"It's important to reassure people that we do disinfect and that we're very diligent in our testing," said Karen Probert, water quality specialist for the Town of Payson.
The recent deaths of two young Peoria boys from a form of meningitis linked to an amoeba found in the water system that serviced their community has raised questions about the safety of drinking water throughout the state.
Payson water customers needn't be concerned, according to Probert.
"The issue with the (Rose Valley water system in Peoria) was they weren't chlorinating, and because they weren't disinfecting, they were vulnerable," Probert said. "Both the Arizona Department of Environmental Quality (ADEQ) and the Arizona Department of Health Services say that systems are safe that are disinfected properly throughout the distribution system and that are checked on a regular basis."
Payson's water has been chlorinated since the early 1990s, according to Public Works Director Buzz Walker, and the water department goes above and beyond in its testing program.
"We do our minimums, but then we go out whenever we have a concern or any kind of question from anybody and pull additional samples," Probert said. "We have a lot of data that shows that our system is being disinfected correctly."
The Rose Valley system was operated by a private water company separate from the Peoria municipal system.
"They took the well that was affected off line and then they did a lot of additional testing and they found the parasitic amoeba in a kitchen water filter and possibly one of their reservoirs," Probert said. "They did some other testing and some of it was negative, but they were able to confirm that (the amoeba) had been there.
"The City of Peoria came in and ran a special pipeline to connect (Rose Valley customers) up to the city system," Probert said.
The particular amoeba that caused the deaths of the two boys, Nagleria fowleri, is found worldwide, most commonly in soil and in warm, stagnant bodies of fresh water, according to the Centers for Disease Control in Atlanta. The amoeba enters the body through the nose and travels to the brain and spinal cord.
"This amoeba is prevalent in the environment," said Patrick Gibbons, a spokesperson for ADEQ. "If you've jumped into a lake or any surface water, you've jumped into water with this amoeba. It's there."
While water companies that utilize surface water sources such as canals or rivers are required to both filter and disinfect, most rural groundwater systems, including those in the Rim country, do not chlorinate.
"Groundwater systems are not required presently to have any kind of chlorination or disinfection, and that's primarily because the water is typically drawn from hundreds of feet below ground surface through the natural filtration of the earth, so in general it's believed to be clean," Gibbons said.
But just to be sure, regular testing is employed.
"The standard practice and the best indicator of any kind of bacterial presence is a monthly test called total coliform, and that would indicate the presence of some type of bacteria," Gibbons said. "Typically if that test were to come back positive for any presence of bacteria, a water system would treat with chlorination or some other form of disinfection, and once they've done that, they'll retest to assure they have eliminated the bacterial contamination."
All systems serving at least 25 people or having 15 service connections are governed by state and federal drinking water laws.
The Environmental Protection Agency is in the process of revising its regulations concerning the possible disinfection of drinking water systems that use groundwater as their sources. While chlorination provides protection, it can also create cancer-causing byproducts, according to a fact sheet issued by ADEQ.
"Therefore, when chlorinating water systems it is necessary to weigh the benefits against the possible creation of health risks," according to the fact sheet.