San Pedro Valley News-Sun, Thelma Grimes
Published December 4, 2001
Officials at Apache Nitrogen Products Inc. (ANPI) say there's no need to worry about drinking contaminated water, even though the U.S. Environmental Protection Agency (EPA) revealed it leads the state with 666 parts-per-billion more than the acceptable level of perchlorate, a chemical believed to cause thyroid problems.
The EPA documents were publicized in a report released by the Environment Working Group (EWG) in July. Perchlorate, the main ingredient used to make missile and rocket fuel, was detected in the water and soil of 18 states, Arizona being one of them.
In Arizona, several sites containing perchlorate were named, ANPI was at the top of the list, with 670 parts-per-billion of perchlorate found in a monitoring well. Second on the list, at 80 parts-per-billion, is a monitoring well at Phoenix-Goodyear Municipal Airport, a former military base. Four parts-per-billion is the maximum acceptable level allowed in drinking water, according to recent federal decisions regarding perchlorate cleanup sites. Nonetheless, perchlorate is an unmonitored chemical and no regulation exists as to what level is safe.
Since the report was released, Pamela Beilka, ANPI director of Environmental Health & Safety, said the monitor well containing perchlorate is in a perch zone where there is no chance of it entering drinking water in the St. David area. A perch zone is a puddle of water underground collecting water on top of clay 40 feet underground that spills into a small aquifer, Beilka said.
"No people are really affected," Beilka said. "In this area (St. David), there is a shallow aquifer and a deep aquifer. The shallow aquifer affected by the perchlorate is on our (ANPI) property, so there is no way for people to be exposed."
In St. David, Beilka said of the two aquifers, the shallow aquifer comes from the river and the quality of water isn't as good. She said most of the area population extracts their water from the deep aquifer.
Beilka said she wasn't surprised by the EWG report. She said ANPI has been aware of the perchlorate issue for some time now, although little has been done to clean up the chemical.
Beilka added, that ANPI no longer uses perchlorate in manufacturing, howeverthe level is still increasing because they stopped using nearby ponds for disposal. She said as the water in the ponds decrease, the perchlorate level increases.
All hope is not gone, according to Beilka. She said an ANPI study has turned up bacteria that can break down nitrates and perchlorate, adding ANPI is currently working on the possibility of growing the bacteria for biological treatment.
"The good thing is it's (perchlorate) staying in the perch zone," Beilka said. "We were worried that with the release of the working groups report in July, people would read it and overreact. There is definitely no need for concern. The perchlorate can't reach drinking water."
Bill Walker, of EWG said, their report didn't necessarily mean all the perchlorate findings were in drinking water. He said ANPI may be right in saying the extremely high level of perchlorate won't adversely affect the area population.
However, Walker added, "We aren't contesting what they (ANPI) are saying, we are saying there is a potential. It (perchlorate) may not be in drinking water right now, but it doesn't mean it can't happen somewhere in the future."
Perchlorate is believed to cause damage to the human thyroid gland, which controls growth, development and metabolism. Too much perchlorate can especially damage fetuses, infants and children. The EWG report said with thyroid damage those afflicted may suffer mental retardation, loss of hearing and speech, or deficits in motor skills. At higher levels of exposure, perchlorate is known to cause cancer.
EWG officials say the EPA is scheduled to begin nationwide sampling this year, but it will be years before there are enforceable federal drinking water standards. It's unlikely that those standards will protect the public, particularly children, according to EWG officials.
EWG calculates that the EPA's latest proposed standard of four parts-per-billion would leave formula-fed infants exposed to between 7.5 and 2,000 times the safe level of perchlorate in drinking water.
"We (EWG) are hoping the EPA will move quickly to establish a national standard," Walker said, "instead of letting each state set their own perchlorate standard. Right now there isn't even a standard set in Arizona."
Walker said testing water for perchlorate levels didn't start until 1997. He said in California, a laboratory method has been established to detect perchlorate in drinking water, even at low levels.
At present, the EPA estimates 20 million people in California, Arizona and Nevada have some level of perchlorate, often undetectable, in their drinking water supplies.
The EWG report is available on the World Wide Web at
www.ewg.org/pub/home/reports/rocketscience/.
