Harmful Cyanobacterial Bloom Advisories in Massachusetts

Current as of August 12, 2026

This list includes waterbodies that have been reported to DPH by local, state and federal partners that manage or regulate the respective waterbody, including recreational waterbodies without swimming beaches.

Current List of Waterbodies

  • Charles River between Kendrick St./Nahanton St. (Needham/Newton) and Bridge St./Spring St. (Dedham/West Roxbury)
  • Cliff Pond, Brewster
  • Walkers Pond, Brewster
  • Chicopee Reservoir, Chicopee
  • Chilmark Pond, Chilmark
  • Squibnocket Pond, Chilmark
  • Tisbury Great Pond, Chilmark/West Tisbury
  • Heritage Pond, East Longmeadow
  • Redd’s Pond, Marblehead
  • Turner’s Pond, Milton
  • Head of Hummock Pond, Nantucket
  • John’s Point, Nantucket
  • Billington Sea, Plymouth
  • Boot Pond, Plymouth
  • Clear Pond, Plymouth
  • Great South Pond, Plymouth
  • Halfway Pond, Plymouth
  • Little West Pond, Plymouth
  • Russell Mill Pond, Plymouth
  • Whites Pond, Plymouth
  • Ames Pond, Stoughton
  • Mink Meadows Pond, Tisbury
  • Pratt Pond, Upton
  • Hardy Pond, Waltham
  • Coes Reservoir
  • Indian Lake, Worcester
Important notice: Please note:

This should not be considered a complete list of all advisories in Massachusetts.

This list includes waterbodies that have been reported to DPH by local, state and federal partners that manage or regulate the respective waterbody. If you think an algal bloom may be present you are encouraged to avoid contact with the water — WHEN IN DOUBT, STAY OUT! To see examples of what algae blooms look like, please visit the Identifying cyanobacterial blooms and scums page.

Contact

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Address

250 Washington St., 7th Floor, Boston, MA 02108

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