Drinking Water

Drinking water can become contaminated from natural or human-made causes.

• Naturally occurring chemicals such as arsenic or uranium can enter groundwater from bedrock. If a well is drilled into bedrock that contains a naturally occurring element, drinking water can become contaminated.

Humans may add chemicals to water, both intentionally and by accident.

• Adding chemicals, such as chlorine, to water to kill disease-causing organisms can produce other potentially harmful chemicals called disinfection byproducts, or DBPs.

• An herbicide can be spread too close to a well or other water supply and accidentally contaminate a water source.

• Nitrates or bacteria from failing septic systems or animal waste can seep into water.

• Lead or copper can seep into water from plumbing fixtures.

Public community water supplies are systems that serve at least 15 connections, or serve at least 25 people who live year-round in Vermont. All water systems that fit this designation are tested for bacterial, chemical and radiological contaminants on a regular basis. The Environmental Protection Agency (EPA) and the state regulate more than 90 contaminants in public drinking water. If a public community water supply is found to contain any of those 90 contaminants in excess, the residents served by the water system are notified and actions are taken to remove any contamination.

Private water supplies are systems that serve single family homes, duplexes, or small groups of homes. Private systems need to be permitted, but after the initial permit, they are monitored and maintained by their owners. It is important for owners to do their own water testing and maintenance to make sure their drinking water remains safe.

Contaminant data for community systems serving 500 people or more:

There are about 100 community systems that serve more than 500 people. For each of these systems, annual data are presented for 10 contaminants, starting in 1999.

Number of community water systems and people served by contaminant concentration:

These data show the number of community water systems and the number of people served by these systems in each contaminant category. Estimates of the population served are self-reported by each water system and are typically updated every three to five years depending on system type.

Information for all public systems (community, transient and non-transient):

These data are found on the Vermont Department of Environmental Conservation Drinking Water Watch website.

Data for arsenic, fluoride, gross alpha radiation, nitrate, radon and uranium in private drinking water are included in Vermont Tracking. Data are presented by town when at least 20 test results for the contaminant were available. The test results are displayed on Vermont maps and in data tables.

Vermont Tracking includes data about naturally occurring chemicals:

• Arsenic

• Fluoride

• Gross alpha radiation

• Nitrate

• Radium

• Radon

• Uranium

Vermont Tracking includes data about human-made chemicals and disinfection byproducts:

Human-made chemicals:

• Atrazine

• Di(2-ethylhexyl) phthalate (DEHP)

• Tetrachloroethylene (PCE)

• Trichloroethylene (TCE)

Disinfection byproducts:

• Haleoacetic acids (HAA5)

• Total trihalomethanes