Laserfiche WebLink
Mr. George Luxbacher -2- 11 January 2011 <br /> The Work Plan also proposes to collect grab groundwater samples from these borings. Two <br /> additional grab groundwater samples have been proposed from boring PWB-1 at 35 feet and <br /> 50 feet bgs. Grab groundwater samples will be analyzed for DBCP, EDB, sulfolane and OCP. <br /> Central Valley Water Board staff conditionally concurs with the Work Plan with the following <br /> two conditions: <br /> 1. No boring location has been proposed between the excavation area and the UST area. <br /> The spacing between these two areas is approximately 200 feet. No groundwater data <br /> from this area is available in the shallow groundwater zone, including the water table <br /> zone. Therefore, at least two additional groundwater sample locations are needed to <br /> laterally define the extent of COCl in the shallow groundwater within the AgChem area. <br /> 2. The Work Plan proposes to analyze groundwater samples for DBCP, EDB, sulfolane <br /> and OCP. Historical investigations indicate detection of benzene hexachloride isomers, <br /> organophosphorus pesticides, herbicides, nitrate, chloride, and sulphate in <br /> groundwater. Therefore, GHS needs to include analysis of these additional CDCs in <br /> groundwater samples collected from the soil borings. <br /> In summary, Central Valley Water Board staff conditionally concurs with the Work Plan as an <br /> initial phase of investigations for soil and groundwater in the AgChem Area. Given the <br /> elevated concentrations of CDCs detected in well PW-22-071 (screened from 63 to 68 feet <br /> bgs), additional deeper groundwater investigations may be,needed. <br /> By 30 April 2012, please submit the results of the investigations in a site assessment report. <br /> Provide at least one-week notice of field activities to allow Central Valley Water Board staff to <br /> observe the boring installations. <br /> If you have questions or comments, please contact me at 916-464-4658, or by e-mail at <br /> ssewalia(bwaterboards.ca.gov <br /> Siddharth Sewalia <br /> Water Resource Control Engineer <br /> Private Sites Cleanup <br /> cc: Mr. Monty Johnson, J.R: Simplot <br /> Mr. Nam Baek, Glenn Springs Holdings, Inc. <br /> Mr. Ryan Mock, J.R. Simplot <br /> Ms. Liz Sewell, ARCADIS Inc., Roseville <br /> Mr. Alan L. Prouty,.J.R. Simplot Company, Boise, ID, <br /> Mr. Garrett Backus_, San Joaquin County Environmental Management Department, <br /> Stockton <br />