Arthur Swope admits he was a little nervous when he received a letter from the Boone County Public Water Supply District 9 saying radium levels in the water exceeded maximum contaminant levels during 2003.
“It makes you wonder what’s going on,” Swope said.
The July 2 public notice stated the system’s levels of alpha emitters and combined radium 226 and 228 violated standards, but the situation was not an emergency and no special precautions were needed. The notice is the first the district has had to send since its creation in 1965.
“I live in the water district and personally am not concerned,” said Kenny Duzan, the coordinator of radionuclide testing for the Missouri Department of Natural Resources.
Both contaminants, the results of erosion of natural deposits, can cause cancer if large amounts are ingested. Duzan said if a person consumed two liters of water every day for a year at the maximum allowable contaminant level of five picocuries per liter, or pCi/L, they would receive four millirems of exposure. After 70 years, they would have a one in 10,000 chance of getting cancer from exposure.
In comparison, the average smoker gets 1,300 millirems per year.
“The risk (from the water) is minimal,” Duzan said.
Only one of the district’s four wells was in violation. Use of water from the Harg well has been reduced and the district is in the process of acquiring easements and materials to run a line from another well to Harg to dilute the water and get it back to compliance. Roger Ballew, the district 9 manager, expects the project to take up to a year.
The well in violation averaged 7.2 pCi/L of combined radium, while the maximum allowed is five pCi/L. The level of alpha emitters averaged 24.4 pCi/L, exceeding the 15 pCi/L limit.
“Residents will continue to get these letters every three months until the line is run,” said Ballew.
Ballew and Duzan attribute the violation to a change in standards, not a change in the quality of the water. Regulations for radionuclides in drinking water were first established in 1976 as part of the Safe Drinking Water Act. In 1991, the Environmental Protection Agency considered increasing the levels allowed, but the proposal was never enacted, and in December 2000 the Radionuclides Rule was published. The rule retained the existing maximum contaminant levels for combined radium and alpha emitters, but changed monitoring requirements.
Previously, water systems with multiple entry points to the distribution system were not required to test at every entry point, but rather at a representative point, which would usually include water from two or more wells, according to the EPA Web site. The 2000 rule, which went into effect in December 2003, now requires the monitoring of individual wells.
“The water is the same as it’s always been, now we’re just out of compliance,” Ballew said.
Samples are taken quarterly. Duzan said the reason for the delay in notification of the violation is because a year’s worth of quarterly samples was needed.
“It seems like they should have let you know sooner that there’s something wrong with the water,” Swope said.
District 9 has about 3,600 active connections and serves about 10,000 people. Boundaries are east of Columbia and the Highway 63 corridor, to Route OO to the north, Bass Lane to the south and out to Callaway County in the east. Neighborhoods served include Sunrise Estates, El Chaparral, the Woodlands and Lake of the Woods.
Ballew said he has received between 20 to 25 calls from concerned residents, but said once they were informed of the risks, they were no longer concerned.
“It just don’t worry me in the least,” said El Chaparral resident Lois Marcum. “They found the problem, and they’re trying to alleviate it.”
Shauna Waites said she is also unconcerned. “Before I read the notice completely, I thought ‘Oh no,’” she said. But afterwards it didn’t worry me as much.”
The public notice states it is not necessary to use an alternative water supply such as bottled water. It also said boiling the drinking water would not correct the problem. However, Duzan said water softeners or some filters will take out the radionuclides.
Bon Gor Lake Estates was the only other system in Boone County cited on the EPA’s Web site as having a health-based violation in 2003. According to the Web site, the contaminant coliform was found. Coliform is a bacterium naturally present in the environment used as an indicator that other, potentially harmful, bacteria may be present.