SITE INFORMATION AND CORRESPONDENCE

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Bioremediation Report 5 - 4 October 1994 16 S. Cherokee Lane, Lodi • Comment - They did not list the wells from which vapor samples will be collected. According to Mr. Hoeltgen, environmental conditions do not and will not exist at the site that would promote the growth of methanogenic bacteria. Therefore, GeoAudit did not propose to sample for methane. Comment - Lack of experience limits me here, but I tend to agree. However, I recommend that they monitor methane quarterly until more data has been gathered. Soil Monitoring - They propose drilling not less than one but not more than three soil borings per quarter. Placement of the borings will be based on data from the previous quarter. The Regional Board will be notified at least S days in advance of the drilling. Initially they propose to drill one boring approximately 3 feet northeast of VW7, which will be inoculated, and one boring 3 to 5 feet southeast of VW4, which was inoculated during the Pilot Study. Comment - The only way to tell if the soil remediation is working is to collect soil samples from borings. GeoAudit may not have proposed enough quarterly borings. For the next quarter, I suggest a third boring in the VW1 series, about 2 feet from P2, or approximately 7 feet from VWl. The borings will be drilled to a minimum of 40 feet and samples will be collected at 5 • foot intervals. Samples will be screened with a PID and selected samples will be analyzed in a lab for TPHg and BTEX. Soil samples will also be analyzed for the inoculated bacteria. Bacterial numbers and "different strains" will be reported. However, the species are considered proprietary information and will not be reported. Comment - How are we to know that the inoculated bacteria are present if they will not report the bacteria they have found? Comment - Samples should be collected at changes in lithology, therefore, continuous cores are recommended. Ground Water Monitoring - The program established in the Monitoring and Reporting Program with the C&A will remain with additional monitoring for the first 6 months after inoculation. After 6 months, the additional monitoring will be evaluated and changed as necessary. MW12, MW14, and EW1 will be monitored bi-monthly for PH, TPHg, BTEX, DO, and microbial species and numbers. MW6, MW10, and MW13 will be monitored quarterly for microbes. Coliform bacteria will be monitored in MW8, MW14, and EW1. Comment - MW6 and MW10 are upgradient, MW8, MW12, and MW13 are downgradient while MW14 and EW1 are near the center of the plume. More ground water monitoring than proposed may be necessary. I suggest that rather than quarterly microbial sampling in MW6, MW10, and • MW13; the monitoring be changed to monthly for six months and include MW7, MW8, MW9, and MWll. It may be necessary to reinoculate wells or to inoculate MW6, MW7 and MW10. Comment - Frequency of coliform sampling was not included. I suggest quarterly.