Tisbury board of health will present nitrogen regs at public hearing

The revamped proposal would require Tisbury homeowners to install and maintain costly, advanced septic systems.

The Tisbury board of health unanimously approved their nitrogen regulations for the Lagoon Pond and Lake Tashmoo watersheds, requiring property owners to install enhanced denitrification systems. Lake Tashmoo, shown here. — Nelson Sigelman

The Tisbury board of health, rebuffed when it proposed imposing mitigation fees to reduce nitrogen loading in the Lake Tashmoo and Lagoon Pond watersheds, will return with a revamped set of draft regulations built around the newest technology to remove nitrogen from wastewater.

The board of health draft regulation would require property owners in the Lake Tashmoo and Lagoon Pond watersheds who meet one of four specific triggers to install advanced septic systems to reduce nitrogen that could cost as much as $22,000 to install and up to $2,000 annually to maintain, based on industry expert estimates.

The board of health will hold a public hearing on the draft of nitrogen regulations Tuesday, Sept. 13, at 4:30 pm in the Emergency Services Facility. The Tisbury selectmen meet the same day, one hour later, at 5:30 pm, in the town hall.

Health and safety

The introduction to the regulations state, “The Town of Tisbury’s population has grown to the point where the wastewater treatment infrastructure in place lacks the capacity and/or capability to remove sufficient nitrogen to assure that Tisbury’s ponds and other water resources meet applicable water quality standards as well as provide for the safety of those using those resources.

“It is now established that excess amounts of nitrogen, in the form of oxides, have the potential to damage human health, particularly in infants, young children, pregnant women, and some people with compromised immune systems who consume nitrates in excess of established Safe Drinking Water Standards.”

The board of health also invokes the Massachusetts Estuaries Project reports for Lake Tashmoo and Lagoon Pond, “which concluded that 6,435 (32 percent) and 13,016 (35 percent) pounds, respectively, of the current nitrogen load entering these water bodies annually must be removed in order for Lake Tashmoo and Lagoon Pond to satisfy the nitrogen standards in the federal Clean Water Act and remain sustainable water resources.” The draft said that according to the reports, “nitrogen from human wastewater is considered to be controllable locally and … constitutes 80 percent and 76 percent of the overall controllable nutrient loading for Lake Tashmoo and Lagoon Pond, respectively.” 

Essentially, advanced septic systems are supposed to remove a larger amount of nitrogen. The new regulations require “on-site denitrification wastewater disposal technology that is intended to meet a nitrogen groundwater discharge standard of not more than 19 milligrams per liter.

One of four triggers would require a property owner to install the new technology: a new wastewater treatment system is required to serve a property (i.e., new construction); a property’s existing wastewater treatment system fails and replacement is necessary, as determined by the board of health; a property’s existing wastewater treatment system capacity is insufficient to handle any proposed additional development, as determined by the board of health; and a property is transferred to another owner and, based on a septic-system inspection, the board of health determines that a new system or system upgrade is necessary.

He’s not buying it

West Tisbury civil engineer Kent Healy, a critic of the first set of proposed regulation, questions whether nitrogen from septic systems is really a problem. The board of health invited Mr. Healy to consult with them in drafting the second set of regulations; however, Mr. Healy told The Times he is not sure they are listening to what he has said.

“The board of health really should pay attention to health problems, I think. Drugs, alcohol, HIV, Lyme disease, it goes on and on,” Mr. Healy said. “People don’t get sick from septic systems. They just don’t. It doesn’t happen.”

The taciturn Mr. Healy is well respected around the Island. He has been designing and building septic systems for 50 years, and previously taught in the University of Connecticut civil engineering department. Mr. Healey has pressed the board for more data to back up their findings. 

“I call it a symptomless disease with no known cause,” Mr. Healy said of the nitrogen debate. “They haven’t established a problem.”

Mr. Healy said the notion that nitrogen threatens public health is grounded in a rather antiquated view from the early 1900s in the United States, when children living on farms were getting sick from the drinking water. The illness was referred to as methemoglobinemia or cyanosis, or colloquially as “blue baby syndrome,” because it made babies turn blue from an inability to absorb oxygen.

Mr. Healy said that it was 100 parts per million of nitrogen in the water that would cause cyanosis in infants. He explained that the solution — in the 1900s — was to set the drinking water standard number at 10 parts per million, a dramatically lower concentration, as a safety precaution to avoid illnesses like blue baby syndrome.

He pointed to the first page of the board’s new draft regulations, which references Safe Drinking Water Standards. “They’re still talking about this blue baby syndrome,” Mr. Healy said. “Even back in the early 1900s, they only had five or six cases a year in the United States.”

Mr. Healy said the board of health claims that 55 pounds of nitrogen a day goes into Lake Tashmoo; Mr. Healy said that no matter what he does, he can’t calculate more than 12 pounds of nitrogen a day.

“If nitrogen is a problem in the estuaries, then make sure you know where it’s coming from, and make sure you know what you’re going to do about it,” Mr. Healy said. “I don’t think public agencies should advocate spending money without some notion that it’s going to do us good.”

‘Not cheap’

Mike McGrath is a principal engineer at Holmes and McGrath Inc., a land-surveying and civil engineering company based in Falmouth. Their sister company is Innovative RUCK Systems, which manufactures alternative septic systems and is one of the approved systems on the board’s list.

For a year-round home, Mr. McGrath said, the site needs to be maintained about four times a year. For a seasonal home, it has to be visited three times in a season — the system has to be turned on, checked once, and then turned off.

“They’re not cheap,” Mr. McGrath said. “It’s hard to get rid of nitrogen.”

Another approved system is the Amphidrome. Dennis Geran of F.R. Mahony & Associates, based in Weymouth, said that for a single-family home, the system costs $7,500, and the price does not include the cost of the tanks or the installation. Mr. Geran estimated that the total cost would be about $15,000. That price, he said, doesn’t include the cost of a leaching field, which could add about $6,000 to $8,000, according to one estimate.

He said that most towns require that the systems be maintained between one and four times a year, estimating it would cost a homeowner roughly $450 to $500 for a single visit, which wouldn’t include the price of parts if they were needed in the system’s maintenance.


Concerns over excess nitrogen in Martha’s Vineyard’s ponds are grounded in the findings of the Massachusetts Estuaries Project (MEP). Based on computer-generated models, the report said that the ponds and estuaries in southeastern Massachusetts had been overcome by nitrogen and that the source was septic systems.

Professor Brian Howes, from the University of Massachusetts Dartmouth School for Marine Science and Technology (SMAST), has been researching estuaries for the past 30 years and spearheaded the MEP.

In a phone conversation with The Times, Mr. Howes said that the MEP was set up originally as a joint project with the U.S. Environmental Protection Agency (EPA), the Massachusetts Department of Environmental Protection (DEP), the University of Massachusetts Dartmouth, and different scientific colleagues. The MEP was funded primarily by the DEP, by roughly 45 percent. The rest was funded mostly by the EPA, UMass, and Barnstable County. It was the university’s responsibility to “go out and beat the bushes,” he said.

Mr. Howes described the project as “site-specific,” an analysis of 89 estuaries in southeastern Massachusetts that ranged from Mount Hope Bay to Plymouth and south to Cape Cod, Martha’s Vineyard, and Nantucket. The project, he said, aimed to determine safe levels of nitrogen while being protective of the environment. Mr. Howes said that they knew that the ecosystems needed some nitrogen; the question was, How much? How much did it need to be lowered? Those were the questions that the MEP sought to answer for restoration and protection of the estuaries. 

The project’s findings, Mr. Howes said, was that “the biggest source [of nitrogen] by far is wastewater.”

Testing the water

Mr. Howes said that testing the groundwater is not an effective way to determine the concentration of nitrogen, and that it has been “abandoned as an approach” due to inaccuracy and variables that complicate groundwater testing like varying land use and groundwater plumes.

“So the bottom line is the physics of groundwater movement. Nitrogen is not homogenous with groundwater. It’s very patchy, and when things are patchy, you have to take a lot of measurements.”

The MEP focused on what Mr. Howes called a “parcel-by-parcel analysis,” where researchers predicted the nitrogen distribution by looking at individual properties in each watershed and projected their water use and wastewater flow. He said they also found loading rates through a property’s lawn size.

“People should take a lot of confidence that this has been reviewed by the top people in the U.S.,” Mr. Howes said of the data presented and the multiagency review process.

Asked about the high cost of advanced denitrification systems, Mr. Howes said “the mission was to find new ways, new approaches, and new tools so that the mitigation method, which works, but it’s expensive, that it [the cost] would be minimized as much as possible.” 

Mr. Howes said that although some advanced systems look promising and “are coming along,” it doesn’t necessarily mean people should “run out and buy them.”

“I don’t know if there’s any community that is mandating them [advanced denitrification systems] as their sole system of nitrogen removal,” Mr. Howes said.

Calling for a “hybrid approach,” Mr. Howes said there were a number of solutions that, when combined, could work best for a given community while keeping the cost for homeowners down, like permeable reactive barriers, lawn fertilizer bylaws, wetland restoration or protection, and even shellfish production.

“We don’t just jump to one,” Mr. Howes said. “The reason for the hybrid approach is first to keep the cost down.”