Mashpee residents shared differing opinions this week about a potential horsepower and speed restriction bylaw amendment for boats and other water craft as part of an effort to mitigate historical water quality problems in Santuit Pond.
About a dozen community members attended the meeting for the educational presentation and discussion by environmental engineering consulting firm Fuss & O’Neill during the Mashpee Select Board meeting Monday evening, January 9.
The purpose of the bylaw amendment is to protect water quality in the pond to allow for continued safe recreational use. The current proposal from the Mashpee Department of Natural Resources, if approved, would set a threshold for motors of a certain horsepower and eliminate the use of internal combustion engines on Santuit Pond only.
Electric motors that are at or below the particular threshold and nonmotorized boats would still be allowed to access the pond for recreation.
This was the start of a series of public information sessions, DNR Director Ashley K. Fisher told the select board. The DNR will also be letting abutters in a 300-foot buffer around the pond know through certified mail of any potential bylaw changes that will appear on the May Town Meeting warrant.
The chief resilience and sustainability officer at Fuss & O’Neill, Diane Moss, has been working with the town on its Municipal Vulnerability Preparedness (MVP) program grant. Ms. Moss spoke during the presentation on the significant cyanobacteria blooms and other sources of phosphorus such as sewer systems and stormwater runoff that contribute to the continued decline of the pond.
In freshwater systems, cyanobacteria are microorganisms that can produce harmful algae blooms. These blooms can harm people, animals, aquatic ecosystems, the economy, drinking water supplies, property values and recreational activities including swimming and fishing, according to the US Environmental Protection Agency.
As part of the Fiscal Year 2022 MVP grant, Fuss & O’Neill was tasked with looking into the town’s bylaws, regulations and policies to identify opportunities for water quality protection particularly related to nutrients and Santuit Pond as well as to enhance climate resilience. During the presentation, Ms. Moss emphasized the need for internal and external solutions to address the sources of nutrients in the pond.
Reducing the horsepower on the pond Ms. Moss said would reduce the potential of resuspension of the top layer of sediment, which is where pond studies have demonstrated roughly 80 percent of phosphorus contamination is located.
“There are similar restrictions and protections here on the Cape. I think there are about 10 communities that have horsepower restrictions,” Ms. Moss said.
Ms. Moss also cited additional studies that have demonstrated a mixing depth associated with motorized boats. With a higher horsepower comes a deeper mixing depth, risking the continued redistribution of sediment through motorized boat use. This is also especially problematic for shallow ponds like Santuit, which has a maximum depth of almost 11 feet, she said.
“A 10-horsepower motor typically has a mixing depth of about six feet, so in a very shallow pond, the concern becomes how are we mixing that water column, how are we resuspending that bottom sediment and what is the potential impact for phosphorus release? So thinking about again how are we going to use all the tools in the toolbox to limit both internal and external sources, this is one possibility,” Ms. Moss said.
Taking questions from the select board, members John C. Cotton and Thomas F. O’Hara said they had yet to hear a significant plan to clean up the water in the pond. Mr. O’Hara, among others, cited septic systems as the main cause of contamination and asked the town to address those issues first.
In response, Ms. Moss said the horsepower restriction is just one tool in the toolbox to address the overall issue.
“The issues that Santuit is having did not happen overnight; they are not going to go away overnight. It is going to take multiple of those tools in the toolkit; this is one,” she said. “Any water quality issue never gets solved immediately. It takes decades of working on this problem because it took decades to get you here.”
Ms. Fisher said it is well-known that a multitude of issues are affecting the pond’s water quality. The horsepower restriction is just one way to help solve the problem, she said.
Addressing comments about septic systems, Ms. Fisher said a survey of a 300-foot buffer of all units in that area was completed and all are in the process to come under current Title 5 compliance.
“This is a step we can take now to reduce the redispersion of the sediments. That is why we are here tonight, to discuss that issue,” she said.
Chairman David W. Weeden asked about the feasibility of an alum treatment and how boating would affect that. Ms. Fisher said a restriction on horsepower would be required to complete the treatment without disrupting the top layer of sediment. In lakes and ponds alum is used to reduce the amount of phosphorus in the water.
“You want to make sure you are not redistributing the bottom, the alum, that is working to suppress those nutrients at the bottom,” she said.
During public comment, Allen M. Waxman, a resident of Santuit Pond Way and founder of two pond alliances and coalitions in town, said there were a number of area residents and members of pond coalitions who are in favor of the horsepower ban.
Other town members sought out other solutions beyond restricting horsepower to address the issues. Those in opposition felt it was an easy infringement on residents’ rights over a well-calculated tactic to address the ponds issues directly. The primary solution referenced was installing updated septic systems at homes around the pond.
Those who said the restriction would devalue properties were opposed by comments on a recent New York Tims article titled “A Toxic Stew on Cape Cod: Human Waste and Warming Water,” which highlighted the poor quality of Mashpee’s water bodies, particularly in Santuit Pond. Residents cited this as a reason for property devaluation as well.
Nathan Adams of Edgewater Road said he has not been shown evidence of how boats turn up sediment based on the scientific studies presented by Fuss & O’Neill. Mr. Adams said he is heavily invested in the pond and will do whatever it takes, including installing a sewer, to address the underlying issues of restricting horsepower to improve quality.
“We could work together on the real solutions, but I feel this is just a Band-Aid, a feel-good thing. It is not a tool in the toolbox. Instead of working with us [boaters], we are going to be turned into the scapegoats,” he said.
Conservation Agent Andrew R. McManus, who is also a Mashpee resident, also spoke during public comment, touching on the invasive milfoil and bladderwort species that have taken over sections of the pond. Milfoil, if cut up, can disperse in the water column and quickly reseed, he said.
“I am in favor of this restriction. It is not a ban, and I guess my biggest question for the board to consider is how much is this adversely impacting the ability to fish the pond by restricting horsepower. There is no restriction on fishing. There is just a restriction on horsepower,” he said.
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