Laserfiche WebLink
Californi egional Water Quality Cc — of Board <br />Central Valley Region <br />Katherine Hart, Chair a, <br />11020 Sun Center Drive, #200, Rancho Cordova, California 95670-6114 <br />Matthew Rodriquez (916) 464-3291 • FAX (916) 464-4645 Edmund G. Brown Jr. <br />Secretary for http://www.waterboards.ca.gov/centralvalley Governor <br />Environmental Protection RECEIVED • a�VEIY`I <br />ED <br />16 August 2011 <br />AUG 18 <br />ENVIRONMENTAL HEALTH <br />Mr. Eric Jenks PERMIT/}:=RVICES <br />Wilbur -Ellis Company <br />P.O. Box 1030 <br />Marysville, CA 95901 <br />REVIEW OF PHASE 11 DEEPER GROUNDWATER INVESTIGATION WORKPLAN, JOHN <br />TAYLOR FERTILIZERS CO. STOCKTON, SAN JOAQUIN COUNTY <br />Staff of the California Regional Water Quality Control Board, Central Valley Region (Central <br />Valley Water Board) have reviewed the Phase 11 Deeper Groundwater Investigation Work Plan <br />(Work Plan) for the subject site, located at 1819 South Argonaut Street in Stockton, San <br />Joaquin County, California (Site). The Work Plan was prepared on your behalf by Geosyntec <br />consultants, and was received by the Central Valley Water Board on 15 June 2011. <br />Background <br />A retail outlet and distribution center for agricultural chemicals and pesticides was formerly <br />located at. the Site. Several groundwater investigations have been conducted at the Site from <br />1999 to 2010. Site investigations show that the pesticides 1,2-dichloropropane (1,2-DCP) and <br />1,2,3-trichloropropane (1,2,3 -TCP) are found in shallow groundwater. A CPT investigation <br />conducted in 2009 found contaminants in groundwater at approximately 50-80 feet below <br />ground surface (bgs). Four onsite wells, screened from 56.3 to 80.5 feet bgs were installed in <br />August 2010 to confirm the direction of groundwater gradient. These investigations show that <br />pesticides from the facility have leached into the groundwater and have migrated off the Site <br />towards the east. <br />Proposed Work Plan <br />The Work Plan proposes to advance twelve (12) offsite CPT borings downgradient of the Site. <br />The borings will be advanced through a coarse-grained layer anticipated to exist from <br />approximately 60 to 80 feet bgs. Grab groundwater samples will be collected from the gravel <br />zone at each location. The Work Plan also proposes to collect additional groundwater <br />samples from continuous intermediate coarse-grained layers between 45 and 60 feet bgs, if <br />identified by the CPT. <br />Grab groundwater samples will be analyzed for VOCs including 1,2-DCP by EPA method <br />8260B, and 1,2,3 -TCP by low level SRL 52M -TCP. The results of the investigations will be <br />used to plan future investigations to define the downgradient extent of Site -related chemicals <br />of concern. <br />California Environmental Protection Agency <br />(a Recycled Paper <br />