COMPLIANCE INFO_1997-1999 - Laserfiche WebLink

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from this office. Selected soil samples shall include at a minimum the historic low and high groundwater elevation equivalent and the current capillary fringe. Traditional TPH as gasoline and diesel as well as BTEX analyses are also required. The FGL analytical data report submitted to this office confirms the presence of 1,2-Dichloropropane at 1.8 ug/L from the Public Water System Wellhead (PHS/EHD #WA460903) sampled July 15, 1997. 1,2- Dichloropropane is a Regulated Organic Chemical and is a known carcinogen. PHS/EHD strongly recommends that the responsible parties at this site carefully monitor this wellhead to protect consumers and or users of this water supply. On July 7, 1997 PHS/EHD staff requested, during a telephone conversation with Don Thompson and later with Frank and John Guinta, that the public water supply well construction details be provided immediately in order to assess potential public health risks associated with contaminants at this site. On July 9, 1997 PHS/EHD staff visited the site to record the approximate distance of the well in question to the known contaminant plume. Again Mr. Guinta was asked for constuction details in the presence of Mr. Thompson. During our July 9, 1997 meeting at the San Joaquin County District Attorneys offices PHS/EHD formally requested well construction details for this public water supply well. PHS/EHD now directs the responsible parties to immediately evaluate and report to PHS/EHD the construction details of this well to insure that this well does not act as a conduit for vertical contaminant transport. The responsible party shall at a minimum determine the total depth, screen interval,and type and depth of grout seal if any. In the event this information is not available in the form of boring logs and well drillers completion reports the well shall be evaluated by down hole video logging performed by a qualified contractor. In addition the workplan addendum must include investigative methodologies for chlorinated solvents particularly in the vicinity of the former waste oil tanks at this site. A full scan report utilizing EPA Method 8260 is mandatory on a quarterly basis until further written notice from this office. Conventional monitoring well networks proposed in the REE workplan for this Underground Fuel Tank (UST) leak site may be insufficient to properly locate and define the extent or existence of MTBE / Fuel Additive / Chlorinated Solvent plumes as evidenced by the vertical and horizontal variations of contamination observed at this site. MTBE plumes can be non-elliptical, long, narrow and erratic (meandering), chlorinated solvent plumes can be unlimited in depth and length. Therefore, PHS/EHD directs you to perform a detailed, expedited site assessment using depth discrete and continuous core sampling to define and quantify the full three-dimensional extent of MTBE and other additives,Total Petroleum Hydrocarbons, Benzene, Solvents and other known or suspected contaminants in groundwater. In addition, and as agreed to during our July 9, 1997 meeting at the District Attorneys Offices the responsible party(Frank Guinta)was to submit UST removal and replacement plans to PHS/EHD no later than August 1, 1997. The relevance of the tank system pull and replacement plan to the site assessment is in monitoring well placement. Since the responsible party has failed to meet the tank system closure and replacement submittal deadline to date, PHS/EHD cannot insure that monitoring wells placed at the site will not be destroyed,need to be replaced or duplicated as a result of future construction activities at the site. The REE workplan proposes several wells to be located a considerable distance to the North-West from the current known core contaminant sources. These wells shall be relocated and redistributed at the site. No less than seven boreholes completed as monitoring wells must be placed at the following positions with appropriate discrete screen intervals(each borehole may require more than one well completion); surround each of the current UST and dispenser island locations to further assess past, current or potential future releases recognizing the inconsistencies in past and current monitoring equipment performances and the known contaminant distribution. At least three of these boreholes shall be continuous cores. At least two separated dual completion (nested)wells shall be installed as sentry wells on the south side of the facility building to intercept contaminant migration toward the public water supply well. These boreholes shall also be employed to further define any potential chlorinated solvent plume which may have originated 2 I