Tested Water

Manganese in Massachusetts well water, by county

Manganese is widespread, over the limit in 15% or more of tested wells, in 4 of the 5 Massachusetts counties with 10 or more tested wells. A county's share tells you how likely a problem is nearby. Only a test of your own well tells you what's in it.

How Massachusetts compares with the rest of the country

Across Massachusetts, about 2 in 10 tested wells had manganese over the EPA health advisory of 0.3 mg/L (58 of 297). Across all tested wells in the US it's about 1 in 7. So manganese turns up somewhat more often in Massachusetts than in the country as a whole. Check your county below.

Why it matters: High levels over many years may affect the nervous system, and babies are more sensitive to it. It also leaves black stains.

Manganese dissolves out of rock and soil, especially in water with little oxygen.

Manganese in tested wells, county by county

Share of each county's tested wells with at least one result over the EPA health advisory of 0.3 mg/L. Counties need 10 or more tested wells to be listed. Widespread means 15% or more, worth checking 5 to 15%, rare under 5%.

CountyWells testedWells over the limitLevel
Middlesex County 12
33% 4 of 12
Widespread
Plymouth County 19
26% 5 of 19
Widespread
Barnstable County 168
21% 36 of 168
Widespread
Hampden County 11
18% 2 of 11
Widespread
Worcester County 64
9% 6 of 64
Worth checking

5 more Massachusetts counties have 1 to 9 tested wells for manganese, too few to rate.

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Where to get your well tested for manganese in Massachusetts

1

Your county health department

Massachusetts doesn't run a statewide free testing program that we know of. Some county health departments test wells or sell kits, so call yours first.

Massachusetts's private well page
3

A mail-in kit

Fill the bottles at your kitchen tap and mail them back. We mark the kits that include manganese.

Compare kits

Keep reading about wells in Massachusetts

Questions people ask about manganese in Massachusetts

Is there manganese in Massachusetts well water?

Manganese is widespread, over the limit in 15% or more of tested wells, in 4 of the 5 Massachusetts counties with 10 or more tested wells. Across Massachusetts, about 2 in 10 tested wells had manganese over the EPA health advisory of 0.3 mg/L (58 of 297). Across all tested wells in the US it's about 1 in 7. So manganese turns up somewhat more often in Massachusetts than in the country as a whole. Check your county below.

Where can I get my well tested for manganese in Massachusetts?

Use a lab certified by Massachusetts for drinking water, or a mail-in kit that includes manganese from a certified lab. Some county health departments test wells too, so call yours first.

See Massachusetts's list of certified labs, or compare mail-in kits.

Where these numbers come from

  • Lab tests: Water Quality Portal (USGS and EPA), well samples since 2000. A well counts as over if any of its tests was over the EPA health advisory of 0.3 mg/L. Wells tested for studies and monitoring, not a random sample of homes.
  • Likely overstated: our own check of who tested the wells, when and where. How we check.
  • State programs and links: Massachusetts Department of Environmental Protection (MassDEP).