DENR to conduct study for radon in drinking water The South Dakota Department of Environment and Natural Resources (DENR) will conduct a statewide testing program to determine radon levels in drinking water for community drinking water systems in South Dakota. The testing program is being done to prepare for an upcoming federal rule scheduled to go into effect in January 2002.
Water samples will be tested in every South Dakota county. In Clay County, samples from the Clay Rural Water System and the city of Vermillion will be collected and analyzed for radon.
The DENR study is being conducted in response to a new U.S. Environmental Protection Agency (EPA) rule that will regulate radon in drinking water. Radon has never been regulated under the Safe Drinking Water Act. The new rule will apply to all 350 public drinking water systems that serve communities in South Dakota.
Staff from DENR's Drinking Water Program will collect samples and have them analyzed at the state health lab during the testing program. The sample collection is expected to take two to three months. The department will use a special EPA grant to pay for all the samples and lab work.
"Keeping our drinking water clean, safe and in compliance with all federal standards has to be one of our most important priorities," said DENR Secretary Nettie H. Myers. "Through this early testing program we are giving the owners, operators and customers of the community systems more information about the quality of their drinking water."
The federal standard for radon has not yet been proposed. EPA is scheduled to announce the proposed standard in July 2000. Drinking water systems will have until January 2002 to be in compliance.
Radon is a radioactive gas that comes from the decay of naturally occurring radioactive elements, such as uranium, found in nearly all soils. Inhalation of radon increases the risk of lung cancer.
Radon gas from certain soils is the main cause of radon problems. The primary source of radon gas to humans is when the gas enters a home or building through cracks in basements and foundations, and accumulates indoors. However, if radon gas is in drinking water, the gas is released from water as it comes out of a faucet or showerhead at home. The amount of radon in a building that comes from the water is generally less than one percent.
A normal treatment method for removing radon gas from drinking water is to aerate the water before it enters the city distribution system. The water can be aerated by spraying it into a tower while blowing large volumes of air into the water spray. The radon gas is stripped out of the water and released to the air, where it is diluted with the rest of the atmosphere.
Aeration treatment is already used by several public water systems in the state to remove dissolved iron from drinking water.
"Since several communities in South Dakota already use aeration to remove iron from drinking water, the radon testing will provide an opportunity to evaluate the effectiveness of aeration treatment for also removing radon," said Myers.
For more information on the radon study in drinking water systems, contact Darron Busch at DENR at 605-773-3754.