Disinfection byproducts in tap water vary widely based on the source of the water, the geographic location, the treatment methods used and even the season and weather.

Karen Cotton, spokesperson at Illinois American Water Co. in Peoria, said treatment methods used in Peoria are significantly different from the treatment protocols used in East Peoria and Morton.

In 2012, Illinois American Water Co. spent $24 million to upgrade the treatment plant in Peoria and install a new ultra violet disinfection facility. UV treatment inhibits infection-causing microorganisms and allows the same level of purification with less chemical additives, Cotton wrote in a statement sent to Community Word: “UV technology is effective in inhibiting infection-causing microorganisms and provides another layer of protection to our customers. At the time of construction, the UV disinfection facility was the second one like it in Illinois. UV makes it possible for us to use less chemical treatment, which naturally reduces DBPs.

“Also, in 2011 we began treating our water with chloramines rather than free chlorine. Chloramination is a preferred disinfection method because it reduces the creation of DBPs during the treatment process. DBPs form when disinfectants react with naturally occurring organic materials in the source water. Chloramines reduce the occurrence of those materials.”

Levels of disinfection byproducts in water supplied to Peoria customers are below those allowed by law but above state averages. David Andrews, Ph.D. and senior scientist with Environmental Working Group, said, “All legal limits are not necessarily safe limits.”

Many of the “safe” legal limits have not been updated in decades, he said.

Also problematic is that safe limits for exposure are usually based on one compound, not on the combination of chemicals – sometimes referred to as a chemical cocktail –– present in the real world. In combination, toxicity levels often increase. Additionally concerning is that safety levels are generally established for adult men, not for developing fetuses and young children who have a lower threshold for harm.

Andrews said that studies of disinfection byproducts are often based on human studies. (What should be alarming in this regard is the recent proposal by EPA Secretary Scott Pruitt calling for full disclosure of all research data. While that superficially sounds good, it’s a problem because epidemiological human studies are based on confidentiality agreements between the subjects and the researchers. Full disclosure would mean the elimination of epidemiological studies to evaluate health impacts. Epidemiological studies were the gold standard in evaluating the risks of cigarette smoking.)

The Environmental Working Group would like more research on the impact of chemical mixes by the National Toxicology Program at the National Institute of Environmental Health Sciences. The EPA generally does not conduct its own research and depends on studies often funded by the corporations that benefit from lower standards.

“The EPA no longer has a leadership role regarding the effects of these chemicals. It has not set a new standard in over two decades,” Andrews said, noting there are also nonregulated contaminants in drinking water.

“This all points to a failure to insure safe clean drinking water,” he said, noting that by contrast, the European Union is more prone to base recommendations on precautionary research findings.

Andrews said he has young children and he uses an under-the-sink carbon water filtration system. That means his family showers and bathes in water provided by his utility.

“People should become educated and aware. A whole-house filtration system is more expensive. For a cost-efficient system, we use an under-the-sink filter,” he said.

Joyce Blumenshine, spokesperson with Heart of Illinois Group Sierra Club, said, “I’m really concerned about what chloramination does for the long term in Peoria tap water. I don’t think Illinois American has been transparent on this issue.”

Cotton said in a statement that customers were informed of the addition of chloramination to the treatment protocol. She said it has been used since the 1900s and almost one in three surface water treatment facilities in the United States currently use chloramination.

A chart showing disinfection byproducts in Peoria water breaks down the numbers for trihalomethanes, cancer-causing contaminants that form during water treatment with chlorine and other disinfectants. The total trihalomethanes group includes four chemicals: chloroform, bromodichloromethane, dibromochloromethane and bromoform.

The health guideline is 0.8 ppb. The national average for the level of TTHMs detected in tap water is 23.2 ppb. The average for the state of Illinois is 26.7 ppb. The level for IL American – Peoria is 34.4 ppb.