AYER -- Flannagan Pond is closed to recreational activities such as swimming, boating and fishing.
The pond will be chemically treated with herbicides registered with United States Environmental Protection Agency of Massachusetts to control nuisance aquatic vegetation. The pond will be restricted from drinking or any other type of domestic use until May 22. Livestock watering and lawn care of any kind will be restricted for 90 days. Signs detailing applicable water use restrictions will be posted during the time of Flannagan Pond's treatment.
Conservation Commission secretary Becky DaSilva-Conde said that to her knowledge, most Ayer residents use the public drinking supply.
"Once the pond gets treated there are certain limitations for what can be done with the water," DaSilva-Conde said.
"The herbicide is at its highest concentration," DaSilva-Conde said, explaining why any domestic use is restricted for the five days following the initial treatment. However, "the irrigation (prohibition) continues for 90 days."
DaSilva-Conde emphasized the importance of keeping residents from using the pond while its undergoing treatment.
"We don't want anything that is consumed to be used with that water," she said.
Nuisance aquatic vegetation is comprised of aquatic organisms that have been washed in from varying sources that threaten and alter natural resources and the ecosystem.
The herbicide treatments are performed by Aquatic Control Technology of Sutton, which is licensed by the state.
The Department of Environmental Quality reports that "excessive plant growth can sometimes be a nuisance for owners and lake users." When grown in large numbers, weeds can be destructive to the operation of boat engines and dangerous for swimmers who can become entangled in them.
The macrophyte and European green crab are two of the nuisances Ayer is trying to repel from Flannagan Pond. Another nuisance is Swimmer's Itch. Swimmer's Itch is caused by parasites that typically live in freshwater snails and water birds. Humans are most vulnerable to these parasites on warm and sunny days -- days that are usually perfect for swimming.
These parasites are more of an irritation that medically threatening. A symptom of Swimmer's Itch is an uncomfortable and itchy rash. The rash is temporary because humans are not good hosts for the parasites, which eventually die. According to the Mayo Clinic, Swimmer's Itch can be treated with over-the-counter or prescription medications.
There will be 1-2 additional follow-up treatments to Flannagan Pond within the next 45-60 days from the initial May 16 regimen. Notices for these "booster" treatments will be posted on the town's website at www.ayer.ma.us.