Manganese Health Advisory

TL;DR: Groton’s Whitney wells are experiencing elevated levels of manganese. Until a permanent solution is in place, Groton Water customers are advised not to give unfiltered water, or infant formula prepared using unfiltered water, to children under 12 months of age.

Latest News:

  • Filtered water from the Baddacook Well, which has near-zero levels of manganese, is providing as much water as possible to minimize the use of water from the Whitney Wells. Unfortunately, Baddacook alone is incapable of providing all of our customers’ water needs.
  • Concerned Town residents may fill their own water containers from a filtered faucet at Groton Town Hall any time the building is open for normal business hours or during any public meetings at Town Hall as posted on the Town website. The faucet is located in the lunch room on the first floor at the back of the building.
  • Town officials and state regulators have come to terms on the administrative consent order required to implement the GWD’s manganese mitigation plan. The GWD is moving forward this Spring with a pilot program to test available filtering methods. The results will inform a detailed conceptual plan that will be brought to Town Meeting in Fall 2020.

Background Information:

How much manganese is too much manganese?

In Massachusetts, MassDEP sets the regulatory limit for manganese in public drinking water sources as follows:

Manganese in GWD Water:

While the elevated levels of manganese persist at the source, the GWD has been taking regular samples at the affected wells, in the Chestnut Hill tank, and at multiple locations throughout the distribution system for informative purposes.

Decision Analysis:


Filtered Water Available

A manganese water filter has been installed in the Kitchen sink at Town Hall, on the 1st floor. We welcome any residents concerned about our manganese levels to fill their own containers in the Kitchen. You can access the Kitchen during normal Town Hall business hours (Monday 8am-7pm, Tuesday-Thursday 8am-4pm, Friday 8am-1pm). You can also enter the building anytime there are public meetings scheduled (see scheduled meetings at

Please contact the Water Department with any questions on concerns at 978-448-1122.