Chickasha released a letter this week stating the city's drinking water did not meet a standard set by the Environmental Protection Agency.
"Our water system recently violated a drinking water standard," the letter details. "Although this incident was not an emergency, as our customers, you have a right to know what happened and what we are doing to correct the situation."
The letter states the city routinely monitors the water for drinking contaminants. Based on a January 2013, through December, 2013 test, and a April, 2013 through a March 2014 test the water exceeded the standard maximum contamination level for trihalomethanes. The standard average for trihalomethanes in drinking water is .080 milligrams per liter. The average number in the Chickasha system locations were .095, .103, .110, .083, .098, .105, .114, and .084 mg per liter, according to the letter.
Trihalomethanes are by-products of disinfecting drinking water that form when chlorine and chloramine react with organic and inorganic material that's already there, according to the Environmental Protection Agency.
"The good thing about using chlorine to disinfect is it eliminates harmful bacteria," Skylar Mcelhaney, public information officer with the Oklahoma Department of Environmental Quality, said. "Unfortunately, it can also produce by-products."
EPA regulations stipulate that a running annual average of the amount of trihalomethanes in large surface public water systems cannot rise above 80 parts per billion, or .080 milligrams per liter. Calculating the running annual average is why it takes at least a year to conclude the tests and produce a result. The latest testing of Chickasha's water occurred in March 2014, according to the notice.
"Several years ago, the maximum was 100 parts per billion," Mcelhaney said. "Since the EPA lowered the amount, many Oklahoma towns find themselves in violation of the new standard."
City Manager said there is no immediate health risk to citizens due to the drinking water. He said the city is working with Severn Trent water company to flush the system. Fairburn said the city flushes the lines every year, but didn't in 2013 due to the drought.