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Californi gional Water Quality Co> l Board <br /> Central Valley Region WI- <br /> Katherine Hart, Chair � r <br /> Linda S.Adams 11020 Sun Center Drive 4200,Rancho Cordova,California 95670-6114 Arnold <br /> Secretory for Phone(916)464-3291 •FAx(916)464-4645 Sehwarzenegget <br /> Eli vironmental Protection http://www.waterboards.ca.govicentralvalley RECEIVED <br /> Governor <br /> 18 November 2010 NOV 2 2 2010 <br /> ENVIRONMENTAL HEALTM <br /> Mr. Jeff Johnson PERMIT'/SERVICES <br /> Chevron Pipe Line Company <br /> 4800 Fournace Place/E320C <br /> Bellaire, TX 77401-2324 <br /> REVISED SOIL AND GROUNDWATER INVESTIGATION WORK PLAN, MOUNTAIN <br /> HOUSE DEVELOPMENT SITE #4, BYRON ROAD, SAN JOAQUIN COUNTY <br /> Regional Water Quality Control Board, Central Valley Region (Central Valley Water <br /> Board) staff reviewed the 4 November 2010 Revised Soil and Groundwater <br /> Investigation Work Plan (Revised Work Plan) submitted by The Benham Companies, <br /> LLC, a SAIC Company (SAIC) on behalf of Chevron Pipe Line Company (Chevron). <br /> The Revised Work Plan was submitted in response to our 13 October 2010 letter <br /> requesting that Chevron revise its 23 September 2010 Groundwater Investigation Work <br /> Plan (Work Plan). Our letter requested that Chevron (1) propose a strategy for <br /> delineating the vertical and lateral extents in soil and groundwater, (2) conduct <br /> laboratory analysis to speciate organic lead, and (3) submit quality control (QC) <br /> documentation, including laboratory standards and calibration curves, to substantiate <br /> identified compounds. <br /> The Revised Work Plan <br /> • proposes to perform soil and groundwater sampling in borings stepped-out from <br /> the northeastern most borings, if contaminated soil or groundwater is observed in <br /> these borings. Samples will be screened using a photoionization detector (PID). <br /> If there are no visual indications of contamination, a single soil sample will be <br /> collected from just above the groundwater table-, <br /> • proposes to deepen the borings from the previously-proposed uniform depth of <br /> 20 feet below ground surface (bgs) to a depth of 45 feet bgs at the boring closest <br /> to the hot spot, and 3 to 5 feet greater than the depth to first-encountered <br /> groundwater for borings located further away; <br /> • rescinds the proposal to submit groundwater samples for laboratory analysis for <br /> tetraethyl lead (TEL) and tetramethyl lead (TML), and <br /> • requests a Level IV QC data package containing the standards and curves used <br /> to quantify detected compound concentrations. <br /> Chevron anticipates that field work will begin 30 days following concurrence with the <br /> work plan and procurement of all necessary access permits. <br /> California Environmental Protection Agency <br /> (c3 Recycled Paper <br />