Update: Sept. 10, 2019 – 11:28am –
Lake Massapoag in Sharon is reopened for all water activities
From the Sharon Board of Health: Test results confirmed that there are no harmful levels of blue-green algae. We thank the residents for their patience this past week.
August 29, 2019 — Press release from Sharon, MA Board of Health
The Sharon Board of Health advises Sharon residents not to use Lake Massapoag beaches, both private and public, due to the presence of a bloom of blue-green algae (cyanobacteria) in the water.
This photo, taken at Lake Champlain in 2016, shows an example of what cyanobacteria can look like.
On August 28, 2019 the Massachusetts Department of Public Health’s Environmental Toxicology Program reviewed evidence of the bloom provided by the Sharon Health Department and confirmed that the material is likely to be cyanobacteria, also called blue-green algae. Blue green algae can be toxic to humans, particularly young children,and to pets exposed to waters where the organism grows.
The Sharon Board of Health will continue to evaluate the conditions in the water and will need to test and retest the Lake water a week later before confirming the water is safe for recreation.
Algae blooms occur more frequently in the Spring and early Fall, and can multiply rapidly during warm weather. These blooms consist of cyanobacteria, which can cause significant health impacts depending on their concentration in the water and exposure factors. Exposure to blue-green algae can cause skin and eye irritation, and may also cause gastrointestinal problems, neurological damage, and liver disease if water is swallowed. Due to the potential health impacts of cyanobacteria, all water activities in Lake Massapoag including boating,surfing, swimming, and wading should be stopped until testing shows the algae bloom has ceased. For more information on cyanobacteria exposure, go to: https:/www.cdc.gov/habs/be-aware-habs.html
Pets may become ill after exposure to blue-green algae,and pet fatalities following ingestion of contaminated water have been documented. Sharon Board of Health regulations specify that dogs or other pets are not allowed to swim in Lake Massapoag waters at any time. The Board of Health advises pet owners to keep animals a safe distance away from the beach water and on a leash to prevent exposure to the algal bloom.
In addition to weather conditions, animal waste, fertilizer, failing septic systems, and phosphate-containing detergents contribute significantly to the growth of harmful algae blooms.
For more information on blue-green algae blooms, go to:
For additional information contact the Sharon Health Department at 781-784-1500 x1143.