SITE INFORMATION AND CORRESPONDENCE

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Thanks, Melissa -----Original Message----- From: Amy Terrell [mailto:aterrell@waterboards.ca.gov] Sent: Wednesday, August 25, 2010 10:24 AM To: Buciak, Melissa/RDD Cc: Mike Infurna Subject: koppels mw work plan and schedule Dear Ms. Buciak, Thank you for providing the August 2010 Monitoring Well Abandonment and Construction Work Plan prepared by CH2M Hill for the Koppel Stockton Terminal at 2025 West Hazelton Avenue in Stockton. In this work plan, Koppel proposes to locate and destroy three shallow and one deep monitoring well that have been buried or damaged, and install one shallow and one deep replacement monitoring well. California Regional Water Quality Control Board, Central Valley Region (Central Valley Water Board) staff concur with the destruction of the damaged or buried wells (KP-5S, KP-5D, KP-10S and KP-BG-1) and with the location of the new monitoring wells (KP-10S-R and KP-4D). In the well destruction description, CH2M Hill proposes to overdrill the wells and backfill with a grout mixture. The language is not clear as to the height of the grout backfill. Since the damaged wells are in areas in which earth disturbance appears to be a regular event, the grout should extend to about three feet below the soil surface and the boring should be backfilled with earth to the ground surface. In the location of KP-5S and KP-5D, where an earth ramp has been built above the well heads, the grout should extend to about three feet below the lower predominate earth surface. Central Valley Water Board staff conditionally concur with the August 2010 Monitoring Well Abandonment and Construction Work Plan provided that the implementation is conducted to the satisfaction of San Joaquin County Environmental Health Department, and, if practical, three feet of earth fill is placed between the ground surface and the top of the grouted well bore. Scheduling: Koppel has proposed to conduct the work in September, to coincide with the annual groundwater sampling event which is to occur in the third quarter per Monitoring and Reporting Program No. R5-2004-0835. In view of San Joaquin County's limited staffing capabilities for oversight of field work, Central Valley Water Board staff suggest that Koppel schedule the monitoring well destruction and installation in early October. To maintain Koppel and CH2M Hill's efficiency in light of this suggestion to schedule the work in early October, Central Valley Water Board staff agree to permit Koppel to conduct the annual monitoring event in October instead of September, and will allow the Annual Report to be delivered by 30 November 2010. In considering this extension of the third quarter sampling period, Central Valley Water Board staff assume that early October will continue to be representative of the dry season. Koppel may combine the well destruction and installation reports with the Annual Report which shall be due 30 November 2010, if the monitoring well work is scheduled for early October. Thank you for providing the means to destroy the damaged well, providing suitable replacement wells, and considering this suggestion to schedule the work in October. A copy of the Work Plan is attached for your convenience. If you have any questions, you may contact me by telephone at (916) 2