COMPLIANCE INFO_1991-1997 - Laserfiche WebLink

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release. The initial investigation included soil boring and ground water quality testing along the upgradient and downgradient edges of the landfill. The results of the borings along the downgradient edge of the landfill showed that the water quality in the upper two water zones has been impacted. It was determined that the upper two water zones are interconnected, or essentially one continuous zone. Further investigation will include off-site exploration for determination of the horizontal extent of the release, and an evaluation of the third water zone to determine if it has also been impacted. A verification (evaluation) monitoring program was implemented in three phases to determine the vertical and horizontal extent of contamination. Phases I and II confirmed VOC impact along the entire downgradient edge of the landfill and in the first encountered water bearing zone. In April 1991, Phase III indicated the chlorinated hydrocarbon impacted ground water extends laterally as far as 1.000 feet downgradient of the edge of the landfill and that the second water bearing zone beneath the landfill did not appear to have been impacted. The extent of the contamination is suspected to be extended by a recent finding of VOC contamination in an agricultural well located on CYA property adjacent to Austin Road approximately 3,750 feet downgradient of the landfill. A Conceptual Corrective Action Plan was proposed by the Discharger on 24 April 1991 to address the chlorinated hydrocarbon impact to ground water. The plan was approved by the Board on 10 June 1991. A Corrective Action Plan dated 29 August 1991 was prepared consistent with the Conceptual Corrective Action Plan and involves the following actions: 1) reduction of leaching of chlorinated hydrocarbons into the ground water by checking incoming loads into the landfill for hazardous materials and implementing measures to reduce storm -water infiltration into the refuse; 2) extract ground water from the two existing extraction wells to reduce the off-site migration of chlorinated hydrocarbons;, 3) instaff a system for treating the extracted ground water prior to discharge; and 4) monitor the effectiveness of the corrective action and potential need for modifications. Waste Discharge Requirements Order No. 92-143. NPDES No. CA0082911. for the Ground Water Treatment System and Storm Water Discharge was adopted by the Board on 14 August 1992. The Discharger submitted an Effluent and Receiving Water Quality Assessment Report ERWQA ) dated 22 October 1993 to determine If the proposed discharge from the ground water treatment system would have any impacts on the receiving water quality and, if necessary, develop a plan to mitigate the impacts. The ground water treatment system is designed to treat approximately 305 gallons per minute (gpm). which will be discharged to the north branch of the south fork of Littlejohn Creek. The Report indicates that the discharge from the ground water treatment system would have no impacts on the receiving water. Littleiohns Creek.