SITE INFORMATION AND CORRESPONDENCE

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S.R. Moore 9 2 - 20 March 200 Duel Vocational Institution 4. Item No. 7 from staffs 15 November 2005 review of the RWD states: Since the facility is in a 100 year floodplain, the following (Title 27, Section 21750(d)(2)) needs to be submitted: (a) engineering analysis to indicate the various hydrodynamic and hydrostatic forces expected to result at the site as a consequence of a 100 year flood and(b) structural or other engineering studies showing the design of the ponds and the flood protection devices at the facility and how these will prevent washout. This information was not included in the revised RWD. 5. A description of the surface area, depth, and volumetric capacity with two feet of freeboard shall be provided for each pond. Class II surface impoundments structures shall be constructed and maintained to prevent, to the greatest extent possible, inundation, erosion, slope failure, washout, and overtopping under 1000-year, 24-hour precipitation conditions, and shall be designed to contain the 100-year wet season precipitation without using the required two feet of freeboard. A water balance shall be provided that includes a two-year projected monthly water balance for the proposed facility demonstrating adequate containment capacity for the 100-year return period total annual precipitation, including consideration of at least the following: a.. A minimum of two feet of freeboard in each pond at all times. b. Historical local evaporation data(monthly average values). c. Local precipitation data with the 100-year return period annual total distributed monthly in accordance with mean monthly precipitation patterns for the first year followed by an average precipitation year. d. Proposed wastewater loading rates distributed monthly in accordance with expected seasonal variations (if applicable). e. Include the 1000-year, 24-hour precipitation event. 6. There are no shallow groundwater monitoring wells installed at the facility. The groundwater direction of east/northeast has been approximated based upon the deep groundwater water supply wells installed within the deep aquifer (total depth 490 to 615 feet). Based upon discussions with Mr. Kalkman of Carollo Engineers, three monitoring wells will be installed to initially determine the groundwater gradient. Once this gradient is established, one or more groundwater monitoring wells will be required such that the detection monitoring well network complies with Title 27. 7. The revised slope stability report was reviewed and needs additional information to comply with the requirements of Title 27 Section 21750(f)(5). The analysis evaluated the stability of the fill foundation pad that the ponds will be constructed in. The liner system was not evaluated. Title 27 states, "The stability analysis shall ensure the integrity of the unit, including its foundation, final slopes and containment systems under both static and dynamic conditions throughout the units life, closure period and post-closure maintenance period (emphasis added)." A report shall be provided that includes an analysis of the liner system and the weight the waste exerts (at maximum storage capacity) on the liner system. The analysis shall include the shear resistance/strength of the geosynthetic layer and soil.