TFX Aviation Incorporated Newbury Park Facility, Post-Closure Permit Renewal

The Department of Toxic Substances Control (DTSC) pursuant to authority granted under Chapter 14, Division 4.5, of Title 22, of the California Code of Regulations intends to approve a Post-Closure Permit Renewal (Renewal). The project is the issuance of a Renewal Permit for the Hazardous Waste Management Facility (HWMF) at TFX Aviation Incorporated Newbury Park Facility. The term of this Renewal will be 10 years and includes the continuation of post-closure care activities and a request to reduce ongoing groundwater monitoring frequency. Project Activities: The Renewal proposes continued post closure care activities at the Facility and the proposal to reduce the ongoing groundwater monitoring frequency. There are no other proposed changes to the Facility, or any of the waste being received or treated, or to any other operations or units. There will be no operational changes or ground disturbance. All previous Post-Closure Permit requirements will remain in effect. This Renewal will not result in any new or substantially more severe significant impacts on the environment. Background: The Facility was used for manufacturing civilian and military aircraft components between 1956 and 1989. During the manufacturing process, hazardous wastes that included metals, cyanide, chlorinated solvents, and wastes oils were generated. Soil and groundwater at the Facility were impacted from the on-site waste disposal practices that included use of a surface impoundment. As a result, 3,000 cubic yards of contaminated soil were removed, and groundwater and soil vapor treatment and extraction systems were installed. The former surface impoundment was acknowledged certified closed by DTSC on August 26, 1987. A final post closure permit was issued by DTSC on November 24, 1992. The post closure permit addressed water quality monitoring of the former impoundment and post-closure care of the former impoundment. The Post-Closure Permit was renewed/reissued on October 7, 2005, and was renewed again in 2016. The groundwater remedy is ongoing and is expected to continue throughout the permit cycle. The Facility has land use restrictions under a Land Use Covenant. There is a groundwater monitoring and extraction well network installed at the Facility. Groundwater treatment, which occurs at this Facility and is permitted by Ventura County, includes treatment of groundwater contaminated with metals (primarily Hexavalent Chromium) to reduce the metals to a lesser form (primarily Trivalent Chromium), and remove these metals from the water. Groundwater treatment also includes treatment of groundwater contaminated with chlorinated volatile organics through an air stripper and scrubber utilizing activated carbon. Hazardous waste is generated as a result of groundwater extraction, treatment and remediation activities, but is not a part of this permit. The hazardous waste generated by the treatment includes bag filters containing waste metals, small volumes of liquid waste, and accumulated rainwater (when the treatment system is non-operational) totals less than 500 kilograms of hazardous waste per month. No other industrial operations take place at the TFX Aviation Facility.