NEW DURHAM — For decades, the Powder Mill Fish Hatchery at Merrymeeting Lake was pumping out water with concentrations of phosphorous that were 12 times higher than the water it was taking in. It wasn’t until 2015 that the nutrient load reached the level that toxic cyanobacteria blooms were observed downstream.
“That’s how resilient that waterway is,” said Fred Quimby, who lives on Merrymeeting Lake and sits on the Cyanobacteria Mitigation Steering Committee, formed as a joint effort between the towns of Alton and New Durham.
After water leaves the Powder Mill Fish Hatchery – which is operated by the state of New Hampshire Fish and Game Department – it flows into the Merrymeeting River and through a series of small ponds, ultimately ending up in Lake Winnipesaukee’s Alton Bay.
That’s why the Lake Winnipesaukee Watershed Association has taken an interest, said Pat Tarpey, executive director. The association is calling on the public to pressure the EPA to issue a new permit to the fish hatchery, one which will reduce the amount of phosphorous it is allowed to discharge.
A threat for Winnipesaukee
“Whatever’s coming from that fish hatchery has the potential to eventually end up in the lake,” Tarpey said. “Phosphorous is our biggest concern as far as nutrient loading. Lake Winnipesaukee and surrounding lakes, phosphorous is the limiting nutrient, it’s not naturally abundant. Any additional amounts have the potential to have an impact on water quality.”
Bob Craycraft, who oversees the Lay Lake Freshwater Monitoring Program for the University of New Hampshire, agreed. “Phosphorous is a primary driver of growth in our freshwater systems. As the amount of phosphorous increases, so the amount of algal growth.”
Depending on the type of algae that’s present, the phosphorous can lead to a bloom of cyanobacteria, which produces toxins that can cause rashes and gastrointestinal problems for humans, and which can be fatal for animals such as dogs.
Craycraft said that his program has seen phosphorous levels increase in some areas of Winnipesaukee, and has also noted other water quality concerns, such as lessening water clarity and algal growth in the deepest parts of the lake.
“Winnipesaukee varies tremendously over location,” Craycraft said. “The water quality on the whole is still pretty good, but there are some threats.”
Phosphorous in Merrymeeting Lake is concentrated at about 5 parts per billion. The water that was being discharged from the Powder Mill Fish Hatchery had concentrations, until recently, 12 times higher. Downstream from the fish hatchery are March, Jones and Downing ponds, and it’s a bad time to be a waterfront homeowner on one of those ponds. Red signs on the shorelines warn of health hazards presented by the cyanobacteria. New Hampshire Public Radio reported that some have even pulled up their docks to prevent visitors or animals from mistakenly entering toxic waters.
“Currently, there is a tremendous amount of phosphorous going into Winnipesaukee,” Quimby said. “What nobody knows is when the lake will become saturated and the phosphorous will do, in Winnipesaukee, what it has done in New Durham and it has begun to do in Alton.
Workers at the fish hatchery declined to comment, and Jason Smith, chief of Fish and Game’s Inland Fisheries Division, who oversees the hatchery, didn’t return a call for comment. Their reticence may result from a legal action by the Conservation Law Foundation, which is suing the state for allegedly violating the Clean Water Act.
In a statement issued on Nov. 1 of last year, Tom Irwin, director of CLF New Hampshire, said, “The state’s Powder Mill hatchery is endangering public health by illegally polluting the iconic Merrymeeting River. Residents and visitors flock to New Hampshire’s rivers and lakes every summer to swim and boat, not to be told to stay out of the water, and certainly not to be sickened by toxic cyanobacteria outbreaks. Protecting public health must be the primary concern among our state leaders, and they must put a stop to the pollution coming from this facility.”
Though they wouldn’t speak to The Daily Sun, Quimby said that employees at the hatchery have already taken steps to limit the phosphorous leaving the hatchery. They’ve moved the salmon to another hatchery, have changed the formulation of the food they’re using to include less phosphorous, and they’ve improvised a series of “settling ponds,” seeded with duck weed, which consumes the phoshorous from the discharge water before it is released.
Since these changes have been made, Quimby said the phosphorous concentration of the water leaving the facility is lower than they’ve ever recorded. And he believes that Fish and Game would be willing to do even more, including construction of a wastewater treatment facility to meet whatever specification is detailed in their next permit from the EPA.
The problem, Quimby said, is that the hatchery’s permit expired in 2016, and the state has been waiting three years now for the EPA to issue a new one. The state doesn't want to spend taxpayer dollars on a wastewater facility until it knows how clean its outflow needs to be. The latest news from the EPA is that it estimates it will have a draft permit ready by Oct. 1. Once it releases a draft permit, a 90-day period will follow to allow for public review and comment.
The Lake Winnipesaukee Watershed Association is urging the public to ask their elected officials to pressure the EPA to keep to that estimate, so that waters downstream of the hatchery can be protected.
“The EPA has no excuse to not do that at this point,” Quimby said.