Levels of trihalomethanes were elevated in December.
By: Linda Seida
LAMBERTVILLE Although experts say there is no need to boil tap water, Mayor David Del Vecchio says there is a need for answers from United Water on why the city’s drinking water had elevated levels of trihalomethanes in December.
Trihalomethanes, or THMs, are potentially harmful byproducts of the chlorination process. Chlorine is used to disinfect and protect the water supply. But the process can result in the formation of THMs when chlorine reacts with naturally occurring organic matter.
Tests conducted Dec. 18 by United Water found the level of THMs in the city’s drinking water was 83 parts per billion. Federal and state standards say 80 parts per billion is an acceptable level.
Subsequent testing has shown THMs are now below 80 parts per billion, according to United Water spokeswoman Deborah Rizzi.
"We are seeing that THM levels are back at acceptable levels," she said.
The four trihalomethanes that can form during the treatment process are chloroform, bromoform, bromodichloromethane and dibromochloromethane.
Experts say prolonged exposure can cause serious health problems.
EPA spokesman Elias Rodriguez said via e-mail, "Some people who drink water containing trihalomethanes in excess of EPA’s standard over many years (long-term exposure) may experience problems with their liver, kidneys or central nervous systems and may have an increased risk of getting cancer."
Mayor Del Vecchio also has asked United Water for information on testing procedures and safety measures that will protect residents. He requested a United Water representative to attend the City Council meeting scheduled for Feb. 20.
"We would like to know what people with compromised health might be at risk due to the violation of drinking water standards," he wrote to United Water in a letter dated Jan. 23. "Also, we are interested in United Water Lambertville’s understanding of why the organic loading is higher."
The mayor continued, "The City Council would like updates on the data collected during the increased frequency of testing. The method of keeping our residents abreast of the improvements of the treatment facility can be discussed in the meeting."
Water companies are required to perform testing on a schedule set by the EPA.
Mr. Rodriguez said, "Compliance is based on a running annual average. The number of samples vary based on source water type-size of system and are collected in the distribution system."
A letter from United Water to customers, dated Jan. 18, said, "Because the THMs drinking water standard is defined as a running annual average by quarter, compliance is determined on a quarterly basis. We will also be increasing the frequency at which we test the water in the system until we can ensure that we can maintain reliable and consistent levels below the maximum limit."
An elevated level of THMs is considered a Tier 2 violation by the EPA and does not require immediate customer notification, according to Ms Rizzi. Instead, she said, companies have 30 days to inform customers because it is considered a "far less serious violation" than one that would require the immediate boiling of water before drinking.
"Basically, the EPA says there’s really no need to drink bottled water," Ms. Rizzi said.
For those who want to take additional precautions, "a carbon filter will help," Ms. Rizzi said.
However, she cautioned that to work efficiently the filter must be changed on a regular basis, according to manufacturer’s directions.
Ms. Rizzi said United Water received about a dozen phone calls from concerned residents. She said United Water appreciates the patience shown by customers as the company dealt with the situation.
In his e-mail, Mr. Rodriguez of the EPA explained the difficulties faced by water companies in keeping supplies of drinking water safe.
He said, "Many water systems treat their water with a chemical disinfectant in order to inactivate pathogens that cause disease. The public health benefits of common disinfection practices are significant and well-recognized, however, disinfection poses risks of its own.
"While disinfectants are effective in controlling many harmful microorganisms, they react with organic and inorganic matter (disinfection byproduct precursors DBPs) in the water and form DBPs, some of which pose health risks at certain levels.
"Since the discovery of chlorination byproducts in drinking water in 1974, numerous toxicological studies have been conducted that show some DBPs to be carcinogenic and/or cause reproductive or developmental effects in laboratory animals. Additionally, exposure to high levels of disinfectants over long periods of time may cause health problems, including damage to blood and kidneys.
"While many of these studies have been conducted at high doses, the weight of evidence indicates that DBPs present a potential public health problem that must be addressed. One of the most complex questions facing water supply professionals is how to reduce risks from disinfectants and DBPs while providing increased protection against microbial contaminants."