Pacific Gas and Electric Co. on Monday denied that there has been an expansion of an underground cache of contaminated groundwater, as reported in a story Monday in the Los Angeles Times, based on allegations by residents in Hinkley, CA, and a regional water board official.

San Francisco-based PG&E spokesperson Jeff Smith told NGI the utility is continuing its remediation work to bring chromium 6 levels in the local groundwater near Hinkley, 120 miles north of Los Angeles, to levels present before it was contaminated by leakage from PG&E compressors in the 1950s and 60s.

That work has required the testing of much wider areas surrounding the Hinkley concentration.

A study conducted by the utility a few years ago concluded that there are naturally occurring chromium 6 levels at 3.1 parts per billion (ppb). Residents and the local water district have questioned the validity of the work, so the U.S. Geological Survey (USGS) is conducting an independent study to determine what level of naturally occurring, or background, contamination there is in Hinkley’s water.

California last year set a maximum contamination level for chromium 6 of 10 ppb, and all of the of Hinkley water now meets that standard, Smith said.

Despite the new media attention and the concerns of a few residents, Smith contends PG&E has the situation well in hand, and when it has the USGS results next year on the naturally occurring levels of chromium 6, it will gear the ultimate restoration efforts to bringing Hinkley’s levels down to the naturally occurring level.

The Hinkley area is the site of a decades-long toxic contamination, $333 million settlement and ongoing cleanup surrounding one of PG&E’s natural gas transmission pipeline compressor stations.

That situation stirred news media attention with the help of legal clerk Erin Brockovich, whose past exploits were the basis for a hit motion picture of the same name in 2000.

Elsewhere, Smith said PG&E’s similar remediation efforts have been successful at the Colorado River and Topock, AZ, keeping past contamination of chromium 6 from the utility’s transmission pipeline operations at the California border out of the river, which supplies water to some 21 million people in Southern California.

More than a decade ago the utility began addressing the situation at Topock. PG&E’s gas utility officials expressed confidence at the time that the efforts would be successful in preventing any contaminated water supplies from getting into the Colorado River at Topock, where a major PG&E natural gas transmission pipeline picks up interstate supplies from the Southwest (see Daily GPI, March 15, 2004).

That is exactly what has occurred, said Smith, adding that the situation there is completely different than Hinkley — not involving a local population living above the contamination, but involving various issues with Native American tribes that consider some of the land involved to be sacred.

In early February 2006, PG&E announced it had reached a $295 million settlement with Hinkley plaintiffs related to toxic chromium exposure in the 1950s, 60s and 70s at three gas compressor stations spread across its 350-mile Southern California gas transmission pipeline system from the Arizona border to Kettleman on the northwest side of the state’s central valley (see Daily GPI, Feb. 7, 2006). It was the second nine-figure deal involving chromium 6 for PG&E.

Earlier, following a $333 million settlement, PG&E undertook mitigation programs, some of which are still under way.