EPA moves to get perchlorate out of drinking water
The Environmental Protection Agency announced this morning it's going to regulate perchlorate in drinking water, tackling a toxic chemical that's contaminated ground water near military bases and old fireworks, rocket fuel and munitions plants throughout the country, including here in Maryland.
In making the announcement, EPA Administrator Lisa P. Jackson reversed a decision by the Bush administration not to regulate perchlorate. She cited a new review of the research by public health experts and independent scientists, finding that perchlorate poses a health risk. Research indicates perchlorate may affect the thyroid's production of hormones that are essential for normal development and growth in fetuses, infants and children.
Perchlorate is both a naturally occurring and man-made chemical, according to EPA, and has been detected in more than 4 percent of public water systems serving up to 17 million people. One of those is Aberdeen, where it was detected in 2002 in four of the town's wells and in its finished water supply.
In the absence of action by EPA, the Maryland Department of the Environment did set its own recommended safety threshold for perchlorate of one part per billion. Aberdeen has taken steps, including installing filters, to keep perchlorate levels in its finished water below that level. The town's 2009 annual report on its drinking water quality indicates perchlorate concentrations were measured at less than half the state's safety threshold.
According to EPA, monitoring wells have identified a plume of perchlorate-tainted ground water 4,000 feet long and 1,000 feet wide at Aberdeen Proving Ground, where the military has developed and tested both chemical weapons and other munitions since 1917. Concentrations average 4 to 10 parts per billion, with some hotspots of up to 50 parts per billion. About 36,000 people live within three miles of the plume, EPA estimates.
The Army has previously rebuffed requests to clean up hotspots of soil with high levels of perchlorate, according to EPA. But the Pentagon has been working with the town and government regulators to test a new ion exchange technique that may be used to treat the town's water, the agency notes.
UPDATE: Most of the perchlorate contamination documented to date has been in California. But it has been detected in public or private wells in several places around Maryland, according to Dawn Stoltzfus, spokeswoman for the state Department of the Environment. It's not clear if contamination is limited to those places, she noted, because public drinking water systems are not required to check for it now since EPA does not regulate the chemical.
Besides Aberdeen, Stoltzfus said perchlorate has been found at levels above Maryland's recommended threshold in the Sherwood mobile home park in Cecil County and at a site in Elkton operated by ATK, or Alliant Technosystems Inc., a spinoff by Honeywell Inc. of its defense business. The state also has been supplying bottled water to 15 homes along Route 7 in Elkton where the chemical has been detected, the MDE spokeswoman said. Moreover, a developer is cleaning up contamination at a farm in Elkton once used to test rocket fuel and dump hazardous wastes.
Perchlorate at levels below the state's threshold also have been picked up in Hagerstown's drinking water, Stoltzfus said. The city draws its water from the Potomac River, and the suspected source was a facility across the river in West Virginia. The municipal water has been treated, and levels have been below 1 part per billion, according to MDE.
According to the EPA, perchlorate has been detected in ground water at three other military facilities in Maryland besides Aberdeen Proving Ground. The highest levels were picked up at the Naval Surface Warfare complex at Indian Head on the Potomac in Charles County, but contamination also was found at lower levels at the White Oak naval surface warfare facility in Silver Spring and at Fort Meade in Odenton.
A group of aerospace and defense companies using or manufacturing perchlorate disputes the need for EPA to set nationwide limits on the chemical in drinking water. The Perchlorate Information Bureau contends that in all but 1 percent of the public water systems where the chemical has been detected, levels of contamination are well below the safety threshold recommended by the National Academy of Sciences. The Perchlorate Information Bureau is underwritten by Aerojet, American Pacific Corp., ATK and Lockheed Martin.
The academy in 2005 suggested perchlorate concentrations in drinking water be kept below 24.5 parts per billion. EPA in 2009 set an interim health advisory of 15 parts per billion.