Laserfiche WebLink
<br />1-5 <br /> <br />1.1.1 Final Cover System <br />The FSL final cover system consists of a minimum of 4.5 feet of evapotranspirative (ET) soil cover. Partial <br />closure of LF-1 was completed in 2006 as part of the FSL Site Improvement Project and was approved by <br />the RWQCB on July 11, 2014. Partial closure of LF-1 consisted of installing a minimum of 4.5 feet of ET <br />soil cover, including approximately 1.5 feet of existing intermediate soil cover over the LF-1 top deck. <br />Additionally, a one (1) foot thick soil cover was installed over existing intermediate soil cover along the <br />LF-1 north, west, and east side slopes, and the upper portion of the LF-1 south side slopes. The one (1) <br />foot of soil was placed to achieve a minimum two (2) feet of soil cover over the side slopes. A barrier liner <br />system and overlying operations soil layer were installed on the LF-1 south side slopes during the <br />Module 1 construction. The soils used for the ET soil cover, intermediate soil cover, and the LF-1 side <br />slopes cover were obtained from on-site borrow sources located north and south of LF-1. <br />1.1.2 Landfill Gas Collection and Control System (GCCS) <br />The FSL has an active landfill GCCS and is comprised of the following components: <br /> Ten (10) soil gas monitoring probes are installed around LF-1, two (2) are single level probes <br />(one installed to a depth of 30-feet, and the other to a depth of 255 feet), and eight (8) are <br />nested triple level probes <br /> Twenty-five (25) nested triple level soil gas monitoring probes are installed around the <br />perimeter of the FSL permitted waste boundaries <br /> Seventeen (17) vertical landfill gas (LFG) extraction wells <br /> Five (5) horizontal LFG extraction wells installed in LF-2 <br /> A network of lateral LFG collector pipes (3-, 4-, 6-, and 8-inch diameters) and main LFG <br />collection header pipe (12-inch diameter) <br /> Blower and flare equipment station. <br /> LFG-to-Energy power plant <br />The GCCS location and components are presented on Figure 2. <br />1.1.3 Soil Pore Water Monitoring System <br />The FSL has five (5) suction lysimeters. Four (4) lysimeters are installed beneath the LF-2 containment <br />system (LZ-2 through LZ-5) and one (1) background lysimeter (LZ-1) is installed beyond the waste limits of <br />LF-1 and LF-2. Because LF-1 is unlined and predates the Chapter 15 regulations, it does not have a soil <br />pore water monitoring system. <br />1.1.4 Leachate Management System <br />The FSL leachate management system includes two (2) LF-2 leachate sumps (L-1 and L-2A), two (2) 10,000- <br />gallon leachate storage tank, leachate riser pipes, return lines, and condensate traps. Leachate <br />monitoring is conducted at the two leachate sumps. Because LF-1 is unlined and not equipped with a <br />leachate collection system, monitoring is not conducted for LF-1. <br /> <br />1.1.5 Groundwater Monitoring System <br />The FSL groundwater monitoring system consists of nine (9) groundwater monitoring wells that are <br />actively monitored and maintained. Two (2) of the nine wells are located upgradient (MW-4 [dry] and <br />MW-4A), and all other wells are located downgradient (MW-1 [dry], MW-1A, MW-2R, MW-3, MW-5,