By Larry FloerschIf you live in Montpelier, you might recently have seen a notice to boil your tap water before using it. But what does that mean? What’s the worry exactly? Should you comply?
Boil-water notices are required by state law whenever the integrity of a water system has been compromised. The state’s procedures for boil-water notices state that a notice is mandatory when “operational issues (e.g., leaks, breaks, or other emergencies) experienced by the water system…result in all or a portion of the water system distribution system experiencing a loss of pressure below 20 psi.”
A water system such as Montpelier’s is designed to filter and disinfect harmful organisms and maintain residual disinfectant through the system to protect against recontamination as it travels to your faucet.
“The water system in Montpelier is like a pressurized vessel,” says Ben Montross, compliance and support services section chief of the Drinking Water and Groundwater Protection Division of the Department of Environmental Conservation. “If there is a break in a main, the water will flow out of the break under pressure, but if the pressure drops, harmful organisms can be drawn into the system. The leak creates a vulnerability in the system, and you therefore need to boil your water to protect your health.”
“Water is tested for coliform bacteria, which is an indicator organism for pathogens such as viruses, protozoa, and parasites. Waterborne pathogens can cause diseases such as hepatitis, giardiasis, and dysentery,” says Kurt Motyka, an engineer with the city’s water department.
Coliform bacteria are normally present in vegetation and soil. The most well known of the coliform bacteria is Escherichia coli, or E. coli for short. It is a product of human and animal waste (feces) and can be a serious threat to health. For example, a type of E. coli was implicated in last year’s national recall of romaine lettuce grown in the area around Yuma, Arizona. The E. coli caused illness in over 200 people in 36 states and resulted in five deaths.
Other culprits that can make their way into drinking water include Vibrio (a species of which causes cholera) and Legionella (which causes Legionnaires Disease), the virus that causes hepatitis A, the protozoa Cryptosporidium (which sickened over 400,000 and killed 69 people in Milwaukee in 1993), and the parasite Giardia.
Infections from some of these organisms can be deadly, and such infections are much more serious for infants, elderly persons, and persons with compromised immune systems. It is therefore strongly recommended that you follow the instructions of the boil-water notice until sampling can confirm the absence of coliform bacteria and the notice is lifted.
After a boil-water notice is issued, the city will sample the water for total coliform content. The number of samples taken is proportional to the population affected. “If the break only affected four or six houses, only two samples may be necessary,” says Montross. “In the case of the Elm Street break, which was significant and affected the entire city, 10 samples were taken. In addition, water was sampled at the Berlin mobile home park to which Montpelier sells water,” he added.
According to Motyka, if the samples show no coliform bacteria and the amount of residual free chlorine in the samples is high, then no further sampling is done.
Your tap water must be boiled for one minute at full boil to kill these harmful organisms. Water should be boiled before using the water for drinking (including using it to make juices or formula), making ice, brushing your teeth, washing and preparing your food, and washing your dishes (that includes rinsing them). You can also use bottled water for drinking.
Although boiling water will kill live organisms, it will not remove chemicals or minerals, metals, or contaminants, such as arsenic, manganese, or lead. In fact, according to Montross, because of evaporation, boiling water for a long period of time may concentrate such contaminants. “Such contaminants are not a problem in Montpelier because the city has a very good source of water,” he added.
The color of the water will not affect its safety as long as it has been boiled for at least one minute. According to Motyka, color is associated with taste and odor issues, and he advises to run the cold water for 5–10 minutes to help clear it up.
Motyka also notes that filter systems, such as a Brita filter, are not designed to remove microbiological contamination. The water must still be boiled to make it safe.