Gas Seepage Closes Lake in Cajon Pass

Discovery of naturally occurring hydrogen sulfide gas has forced closure of a popular lake in San Bernardino County’s Cajon Pass to swimmers and fishermen, health officials said Friday.

Lost Lake, a natural pond about the size of a football field and 20 feet deep, was closed Aug. 15 when San Bernardino County Sheriff’s Department divers complained of dizziness and nausea after searching for a stolen car believed ditched in the lake, officials said.

The gas, which smells like rotten eggs, was “probably released when the divers stirred up decaying organic matter at the bottom of the lake,” said Jim Smith, a specialist with the county Environmental Health Services Department’s hazardous waste section.

Tests of water samples taken from the lake by the department, the U.S. Forest Service and the Santa Ana Regional Water Quality Control Board’s enforcement section showed low levels of the gas in the water, Smith said.

“From what we know it is not dangerous at all,” Smith said. “The gas is dissolved in the water and none of it is escaping into the atmosphere.”

He added, however, that the lake, which is located on U.S. Forest Service property, will remain closed for at least two more weeks pending the results of additional testing of water samples.

Last week, scientists believe a temblor shook a lake in Cameroon, releasing a deadly bubble of toxic gas that broke the surface and then drifted over nearby villages, killing thousands of people and livestock. The gas involved may have been hydrogen sulfide.