COMPLIANCE INFO - Laserfiche WebLink

Home Browse Search

California egional Water Quality Co rol Board L_�N Qa; Central Valley Region ion Karl E. Longley,ScD, P.E.,Chair Linda S.Adams 11020 Sun Center Drive 11200,Rancho Cordova,California 95670.61 14 Arnold Secretary for Schwarzenegger Environmental Phone(9]6)464-3291 •FAX(916)464-4645 http://www.waterboards.ca.gov/centralval ley Governor Protection TO: Antonia K. J. Vorster FROM: Nathan Casebeer Site And Groundwater Cleanup Priva e i es Cle nup Unit Program Manager SIGNATURE: Duncan Austin Chief, Private Sites Cleanup Un DATE: 24 November 2008 SIGNATURE: SUBJECT: RATIONALE FOR CONSIDERING NO FURTHER ACTION ON DOW CHEMICAL FACILITY, 400 WEST GANDY DANCER DRIVE, TRACY, SAN JOAQUIN COUNTY Rationale: Residual groundwater contamination remaining at the site is at concentrations less than water quality objectives. Residual groundwater and soil vapor concentrations do not present a vapor intrusion hazard. Residual soil concentrations are below levels that threaten groundwater and the 2008 US EPA Preliminary Remediation Goals (PRGs). Issues: In 2001, staff of the Central Valley Regional Water Quality Control Board inspected the facility (formerly owned by the Celotex Corporation) to determine compliance with the State Water Resources Control Board Order No. 97-03-DWQ, NPDES General Permit No. CAS000001, for Discharges of Storm Water Associated with Industrial Activities. The inspection identified chemical spills in the unloading area and on the railroad tracks. Identified constituents of potential concern include Freon 11, Freon 12, Freon 113, 1,1- dichloroethene, and methylene chloride. Setting: The site consists of approximately 16 acres of land and is occupied by a 150,000- square-foot manufacturing, warehousing, and office building. Source: Surface spills of chemicals from unloading activities. Actions: Investigation commenced in 2001. • A sample of stained soil collected from between the railroad tracks in June 2001 contained methylene chloride at a concentration of 17 milligrams per kilogram (mg/kg). Additional soil samples collected at the site from depths of 2 and 5 feet in August 2002 also contained methylene chloride at concentrations ranging from below a detection limit of 0.010 mg/kg up to 0.021 mg/kg. Freon 11 was also detected in two soil samples at concentrations of 0.17 and 0.043 mg/kg. California Environmental Protection Agency 0 Recycled Paper