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1 ' Corral Hollow LFG System Audit and Upgrade Report LFG Extraction Device Operation ' The County has implemented procedures to provide and maintain continuous negative pressure in each LFG extraction well. Each extraction well is monitored on a monthly basis by the County or County contractors. Each wellhead is equipped with a sampling port and adjustment valve. The wells are operated and adjusted in accordance with San Joaquin County Air Pollution Control District (APCD) permit conditions (APCD, 2012). Methane, carbon dioxide, oxygen, ' balance gas (nitrogen), temperature, and pressure/vacuum are measured monthly at each wellhead. Based on data collected during these measurements, the wellheads are adjusted as necessary. Maximum concentrations for individual wellheads are 5 percent (%) oxygen, 20 % nitrogen, 130 degrees, and negative pressure (vacuum). These criteria are mandated by air quality regulations and permits that apply to CHLF. In addition, the CDO requires that measures be taken to ensure negative vacuum at each well. ' LFG Conveyance Piping An extensive piping network is installed to convey LFG from the collection devices to the control ' equipment. The LFG extraction devices are generally connected to small diameter lateral gas pipes which convey collected gas to the 8-inch diameter perimeter header. The gas collection header system is a double loop configuration. The loop headers convey gas extracted from the interior ' wells, and a single 6-inch branch header conveys gas from the perimeter wells. All gas is conveyed to the blower flare station. Lateral and header piping is either HDPE and sized per the projected LFG flow rate. The header system is also equipped with isolation valves at select locations ' along the main header(s). Lateral and header piping layout is shown in Figure 2. Liquid condensate, which forms in the conveyance piping during LFG extraction, drains to a ' series of condensate sumps located at header low points. These sumps are equipped with pneumatically-operated pumps that remove condensate from the sumps, and deliver the liquid to a common condensate force main. Condensate is then routed to an aboveground storage tank ' located at the Blower/Flare Station (BFS) and is evaporated, and the entrained VOCs oxidized via injection into the enclosed ground flare. The County reports that the typical condensate injection rate is 0.2 gallons per minute (gpm). LFG Blower/Flare Station ' Collected LFG is routed to the BFS for thermal destruction. The gas handling equipment consists of the following: • One enclosed flare (LFG&E Triton GF-200 Enclosed Ground Flare), which became operational in 2001. The flare has a maximum permitted thermal destruction capacity of 4.95 million BTUs per hour (MMBTU/hr), or approximately 163 standard cubic feet per minute (scfm) for LFG with a methane content of 50 percent by volume (% v/v). The flare is also equipped with a condensate injection system to thermally destroy accumulated condensate, rated at maximum flow rate of 3 gallons/minute. • Two (2) 200 scfm centrifugal blowers. The blowers are manufactured by Hoffman and are equipped with Toshiba 7.5 Horsepower (HP) motors rated at 3,485 revolutions per 5 December 2013