Harvard residents are advised to have no contact with the water in Bare Hill Pond because of the possibility that the algal bloom there may be producing harmful toxins. The advisory was issued Aug. 28 by the Board of Health and the Nashoba Associated Boards of Health. The boards also advised keeping pets out of the water. A no-swimming order, issued Aug. 24 because of poor water clarity, remains in effect.
Water samples are currently being tested to determine if the overgrowth of blue-green algae, called cyanobacteria, is producing toxins that can make people and pets sick. Not all cyanobacteria are harmful, but the boards issued the no-contact order as a cautionary measure. Test results will be available later this week.
In the meantime, the town advises no kayaking, paddleboarding, waterskiing, or tubing. Harbormaster Bob O’Shea told the Select Board at its meeting on Tuesday this week that he would close the gate to the boat launch area and close the boat rental kiosk until test results are in. These advisories and closings may be lifted when results are known, but swimming will remain prohibited until water clarity improves.
The Board of Health’s handling of the situation came under fire by the Bare Hill Pond Watershed Management Committee last week. On the weekend of Aug. 22, committee chair Bruce Leicher informed the board that wetlands consultant Wendy Gendron had identified an algal bloom of blue-green algae at the pond, and she recommended that the water be tested for toxins. At its Aug. 25 meeting, the Board of Health voted to accept what it thought was an offer from the Department of Public Health (DPH) to test the pond water for toxins at no charge.
But two days later, board Chair Sharon McCarthy found out that the DPH’s offer applied only after the algae had cleared, to make sure the water was safe for recreation. McCarthy notified Leicher that DPH wouldn’t be testing, so he contacted Select Board Chair Alice von Loesecke, and she assured him that pond committee funds could be used to pay for the tests. McCarthy agreed that was the best way forward. Rather than wait for the pond committee to meet, Leicher took three water samples—one from the town beach, one from Thurston’s Beach, and one near the dam—and brought them to the University of Connecticut Center for Environmental Science and Engineering for toxin analysis. He paid the $600 test fee ($200 per sample) himself, but the pond committee met Aug. 31 and voted unanimously to reimburse him and to approve additional expenses that might be needed for further toxicity testing.
Leicher and other pond committee members said the Board of Health should have acted with more urgency to test the water and done more to notify residents that it might be harmful. The board had posted a no-contact advisory on the town website Friday, Aug. 28, and on the social media site Nextdoor the following day, but the signs at town beach continued to just say “No swimming” throughout the weekend and into the next week.
Leicher, McCarthy, and Nashoba Associated Boards of Health (NABH) Agent Ira Grossman attended the Select Board’s Sept. 1 meeting and discussed how this process might be handled more efficiently in the future. Grossman said the town can generally ask for additional pond water tests, but testing for blue-green algae toxins would require money, so the town would need a budget for that. Von Loesecke asked if the town could hire a contractor to do testing, and Grossman said it could. She said she would create a small group to iron out the details for testing and notification in the future.
Algal bloom could put people and animals at risk
Some blue-green algaes produce highly potent toxins called cyanotoxins, and as algae levels increase, so do the cyanotoxin levels. According to the Centers for Disease Control and Prevention (CDC), water contaminated with cyanotoxins can cause people to get sick from swimming, kayaking, fishing, or wading through the water, breathing in tiny water droplets or mist, drinking the water, or eating fish caught in the water. CDC lists the following symptoms: skin, eye, nose, or throat irritation, abdominal pain, headache, neurological symptoms, vomiting, and diarrhea.
The CDC also warns that animals who come in contact with cyanotoxin-contaminated water are especially vulnerable and can die within hours of exposure. It advises contacting a veterinarian without delay if a sick pet is suspected of having been in contact with a harmful algal bloom. Symptoms in animals include excessive salivation, weakness, staggered walking, difficulty breathing, and convulsions.