Laserfiche WebLink
PUBLIC LHEALTH SERVICES <br /> op4u1"!. c <br /> SAN JOAQUIN COUNTY <br /> ENVIRONMENTAL HEALTH DIVISION a`. :< <br /> Ernest M. Fujimoto, M. D., M.P.H., Acting Health Officer <br /> 304 East Weber Avenue, Third Floor • Stockton, CA 95202 "t;Fopa`Y <br /> 209/468-3420 'V( <br /> BRETT HUNTER ] 9 <br /> CHEVRON USA PRODUCTS COMPANY JUN <br /> 07 <br /> PO BOX 5004 <br /> SAN RAMON CA 94583-0804 <br /> RE: former Chevron Station #9-4054 SITE CODE: 1780 <br /> 2103 Country Club Blvd. <br /> Stockton, CA. 95204 <br /> San Joaquin County Public Health Services, Environmental Health Division (PHS-EHD) <br /> has reviewed the recently submitted "Utility Survey and Plume Stability Evaluation", as <br /> submitted by your consultant, Terra Vac, and has the following comments. <br /> Although a thorough explanation and educational format was utilized to explain the <br /> processes that may be occurring in the soil and groundwater beneath the site, PHS- <br /> EHD cannot agree with your consultant's conclusion that natural attenuation is actually <br /> occurring or effectively reducing the petroleum impact to the groundwater around this <br /> site. <br /> Benzene contamination levels in the groundwater at MW-1 have been increasing since <br /> August 25, 1995. If natural attenuation is occurring as your consultant has concluded, <br /> PHS-EHD feels that it is occurring at a rate that is ineffective. The resultant increase in <br /> Benzene levels in the groundwater strongly indicate that a source is still present in the <br /> soil located on site. It is this source that Chevron needs to identify and remediate. A <br /> definite and consistent decrease in the groundwater Benzene and TPH-G <br /> concentrations over a prolonged period of time can be used as evidence to support a <br /> conclusion that natural attenuation is occurring at this site. <br /> As of this date, there has been no formal plan, recommendation, or study submitted to <br /> PHS-EHD that indicates that Chevron is planning to clean up this site. <br /> Soil vapor extraction tests were performed at this site and the findings suggested that <br /> this remedial action may be cost-effective. Per Corrective Action Requirements <br /> (California Code of Regulations, Title 23, Division 3, Chapter 16, Article 11), a <br /> Feasibility Study is to be submitted to PHS-EHD that identifies and evaluates at <br /> least two alternatives for restoring or protecting groundwater beneficial uses. <br /> Chevron will need to evaluate another alternative for this site's remediation. <br /> A Division of San Joaquin County Health Care Services <br />