Corrective Action Plan for Corrective Action Unit 335: Area 6 Injection Well and Drain Pit Nevada Test Site, Nevada

Abstract

This Corrective Action Plan (CAP) has been prepared for Corrective Action Unit (CAU) 335, Area 6 Injection Well and Drain Pit, in accordance with the Federal Facility Agreement and Consent Order (FFACO) (1996). This CAP provides the methodology for implementing the approved corrective action alternative as listed in the Corrective Action Decision Document (CADD). However, there is one modification to the selected alternative. Due to the large area that would require fencing, it is proposed that instead of fencing, an appropriate number of warning signs attached to tee posts be used to delineate the use restriction area. CAU 335 is located in Area 6 of the Nevada Test Site (NTS) which is approximately 105 kilometers (km) (65 miles [mi]) northwest of Las Vegas, Nevada. CAU 335 is located in the Area 6 Well 3 Yard approximately 39 km (24 mi) north of Mercury, on the Mercury Highway and several hundred feet (ft) west along Road 6-06. CAU 335 consists of the following three Corrective Action Sites (CASs): CAS 06-20-01, Drums, Oil Waste, Spill; CAS 06-20-02, 20-inch Cased Hole; CAS 06-23-03, Drain Pit. The site history for CAU 335 is provided in the Corrective Action Investigation Plan (DOE/NV, 2000). Briefly, CAS 06-20-01, was used for storing material that was pumped out of CAS 06-20-02 and placed into four 208-liter (L) (55-gall [gal]) drums. The drums were taken to the NTS Area 5 Hazardous Waste Accumulation Site in 1991. CAS 06-20-01 will be closed with no further action required. Any spills associated with CAS 06-20-01 are addressed and considered part of CAS 06-20-02. CAS 06-20-02 was used for disposal of used motor oil, wastewater, and debris for an undetermined amount of time. In 1991, the casing was emptied of its contents, excavated, and backfilled. CAS 06-23-03 was used as a depository for effluent waste from truck-washing activities from 1960-1991.