IMPORTANT INFORMATION ABOUT
TOWN OF BROWNVILLE WD #1 DRINKING WATER
The Town of Brownville WD #1 exceeded the Maximum Contaminant Level (MCL) of 80 ug/L for Total
Trihalomethanes (TTHM’s) present in drinking water. During the four calendar quarters ending June 30, 2022 the
running annual average (RAA) for total trihalomethanes was 81.1 micrograms per liter, respectively. This level is
based on a locational running annual average of quarterly samples. Although this is not an emergency, as our
customers, you have a right to know what you should do, where these contaminants came from, and what is being
What should I do?
You do not need to boil your water or take other corrective actions. No immediate action is required or
Where do TTHM’s come from?
Trihalomethanes are a group of chemicals that includes chloroform, bromoform, bromodichloromethane, and
chlorodibromomethane. Trihalomethanes are formed in drinking water during treatment by chlorine, which reacts
with certain acids that are in naturally-occurring organic material (e.g., decomposing vegetation such as tree leaves,
algae or other aquatic plants) in surface water sources such as rivers and lakes. The amount of trihalomethanes in
drinking water can change from day to day, depending on the temperature, the amount of organic material in the
water, the amount of chlorine added, and a variety of other factors. Drinking water is disinfected by public water
suppliers to kill bacteria and viruses that could cause serious illnesses. Chlorine is the most commonly used
disinfectant in New York State. For this reason, disinfection of drinking water by chlorination is beneficial to public
Some studies suggest that people who drink chlorinated water (which contains trihalomethanes) or water containing
elevated levels of trihalomethanes for long periods of time may have an increased risk for certain health effects. For
example, some studies of people who drank chlorinated drinking water for 20 to 30 years show that long term
exposure to disinfection by-products (including trihalomethanes) is associated with an increased risk for certain
types of cancer. A few studies of women who drank water containing trihalomethanes during pregnancy show an
association between exposure to elevated levels of trihalomethanes and small increased risks for low birth weights,
miscarriages and birth defects. However, in each of the studies, how long and how frequently people actually drank
the water, as well as how much trihalomethanes the water contained is not known for certain. Therefore, we do not
know for sure if the observed increases in risk for cancer and other health effects are due to trihalomethanes or some
The individual trihalomethanes chloroform, bromodichloromethane and dibromochloromethane cause cancer in
laboratory animals exposed to high levels over their lifetimes. Chloroform, bromodichloromethane and
dibromochloromethane are also known to cause effects in laboratory animals after high levels of exposure, primarily
on the liver, kidney, nervous system and on their ability to bear healthy offspring. Chemicals that cause adverse
health effects in laboratory animals after high levels of exposure may pose a risk for adverse health effects in
humans exposed to lower levels over long periods of time.
Drinking water is disinfected by public water suppliers to kill bacteria and viruses that could cause serious illnesses.
Chlorine is the most commonly used disinfectant in New York State. For this reason, disinfection of drinking water
is beneficial to public health.
What happened and what is being done?
The combination of the quantity of disinfectant needed and the amount of naturally occurring organic material in the
incoming water resulted in a level of TTHM’s in excess of the MCL. In order to kill disease-causing
microorganisms, water treatment regulations require a certain contact time for the chlorine and water before it enters
the distribution system. Town of Brownville personnel are currently working with the Department of Health to
identify solutions to this problem.
If you have any questions, please contact the Town of Brownville’s Water Operator, Mr. Alan Savage at (315) 639-
6266 or the New York State Department of Health, Watertown District Office at (315) 785-2277.
IMPORTANT INFORMATION ABOUT