SITE INFORMATION AND CORRESPONDENCE

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Mr. Gregory Torlai, Jr. . - 3 - 24 May 2010 H&H Marina depths into peat and clay beds through three geoprobe borings each upgradient of MW-4 and B-30A. AGE stated that these locations were chosen due to a combination of favorable access conditions, available pre-existing subsurface characterization data, and contaminant mass. Water levels in MW-2, MW-4 and MW-6 will be monitored for mounding during the slurry injection. Post injection sampling will consist of three once-monthly groundwater samples from MW-4 and a single grab groundwater sample from a second proposed Geoprobe® boring B-30B. The grab groundwater sample will be collected during the third month. A report will be prepared presenting the findings, conclusions, and recommendations. Our comments are presented below. 1. The historical groundwater monitoring results presented for MW-2 and MW-4 in the First QMR offered evidence that concentrations of TPHg, MTBE, and tertiary butyl alcohol (TBA) had attenuated significantly. However, the advance monitoring results included in the Work Plan from April 2010 sampling showed that TPHg concentrations in MW-4 rebounded to historical levels. Because H&H Marina ceased operation of the groundwater treatment system in June 2009, there will not be an opportunity to determine whether the decreases in concentration can be sustained through operation of the treatment system. However, the significantly attenuated contaminant concentration trends observed in MW-2, and the historically stable concentrations at MW-4 indicate that an enforcement action to require cleanup of these plumes may presently be unwarranted. As we informed the participants in the 18 May 2010 meeting, Central Valley Water Board staff has suspended our efforts to finalize the CAO for this Site. 2. We concur with the H&H's recommendation in the Work Plan to submit an NOI to enroll in Order No. R5-2008-0149 and perform the ORC Advanced TM injection. However, as AGE stated during the meeting, Regenesis, the manufacturer of ORC Advanced TM has expressed concern that the ambient biological oxygen demand of the aquifers underlying the Site may exceed the capacity of the ORC Advanced TM product to establish oxidizing conditions. Therefore, Regenesis has proposed to supplement the ORC Advanced TM application with an additional Regenesis product called RegenOxTA°, a stronger in-situ oxidant. Literature obtained from Regenesis' website describes RegenOxTm as producing "an effective oxidation reaction comparable to that of Fenton's agent without a violent exothermic reaction." 3. During the 18 May meeting, Central Valley Water Board staff requested that H&H Marina conduct a bench-scale test prior to the pilot study in order to determine what byproducts might be produced. H&H Marina concurred and stated that an addendum to the Work Plan will be submitted by 10 June 2010 and will include the procedures for the bench-scale test. 4. As discussed during the meeting, H&H did not conduct monitoring during the third or fourth quarters of 2009, and thus missed monitoring the wells required to be sampled annually during the fourth quarter (annual sampling event). These include wells MW-3, MW-6, MW- 7, MW-8, MW-9, MW-10, MW-11, and MW-12. H&H's failure to conduct monitoring during the third and fourth quarters constitutes a violation of MRP No. R5-2009-0833. To address this deficiency, H&H will conduct the annual sampling event during the third quarter of 2010 and sample in accordance with quarterly requirements during the fourth quarter of 2010. Sampling during 2011 will occur in accordance with the MRP. Conducting the annual sampling event during the third quarter will also provide baseline data for the pilot study, which is anticipated to be performed in September to allow time to prepare the Notice of