Laserfiche WebLink
I <br />PARS Ctj N S • <br />Parsons Engineering Science, Inc. A Unit of Parsons Infrastructure & Technology Group Inc. <br />2101 Webster Street • Suite 700 • Oakland, California 94612 • (510) 891-9085 • Fax (510) 835-4355 <br />November 19, 1998 <br />Ref: 729801 <br />California Regional Water Quality Control Board <br />Central Valley Region <br />3443 Routier Road, Suite A <br />Sacramento, California 95827-3098 <br />Attention: Mr. Philip S. Isorena <br />Subject: Amendment to Remedial Action Work Plan <br />for Former Hazardous Materials/Waste Storage Area <br />Applied Aerospace Structures Corporation Facility <br />Stockton, California <br />Reference: Comments on the Remedial Action Work Plan <br />Letter from Philip Isorena, CRWQCB, to Werner Sievol, BP Oil Company <br />Dated: 13 October 1998 <br />Dear Mr. Isorena: <br />This letter addresses your comments and requirements in the above -referenced letter and <br />is submitted by Parsons Engineering Science, Inc. (Parsons) on behalf of BP Oil <br />Company. The Remedial Action Work Plan is hereby amended to include the following <br />additional work items: 1) additional groundwater sampling along the north property line, <br />2) groundwater capture zone modeling, and 3) a feasibility analysis of technological and <br />economic impracticability of further remediation if background concentrations are not <br />achieved by pumping and treating groundwater associated with the Former Hazardous <br />Materials/Waste Storage Area. A revised project schedule is attached; several target <br />dates have been adjusted by one week relative to the version transmitted to you by email <br />on November 9. <br />Responses to General Comments on SVE and Groundwater P&T <br />1. It is agreed that establishing adequate cleanup of the site will include confirmation soil <br />sampling and residual soil gas concentrations. We propose to use soil vapor samples <br />from the 6 vapor monitoring points (17 discrete sampling locations) to provide the <br />residual soil gas data. An appropriate vadose zone transport and fate model such as <br />SESOIL' or VLEACH® will be used to evaluate whether any detectable vadose zone <br />contamination remaining after remediation could result in an impact to groundwater. <br />2. Recent experience in remediating groundwater contaminated with chlorinated VOCs <br />indicates that it is unlikely that restoration to a background water quality of zero <br />concentration will be achievable by any remedial approach. On the other hand, <br />