New England's Drinking Water

Residents and businesses obtain their drinking water through drilling wells into the region's ground water or by pumping water from reservoirs and rivers. Many community water departments and private water companies in New England provide drinking water to residents and businesses. These systems are regulated as "public water supplies" and include water systems which regularly serve 25 or more people per day or which have at least 15 service connections. Public water systems may be publicly-owned or privately-owned and are regulated nationally by the Safe Drinking Water Act. If you are served by a public water supply you can learn more about your drinking water source by calling your water supplier or local health department. Your state drinking water agency also has information about public drinking water supplies.

Public water systems are unavailable in many parts of New England, including many rural areas. Instead, residents and small businesses get their drinking water by using private wells. Approximately 23 million people in the U.S. obtain water from their own private drinking water supply. EPA does not oversee private wells, although some state and local governments have rules and information to protect users of these wells. EPA encourages these households to take special precautions to ensure the protection and maintenance of their drinking water supplies. Find out more about how to protect private wells here, including how to learn about your well water, test the quality of your drinking water and protect it from contamination.

When water falls to the earth in the form of rain, sleet, hail or snow, some of it runs off the surface of the ground and enters stormdrains or nearby streams, some of it falls into oceans, lakes, rivers and other water bodies, and some of it soaks into the ground. When water seeps into the ground, it moves downward due to gravity through the pore spaces found between soil particles and cracks in rock. Eventually, the water reaches a depth where the soil and rock are saturated with water. Water which is found in the saturated (or wet) part of the ground underneath the land surface is called, "ground water."

Many areas of New England are underlain with rock and soil that contain large quantities of ground water which can be used for drinking water. In the United States, ground water can be found at or close to the land surface, or as deep as 200-600 feet. In New England, ground water is usually found close to the land surface (0-50 feet deep). A rock or soil formation that is capable of yielding enough ground water for human use is called an aquifer. When people use ground water as a water supply source, the water is usually pumped to the surface using a well. Wells are drilled deep into the ground until they reach ground water. They pump water out of the pore spaces around soil particles, and cracks and fractures in rock, and bring it to the land surface where it is piped into homes and businesses. A much smaller number of water supplies use springs, in which ground water flows naturally onto the surface.

Today about half of the American population uses ground water for its domestic needs, and many rural New Englanders get their household drinking water from private wells. More than 89 percent of public water supply systems draw some or all of their drinking water from sources found underground in rock, sand, and gravel aquifers. With increased use of water by industry, agriculture, homes, and municipalities, our regional reliance on ground water is expected to increase.

Ground water is a vital link in the water cycle. Ground water feeds rivers, lakes, and streams used for drinking water. Aquifers are replenished by rainfall or other surface water percolating through the soil. In turn, ground water provides the base flow of many streams and feeds lakes through underground springs. Ground water can move across town and state boundaries. It continually moves, sometimes flowing into surface waters miles from where it started.

Preventing the contamination of ground water resources is an important public concern. When pollutants are dumped, spilled, or discharged into the ground or into rivers, lakes and streams, they too may seep through the soil and rock and enter into the ground water found below the land surface. Ground water is usually assumed to be of high quality and is often used with little or no treatment. But, if contaminated, it may be decades or even centuries before a contaminated aquifer can be used. In some cases, the contamination can never be removed and the water resource may be lost.

In addition to ground water, many communities draw water from reservoirs, lakes and rivers to provide drinking water. Many of the largest drinking water systems in New England use surface water supplies to provide water, including the systems serving major urbanized areas like Boston, Hartford, Nashua, Providence, Burlington, and Portland. Surface water supplies are susceptible to contamination from a variety of sources including storm water runoff, pesticide application, sedimentation and erosion, septic systems, hazardous materials spills, injection wells, leaking chemical storage tanks, and wildlife.

• U.S. Geological Survey
• New England Interstate Water Pollution Control Commission