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Leachate System Monitoring,and Maintenance The flow rate provided by the sump pump is tested monthly. A decrease in pumping rate will indicate the need to clean a filter or to investigate pump wear. Leachate production rate is greater in the late winter and spring, compared to summer and autumn,because little or no rain falls on the site from April to November of each year. The LCRS includes pipe risers at the end of each leachate lateral to enable video camera inspection of key portions of the pipe network. The moderate pipe bends of the risers allow cameras to be pushed several hundred feet into the network to record pipe conditions and depth of flows in the LCRS network. A wire rope is installed in each leachate lateral pipe to enable the pulling of a camera through the entire length of the risers. The secondary leachate sump is monitored monthly for the presence of LFG condensate. If possible, this condensate is removed, and if removed,the volume is recorded. Landfill Gas Condensate Removal from Module 1 Secondary Sump Investigations by the County indicated that the landfill gas condensate accidentally delivered to the secondary sump of Module 1 was forced into the anchor trench near the surface along the edge of the secondary sump liner. Removal of LFG condensate remaining in the secondary sump began in April 2009, and now continues monthly concurrent with landfill inspection. Monitoring of condensate removal includes measuring the depth of condensate in the secondary sump before and after pumping, and measuring the volume of condensate withdrawn during pumping. The depth of condensate in the secondary sump is measured by a bubbler tube installed into the sump. The bubbler tube is pressurized with air, and the resulting maximum pressure maintained in the tube indicates the level of water over the end of the tube. Condensate is removed using a centrifugal pump also installed in the sump. The volume of condensate removed is measured by measuring the time of pumping, having establishing that the pumping rate is 10 gallons per minute. The pump is allowed to run until lack of condensate causes the pump safety features to shut down the pump. Condensate removed from the secondary sump is delivered to the landfill surface over the lined area of Module 1. After the initial removal event of mid April,withdrawal of condensate continues to decrease from an initial 27 gallons per day in late April to approximately 0.3 gallons per day presently(Table 8 and associated Figure). Before pumping, the condensate level in the secondary sump is found to be approximately six inches prior to pumping. After pumping,the condensate level is approximately 3.5 inches. It is anticipated that removal will continue to decrease as the condensate slowly drains to the sump from the drainage mesh installed between the primary and secondary liner. Foothill Sanitary Landfill 12 Department of Public Works/Solid Waste 1s`Semester 2010 Groundwater Monitoring County of San Joaquin—July 21,2010