Laserfiche WebLink
C E tC0PY <br /> ENVIRONMENTAL HEALTH DEPARTMENT <br /> PpUlnV SAN JOAQUIN COUNTY <br /> Unit Supervisors <br /> Donna K.Heran,R.E.H.S. <br /> 304 East Weber Avenue, Third Floor Carl Borgman,R.E.H.S. <br /> Director <br /> Mike Huggins,R.E.H.S.,R.D.I. <br /> Al Olsen,R.E.H.S. Stockton, California 95202-2708 Douglas W.Wilson,R.E.H.S. <br /> rq- �P Program ManagerTelephone: (2 09) 468-3420 Margaret Lagorio,R.E.H.S. <br /> F o R Laurie A.Cotulla,R.E.H.S. <br /> Fax: (209) 464-0138 Robert McClellon,R.E.H.S. <br /> Program Manager Mark Barcellos,R.E.H.S. <br /> SAIYED ALI JUN 0 3 2002 <br /> CALTRANS DISTRICT 10 <br /> PO BOX 2048 <br /> STOCKTON CA 95201 <br /> RE: Stockton Maintenance Station SITE CODE: 1018 <br /> 1604 B Street <br /> Stockton CA 95201 <br /> San Joaquin County Environmental Health Department(SJC/EHD) has reviewed the"Site Investigation <br /> Report"dated April 4, 2002, prepared on your behalf by IT Corporation and has the following comments. <br /> The report documents a field investigation completed February 13-14, 2002,when two cone <br /> penetrometer test(CPT)borings were advanced onsite. The first boring was advanced for lithological <br /> interpretation, the second boring to collect depth discrete groundwater samples for analysis. <br /> Groundwater samples were collected from three different depths of the aquifer and analyzed for <br /> petroleum hydrocarbons and fuel oxygenates. The sample depths were 60 feet below surface grade <br /> (bsg), 90 feet bsg and 100 feet bsg. Results of the analyses were positive for petroleum hydrocarbon <br /> constituents in each sample, but non-detect for fuel oxygenates. The concentrations of contaminants <br /> detected in the CPT samples were significantly lower than those reported in the monitoring well samples <br /> from the same area. <br /> The report presented a contaminant mass calculation, as requested by Cal Trans, but used only the data <br /> collected from the CPT investigation in determining the quantity of contaminants remaining in the aquifer. <br /> SJC/EHD considers a more appropriate approach would have been to use data from the monitoring wells <br /> located within the plume area as well. In addition, the report states that a planimeter and a map showing <br /> the surface area of the plume are located in Appendix D, but there was no Appendix D in the report. <br /> The report includes a recommendation to prepare a Remedial Action Plan in order to perform cleanup <br /> activities at the site. SJC/EHD agrees that the site needs to be remediated, and that a plan for doing so <br /> should be prepared. Per the California Code of Regulations,Title 23, a feasibility study must be included <br /> in any plan for corrective action. The feasibility study must evaluate at least two alternatives for <br /> remedying or mitigating the actual or potential adverse effects of the unauthorized release. The <br /> Corrective Action Plan should include a site conceptual model with maps and cross-sections depicting the <br /> geological and plume migration models, and is due for submittal to SJC/EHD by August 2, 2002. In <br /> addition, please forward a copy of the missing Appendix D to SJC/EHD as soon as possible,for inclusion <br /> with the latest report, and a revised calculation of contaminant mass. <br /> Donna Heran, REHS, Director <br /> Environmental Health Department <br /> r��Lw►Co��. � �� <br /> Lori Duncan, Senior REHS Nuel C. Henderson, Jr., R.G. <br /> LOP/Site Mitigation Unit IV LOP/Site Mitigation Unit IV <br /> cc: Marty Hartzell, CVRWQCB <br /> Martha Adams, IT Corporation <br />