PAULA TRACY begins her 2025 Lakes Watchdog series today.
These listings can change frequently so best to check the Department of Environmental Services Healthy Swimming Mapper often. Click here: https://www.arcgis.com/apps/dashboards/8d84a6b03acb4efaab571b222c78447b
DES will update up to Thursday afternoon for cyanobacterial and fecal matter to be safe on Fourth of July.
This story will be update Thursday afternoon as well.
By PAULA TRACY, InDepthNH.org
BARRINGTON – Going into the Fourth of July holiday week with the weather seemingly cooperating for those who want to swim in state lakes and ponds, there is only one lake in the state currently on the New Hampshire cyanobacteria warning list as of Thursday: Swains Lake in Barrington.
It has been on the list since June 19, but re-testing showed bloom conditions on Swains Lake have significantly improved since last week, according to the July 2 retesting. Multiple samples from around the waterbody had no cyanobacteria present. However, one sample did exceed the recreational threshold of 70,000 cells/mL, so the warning will remain in place.
“If you choose to recreate this upcoming weekend, be sure to perform a visual assessment of the water and avoid swimming near any bloom accumulations,” the retesting July 2 findings said..
“It’s important to remember that cyanobacteria blooms are dynamic. The cyanobacteria grow lake wide and pile up on different shorelines based on wind, wave, boat action and lake morphology. Samples collected (Tuesday) are a snapshot in time of where the cyanobacteria were accumulating yesterday. It’s best practice to perform a visual assessment of cyanobacteria before choosing to recreate,” said Michele Busi, Beach Inspection Program Coordinator / Interim Cyanobacteria HAB Program Coordinator.
A red triangle on the DES Healthy Swimming Mapper map represents a location where a sample was collected, and the cyanobacteria cell density exceeds the recreational threshold of 70,000 cells/mL. An orange triangle represents a location where a sample was collected but the cyanobacteria cell density is only approaching the recreational threshold. A black triangle represents a reported bloom, but no sample was collected. If you click on any triangle, a pop-up box will be displayed that has more information including the cyanobacteria cell density.
There are, however, citizen reports of potential blooms that are also being investigated reported June 30 at Lee’s Pond in Moultonborough and Kezar Lake near Sutton and on June 27 at Milton Three Ponds and Arlington Mill Pond while on June 24 a suspected bloom was seen on Country Pond in the southern part of the state and on June 23, Province Lake in Effingham.
But no warning or watch on those water bodies has yet been listed.
Cyanobacteria or blue green algae is naturally occurring in the water but in high concentrations can in some cases be harmful to humans and pets. Last year the state saw record warnings listed and also federal money has flowed in to help lake associations perform master plans related to protecting the water from future cyanobacteria blooms.
The state’s Cyanobacteria Harmful Algal Bloom Program within the Department of Environmental Services monitors waterbodies when a potential cyanobacteria bloom is reported by a member of the public.
“A cyanobacteria warning is issued lake-wide when cyanobacteria cell concentrations exceed 70,000 cells/mL at multiple locations. Warnings are not based on toxin evaluation but occur at cyanobacteria cell count densities when toxin production may be likely. These are intended as a precautionary measure for short-term exposure to cyanotoxins. When a warning is issued, resampling is performed weekly until the bloom subsides. Warnings are issued from May 15 through October 15,” the site reads.
A watch may also be issued for a waterbody to serve “as a statement to be on the watch for a potential cyanobacteria bloom. Sometimes watches become warnings, and sometimes the bloom will pass before a warning is issued. Watches remain active for a week.
“Resampling only occurs if further bloom reports are submitted. Watches are issued year-round as needed. To keep updated this week and throughout the summer go to https://www.arcgis.com/apps/dashboards/8d84a6b03acb4efaab571b222c78447b.
There, you can sign up for advisories for your particular water body.
Andrea LaMoreaux, president and policy advocate for NH LAKES said Tuesday that with the rainy spring and now warm temperatures, “we are seeing cyanobacteria blooms appearing in lakes throughout the state.”
She said to date the organization has awarded $400,000 in grant funding to support lake protection projects in six communities through summer 2026.
The funding comes from the federal American Rescue Plan Act.
“Thanks to these grants, the following communities are using the grants to take action:
– Acton Wakefield Watershed Alliance is sending its Youth Conservation Corps to 15 lakefront properties to reduce pollution around Lovell Lake, Pine River Pond, Great East Lake, and Province Lake. Separately, the Watershed Alliance will also fix erosion on two nearby roads.
– Country Pond Lake Association, in partnership with the Town of Newton, is improving the town boat ramp to prevent runoff from flowing into Country Pond.
– Lake Sunapee Protective Association is working with the Town of Sunapee and Little Lake Sunapee Protective Association to fix shoreline erosion near Georges Mills Town Beach and Little Lake Sunapee.
– The Town of Alton is upgrading roads to stop polluted water from entering Mill Pond, which drains into Lake Winnipesaukee.
– Wentworth Watershed Association is tackling runoff into Lake Wentworth, especially near Red Brook Circle.
– White Oak Pond Association is creating a Watershed Management Plan to pinpoint and reduce pollution sources in White Oak Pond.
“By completing these projects, these local groups are helping to clean up our lakes and prevent cyanobacteria blooms in the future,” LaMoreaux said.
Lake Kanasatka in Moultonborough, which has battled with cyanobacteria over the years, had a warning issued June 10 but was lifted June 25.
FECAL BACTERIA ALSO MONITORED
The Beach Inspection Program also monitors public beaches for the presence of fecal bacteria from Memorial Day through Labor Day.
A beach advisory is issued when a water sample contains fecal bacteria levels that exceed the state standard, indicating unhealthy swimming conditions. Enterococci is used as the indicator of fecal bacteria at coastal beaches while E. coli is used at freshwater beaches.
A coastal beach advisory is issued if 1 sample exceeds 104 MPN/100 mL.
A freshwater beach advisory is issued if 1 sample exceeds 158 MPN/100 mL or 2 samples exceed 88 MPN/100 mL.
Once an advisory is issued, resampling will occur the following day and will continue until the fecal bacteria levels do not exceed the state standard. Check DES Healthy Swimming Mapper for list.
State Sen. Mark McConkey, R-Freedom, sought funding last year when he was a state representative.
He asked for the one-time ARPA funds to help towns understand the extent this is a problem because they need to hire people to help with master plan studies of watersheds where areas of pollution may exist.
Cyanobacteria growth is aided when nitrogen and phosphorus enter lakes particularly after heavy storms.
Those toxic blooms can can kill dogs, sicken people, force warnings for people to stay out of the water and reduce property values on lakes and ponds.
Former Gov. Chris Sununu supported the idea but he cautioned legislators who might be asked through legislation in 2025 to create a long-term fund through the creation of a new license plate. That bill failed in the legislature this term.
“Every time you institute a new license fee program you dilute all the other license plate dollars that are going to an already established, dedicated program,” such as the Moose plates, Sununu said.
Fish and Game Executive Director Stephanie Simek told the Senate Finance Committee this spring that the department opposed the bill because it would take money away from the current license plate and it would not help the loons, which were to be featured on the plate.
McConkey said cyanobacteria is a “bipartisan” issue that the state needs to get ahead of and he called clean water “extremely necessary” for the financial health of the state as well.
He said there could be a “tragic loss” to people’s property values if cyanobacteria blooms persist on water bodies in the summer.
Cyanobacteria blooms on lakes and ponds have been something that the state has been monitoring since 2003 but New Hampshire’s cyanobacteria lab has never been busier than it was last summer analyzing samples from a growing number of locations, including Lake Winnipesaukee.
David Neils, administrator for the Watershed Management Bureau of the NH Department of Environmental Services Water Division, within the NH Department of Environmental Services said there were at least 58 warnings issued to water bodies in 2024.
He said his department’s focus has been teaching the public what blooms look like and letting them know that their eyes are the best tool.
If there are more warnings because people are more educated and know what to look for or if the problem is increasing is still unknown.
“We’ve always known the program will never catch every bloom and that numbers may fluctuate yearly,” he said last fall. “That’s why public awareness about what to look for is the most important thing.”
On its website, DES warns the public against swimming in locations where there is a bloom and also says it is OK to boat or otherwise recreate without contact.
According to DES:
Watches are issued when samples are evaluated and cyanobacteria are in higher abundance than normal background levels at multiple locations, but that densities are below 70,000 cells/mL or when clear photographic evidence indicates a bloom is occurring.
Warnings are issued when samples are evaluated microscopically, and cell counts exceed 70,000 cells/mL and the bloom is widespread or extends to multiple locations on the waterbody. A warning does not close the waterbody to recreational use. The warning is intended as a precautionary measure to inform the public of the potential health risks associated with cyanobacteria blooms. Please see our updated FAQs for more information.