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North County RC&SL Page 22 of 64 Public Works/Solid Waste Joint Technical Document County of San Joaquin – Revised July 14, 2025 liner. The base is provided with a geonet drainage layer for the collection of leachate. Leachate drains through the geonet to shallow gravel-filled “V” ditches which drain the leachate through pipes to a sump in Area 1. An operations soil layer, not less than 2 feet thick, was placed on the side-slopes and base prior to the placement of refuse. • Lined Area 3 was constructed in 1995 in conformance to RCRA Subtitle D and CCR Title 27 standards. The base of Area 3 is covered with a composite liner consisting of a geosynthetic clay liner (GCL) under a 60-mil HDPE membrane. The GCL extends under the HDPE approximately 6 feet up the side-slopes. The side slopes are protected by 80-mil HDPE over a minimum 6-inch layer of compacted soil. Base and side-slopes are provided with a geonet drain layer. An operations soil layer, not less than 2 feet thick, was placed over the geonet prior to the placement of refuse. Leachate drains through geonet to shallow “V” trenches, then through pipes to a leachate sump. The interface between Areas 2 and 3 is composed of an anchor trench/berm, raised approximately three feet above the surrounding surfaces. • Lined Area 4 was constructed in 2003, also in conformance to RCRA Subtitle D and CCR Title 27 standards. This area is lined with a composite liner comprised of 60-mil HDPE over GCL. On the side-slopes, the composite liner is placed on a 6-inch thick layer of prepared soil, and is overlaid by a geonet drain layer. At the base, the composite liner is over a one- foot thick layer of soil with not less than 30% passing No. 200 sieve, compacted to not less than 90% relative density. A 9-inch layer of pea gravel is installed above the base liner, over which filter fabric and not less than two feet of operations soil is placed. In addition, the first two feet of refuse placed on the operations layer is “packer waste” or other material free of large objects that could penetrate through the operations layer and the liner beneath. • Lined Area 5A was constructed in 2015, and Lined Area 5B was constructed in 2017. The design of these Areas was the same as Area 4. • Lined Area 6 was constructed in 2022, but suffered damage from abnormally heavy rain that occurred in early 2023. The heavy rain primarily eroded the new operations layer on the south and west slopes that were recovered and certified in August 2023.