PERCHLORATE RISK WEIGHED WATER OFFICIALS SAY HAZARD LIKELY DILUTED.

Byline: Lisa Mascaro Staff Writer

SANTA CLARITA - It was more than two years ago that local agencies found perchlorate in four groundwater wells and shut them down, before ``Erin Brockovich'' launched chemical contamination into popular conversation.

Agencies had never been required to test for the chemical, which was becoming known publicly after years of use in the manufacture of solid rocket fuel, and when they did, they got a hit.

Still, most water officials are confident that while perchlorate may have been making its way into the groundwater supply, dangerous doses did not make it to the taps.

``I'm very confident the water has been safe and potable,'' said Bob DiPrimio of Valencia Water Co.

They say because perchlorate was found at low levels, and because well water was mixed with general supplies, any trace of the chemical would have been at low levels allowed by the state.

One agency, Newhall County Water District, said that after perchlorate was found in its well, tests were done on its general supply, and no chemical traces were found.

``It's pretty clear to me that based on the concentration of perchlorate - they were at very low levels - the actual water delivered to our customers is likely to be nondetect, or zero (readings for perchlorate),'' Di Primio said.

Perchlorate was discovered in four municipal wells in 1997 when the Department of Health Services first asked that tests be conducted.

The compound in high doses can inhibit production of the thyroid hormone needed to relegate growth in youngsters and metabolism in adults.

As soon as the chemical was found, water officials said, the wells were shut down.

Two of the wells, operated by the Santa Clarita Water Co., now a division of the Castaic Lake Water Agency, showed contamination at higher levels than the state's 18 parts per billion.

Two others, one operated by Valencia Water Co. and the other by Newhall County Water District, had levels lower than the state level, officials said.

Water agency officials say the wells, which tap into the deep Saugus Aquifer under the city, provided an alternative to imported state water and have been used in varying amounts over the years.

For example, the two wells showing the highest contamination were built in the early 1990s to help provide water during drought years and were shut down in 1997, said Bill Manetta, president of what is now the Santa Clarita Water Division of the CLWA.

The Newhall County well, drilled in 1973, was providing about 10 percent of the district's supply when it was closed for refurbishing in 1996 - one year before it was closed for contamination, said general manager Tom Shollenberger.

Valencia Water Co. said its well was drilled in the early 1960s but wasn't used for municipal supply until the 1980s - and had increased pumping in 1991 during the drought.

``The wells were operated and used as backup,'' said Manetta. ``We keep that as an emergency, an ace in the hole.''

He said, ``Some years we didn't use them at all, some years we used them a lot.''

Since those wells were shut, perchlorate has become more known - it's being found in low levels in more locations, and last month it was announced that Loma Linda Medical Center would pay human volunteers to ingest the chemical to determine whether it is harmful to human health.

``It's under a huge investigative look-see,'' said Charles Miller, a toxicologist with the state Department of Toxic Substances Control, adding that it had been used in the 1950s and 1960s as part of thyroid therapy. ``It's very much at the epicenter of investigation.''

The water agencies recently sued the past and current owners of the former Bermite munitions factory site, which they suspect caused the contamination, to bear financial responsibility and clean up the wells.

The current property owner, Remediation Financial Inc., which is planning up to 3,000 homes on the site as the Porta Bella development in the heart of the city, is investigating the source of the contamination, officials said.

Without having done testing, the water agencies say it is difficult to say precisely how much perchlorate, if any, entered the water supply before the wells were shut down.

``I just have no idea of knowing,'' said Shollenberger, comparing it to MTBE and TCE, other contaminants now requiring more testing than in years past. ``As they continue to add to that list, we will continue (to test).''

However, based on the low levels found in 1997 and the way water is diluted with other sources in the system, most believe the water had always been safe for consumers.

State officials, in part, agree, saying the perchlorate takes time to make it down to the groundwater.

``I think that amount today represents a greater amount than five to 10 years ago,'' said Miller, the state toxicologist.

DiPrimio is confident the water was safe.

``You're not drinking the water that comes out of the well, you're drinking a blended supply,'' DiPrimio said.