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There were no breeches in any of the run-on/run-off facilities during this semester. These facilities will continue to be monitored. LEACHATE COLLECTION AND RECOVERY SYSTEM Leachate is collected in the Leachate Collection and Recovery Systems (LCRSs) of the three landfill Modules. This leachate is returned to the refuse in accordance with the WDRs for this site. Landfill gas condensate is pumped into the LCRS of Module 4, and is handled as leachate also in accordance with the WDRs. The semi-arid climate of the North County Landfill and the waste shed from which the refuse is collected provides dry refuse in which the leachate can be absorbed. Leachate quantities do not indicate significant intrusion of water, or difficulty in meeting regulatory limits. Normal operation of the leachate system at the North County Landfill provides redundancy in absorption. Leachate may be pumped to the deep infusion points, to a leachate storage tank, to the active landfill face if the active face is over Module 3, 4, or other future lined modules. Facilities The leachate facilities for each Module include: ■ Sump with dedicated leachate pump. ■ Volumetric flow meter for the sump pump, indicating total gallons pumped (the meter for Module 4 also indicates instantaneous flow rate). ■ A leachate storage tanks. These tanks are normally not in use but are available if leachate cannot be returned to the refuse directly from the sump. o Modules 1 and 3 sumps share one tank(3,000 gallons) o Module 4 is provided with a separate tank(12,000 gallons). ■ Float switches within each leachate tank activate alarms based on high or low level conditions. o Under high-level conditions, the leachate sump pump are deactivated. This prevents overflow of the tanks. o Under low-level conditions, pumps that can remove leachate from the tanks are deactivated,preventing the operation of these pumps with insufficient fluid. ■ Transfer pumps at each leachate tank which can deliver leachate into a water truck if needed. ■ Return pump at Module 4 leachate tank to deliver leachate to a location other than a water truck, if needed. Although not yet needed, this pump would be used to deliver leachate to a Module with a Subtitle D-approved liner. Semi-permanent points of return of leachate to the refuse include three Deep Infusion Points ("dry" wells), all installed over Module 3. The highest elevation of the base of Module 3 in this area is approximately 96 NGVD. The bottom of these Deep Infusion Points (DIPS) are approximately at elevation 140 ft NGVD. Approximately 50 feet of refuse in multiple lifts exists between the point of infusion and the base of the landfill. Construction and alteration of the DIPS was reported in detail in the First Semester 2005 Groundwater and Surface Water Monitoring Report. Leachate was not returned to DIPS in this monitoring period. North County RC&SL Public Works/Solid Waste 1"Semester 2012 Groundwater Monitoring 10 County of San Joaquin—July 26,2012