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F Draft Envirorunental Impact Report Page IVY-20 Forward Inc. Landfill Expansion i water monitoring. The quantity and quality of leachate pumped from each sump is measured and reported to the RWQCB in gallons per month. Monitoring devices are also in place beneath the sump of the leachate collection system to detect if there is leakage through the leachate collection system. These lysimeter monitoring devices are sampled and tested for constituents of concern, including VOCs, as required by the RWQCB. Four VOCs—PCE, TCE, methyl Chloride, and acetone—were not detected above their detection limits in Q2-2008 Existing Groundwater Extraction and Treatment System The Corrective Action Plan(CAP) under the RWQCB order is designed to address the VOC I� impacts to groundwater through the extraction of groundwater from two extraction wells (EW- 1 and EW-2)located at the downgradient boundary of the landfill and screened in the depth intervals of concern(as shown by the well monitoring data). The RWQCB staff approved the CAP. 'F The groundwater treatment system is designed to extract polluted groundwater at the northern portion of the landfill (the Austin Road Landfill unit). VOCs are stripped from the extracted water and the treated water is discharged. The treated groundwater extracted by the two wells at a rate of approximately 300 gallons per minute (432,000 gallons per day) is discharged to a surface water impoundment/infiltration area. The objective is to allow the extracted water to infiltrate down into the aquifer(s) again after it is treated, thus mitigating against further aquifer �. depletion. A draft "source control plan" report, required by the RWQCB Order R5-2008-0714 by February 15,2009, was submitted to the Water Board on February 13, 2009 and is currently under review. The objective of the new report is to propose new corrective actions to address further migration of the plume north of Austin landfill. This report is currently being reviewed by the Water Board and was not available for review in this EIR. Impacts and Mitigation Standards of Significance The proposed project would have a significant impact with regard to hydrology and water quality if it would: f • Substantially degrade water quality; • Contaminate a public water supply; • Substantially degrade or deplete groundwater resources; • Substantially interfere with groundwater recharge; • Cause flooding or subject structures to flood hazards; • Modify creek alignment; Cause significant erosion or sedimentation; • Generate more leachate than can be handle but the existing or planed control systems;or + Cause or be subject to substantial flooding, erosion, or siltation. I