Stormwater treatment, the rise of cyanobacteria and road salt use are the most critical factors in the health of New Hampshire’s lakes, and Francestown’s lakes are no exception, according to Ted Diers, assistant director of the Water Division of New Hampshire Department of Environmental Services.
Diers spoke Wednesday night at the Francestown Town Hall during an event sponsored by the Francestown Conservation Commission and the Watershed Study Subcommittee.
“The good news is, New Hampshire has mostly great water, especially compared to most other places,” Diers told the crowd of about 50 people. “The exception to that is stormwater.”
Diers praised Francestown’s citizen scientists who test and measure the water in the town’s two largest lakes, Scobie Pond (also known as Haunted Lake) and Pleasant Pond, for cyanobacteria and pH levels, as well as monitoring for invasive species such as milfoil.
“New Hampshire has more citizen scientists than any other state. Fifty percent of our data at DES comes from volunteers monitoring the health of our lakes,” Diers said.
Diers presented current data on both Scobie Pond and Pleasant Pond, which indicates that both bodies of water have rising phosphorus levels and rising instances of toxic cyanobacteria blooms.
“This is the big warning that everyone is seeing in terms of lake health,” he said. “Cyanobacteria blooms are way, way up in the past 20 years, and a lot of wildlife and a lot of pets have died as a result,” he said. “We know that cyanobacteria are influenced by both temperature and by an increase of nutrients in the water, and we know the temperature is going up.”
According to Diers, the biggest stressors of lakes are nutrients, from fertilizer and agriculture; stormwater runoff, which includes chlorides, sediment and chemicals, and human waste.
Additional stressors to lake health include loss of wetland buffers, development in the watershed, intensity of use and rising temperatures.
The worst year for cyanobacteria blooms in Francestown’s lakes was 2020, which had the hottest July on record in the state.
“In the past 20 years, New Hampshire has had more droughts than in the previous 50 years,” he said.
Data on Pleasant Pond indicates that the lake has “worsening transparency,” an indication of pollution, and some areas that tested positive for E.coli. Diers said the existence of E.coli in lakes is linked to outdated septic systems.
Diers noted that the water samples were taken from multiple locations in each lake, and that the range of data indicates varying conditions on the lakeshores.
Diers presented a slide of a typical developed New Hampshire shoreline (not in Francestown), which showed “everything terrible thing that can happen to a lake,” including heavily fertilized lawns, eroding boat ramps, outdated dock structures, human-made beaches with imported sand and paved surfaces touching the lake.
“What I always say is that ‘lakes just wanna become meadows’,” Diers said. “The stressors accelerate the aging of lakes — they naturally, over time, will fill in with sediment and vegetation. It happens over millennia, but the stressors push lakes forward in time.”
Diers urged residents with waterfront property to consider joining New Hampshire’s LakeSmart program, which provides resources for property owners to institute best practices around lake health. He also praised the LakeHost program, which monitors boats and watercraft for exotic invasive species, including Eurasian water milfoil, water chestnut, zebra mussels and spiny water fleas.
According to Diers, the big picture goal for lakes is “resiliency.”
“We can’t restore our lakes to a ‘natural state.’ — Both Scobie Pond and Pleasant Pond were created by dams, and their shorelines were totally deforested. The ‘way it was’ no longer exists. What we need to think about is where we want to go. What we can do is try to understand the problems that we have, make a plan, control what is controllable and adapt,” he said. “All we can do is try to mimic the process of nature to improve lake health conditions.”
In answer to questions from residents about environmentally friendly ways to treat road ice, Diers said there is “no easy solution,” but said that some states, such as Connecticut, are transitioning to using a brine solution on roadways instead of dry salt.
“Everyone repeat after me: sidewalks should not be crunchy,” Diers said, adding that the dry salt traditionally applied to roads relies on traffic to break it up to enable it to prevent ice from adhering to the roads, and that large quantities of salt “bounce off” and end up in the woods, in culverts and eventually the watershed.
Diers recommended the New Hampshire “Green SnowPro” program for municipalities and commercial snow removal contractors.
“Every property, not just waterfront property, is tied into the watershed,” he said. “Every molecule of salt that starts out on a road or a driveway ends up in a body of water.”
For information about NH DES, LakeSmart, and the LakeHost programs, visit www.des.nh.gov.