RINDGE, N.H. (MyKeeneNow) – The New Hampshire Department of Environmental Services (NHDES) has issued new cyanobacteria warnings for Pool Pond and Emerson Pond in Rindge, following the detection of elevated cyanobacteria levels. The warning for Pool Pond was issued on August 27, while Emerson Pond received its warning on August 29.

Meanwhile, the cyanobacteria warning for Lake Monomonac, also in Rindge, was lifted after being in effect from August 23 to August 29.

Understanding Cyanobacteria Warnings

Cyanobacteria warnings are issued when cell counts exceed the recreational health threshold of 70,000 cells/mL. These surface blooms can change rapidly and may accumulate in different locations around a waterbody. NHDES advises lake users to avoid contact with water in the vicinity of blooms, and to keep pets and livestock out of the water as well.

Warnings are issued as a precautionary measure for short-term exposure to cyanotoxins and remain in effect until the bloom subsides, with resampling conducted weekly. The warning period extends from May 15 to October 15.

Given the unpredictable nature of cyanobacteria blooms, NHDES recommends that individuals perform their own risk assessment by checking the water for any discoloration or unusual growth before engaging in recreational activities. If cyanobacteria are observed after a warning has been removed, it should be reported immediately.

The Difference Between a Warning and a Watch

In addition to warnings, NHDES issues “watches” (formerly known as alerts) under certain conditions: if a bloom is reported based on a photo before a sample can be analyzed, if cyanobacteria density approaches but does not exceed the threshold, or if a bloom was reported but not confirmed. Watches serve as advisories to be on alert for potential blooms, with water users advised to avoid contact with the bloom material.

Unlike warnings, which are regularly resampled, watches remain active for a week and are only resampled if further reports of blooms are submitted. Watches can be issued year-round, as needed.

Cyanobacteria: A Public Health Concern

Cyanobacteria are naturally occurring in water bodies worldwide, but blooms can pose health risks due to the potential release of cyanotoxins. Exposure to these toxins can lead to acute health effects such as skin irritation, numbness, nausea, vomiting, seizures, and diarrhea. If you or your pet experience any symptoms after potential exposure, seek medical attention immediately and inform the healthcare provider of the possible exposure to toxic cyanobacteria. NHDES also encourages reporting such illnesses through their Illness Report Form.

For more detailed information, including frequently asked questions and guidance for healthcare providers and veterinarians, visit the NHDES Harmful Algal Bloom webpage. To stay updated on specific waterbody conditions, consider signing up for waterbody-specific emails that provide updates on warnings, watches, resampling results, and warning removals.