Analyzing water at NEL
The federal government and many state governments (including Massachusetts) do not regulate the testing of private well water. So, the safety of your well water is your responsibility.

The Massachusetts Department of Environmental Protection does make recommendations for when you should test you well water, how often, and what tests should be run. However, check with your local Board of Health who may have requirements for testing of new wells as well as guidelines for testing at other times.

In general, it is a good idea to test well water before you buy a house with a private well, after any repairs or upgrades are made to your well, if you notice any changes to your well water taste, smell, or appearance, or if you previously had testing that indicated the water had contaminants above government standard levels.

In addition, well water in good standing should be tested on a yearly basis for bacteria and nitrate and nitrite. Testing for the following contaminants is recommended at least once every ten years: Arsenic, Chloride, Copper, Fluoride, Hardness, Iron, Lead, Manganese, pH, Sodium, VOCs, Radon

For more information:

EPA Drinking Water and Health