A nonprofit organization claims water suppliers — including those in Butler County — carry a high level of contaminants even though they are well within legal limits.

The contaminants, such as trihalomethanes, are too elevated, according to the Environmental Working Group based in Washington, D.C.

“We think it's higher than it should be,” said EWG senior scientist David Andrews.

The EWG cites studies indicating water contaminants being linked to such health impacts as cancer and nervous system damage.

Andrews said the U.S. Environmental Protection Agency's limit of 80 ppb (parts per billion), or 1 microgram per liter, for trihalomethanes needs lowered.

“We seem to be decades behind,” he said.

Andrews said the adverse health effects are found when examining a large sampling of people.

“Over the population, you would see the impacts,” he said.

EWG lists Pennsylvania American Water Company, which supplies 11 municipalities in Butler County, having a 2015 trihalomethane level of 38.9 ppb, well under the EPA level, but above the national average of 23.2 ppb and state average of 17.7 ppb.

Pennsylvania American services 19,000 customers in Butler, East Butler, Saxonburg, and seven townships: Butler, Connoquenessing, Center, Forward, Franklin, Penn and Summit, as well as portions of Jackson Township.

Gary Lobaugh, external affairs manager for Pennsylvania American Water, said the company takes water quality and safety seriously.

“The U.S. EPA sets water quality standards intended to protect public health, and Pennsylvania American Water treats and delivers water that meets or surpasses all EPA drinking water standards,” Lobaugh said.

While Lobaugh declined to comment on specific aspects of the EWG report due to not seeing the underlying data and related calculations, he did refute its accuracy.

“We have reviewed the Environmental Working Group's report and have identified some inconsistencies between the information in the report and the results in our files,” he said.

The EWG lists the 2015 trihalomethane level for the Cranberry Township water treatment plant as 56.7 ppb.

Mike Sedon, plant manager, stressed the water quality meets all state and federal regulations.

The EWG lists a trihalomethane level of 54.5 ppb for the Adams Township Municipal Water Authority.

Matthew Cranmer, authority manager, pointed out the EWG is using standards from California.

“It's not even recognized as a standard in Pennsylvania,” he said.

Cranmer said EWG recommendations such as 0.08 ppb for trihalomethanes is unrealistic.

“They're impossible to reach,” he said.

For Zelienople, EWG lists a trihalomethane level of 52.1.

Chad Garland, borough public works director, said the 2016 average of that level was 47.8.

Garland pointed out there are byproducts from using chlorine to disinfect the water.

He said the problem with not using such a disinfectant is the risk of an outbreak.

“We can go back to prehistoric days when typhoid and cholera ran rampant,” Garland said.

In comparison, he recalled the EPA stating the statistical odds of three people out of 10,000 getting cancer from water with too much trihalomethanes.

While Garland said the ideal situation is to have no contaminants, he agreed with Cranmer it is unrealistic.

“To get to zero is most likely not going to happen,” he said.

For the Slippery Rock Municipal Authority, EWG lists a trihalomethane level of 53.

“The authority meets all DEP standards they set for us,” Shaun Brown, authority general manager, said.

All the water suppliers pointed out their water quality information is regularly reported in print and online.

Cranmer added there is little control Adams or other areas such as Cranberry have over water quality as they buy it from the West View Water Authority.

The state Department of Environmental Protection stated it adheres to EPA standards.

“EPA uses the best available science when developing the federal safe drinking water standards, therefore, DEP will continue to incorporate these standards,” wrote Neil Shader, DEP press secretary in an email.

Shader stressed the DEP may propose changes, but does not have legal authority to alter the standards.

Robert Daguillard from the EPA's Office of Media Relations in Washington, D.C., confirmed byproducts form when using disinfectants, which are needed.

“Disinfection byproducts form when disinfectant chemicals such as chlorine are added to drinking water to kill disease causing microbes like salmonella or viruses,” Daguillard wrote in an email. “EPA's Disinfection Byproduct standards are set to balance the risks of microbial pathogens and disinfection byproducts.”

Daguillard agreed with Cranmer about EWG using data compiled for another state, pointing out the group is using a health guideline that is a 2009 draft public health goal published for review by the California Office of Environmental Health Hazard Assessment.

“It is important to note that there is a difference between a health goal and an enforceable standard,” Daguillard stated. “Health goals are set at levels at which no known or anticipated adverse effects on health will occur with an adequate margin of safety.”