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<br />Water Boards
<br />EDMUND G. BROWN Jn
<br />GOVERNOR
<br />FI vioo AlIII% MATTREW RODPROUE2
<br />ENvIRONMENTAt ...TEC r .14
<br />Central Valley Regional Water Quality Control Board
<br />21 August 2018
<br />Natasha Molla
<br />Chevron EMC
<br />145 S. State College Blvd #500
<br />Brea, CA 92821
<br />CHEVRON STATION #9-4054, 2103 COUNTRY CLUB BOULEVARD, STOCKTON, SAN
<br />JOAQUIN COUNTY, CASE# 390089
<br />Central Valley Regional Water Quality Control Board (Central Valley Water Board) staff reviewed the
<br />Site Assessment Work Plan (Work Plan) dated 7 August 2018, submitted on your behalf by GHD
<br />Inc. (GHD) for the Former Chevron Station #9-4054 unauthorized petroleum release at 2103 Country
<br />Club Boulevard in Stockton (Site). In the Work Plan, GHD proposes to advance two shallow soil
<br />borings (B9, B10) near the north and south ends of the former waste oil tank (WOT), as follows:
<br />Borings Total Depth
<br />(ft bgs)
<br />Soil Sampling
<br />Depth
<br />(ft bgs)
<br />Analysis
<br />B9, B10 12
<br />4, 8 Naphthalene, PAHs
<br />12 TPHd (SGC), TOG, VOCs,
<br />SVOCs, PCBs, Title 22 metals
<br />PAHs=polycyclic aromatic hydrocarbons; TPHg (SGC)=total petroleum hydrocarbons with Silica Gel
<br />Cleanup; TOG=total oil and grease; VOCs=volatile organic compounds; SVOC=semi-VOCs;
<br />PCB=polychlorinated biphenyls; ft bgs=feet below ground surface
<br />Previous WOT soil samples were collected below the former tank at 11 feet below ground surface
<br />(bgs), and were analyzed only for total petroleum hydrocarbons as gasoline (TPHg), TPH as diesel
<br />(TPHd), benzene, toluene, ethylbenzene, xylenes (BTEX), lead, cadmium, chromium, and zinc. The
<br />proposed scope of work addresses soil data gaps between 0 to 5 and 5 to 10 feet below ground
<br />surface (bgs) for comparison to the Low Threat Underground Storage Tank Case Closure Policy
<br />(LTCP), and gaps related to the nature of the release. As such, Central Valley Water Board staff
<br />concurs with the scope of work as proposed in the Work Plan, with the following conditions:
<br />Please ensure that the borings are advanced just outside the former WOT excavation area,
<br />and that soil samples are collected from native material.
<br />By 23 November 2018, please submit an Assessment Report which details the completion
<br />of the proposed work and the resultant findings. Please also include an evaluation of the
<br />data in relation to the nature of the release, as well as in relation to the LTCP. If based on
<br />the data, you believe this case to be ready for closure, please include a full evaluation of Site
<br />conditions and data as compared to the LTCP, which provides discussion of how each
<br />General and Media-Specific criterion is met, and identifies any remaining data gaps. Please
<br />also include recommendations to address any identified gaps, and include all historical
<br />groundwater, soil, soil gas, and remedial data in tabular form.
<br />KARL E. LOWREY ScD, P.E., C1,41. I PATRICK PULcnA, ESC.. EXECUTIVE OFFICER
<br />11020 Son Center Drive 11200, Rancho Cordova, CA 95670 I wana.waterboards.ca.govrcentralvalley
<br />Ca necrCteo PAPER
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