Chromium plume set to be defined in northern and eastern areas
by Brooke Self
HINKLEY – The agency responsible for regulating Pacific Gas and Electric’s groundwater cleanup in Hinkley issued an amended Cleanup and Abatement order, requiring the plume be definitively set in the northern and eastern parts.
The order issued by the Lahontan Water Quality Control Board Wednesday, requires PG&E to fully define the chromium plume in the northern area at the Hinkley Gap and in the eastern area at Dixie Road.
“It is important that we have a clear and up-to-date understanding of the chromium plume boundaries,” the order from the Lahontan Water Quality Control Board read.
The amendment additionally requires that PG&E test domestic water supply wells at these areas on a monthly basis beginning in March, as opposed to quarterly testing that was done.
Monthly testing will ensure that increasing levels of chromium 6 in residential water supplies will be detected faster Assistant Executive Officer Laurie Kemper said.
The current plume line is set at a 2-mile by 1-mile radius and PG&E spokesman Jeff Smith said it can change based on new information because it is drawn to the most current testing. He said the order means the water board is asking to test in areas that haven’t previously been tested
“They’re quite a long distance from where the initial contamination took place; the water board has not requested these areas previous,” Smith said.
“We received it yesterday so we’re currently reviewing it to make sure we’ve got a good understanding. It’s very important to us that the correct plume line in Hinkley be identified so we can move forward with the clean up, which will be in the best interest of all parties,” Smith said.
PG&E is responsible for groundwater cleanup in Hinkley after it was discovered the company was responsible for discharging hexavalent chromium in unlined ponds near their compressor station in the 50’s and 60’s, and contaminated the town’s water supply.
To see a full copy of the amended Cleanup and Abatement order go to: www.waterboards.ca.gov.
The fenced area located next to PG&E’s Community Center and old compressor station is where the highest levels of hexavalent chromium are detected and the bulk of groundwater cleanup is required.