COMPLIANCE INFO_JTD 9/3/2025 - Laserfiche WebLink

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WASTE DISCHARGE REQUIREMENTS ORDER R5-2015-0058-01 -26- SAN JOAQUIN COUNTY DEPARTMENT OF PUBLIC WORKS FOOTHILL SANITARY LANDFILL, INC. FOOTHILL LANDFILL SAN JOAQUIN COUNTY b. An LCRS or a Leakage Detection System (LDS) within a double liner system. 110. The Discharger propose to construct one new Class II surface impoundment (Calaveras SI, see Finding 9) to contain and evaporate leachate from MSW WMUs. The Discharger propose using an engineered alternative, High-Density Polyethylene (HDPE) liner instead of clay liners, to meet Title 27 construction and design standards for the Calaveras SI. On 7 March 2024, the Discharger submitted Design Basis Analysis Calaveras Surface Impoundment, which included a conceptual design, preliminary construction drawings, water balance, and slope stability evaluation for the proposed 1.5-acre surface impoundment. On 23 April 2025, the Discharger submitted an updated water balance to include LF-1 condensate volumes to the surface impoundment. 111. Pursuant to Title 27, surface impoundments shall have sufficient freeboard to accommodate seasonal precipitation and the design storm specified in Table 4.1 of Title 27, division 2, subdivision 1, chapter 3, subchapter 2, article 4, but in no case less than two (2) feet (measured vertically, from the water surface up to the point on the surrounding lined berm or dike having the lowest elevation), and shall be designed and constructed to prevent overtopping as a result of wind conditions likely to accompany such precipitation conditions (Title 27, § 20375, subd. (a)). 112. The WDRs require the Discharger to submit an Operations and Maintenance plan for the Class II Calaveras SI unit. The Operations and Maintenance Plan must outline strategies and methods for evaporating leachate, minimizing vectors and odors, managing pond levels, conducting liner inspections, cleaning the ponds, and other relevant information and detail how the Discharger will maintain compliance with the WDRs and the requirements of Title 27 implemented there under. (See Facility Specification C.3 and Provision H.9.k). 113. The Discharger submitted preliminary Construction Plans for the construction of Calaveras SI, which incorporate the engineered alternative outlined in Attachment H. 114. The Discharger proposes the following base and slide slope double liner system (top to bottom): a. Base: i. Primary 60-mil HDPE geomembrane; ii. Geocomposite (leak detection layer); iii. Secondary 60-mil HDPE geomembrane; iv. 1-foot prepared foundation layer; and v. Subgrade or engineered fill. b. Side slopes i. Primary 60-mil HDPE geomembrane; ii. Geocomposite (leak detection layer); iii. Secondary 60-mil HDPE geomembrane; iv. 6-inch prepared foundation layer; and v. Subgrade or engineered fill.