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Mr. Kirk Williams . - 3 - • 25 April 2008 to groundwater pollution, then the annual cap inspection program imposed on Western Farm Service could be removed. Please provide a work plan to evaluate the constituent concentrations in soil beneath the north and south ponds, and groundwater beneath the south pond by 20 June 2008. The annual pond inspection report shows that some indentations are present in the asphalt surface of the north pond cap. By 30 September 2008 please restore the surface to a generally convex shape and document the repair in the 2008 Annual Monitoring Report, which is due 1 November 2008. Pilot Study One year after Western Farm Service injected zero-valent iron coated with a carbon substrate into the shallow water-bearing zone, concentrations of constituents appear to be generally declining in monitoring well PM-1, which is about 10 feet downgradient of the injection area. GeoSyntec does not believe that sufficient time has passed for groundwater constituents to have moved from the injection zone to PM-1, and the observed decline could be related to an anomalously high initial concentration recorded in PM-1. Ten feet upgradient of the injection area, monitoring well E-1 is increasing in concentrations of constituents, particularly 1,2-DCP, 1,2,3-TCP, DBCP, EDB, nitrate and ammonium. There is not a monitoring point within the injection grid. Over time, it will be observed in PM-1 whether the iron injection can remove the constituents observed in E-1. Missing Monitoring Wells GeoSyntec Consultants discovered that two groups of monitoring wells (MW-15 A and B, and MW-17 A and B) lie beneath the surface of the recently paved portion of Sutro Avenue. GeoSyntec asked if these wells could be destroyed. Regional Water Board staff do not concur with their destruction at this time. Monitoring well 17A/B bounds the plume on the southern side, and similarly, MW-15 A/B bounds the plume on the northern side. By the third quarter monitoring event, please locate the wells, evaluate well integrity, and sample groundwater for polynuclear aromatic hydrocarbons. San Joaquin County Environmental Health Department may be able to provide assistance locating the monitoring wells if they are provided with copies of the well installation permits. If the wells appear intact, please extend the wellhead collars to grade, or if a monitoring well has been compromise, please recommend destruction and replacement. Western Farm Service should summarize actions taken and provide recommendations in the 2008 Annual Monitoring Report which is due 1 November 2008. MONITORING AND REPORTING PROGRAM In a 15 February 2008 telephone meeting with Ms. Melissa Asher and Mr. Arnab Chakrabarti of GeoSyntec Consultants and me, we discussed proposed revisions to existing Monitoring and Reporting Program (MRP) No. R5-2004-0804. A draft MRP is attached for your review and comment. The following is a summary of our discussion items and conclusions. Monitoring Well Redundancy The Stockton facility monitoring well network includes two upgradient wells, MW-3 and MW-10. We agreed that this is redundant, and Western Farm Service will continue to monitor constituents in MW-10 semi-annually, will monitor water levels in MW-3 at least annually.