Where not to swim on Cape Cod: 12 ponds with bacteria concerns
Trying to salvage a day on the water on Cape Cod through the rainy weather this weekend?
You'll want to avoid the freshwater swimming spots where there may be harmful algae blooms. According to the Association to Preserve Cape Cod (APCC), swimming in water with high levels of cyanobacteria poses a threat of illness.
Symptoms of cyanobacteria ingestion can range from headache and fever to nausea and vomiting or even serious liver damage, warns the Centers for Disease Control (CDC).
Heading into this weekend, the APCC lists 12 freshwater Cape swimming spots under watch for bacteria. Here's where.
The APCC places freshwater swimming spots in one of three categories: acceptable, or low risk for exposure to cyanobacteria toxins; potential for concern, or moderate risk; and use restriction warranted, or high risk. While only town officials can issue advisories or close beaches, the APCC recommends cyanobacteria advisories for those in the "use restriction warranted" category.
According to the APCC, the following freshwater swimming spots, listed by town, have concern or potential for concern of bacteria as of Friday, Aug. 21:
Lovells Pond (Potential for Concern, Town Advisory)
Fawcetts Pond (Potential for Concern)
Hamblin Pond (Potential for Concern)
Long Pond (Potential for Concern, Town Advisory)
North Pond (Potential for Concern)
Cliff Pond (Use Restriction Warranted, Town Advisory)
Walkers Pond (Use Restriction Warranted, Town Advisory)
Chatham: Stillwater Pond (Potential for Concern)
Harwich: West Reservoir (Potential for Concern, Town Advisory)
Mashpee: Santuit Pond (Potential for Concern, Town Advisory)
Shawme Lake (Potential for Concern)
Upper Shawme Lake (Potential for Concern)
A boat sits on the flats off Breakwater Beach in Brewster at low tide Tuesday evening.
Photo taken July 14, 2026 (Merrily Cassidy/Cape Cod Times)Parbati Stallter of Truro works in her garden of day lilies on Pond Street in Truro, Monday morning July 13, 2026. (Ron Schloerb/Cape Cod Times)Sandy Neck Lighthouse in Barnstable is surrounded by hazy skies due to smoke from Canadian wildfires. Photo taken from Short Wharf Creek in Yarmouth Port, July 15, 2026 (Merrily Cassidy/Cape Cod Times)Tree work along the railroad tracks near the entrance to the Yarmouth Camp Ground Association on Oak Avenue in West Yarmouth continued Wednesday afternoon.
Some residents of the Yarmouth Camp Ground Association are upset over the clearing and trimming of trees along the railroad tracks that run in front of their West Yarmouth community.
Photo taken July 15, 2026 (Merrily Cassidy/Cape Cod Times)A vessel was taking on water off Woods Hole on July 17, 2026. (Merrily Cassidy/Cape Cod Times)Chris Tansey has helped organize a group of people that will walk from Pilgrim's First Landing Park in Provincetown to the Plymouth Correctional Facility where immigrants are being held. Photo taken Friday July 13, 2026 (Ron Schloerb/Cape Cod Times)Taylor Kirk of Hyannis takes the throw as Michael Torres of Brewster slides safely into second. Photo taken Thursday, July 16, 2026 (Ron Schloerb/Cape Cod Times)Barnstable High School pitcher Madison Flynn throws out the first pitch for the Brewster at Hyannis Cape League game. It was cowboy day at the park with many wearing cowboy hats. Photo taken Thursday July 16, 2026 (Ron Schloerb/Cape Cod Times)A member of the U.S. Army 54th Massachusetts Infantry Regiment honor guard carries the folded American flag before being presented to a Patriot Guard Rider. A No Veteran Forgotten Ceremony was held at the Massachusetts National Cemetery in Bourne Wednesday morning. Eleven unaccompanied veterans who were previously laid to rest this past quarter were honored during Wednesday's ceremony. Honored for their service and sacrifice included U.S. Army PFC Mark A. Dorazio, Army Captain Roger W. Hartwell, Army PFC Richard T. Lane, Army SP5 James F. Lavers, Navy FTG2 James A. Mahon, Army Sgt. James G. McGee, Army PFC John E. McLaughlin, Army SP4 Henry L. McNamara, Air Force Sgt. William G. Prime Jr., Army SSg Paul S. Sensale and Navy Sr. Charles M. Whittaker. Photo taken July 15, 2026 (Merrily Cassidy/Cape Cod Times)Harwich third baseman Tyler Smolinski fields a ball hit by Adrian Beltre Jr. of Orleans. Photo taken Wednesday July 15, 2026 (Ron Schloerb/Cape Cod Times)Kate Dimascolo of New England Donor Services celebrates with her family after throwing out the first pitch of the Harwich at Orleans Cape League game. Photo taken Wednesday July 15, 2026 (Ron Schloerb/Cape Cod Times)Under hazy skies, the T.S. Patriot State moves through the Cape Cod Canal and under the Sagamore Bridge Wednesday morning. The ship was headed to its homeport at Massachusetts Maritime Academy in Buzzards Bay after serving as the viewing platform for the governor and other officials for Sail Boston's Parade of Sail. Smoke from wildfires in Canada and Minnesota has drifted over Cape Cod creating hazy skies. Photo taken July 15, 2026. (Merrily Cassidy/Cape Cod Times)A dragonfly balances on a Morrow’s honeysuckle near Cold Storage Beach in Truro. Photo taken Monday, July 13, 2026 (Ron Schloerb/Cape Cod Times)A power boat races ahead of a storm off Cotuit Friday, July 10, 2026. (Ron Schloerb/Cape Cod Times)Kayakers paddle through Nauset Marsh in Eastham Monday morning, July 13, 2026. (Ron Schloerb/Cape Cod Times)Owen Paino of Cotuit avoids the slide by Austin Hawke of Bourne.
Tuesday July 14 2026 (Ron Schloerb/Cape Cod Times)Matt Bolton of Bourne arrives safely at second ahead of the tag by Aiden Aguayo of Cotuit. Tuesday July 14 2026 (Ron Schloerb/Cape Cod Times)A walker takes in the morning view from Hamblen Island in Wellfleet harbor Monday July 13 2026 (Ron Schloerb/Cape Cod Times)
APCC partners with officials at the town, county, state and federal levels to conduct cyanobacteria monitoring in Cape Cod ponds, collecting data biweekly. According to the APCC website, the agency typically recommends lifting advisories after two consecutive tests taken a week apart show safe bacteria levels.
The status of Cape Cod ponds can be checked on the website's cyanobacteria monitoring map. People can also check with the town Board of Health for specific information on local ponds.
This article originally appeared on Cape Cod Times: Where not to swim on Cape Cod: 12 ponds with bacteria concerns
