SITE INFORMATION AND CORRESPONDENCE

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J&L Market 8125 South El Dorado Street - 2 - 14 August 2002 Board staff have the following comments on the Q2-2002 Report: 1. Board staff agree that additional soil borings are necessary to define the extent of contamination at this site. However,we believe that the borings should be completed after the groundwater flow direction is confirmed. As pointed out by Upgradient,the San Joaquin County Flood Control and Water Conservation District reports that the dominant groundwater flow direction in this area of San Joaquin County is to the northeast. The current groundwater flow direction measured in June 2002 at the J&L Market site is to the southeast. Therefore,please complete third quarter monitoring prior to scheduling the next phase of drilling. 2. The eleven proposed soil borings for the next phase of drilling seems excessive. As shown on attached Figure 7 in Upgradient's Q2-2002 Report, some of the proposed borings are within 20 feet of previously completed borings. Proposed angle borings JLM-9 and JLM-10 may not be necessary because proposed borings JLM-6 and JLM-14 are located west of the building and may provide suitable information to define the extent of soil contamination in this direction. Therefore, after the quarterly monitoring event is completed and the groundwater flow direction is confirmed,please submit a workplan addendum including a revised soil boring map and justification for each of the proposed soil borings. 3. The next drilling phase of work should include collection of depth discrete groundwater samples to define the vertical extent of groundwater contamination wells at the subject site. Vertical groundwater definition was proposed in the 14 February 2002 Workplan for Further Groundwater Investigation, and approved with our 29 March 2002 letter. Please provide a proposal to collect depth discrete groundwater samples in the workplan addendum. 4. Based on the number of water supply wells in the local area,the emphasis for locating wells should be reduced to 500 feet of the site. Please conduct a door-to-door survey of residents within 500 feet to determine the use of these private wells and any available access for sampling. Provide a map of water supply well locations and a table of well construction information for water supply wells located within 500 feet of the subject site, and provide driller's logs for identified wells, if available. 5. Upgradient recommends properly destroying the abandoned on-site domestic well after collecting a groundwater sample. We concur with this recommendation. Please complete groundwater sampling and well,destruction during the third quarter of 2002. 6. The boring and monitoring well nomenclature used at the subject site is confusing. By looking at the tables,a reviewer without background history of the site could not tell how many borings or monitoring wells exist at the subject site, or which water samples are from grab samples or monitoring wells. In future reports,we request that you distinguish between soil borings and monitoring wells by labeling soil borings sequentially such as JLB-1,JLB-2, etc, and labeling monitoring wells sequentially, such as JLMW-1,JLMW-2, etc. Please complete third quarter monitoring and sampling, and submit the results to this office in a quarterly monitoring report by 30 September 2002. The workplan addendum as discussed above may be submitted as part of the quarterly monitoring report,or submitted under separate cover.