Where does NH’s Clean Water Come From?

New Hampshire is fortunate in that we have a vast supply of clean, fresh drinking water, both above and below ground. Although the state has had issues with water contamination over the years, state monitoring and private testing have maintained an overall high water quality throughout the state. There are a variety of sources of water for home use in New Hampshire. Here is an overview of where the state’s drinking water supply comes from:


Most of the wells in New Hampshire are bedrock wells, also known as artesian wells. These wells are drilled deep into the ground and draw from water that flows through fractures in the bedrock. From 2000 to 2010, an average of 4,350 bedrock wells was drilled in New Hampshire each year. The average depth during this period was 365 feet.

Bedrock wells have very few incidents of bacterial contamination but are more susceptible to naturally occurring contaminants, like radon, arsenic or hardness. Bedrock wells can also be more expensive to drill and run because of their depth.


Shallow wells, also called dug wells, draw their water from the upper layer of the earth’s crust. They are typically less than 50-feet-deep and were once primarily made from fieldstone. Today, these wells are made of concrete and the water is drawn from a long pipe, called a casing. A screen on the bottom of the casing prevents sand and gravel from entering the home water system.

Fewer than 10 percent of wells in New Hampshire are shallow wells. They are susceptible to drought and are at greater risk of contamination from organic and chemical sources. Older shallow wells should be monitored regularly for bacterial contamination.


About 60 lakes and other surface water supplies provide water for public water systems in New Hampshire. One of the largest is Lake Massabesic, which provides water for Manchester and some of the residents in surrounding towns. The NH Department of Environmental Services does not recommend using surface water to provide water for private home use because of the high risk of contamination.


The ability to drill a successful well, regardless of type, largely depends on the geology of the area. Wells that draw water from above the bedrock are possible only in areas where the soil is porous enough to let water flow through, yet can maintain enough moisture to be drought resistant. Some bedrock wells do not provide a high enough yield for the home it serves, so a deeper well must be drilled, or a process called hydrofracking can be used. This is a process where highly pressurized water is injected into the bedrock, loosening debris in the bedrock fissures, allowing water within the bedrock to flow more freely.


Well drillers and pump installers must be licensed in New Hampshire by the Water Well Board.Skillings & Sons is a licensed well drilling company with more than 250 years of combined well drilling service. Although there are no state requirements about water quality or quantity for private home wells, Skillings & Sons is knowledgeable in recommended water quality standards, as well as local requirements for private water wells. Contact for your well water needs.