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Bioremediation Report 3 - 3 October 1994
<br /> 16 S. Cherokee Lane, Lodi
<br /> Comment - Several vapor samples showed a decrease in oxygen and increase in carbon dioxide.
<br /> These conditions may indicate bacterial activity, however, no information on these parameters was
<br /> collected prior to inoculation. In addition, vapor samples from both inoculated and uninoculated
<br /> wells showed the same decrease in oxygen and increase in carbon dioxide. Therefore, it is not
<br /> possible to tell if these conditions are a result of inoculation.
<br /> B. GeoAudit's Bioremediation Proposal
<br /> Despite GeoAudit's "reservations" about the value of the limited inoculation (Pilot
<br /> Study), they concluded that the decrease in soil contamination in PI, knowledge of the
<br /> bacteria which they have not shared with us, the decrease in oxygen, and increase in
<br /> carbon dioxide, all indicate that bioremediation occurred during the Pilot Study.
<br /> Therefore, they plan to proceed with the full scale inoculation of soil and ground water
<br /> as described in the FRP and addendum, with modifications.
<br /> Soil - In the FRP, GeoAudit proposed to inoculate MW1, MW3, MW4, MWS, and VW1
<br /> through VW7 with two well volumes in each well. A total of 432 gallons in the
<br /> monitoring wells and a total of 648 gallons in the vapor wells. However, because they
<br /> have already inoculated MW4, VWl, VW4, VWS, and VW6 during the Pilot Study, they
<br /> have modified the plan. In the new plan, approximately 100 gallons per well will be
<br /> • inoculated into MWl, MW3, MW4, and MW5 to a depth of 30 feet, using a packer.
<br /> Approximately 100 gallons per well will be inoculated into VW3 and VW7 to a depth of
<br /> 35 feet without using a packer.
<br /> Comment - In summary, VW2 will not be inoculated at all; VW1, VW4, VWS, and VW6 will not
<br /> be reinoculated; MW4 will be reinoculated; MWl, MW3, MW5, VW3, and VW7 will be inoculated
<br /> for the first time. GeoAudit did not explain why VW2 will not be inoculated at all as proposed in
<br /> the FRP. They also did not explain why MW4 will be reinoculated but not VWl, VW4, VWS, and
<br /> VW6.
<br /> Comment - The FRP appeared to have the on-site soil contamination near the source fairly well
<br /> covered by injection points. They did not address the off-site soil contamination. The FRP and
<br /> modified proposal assume the bacteria will migrate between the injection points.
<br /> Ground water - The original proposal in the FRP was to inoculate MW7, MW8, MW9,
<br /> MW14, and EW1 with 100 gallons each. However, based on new ground water data,
<br /> they now propose to inoculate MW8, MW9, MWll, MW14, and EWl. Depending on
<br /> data after the initial inoculation, MW12 and MW13 may also be inoculated.
<br /> Comment - They have not explained why the upgradient MW6 and the cross gradient MW10
<br /> will not be inoculated, when they both have had contamination.
<br /> • Comment - GeoAudit did not explain why new data induced.them to inoculate MWll rather
<br /> than MW7 as originally proposed. Both the FRP and the new proposal assume the bacteria will
<br /> migrate between injection points upgradient, cross gradient, and downgradient.
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