SWMU 11 – Old Power Plant/Building 38

SWMU 11, a part of OU 5, consists of areas inside the Old Power Plant (Building 38). This SWMU includes a former concrete pad where transformer fluids containing PCBs were stored. Extensive staining of the pad was identified during investigations. There were also indications that transformer fluids were discarded by pouring them into subsurface cooling-water tunnels at the Power Plant. The tunnels emptied into a nearby bay. Also associated with SWMU 11 is SWMU 45, which includes outside areas surrounding the Power Plant. In addition, there are two abandoned 50,000-gallon underground fuel storage tanks, located outside the Power Plant on the northwest side of the building. An RFI of soils, surface water and sediments, and groundwater was required in the permit for SWMUs 11 and 45.

Status

• RFI work plans were submitted and approved by the EPA in 1995.
• Investigations, in accordance with the EPA-approved RFI work plans, have been completed.
• Possible releases to the building interior may require re-characterization.
• A work plan for re-characterization was submitted to EPA in March 1998.
• The Draft Final RFI Report was submitted in May 2004.
• The RCRA 7003 Administrative Order on Consent recommended interim measures for SWMU 11.
• The interim measures are in place at SWMU 11.

Two ICMs have been completed at SWMU 11/45. The first ICM was a soil removal action which addressed PCB contamination in an area around the building where transformers had been maintained. This effort was successfully completed by meeting established clean-up levels in soil. A project closeout report was submitted to the EPA and was subsequently approved.

The second ICM addressed the USTs and cooling water tunnels associated with Building 38. The USTs were cleaned and abandoned in place by filling with low density concrete. Originally, the cooling water tunnels were to be cleaned to remove the sludges inside them. Groundwater flowed into the tunnels through construction joints and limited the Navy’s ability to clean the tunnels. The tunnels were filled with low density concrete with EPA approval. A project close out report was provided and is presently under review by the EPA.

One important finding came out of the ICM at the tunnels. During and excavation to determine the place where groundwater was entering the tunnels, evidence of oil was seen outside.