Jim Steinberg, Staff Writer
Posted: 07/13/2011 08:18:06 PM PDT
Pacific Gas and Electric Co. has asked a water quality board to reconsider its order requiring the utility to provide permanent replacement water for many Hinkley residents for all indoor uses including drinking, cooking and bathing.
The order potentially affects those living within a mile of the current plume boundary.
PG&E’s request to the Lahontan Regional Water Quality Control Board was filed Tuesday afternoon, the last day comments could be filed before the order takes effect.
For about a year, PG&E has provided bottled drinking water to all water well users with chromium 6 levels above natural background levels as well as to the Hinkley School and the Hinkley senior center, said Jeff Smith, a spokesman for the San Francisco-based utility.
Recently, PG & E has expanded its bottled water program to well water users within one mile of the plume regardless of the chromium 6 level found in their water.
The proposed order “represents an unsupported and unreasonable expansion of water replacement requirements and sends a confusing message to the Hinkley community,” PG&E said in its letter to Harold Singer, the water quality board’s executive officer.
The proposed order has also drawn fire from the California Department of Public Health and the Association of California Water Agencies, which represents more than 90percent of the state’s water delivery providers.
In the 1950s and 1960s, PG&E emptied water containing chromium 6 from a pumping station, which then seeped into the town’s groundwater.
It was common to use chromium 6 as a rust preventative at the time, before its health hazards were known.
Neither the state nor federal government has set a standard for safe levels of chromium 6, also called hexavalent chromium, in drinking water.
But the California Office of Environmental Health Hazard Assessment earlier this year proposed that the state public health goal should be 0.02 parts per billion.
That goal will be used as one of several factors in setting the legally enforceable maximum allowable amount – a process that could take years.
The California standard for all forms of chromium in water, including both chromium 3 and chromium 6, is 50 parts per billion.
Chromium 3 in low doses is considered harmless and is often used as a vitamin supplement. Chromium 6 is a known carcinogen.
The Lahontan board previously determined that the natural background level of chromium 6 in the Hinkley area was between 1.2 parts per billion and 3.1 parts per billion.
The draft order would require PG&E to provide replacement water for wells within one mile of the current plume boundary if chromium levels in their wells were greater than the proposed public health goal of 0.02 parts per billion.
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