Officials Eager To Find Reason For Chemical In WaterMar 17, 2003 | Athens Banner-Herald Oconee County water officials are trying to figure out why a sample of the county's drinking water supply taken two years ago apparently showed a higher reading of the chemical perchlorate, an ingredient of rocket fuel and fireworks, than found in any other water system in the United States.
It seems more likely to be some sort of laboratory error than real contamination of the unregulated substance, said Gary Dodd, director of Oconee County's water system.
Five other samples from Oconee County's drinking water supply taken the same day in 2001 fell below a reporting limit of 4 parts per billion of perchlorate.
But one sample showed 38 parts per billion of perchlorate. That was the highest level found anywhere in nationwide sampling program of public water systems, according to an EPA database.
The EPA official who compiled the perchlorate data also said he would like to know more about how the testing was done.
''This method is actually pretty reliable at that level,'' said Kevin Mayer, an EPA official in San Francisco who tracks perchlorate contamination around the United States. But it raises questions when five samples look normal, but a sixth taken the same day shows a very high reading, he said.
On Monday, Dodd contacted the state Environmental Protection Division laboratory that ran the tests to see if there is an explanation. He hoped to hear back from them by today, he said.
The sampling was part of a nationwide monitoring program of chemicals such as perchlorate and MTBE that are not yet regulated by the federal government, although they may cause cancer, birth defects or other ill health effects.
Perchlorate interferes with the body's ability to take iodide into the thyroid, which can lead to mental retardation in newborns and developing fetuses.
Although the federal government has set no health limits for perchlorate in drinking water, a few states have, including Nevada, which caps it at 18 parts per billion, and Arizona, which sets it at 32.
A scientist with a company that manufactured perchlorate said that levels below 200 parts per billion would not affect human health, but a 2000 Arizona study found thyroid abnormalities in infants whose mothers had consumed water contaminated with five to seven parts per billion of perchlorate.
There seems to be no obvious source of perchlorate contamination in the area another factor that makes Dodd doubt the validity of the high reading.
Perchlorate contamination was found several years ago at the American Linen Supply Co. site on Experiment Station Road in Watkinsville, Dodd said.
The American Linen Supply Co. is one of three sites in the county listed on the state Hazardous Site Inventory of places needing environmental clean-ups. But the site is nowhere near any of the county's water sources, Dodd said.
The chemical is a main ingredient in rocket fuel and fireworks. It has also been found in many commercial fertilizers that include material from from Chile, where it occurs naturally in some areas, Mayer said.
Perchlorate contamination is often found near military bases or military contractors, but it is also found in places where there is no known perchlorate source, said Bill Walker of Environmental Working Group, an environmental group working to have the chemical regulated, especially in California, where it has contaminated numerous water systems.
Oconee gets its water from several sources, but according to the EPA data, the water tested was ''purchased surface water.''
In June 2001, when the sampling was done, the only purchased water Oconee was using came from Athens-Clarke County, Dodd said.
Dodd said the first he had ever heard about the high lab test reading from the 2001 testing was last week, when a California environmental activist contacted his office.
Gary Duck, director of Athens-Clarke's public utilities department, likewise said he had never heard of any perchlorate detection in the county's water.
Only one other water system in Georgia showed elevated levels of perchlorate - in Houston County, near Warner Robins Air Force base. There, a sample showed the presence of 5.4 parts per billion.