Tracking Pollution May Be Tough

Identifying the source of a chromium 6 contamination in southeast Los Angeles County drinking wells will be difficult and time-consuming, given the number of industries that may have used the toxic byproduct in the region, water experts warned Tuesday.

The warning comes as state Sen. Martha Escutia (D-Whittier) prepares a budget request for $15 million to identify and treat the contamination, which was found in one well to be more than 2,000 times the optimum safety level suggested by state experts.

“You don’t have one or two potential sources. You have 600 or 700 potential sources,” said John Chambers, water superintendent for South Gate, which operates one of the contaminated wells.

Routine testing by local water agencies uncovered chromium 6 at 408 parts per billion in a Bell Gardens well, 340 ppb in a Cudahy well and 86 ppb in a South Gate well. The Bell Gardens and Cudahy wells were operated by Southern California Water Co. The South Gate well was operated by the city.

There now is no standard for chromium 6, but the state limits total chromium to 50 ppb as a means to cut levels of chromium 6, which is a chemical byproduct of the metal. Chromium 6 is a known carcinogen when inhaled in vapors, but scientist are split on whether it causes cancer when ingested in water.

Although the concentration levels in the three wells are the highest found anywhere in Southern California in recent years, state and local water experts said residents should not be alarmed. The Bell Gardens and Cudahy wells have been closed for at least 10 years; the South Gate well was shut down in July 2000.

Still, the high chromium 6 levels may signal a contamination that could be spreading through the underground aquifers throughout the south end of the county, water experts said.

“No one knows the magnitude of the source of contamination at this point,” said Richard Nagel, water quality manager for the Central and West Basins Municipal Water Districts.

To address the problem, water quality experts said, the Los Angeles Regional Water Quality Control Board and other local agencies must determine the direction of the underground water flow and identify the potential sources of the contamination.

The first two steps in the process could take several months or years and require water agency officials and consultants to study as much as 45 years of land use history in the region.

“There is something going on and we need to understand it,” said Michael Meredith, a water quality consultant whose company worked on the now-famous chromium 6 contamination case depicted in the movie “Erin Brockovich.” His firm is working on the contamination problem in southeast Los Angeles County.

Once the source is identified and the direction of the contamination is determined, water quality officials must decide whether to remove the contaminated water, treat it or simply abandon the problem wells, water quality officials said.

The $15 million being requested by Escutia would help pay to identify the chromium 6 source. Assemblyman Marco Firebaugh (D-Los Angeles) also has introduced a bill to set aside $1.5 million for research and cleanup in the area.

The search for a contamination source will be difficult because of the industrial nature of the communities in southeast Los Angeles County. There are four current or former industrial sites within two miles of the wells where chromium 6 has been detected in the soil or ground water, according to the Los Angeles Regional Water Quality Control Board.

Still, Meredith said, large industrial firms, such as those found in southeast Los Angeles County, are easier to investigate than smaller companies because they usually keep better historical records of their operations.

In a related matter Tuesday, the Los Angeles County Board of Supervisors voted to hire a water purification consultant to devise a plan to remove chromium 6, arsenic and other contaminants from county-owned wells.

The supervisors also approved a motion to support legislation calling on the state to lower the legal limit for total chromium from 50 ppb to 2.5 ppb, which officials said would slash levels of chromium 6 to 0.2 ppb.

The action comes after tests showing that 32 of 44 county-owned wells tested positive for chromium 6, with concentrations reaching as high as 18.2 ppb.

Although that falls within current state standards, the concentrations are as much as 90 times the level of chromium 6 that has been recommended by a state agency for optimum safety.

County officials said the 32 wells that had detectable levels of chromium 6 are all in North Los Angeles County, serving about 44,000 homes and businesses, and are all operated by the county Public Works Department.

Those results came after other county tests showing that levels reached almost 9 parts per billion in drinking water at 110 county buildings. Tests are continuing at other county buildings and wells.

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Chromium 6 Found

Wells where chromium 6 has been detected, along with the names of the well owners and the level of chromium 6 found, in parts per billion:

Source: Los Angeles Regional Water Quality Control Board