Terry on Aug 9th 2011
Concern about possible cancer clusters prompted project
by Susan Singer-Bart, Staff Writer
Poolesville, Md.-Poolesville is planning to install a radon and uranium removal system on three of its 11 wells.
It is the first community water system in the state to make the installation, said Jay Apperson, spokesman for the Maryland Department of the Environment.
Wells 7 and 10 were taken out of service as a precaution in 2007 after uranium levels were found to be in danger of exceeding the maximum allowable contaminant level.
Since that time, well 7 has exceeded the level, but well 10 has not.
The Environmental Protection Agency sets the maximum allowable contaminant level for uranium at 30 micrograms per liter. It has not established a maximum level for radon.
Poolesville’s 2010-2011 water report found the level for well 7 to be 33.5 micrograms per liter. The level at wells 9 and 10 is 12.05 micrograms per liter, but the radon and uranium removal system is being used to avoid cross-contamination on those sites.
Water seeping from a contaminated well could affect water in another.
“It’s our responsibility to supply the best water we can,” said Paul “Eddie” Kuhlman II, president of the Poolesville Town Commission.
The project started out of concern there might be a cluster of cancer cases in Poolesville, a town of 5,300. A study by the Centers for Disease Control and Prevention concluded in 2009 that was not the case, but the concern was the catalyst for the project, Kuhlman said.
Concentration of radon in drinking water minimally increases the lifetime risk of cancer, said Olga Naidenko, a scientist with the Environmental Working Group, a nonprofit group based in Washington, D.C., with a mission to protect public health and the environment.
“The only safe level is zero,” she said.
“Under no circumstances should water from well 7 be consumed by people,” she added.
Some level of radon and uranium is present in the environment, she said.
Poolesville’s water supply comes from groundwater pumped at 11 wells around the town.
Often when a utility has several wells and one has chemical contamination levels above EPA standards, the water from several wells is blended to dilute it and meet the standards, she said.
She said she is happy to hear Poolesville has not done that.
Poolesville plans to install an ion-selection filtration system, Apperson said. The department is charged with implementing the federal Safe Water Drinking Act in the state.
The town has been planning the project for almost five years, said Town Manager Wade Yost, and has set aside $750,000 for it. The town applied to the Department of the Environment for a construction permit in 2009 and received it in June, Yost said.
The removal system will be housed in a building alongside the well house on Budd Road.
Poolesville is accepting bids for the project and hopes work will begin in October. Work should be completed next spring, Yost said.
Radon linked to lung cancer, other development issues
The following information is provided by the EPA:
-Radon is a colorless, odorless, tasteless and radioactive gas.
-It is formed by the normal radioactive decay of uranium and radium. Underground rock containing natural uranium continuously releases radon gas into groundwater.
-Exposure to radon in the home is more commonly due to radon from rock or soil seeping into homes through foundation cracks than through water. Radon can reach harmful levels if trapped indoors.
-A 1998 report by the National Academy of Sciences confirmed that radon in drinking water is related to cancer deaths, primarily lung cancer.
-Most of the risk from radon in drinking water comes from the transfer of radon into the air and inhaling it or ingesting water containing radon.
-In addition to being present in drinking water, radon in well water becomes airborne through washing dishes and laundry, showering and flushing toilets.
-Drinking water contains dissolved radon and the radiation emitted by radon and its radiation decay products exposes sensitive cells in the stomach and other organs.
-About 21,000 lung cancer deaths in the U.S. each year are radon-related. Exposure to radon is the second leading cause of lung cancer after smoking. The number of lung cancer deaths is 160,000 per year. A National Academy of Sciences report found 184 deaths per year attributable to radon in drinking water.
-Drinking water accounts for 20 of the 13,000 deaths per year from stomach cancer.
-The EPA set a maximum contaminant level for uranium at 30 micrograms per liter of water. No data show a threshold below which exposure to radon is harmless.
According to the Environmental Working Group, a nonprofit environmental watchdog based in Washington, D.C., human exposure to radon has been linked to severe respiratory disease, harmful kidney effects, sexual maturation effects, mutations and increases in lung cancer deaths.