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MEMORANDUM • CALIFORNIA REGIONAL WATER QUALITY CONTROL BOARD • CENTRAL VALLEY REGION 3443 Rouber Road, Suite A Sacramento, CA 95827-3098 Phone: (916) 255-3000 TO: GORDON L. BOGGS CST 8 494-3000 UGT Program Coordinator FROM: ELIZABETH A. THAYER Associate Engineer DATE: 1 March 1994 SIGNATURE: SUBJECT: GF WEKE MONITORING PROGRAM FOR PILOT STUDY The monitoring network at the site consists Of 8 on-site ground .eater monitoring wells, (MW I through 5 are dry or almost dry, MW7, MWg and MW14), 1 ground water extraction we and ring wells ll (E(E and 7 vapor wells (VWI through 7). There are 6 off-site ground water monito MW9, MW10, MWl1, MW12, and MW13). In late 1993, since it was installed. an air blower was connected to the 7 vapor wells and monitoring wells MW3, MW4, MW5, and MW14. The blower has been running On 2 February 1994 GeoAudit inoculated MW4, VWI, VW4 VWS and VW6 with bacteria. The wells were chosen to prevent an impact to water at this time. Packers were used in an attempt to ensure placement of bacteria in specific soil zones. Depth to ground maximum depth of inoculation was 40 feet. Seventy gallons of iwater is about 60 feet and the noculant were placed in MW4, 180 gallons were placed in VWI, 155 gallons were placed in VW4, 155 gallons were placed in VWS, and 100 gallons were placed in VW6. Between 10:00 am and 4:00 pm, on 4 February 1994, I met with Geweke's consultants, Bob Marty and Vic Cherven of Geological Audit Services (GeoAudit), to work out a monitoring and reporting program for the in-situ bioremediation pilot study and remediation proposal. During this time we were able to complete our discussion of the pilot study only. Mr. Cherven stated that barometric pressure effects the vapors and gases in monitoring wells. High barometric pressure forces vapors down, and low barometric pressure allows vapors to come out of formation and rise to a higher level in the monitoring wells. An attendance list, a schematic of the Pilot study system, and an example of an inoculated well are attached. After a great deal of discussion and consideration we came up with the following: MONITORING PROGRAM FOR PILOT STUDY Duration: The pilot study will last for a minimum of 60 days. If the bacteria are working, we should be able to detect some evidence within 60 days. However, if ground water does not show an impact until late in the 60 day pilot study period, then the pilot study will be extended another 30 days in order to collect data.