Laserfiche WebLink
California Regional Water Quality Control Board <br /> Central Valley Region 0 <br /> Karl E. Longley, SO, P.E., Chair <br /> Arnold <br /> Linda S.Adams 11020 Sun Center Drive#200,Rancho Cordova,California 95670-6114 Schwarzenegger <br /> Secretary for Phone(916)464-3291 •FAX(916)464-4645 Governor <br /> Environmental http://www.waterboards.ca,gov/centralvalley <br /> Protection ��^ 1,, -i iZE�Mo <br /> 23 December 2009 DEC 2 S 2009 <br /> DESJC, M.BENSON ENVIRONMSE REALTH <br /> Defense Distribution Depot San Joaquin <br /> PERMITI�ERVICES <br /> P.O. Box 960001 <br /> Stockton, CA 95296 <br /> POTABLE WELL REPORTS FOR DEFENSE LOGISTICS AGENCY, DEFENSE <br /> DISTRIBUTION DEPOT SAN JOAQUIN— SHARPE SITE <br /> The California Regional Water Quality Control Board, Central Valley Region (Central Valley <br /> Water Board) staff has reviewed the following reports: Draft DDJC-Sharpe Potable Well <br /> Evaluation, received on 1 June 2009, and Draft Off-Depot Potable Well Contingency Plan <br /> received 6 October 2009 (Draft Reports). The Draft Reports were prepared by URS Group, <br /> Inc., on behalf of the Defense Logistics Agency Enterprise Support San Joaquin, California <br /> (DESJC). <br /> The stated Draft Reports objectives are to evaluate the need for off-depot monitoring wells, <br /> compare distributions of on- and off-depot volatile organic compounds (VOCs), compile <br /> background information for water contingency plan development, create a sampling decision <br /> logic for off-depot potable wells, identify potable wells down-gradient of the depot, identify <br /> potable wells already affected by depot VOCs, establish constituent of concern (COC) warning <br /> level concentrations, develop response actions when a warning level is reached, and modify <br /> the potable well monitoring frequencies using the created decision logic. <br /> Central Valley Water Board staff has prepared the comments in this letter to assist DESJC <br /> with development of an acceptable potable well contingency plan. The Central Valley Water <br /> Board will only consider groundwater sampling frequency changes that are presented in <br /> Annual Progress Reports required by the Record of Decision documents for the Sharpe Site. <br /> As you know, DESJC's next opportunity for change request approvals is the Central Valley <br /> Water Board review of the Draft Final FFA Annual Progress Report: October 2008 through <br /> September 2009, currently scheduled for completion after 29 January 2010. Staff has <br /> grouped comments into two categories: 1) Potable Well Sampling Frequency and Guard Well <br /> Placement, and 2) Potable Well Contingency Plan. <br /> Potable Well Sampling Frequency and Guard Well Placement <br /> For each private water supply well in which DESJC is considering reduced sampling <br /> frequency, the following questions must be addressed: <br /> 1 . Is there a guard well between the COC plume and the potable well <br /> 2. Is the potable well in a flow path of a COC plume? <br /> California Environmental Protection Agency <br /> �osRecycled Paper <br />