COMPLIANCE INFO_1986-1995 - Laserfiche WebLink

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0 Ripon operates several Municipal Supply Wells in close proximity to this site with moderate to high pumping rates. Please provide to scale drawings of all wells within % mile of this site. Please tabulate your findings and provide the following minimum details; Total depth, screen interval(s), casing size and material description, filter pack, pump size and elevation, pumping rate, seasonal use and/or operating status, owner/operator, and historic/intended uses. The responsible party shall employ these findings in constructing a site conceptual model, including placement and construction of exploratory boreholes and monitoring well networks, which shall include the potential for plumes to dive vertically considering recharge and pumping influences in the area. PHS/EHD directs the responsible party to complete the receptor, well survey, and preferential pathway/conduit study and report their findings to PHS/EHD no later than July 10, 1998 at 5:00 pm. PHS/EHD recommends that Shell Oil secure access agreements from nearby property owners and well owners/operators immediately for both exploratory borehole and water well sampling work as it relates to this site. Existing water wells near this site which may act as conduits or indicators of contaminant distribution must be sampled and analyzed in order to evaluate the presence or absence of fuel hydrocarbons. This data shall also be used to develop a comprehensive well destruction and modified pumping schedule program if needed. You are requested to analyze for fuel lead scavengers including EDB and EDC during each sampling event until further written notice. You are required to analyze all soil and water samples for the above referenced compounds employing the Iowest possible detection limits, EPA Method 8010 is prefered. Report the results of your investigation to this agency within 30 days of completion of the approved scope of work. PHS/EHD has approved the proposed application of Cone Penetration Testing for the purpose of gathering detailed information regarding the hydrogeologic setting at and near your site. You were requested to determine and report the historic high and low ground water elevations during the operational period of this facility and to collect soil and ground water samples from each significantly different lithological encountered. Each unit shall be analyzed by a qualified laboratory. Samples from each significantly different lithologic unit encountered in vertical and lateral assessment efforts shall be submitted to a state certified analytical laboratory for chemical analyses following the guidelines presented in previous correspondence (See Analytical Chemistry Protocol). This data shall be employed in determining the potential rate at which contaminants may migrate in this hydrogeologic setting and shall be considered in the process of positioning and constructing monitoring well networks and sampling strategies. This data shall also be utilized to provide a rationale for expanding the radius of receptor, conduit, and well surveys. Report the results of your investigation to this agency within 30 days of completion of the approved scope of work. We requested that you employ approaches to estimating MTBE/Additive contaminant mass flux across plume transects or fences located perpendicular to the MTBE/Additive plume. We request that you install additional CPT boreholes during this mobilization event, collect and analyze samples from these boreholes at intervals spaced laterally not less than 150 feet from this site to assess the plume. The total depth of proposed boreholes shall also consider recharge and pumping influences in the area, and employ nearby screened interval depths of wells as a rationale for total depth. Include your proposal for the installation of these exploratory boreholes in the work plan addendum requested below. Please report your results in the SWI Report requested in previous correspondence. 2