When selecting a laboratory for water testing, be sure to select a laboratory that is certified by the Massachusetts Department of Environmental Protection (MassDEP). You can request price quotes from several laboratories, but it is recommended that you take into consideration other factors beyond cost, including laboratory detection limits, ability to use US EPA approved methods, and range of testing offered.
Private well owners are generally not required to test their water quality, but MassDEP strongly urges private well owners to get their well tested as least once a year. The Centers for Disease Control and Prevention also recommends testing if there are known problems with well water in your area, you have experienced problems near your well (flooding, land disturbances, nearby waste disposal sites, etc.), you replace or repair any part of your well system, or if you notice a change in water quality (taste, color, or odor).
The University of Rhode Island Water Quality Program has created a testing schedule that outlines what compounds to test for and how frequently you should test them.
Regular testing will allow you to monitor your well over time. Look for trends, and be aware of increasing contaminant levels.
Most contaminants fall under one of two categories: primary and secondary contaminants. Primary contaminants are ones for which EPA has identified a health risk from excessive exposure and has set a maximum contaminant level (MCL) or action level (AL). Secondary contaminants are contaminants that have an aesthetic effect, such as taste, odor, and color. These contaminants are not typically regarded as a health risk.
It is also common to test for Water Quality Indicators (WQI), which include measurements that help to assess the acidity and amount of germs/bacteria in water. Examples of WQIs include total coliform, fecal coliform, and pH.
Many labs offer standard packages for private well owners. These packages include a mixture of common primary and secondary contaminants as well as WQIs. If you have young children, you should be aware of which contaminants might have a greater negative effect on them, such as lead and nitrate.
Some of the chemicals in your report may not have been found at a level the lab could measure. In this case, you may see the words “not detected” or “ND” next to a chemical name. You may also see a “<” followed by a number.
Your report will also show a detection limit or reporting limit. This is the lowest level that the lab can report to you. Laboratories with lower detection limits or reporting limits have more sensitive testing that can measure lower chemical levels. Being below the lab’s limit does not necessarily mean that the chemical is not present in your sample, and can mean that the chemical is present at a low level that the laboratory could not detect.
For each contaminant, we include tips on reducing exposure, including some well treatment options. Our “Water treatment” page includes information on common well water treatment systems and which compounds they are effective at removing.
If you decide to treat your water, there are several things you should keep in mind.
More information on specific water contaminants:
More information about water testing:
More information about home water treatment:
Some labs offer additional testing for emerging contaminants that aren’t regulated in drinking water, like pharmaceuticals and consumer product chemicals. Many scientists are studying the levels of these contaminants in drinking water and their effects on human health and the environment. Pharmaceuticals and consumer product chemicals can make their way into groundwater, surface water, and drinking water wells from septic systems, sewage treatment plants, and landfills. Silent Spring Institute researchers have continued to study these chemicals in water, particularly on Cape Cod, and the effects they may have on our health. To learn about Silent Spring Institute’s research on emerging contaminants in private wells, visit: silentspring.org/privatewells.