Private Wells and Human Health

If you have a private well, then you should make water quality testing a priority. EPA regulations that protect public drinking water systems do not apply to nonpublic sources, including private well water. Unless your state or local government has set rules, individual water system owners remain responsible for making sure their water is safe to drink and use.

Well water commonly contains contaminants that pose a risk to human health. Contaminants may be present both naturally or as a result of human activity. Some contaminants, like arsenic, are colorless, odorless and tasteless, and their presence can only be determined by laboratory testing.

The State of New Hampshire (NH) lowered the Maximum Contaminant Level (MCL) for arsenic in public drinking water in 2019 from 10 parts per billion (ppb) to 5 ppb. After conducting a review as directed by the Legislature, the NH Department of Environmental Services (NHDES) found that recent research supports this lower limit of 5 ppb. Arsenic occurs naturally in the bedrock of many parts of our state, increasing exposure levels forĀ  NH residents through drinking water. It is estimated that two-thirds of all wells in NH have over 1 ppb of arsenic, and about three in ten private wells have arsenic above the NHDES new limit of 5 ppb. This lower standard benefits all NH residents and if you are a private well user, get your well water tested and review this list of FAQs.

Use the resources below to help you be sure to have the safest drinking water possible.

Visit www.ArsenicandYou!

Learn about arsenic and find out if your family might be exposed through private well water, food or other sources. The site includes easy steps to reduce your exposure and additional resources.

Well Water Community Action Toolkit

The Toolkit provides a step-by-step guide to help communities ensure the safety of private well water, by evaluating their needs, capacity and providing resources for an effective outreach campaign.

Well Water Testing Information

At a minimum, most states recommend that you check your well for mechanical problems each spring and that you test once-a-year for total coliform bacteria, nitrates, total dissolved solids, and pH levels. It is also important to test regularly for contaminants of local concern, like arsenic. If you live in New England and it is time to test your well, we have created a page that contains information on where to obtain a test kit and who to contact in case you have questions about what you should test for. Test your well regularly!

Be Well Informed

An online application developed by our partners at the NH Department of Environmental Services will help private well owners choose a treatment system that is effective for their individual water characteristics.

Arsenic in Private Wells Year 2 Report

Planning, Implementation, and Evaluation of Interventions

This report summarizes the work completed as part of the two-year project to evaluate well testing and treatment behavior in New Hampshire and determine appropriate outreach activities to inform and educate well owners about the need to test and treat. Details of our evaluation of outreach efforts are included.

Arsenic in Private Wells Report

The final report on the first year of work for a contract with the NH Department of Environmental Services with funding from the Centers for Disease Control and Prevention to survey private well owners and evaluate exposure and health effects for the NH population.

Dartmouth Resources

Arsenic in NH Well Water Fact Sheet
Arsenic Fact Sheet
In Small Doses: Arsenic
Children’s Environmental Health and Disease Prevention Research Center

External Resources

NH DES Private Well Testing Program
NH Biomonitoring
CDC: Water-related Diseases, Contaminants, and Injuries by Type
EPA: Arsenic in Drinking Water
U.S. Geological Survey: Information on Arsenic in New England Groundwater

New Hampshire Arsenic Consortium

Our Research Translation Core regularly convenes meetings of researchers and stakeholders focused on arsenic to hear research and outreach updates and to discuss the issue of arsenic in well water and food and target efforts to reduce arsenic exposure in New Hampshire.