The Town of Plymouth announced a Cyanobacteria Advisory for Halfway Pond on August 25, 2022. The information below details the advisory, provided by the Town of Plymouth.

Cyanobacteria Advisory - Halfway Pond

Updated: 8/25/22

Halfway Pond (Effective: 8/25/2022)

Visual observations provided by the Department of Marine and Environmental Affairs (DMEA) indicate the presence of cyanobacteria (blue-green algae) cells in this pond.  This evidence suggests that the level of cyanobacteria in the water may exceed the MDPH guidelines for recreational waterbodies in Massachusetts.  Accordingly, as recommended by MDPH, a public health advisory is being issued by the Plymouth Public Health Department.  Signage will be posted at public access points, where available to warn individuals against contact with the water (please see attached sign).

People and animals should NOT go in this water until the pond has been tested and cleared of the algal bloom.

What are the health concerns associated with cyanobacteria?

A confirmation of cyanobacteria bloom does not necessarily indicate it is toxic.  Cyanobacteria MAY give off microcystin toxins.  However, all cyanobacteria blooms are treated as potentially toxic to ensure public health.

• Skin irritation, stomach cramps, vomiting, nausea, diarrhea, fever, sore throat, headache, muscle and joint pain, blisters of the mouth and liver damage.

• Swimmers in water containing cyanobacterial toxins may suffer allergic reactions, such as asthma, eye irritation, rashes, and blisters around the mouth and nose.

• Animals, birds, and fish can also be affected by high levels of toxin-producing cyanobacteria.

• If your animal goes into the water, be sure to rinse them off thoroughly

• If your animal ingests water and shows signs of illness, contact your veterinarian

Advisories are not lifted until the water has been consistently clear for TWO WEEKS

For more information on cyanobacteria, please click here.

An advisory can not be lifted until the bloom has been visibly clear for two consecutive weeks.

To report a cyanobacteria bloom: Take a photo, document location and send to Plymouth Public Health or Plymouth Marine and Environmental Department