A small oil spill on Bass Lake was cleaned up immediately Wednesday, and poses no threat to the lake’s fish or recreationists.
The incident occurred on Wednesday, July 18, at 8:45am, when dredging operations turned up a 55 gallon drum in the mud about 45 feet below the surface of the lake. The legs of the dredging platform punctured the drum, according to PG&E’s report to the National Response Center and Environmental Protection Agency. The puncture caused about five gallons of oil to seep into the lake.
Officials could not say how the drum got into the lake, or how long it had been there. PG&E spokesman Denny Boyles said the drum was not associated with the retrofitting project. Boyles told SierraNewsOnline that the drum was black and had no markings, but its design and condition indicated that it had been at the bottom of the lake for a long time.
“It looked like any drum that had been under water for decades,” Boyles said. The drum itself was not in any way related to the dam retrofit project.”
A sample of the substance, which appears to be petroleum-based, has been sent for testing. The results should be known in about three days, Boyles said.
A large dredging platform was on the lake performing satellite-directed dredging operations about 100 yards upstream from the dam when the incident occurred, Boyles said. After moving the platform to a new location and re-extending its stability legs back down into the lake bed, PG&E workers noticed a black substance rising to the surface.
Divers were already on-site that day examining the turbidity curtain. They were sent down to investigate as soon as the oil sheen appeared on the water. They discovered the punctured, leaking 55-gallon drum that had apparently been buried in the bottom of the lake for quite some time.
PG&E already had two layers of containment booms in place to control turbidity, as is standard practice with these types of operations, Boyles said. The spill, which he estimated to be about 24 by 40 feet, was quickly contained within the booms, according to the California Emergency Management Agency (CalEMA).
Divers attached a rigging to the drum, and the platform’s crane lifted it up. All appropriate agencies were immediately notified, including the Madera County Health Department, the Department of Fish and Game, and CalEMA.
PG&E immediately activated its emergency response plan and brought in a hazardous waste clean-up team. They expect to have the site cleaned up by the end of the day Friday, July 20, but say they will keep their people there until the job is done.
Phil Hudecek of the Madera County Health Department said PG&E has a team in place for just such issues, and that they are “absolutely the best at dealing with this type of incident.” He said he was very pleased with the response.
“It couldn’t have gone better if it had been a mock training exercise,” Hudecek said. “These guys really know what they’re doing, and they had everything handled and under control in short order.”
(Note: the difference in the color of the water is due to the turbidity caused by the dredging operations)