SITE INFORMATION AND CORRESPONDENCE

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• • Bioremediation Report - 2 - 3 October 1994 16 S. Cherokee Lane, Lodi A. Bioremediation Pilot Study • Geweke received a waiver of Waste Discharge Requirements from the Board in January 1994. As a "Pilot Study", on 2 February 1994, approximately 650 gallons of inoculum were injected into MW4, VW1, VW4, VW5, and VW6. Packers were used in the wells to prevent direct inoculation of ground water and soil below 40 feet. As part of the Pilot Study, soil, ground water, and vapor were monitored for 60 days, in February and March 1994. Two borings were drilled and soil samples collected. One of my previous comments on shortcomings of the Pilot Study, was lack of boring logs and a map showing the two borings. The bioremediation report contained the boring logs and a map showing the locations of the two borings. Boring P1 was drilled 3 feet from VW1, which was inoculated. The soil results for PI showed less contamination than the boring for VW1. P2 was installed about 5 feet from VW1 but contamination was higher than in the boring for VW1. GeoAudit contends that the lower concentration in PI was a result of the activity of the inoculated bacteria. Board staff contend that the lower contamination may be a result of chance or poor sample handling techniques rather than biological activity. GeoAudit stated "All inoculation procedures were performed under the direction of • GeoAudit's consulting microbiologist, Mr. James Hoeltgen. It must be noted that because of the restrictions in the inoculation, placed upon the project by the CVRWQCB, Mr. Hoeltgen expressed at the onset severe reservations as to the value of a limited inoculation at the site." Comment - No specific reservations were passed on to us verbally or in writing. GeoAudit stated "Despite reservations and last minute alterations of the inoculation plan, it appears that overall, the data collected during the pilot study indicate that engineered bioremediation due to the inoculation is occurring at the Site". Comment - GeoAudit disputes our contention that the data are inadequate, inconclusive, and/or contradictory. Soil samples from the two borings, Pl and P2, were analyzed for bacteria numbers and types. GeoAudit states "All samples analyzed showed increased densities of inoculated bacteria, as compared with pre-inoculation conditions. An increase in bacterial numbers indicates successful bioremediation. Also measured at the site was a decrease in oxygen ... and an increase in carbon dioxide". Comment - I don't recall seeing information on bacterial numbers and types prior to inoculation. They submitted confidential information on the composition of the inoculant, however, • subsequent reports do not have the genera or species. The statement that all samples showed increased densities of inoculated bacteria is unsubstantiated.