ARCHIVED REPORTS_2012_4 - Laserfiche WebLink

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RUN-OFF/RUN-ON FACILITIES ® The Foothill Sanitary Landfill utilizes several methods to control run-on and run-off. The natural topography of the area controls any run-on into the site. Also,the working area is a significant distance from the property boundary and at a higer elevation, so run-on from surrounding properties into refuse is not possible. To control run-off, a perimeter ditch along the north,west and east ends of the unit directs all storm water run-off into a sedimentation basin on the east side of the site. The rest of the run-off from the unit gathers into a sedimentation basin at the southeast corner of Area 1. There were no breeches to any of the run- on/run-off facilities during this monitoring period. OTHER ANALYSIS Groundwater samples were collected from landfill supply well LW-1 and analyzed for all monitoring and field parameters. The well is not a point of compliance, as stated in the WDRs. LEACHATE COLLECTION AND RECOVERY SYSTEM - PROCEDURES & MAINTENANCE Facilities The leachate collection and recovery system(LCRS) for Area 1 was designed and constructed in accordance with Title 27, Section 20340(g). This system consists of: • East/west oriented collection troughs running the entire length of Area 1 ® A 4-foot deep sump at the southeast corner of the Area • A leachate removal pump installed in an 18-inch diameter HDPE pipe • A 2-foot deep secondary extraction trench beneath the primary composite liner, with 12-inch HDPE riser pipe • A pumping system that allows recording of leachate flows and volumes • A 10,000 gallon leachate storage tank located near the LFG flare station. 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. Disposal: Return of Leachate to the Refuse Leachate drains by gravity to the Area 1 sump. A pump within the sump either returns the leachate to the refuse of Area 1 or delivers it to the 10,000-gallon storage tank from which it is removed by water truck and either returned to the refuse if Area 1 or used as dust control over Area 1. At no time is leachate returned to Area"I". The pump operates automatically, based on leachate level within the sump. Control points for the pump are: Pump Off. 17" Pump On: 43" Alarm:48" Foothill Sanitary Landfill 10 Department of Public Works/Solid Waste 2"d Semester and Annual 2012 Groundwater Monitoring County of San Joaquin—January 15,2013