-off. The compost leachate would be accepted at any wastewater treatment plant. A study from Oregon is attached, and further studies can be referenced in the upcoming CEQA document for the SWFP Revision. This contingency plan has been in place since 1993 without the need to have a letter of record from a waste water treatment plan. We can conduct further analysis beyond pesticides to review the strength of the compost in relation to pH, BOD, and other pollutant types. In most cases, compost leachate is now being viewed as a beneficial resource, "compost tea", with proper application. In context of this RFI, and with the over design of the pond facility, we request the EDGAR&ASSOCIATES, INC. 10 NOVEMBER 6, 2006