Trihalomethanes in Home Drinking Water


If your home receives its water supply through a municipal water system, then you may be faced with some unique drinking water quality issues. Many who live in the city don’t know they need to be concerned with drinking water quality, falsely believing that only rural homes that are on wells face such concerns. In fact, city dwellers may need to be aware of the disinfectant chemicals used in water treatment facilities and the potentially harmful byproducts which can result from those chemicals being added to the water in treatment plants. These byproducts can include trihalomethanes in your home’s drinking water.

What are Trihalomethanes?
Trihalomethanes are byproducts that can result from the water processing or treatment activities that take place in municipal water plants. They occur when the chlorine and chloramine – two of the most commonly used disinfectants – come in contact with organic and non-organic compounds in the source water at city water plants. There are four types of trihalomethanes which can be an issue with city drinking water, including: Bromodichloromethane, Bromoform, Dibromochloromethane and Chloroform.

What are the Risks with Trihalomethanes?
There are some serious health risks associated with the consumption of drinking water contaminated with trihalomethanes. Prolonged exposure to water containing these harmful byproducts of the water treatment process increases health risks. Particularly at risk are the nervous system, kidney and liver functions of individuals who drink contaminated water. There is also the increased risk of developing cancer and seeing other health issues, including stillbirth in pregnant women. As the body easily absorbs contaminants from drinking water and contaminants get into the blood stream, the negative health effects can be far reaching.

What can be done about Trihalomethanes?
The health risks associated with trihalomethanes are well documented and the Environmental Protection Agency (EPA) is well aware of them. This is the reason EPA regulations are in place to govern the processing of city water supplies, including limitations which are placed on the level of each form of trihalomethanes which can be in city water when it is delivered to homes. While there are restrictions in place regarding trihalomethanes in city water, some amount of these harmful compounds may still be present in your home tap water. The EPA denotes certain types of trihalomethanes in city water as acceptable, at least within established limits. This is the reason so many consumers decide to implement home water filtration solutions for themselves by installing on-tap water filters or whole house water filtration systems. There are water filters which are uniquely capable of capturing and eliminating these compounds and which can address other water quality concerns as well.

What Levels of Trihalomethanes are Considered Unsafe?
The EPA has established standards for acceptable levels of each of the previously mentioned varieties of trihalomethanes in city water as well as a combined total for acceptable levels of all varieties based on an annual average. Following are the details of the EPA’s restrictions.

• Bromodichloromethane–Zero

• Bromoform–Zero

• Dibromochloromethane-0.06 milligrams per liter(mg/L) or 60 parts per billion (ppb)

• Chloroform – 0.07 mg/L or 70 ppb

Total Trihalomethanes – 0.080 mg/L or 80 ppb


Please enter your comment!
Please enter your name here