ARCHIVED REPORTS_1996_2 - Laserfiche WebLink

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WASTE DISCHARGE REQUIREMENTS _10 - FOR CITY OF STOCKTON AUSTIN ROAD LANDFILL FACILITY CLASS III LANDFILL SAN JOAQUIN COUNTY 15. All new containment systems shall: include a composite finer which consists of an upper synthetic flexible membrane component *(synthetic liner or SL) and a lower component of sod. The SL shall be at least 40 -mils thick (or at least 60 -mils thick if high density polyethylene) and shall be installed in direct and uniform contact with the underlying compacted soil component. The lower component shall be compacted soil that is at least two feet thick and that has an hydraulic conductivity of no more than I x 10' cm/sec (this specification is referred to as the Prescriptive Design). For landfill covers where clay is compacted over refuse, a hydraulic conductivity of I x 10l cm/sec may be substituted for the I x 10' cm/sec requirement. 17. New landfill units and lateral expansions shall not be located in wetlands unless the Discharger has successfully completed, and the Board has approved, all demonstrations required for such discharge under 40 CFR 258.12(a). 18. Landfill leachate shall be disposed of by a Board -approved method. Surface Impoundment Specifications 19. Design and construction plans and specifications, including a construction quality assurance program, shall be submitted to Board staff for approval before constructioT of any surface impoundment. After surface impoundment construction, a construction quality assurance report shall be submitted to the Board and approved by Board staff prior to operation of the surface impoundment. Landfill Closure Specifications 20. At closure, the unlined modules shall receive a final cover consisting, at a minimum, of a two -foot thick foundation layer which may contain waste materials, overlain by a one -foot thick clay finer, and finally by a one -foot thick vegetative soil layer, or an engineered equivalent final cover approved by the Board pursuant to Subsections 25 1 0(b) and (c) of Chapter 15. Lined landfill modules, or portions thereof, shall be covered with a barrier layer having a permeability at least as low as the liner. 21. Vegetation shall be planted and maintained over each closed landfill unit. Vegetation shall be selected to require a minimum of irrigation and maintenance and shall have a rooting depth not in excess of the vegetative layer thickness. 22. Closed landfill units shall be graded to at least a three percent grade and maintained to prevent ponding.