Americans drink more than 1 billion glasses of tap water per day.
Groundwater is the source of drinking water for about 150 million Americans.
Learning Topic: Private Well Water Quality

There can be both naturally occurring and man-made substances in New Englandís groundwater. As water moves through the environment in the water cycle, it can come into contact with a variety of substances. These substances can get into the groundwater and, subsequently into a private well that taps into the groundwater resource. When these substances get into the groundwater, they can affect the quality of our drinking water.



Naturally occurring substances can get into the water by dissolving from the rock or soil that the groundwater is moving through. Several naturally occurring substances of concern in New England are:

  • Radon is a radioactive, colorless, odorless, and tasteless gas that is formed from the breakdown of uranium in the soil and rocks. Uranium is present in granite rock, which is so common throughout New England. The radon gas may be present in the groundwater. Radon gas dissolved in water can be released to indoor air through normal household activities such as showering, dishwashing, and laundry.
  • Arsenic occurs naturally in the soil and bedrock throughout areas of New England. It also occurs as a result of industrial land use activities and arsenicís use as both a wood preservative and a pesticide.
  • Iron and manganese are naturally occurring minerals found throughout New Englandís soil and bedrock. While not considered a health hazard, their presence often results in staining of laundry and plumbing components and may contribute to offensive tastes and appearances of the water.

In addition to naturally occurring substances, there can be man-made substances present in well water as a result of surrounding land uses and activities that occur near or around the well. These substances and their presence in groundwater varies over the landscape and may include, pesticides, fertilizers, solvents like paint thinner, or gasoline and gasoline additives like MtBE. Proper storage, use, and disposal of chemicals and proper well location and construction are keys to avoiding groundwater contamination. Reducing the use of these chemicals whenever possible is also important. Preventing water contamination caused by these chemicals is much easier than attempting to clean up the groundwater after contamination has occurred.

The U.S. Environmental Protection Agency (EPA) sets limits on the amount that certain substances are allowed in public drinking water supplies. These limits, or standards, are set to protect public health by ensuring good quality water. As a private well owner, you are responsible for the quality of your own drinking water. Homeowners with private wells are generally not required to test their drinking water to meet the EPA standards. However, as the owner of a private well, you can use the public drinking water standards as guidelines when evaluating the quality of your drinking water.

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