Use a lab Massachusetts certifies, or a mail-in kit. Across the state, the ones worth testing for are manganese, nitrate and arsenic, plus bacteria every year.
About 635,000 people in Massachusetts get their water from a private well, about 1 in 11 residents.
Massachusetts doesn't run a statewide free testing program that we know of. Some county health departments still test wells or sell kits, so call yours first.
Massachusetts Department of Environmental Protection (MassDEP): private well testingThe state's list of labs certified for drinking water. Many sell bottles you pick up or get by mail, and their results count for a home sale or loan.
Labs certified by MassachusettsOrder online, fill the bottles at your kitchen tap and get results by email in about a week. Full well tests run about $210 to $220.
Compare kits for MassachusettsShare of tested wells over the limit, from lab tests the USGS, EPA and state agencies collected since 2000. Your own well needs its own test.
Rare: under 5%Worth checking: 5 to 15%Widespread: 15%+
Lab results: Water Quality Portal (USGS and EPA)
5 counties have a full report with local test results and well depths.
No full report for that county yet. The statewide results above still apply, and so do the three ways to get tested.
| County | People on private wells | Share of residents | Typical well depth |
|---|---|---|---|
| Worcester County | 160,468 | 19% | 340 ft |
| Middlesex County | 92,311 | 6% | 320 ft |
| Bristol County | 62,508 | 11% | 265 ft |
| Plymouth County | 58,178 | 11% | 185 ft |
| Hampden County | 48,429 | 10% | 300 ft |
| Norfolk County | 41,938 | 6% | 380 ft |
| Hampshire County | 36,771 | 23% | 282 ft |
| Essex County | 36,435 | 4% | 385 ft |
| Barnstable County | 35,295 | 15% | 54 ft |
| Berkshire County | 28,427 | 22% | 300 ft |
| Franklin County | 25,518 | 36% | 300 ft |
| Dukes County | 5,391 | 26% | 60 ft |
| Nantucket County | 3,211 | 23% | 63 ft |
| Suffolk County | 22 | under 1% | 305 ft |
Massachusetts doesn't require routine testing of existing private wells. Keeping a well safe is up to the owner, so test for bacteria and nitrate every year.
Otherwise, use a lab certified by Massachusetts for drinking water. The state's list is linked on this page.