In March 2012, the Guam Environmental Protection Agency (GEPA) approached EPA with a request for assistance from Guam Power Authority (GPA) regarding transformers at their facilities which had been identified as contaminated with polychlorinated biphenyls (PCBs). In April 2012, the EPA Pacific Islands Office contacted the EPA Region 9 Emergency Response Section (ERS) and requested assistance. GPA had conducted sampling of the transformers. Analytical results were provided to EPA and reviewed by ERS.
On April 23, 2012, ERS conducted a site walk of the substation locations. Two large transformers, which contained approximately 3000 gallons of oil were observed. Both transformers were leaking from different locations. Each transformer contained two compartments, which contained oil and were sampled by GPA. The results of the sampling indicated that 3 of the compartments contained off-spec used oil, regulated by RCRA, with PCB concentrations that exceeded 2 mg/kg. One of the compartments contained PCB oil, regulated under TSCA, with a concentration exceeding 50 mg/kg of PCBs. While the large transformers in Apra Heights and Talofofo were located inside of secondary containment, they were leaking from different locations. While drip pans had been placed underneath some of the leaks, others were being disbursed along the sides of the transformer and could not be contained in one location. The secondary containment areas had oil staining and puddles, and each of the secondary containments were free of water, indicating that they had been drained. Each of the drainage valves discharged into surface soils. It is unknown how long the transformers have been leaking, but GPA has plans to repair the transformers once they are drained of the oil.
In addition, there are a number of smaller transformers that contain PCBs and are being stored at the Dededo storage facility. The condition of these transformers is unknown but they are being stored outside and subject to the elements.
