In a much-watched pilot program, the Martha’s Vineyard Commission is nearly ready to begin installation of a permeable reactive barrier along the shore of the Lagoon Pond that aims to remove nitrogen and improve water quality in the pond.

The project dates to 2018, when the commission secured a $250,000 federal grant from the Environmental Protection Agency to restore water quality in coastal ponds. A study was launched with the University of Massachusetts at Dartmouth to determine the best location and method for the pilot.

“We’ve done a ton of work on this,” said Adam Turner, executive director of the commission, who announced the end of the two-year study at a recent meeting. “We’re going to put this [barrier] in over the next few months, and it’s really exciting.”

A first on the Island, the permeable reactive barrier will be installed on the front lawn of a private waterfront residence off Lagoon Pond Road in Vineyard Haven.

In a phone interview this week Sheri Caseau, water resource planner for the commission, described the project.

The system involves drilling down about 30 feet and installing pipes to inject waterfront wells in the area with a food-grade soybean oil. The oil binds to the surrounding soil and intercepts nitrogen in groundwater flowing toward the pond, allowing the nitrogen to be released into the atmosphere as a gas through a natural reactive process.

“It kind of puts a curtain down, and the [nitrogen-rich] groundwater has to flow through that curtain,” Ms. Caseau explained.

The pilot program aims to improve water quality in the pond. — Mark Alan Lovewell

Nearly all coastal ponds on the Vineyard are impaired by nitrogen, a nutrient found in wastewater, acid rain, fertilizers and runoff from agriculture, landfills and wildlife. The majority of nitrogen, about 76 per cent, comes from septic tanks, Ms. Caseau said. Carried in groundwater, nitrogen percolates through the soil until it ends up in coastal ponds and other saltwater estuaries.

Too much nitrogen in ponds can lead to algae blooms, clouding the water and causing anoxic conditions that are harmful to species like eelgrass and shellfish. When the algae dies, it washes up on shore or falls to the bottom of the pond, where it continues to smother marine life, Ms. Caseau said.

A 2015 study by the Massachusetts Estuaries Project concluded that 13,016 pounds, or 35 per cent of the nitrogen load entering the pond would have to be removed in order to comply with the federal Clean Water Act and restore the pond as productive habitat for marine life.

“Below this level, the pond can maintain itself. Eel grass can grow,” Ms. Caseau said. “Above this level, we have algae blooms . . . which cause fish kills, is not good for the shellfish, and certainly nobody wants to smell it when it dies.”

Because Tisbury and Oak Bluffs share stewardship of the pond, the towns split the necessary match for securing the grant. Ms. Caseau said the bulk of the federal grant still remains to fund the final hurdles of permitting and installation.

The goal is to have the barrier installed by the end of August, Ms. Caseau said. The commission has put out a request for proposals; bids were due back by July 22.

Ms. Caseau said the UMass study resulted in significant changes to the previously anticipated barrier model, which had been discussed for a number of years. The original plan called for digging a trench to be filled with wood chips, which would have carried out a similar reaction process with the nitrogen as the oil injection system.

She said the oil injection system will be about 200 feet long and less invasive. The 30-foot-deep tubes, spaced 15 feet apart, will have access caps flush to the ground. The wells will have to be replenished with soybean oil every five years.

“This system is more efficient, cheaper and doesn’t require excavation,” Ms. Caseau said.

Amelia Hambrecht volunteered the use of her property off Lagoon Pond Road for the project. “I believe in doing what we can to keep our waterways clean,” Ms. Hambrecht said.

Ms. Caseau said the barrier is one of a few methods Island officials have taken up to combat high nitrogen levels. In 2016, the Tisbury board of health adopted a bylaw requiring denitrifying septic systems for all new construction projects. Prior to that, the commission spearheaded a campaign to limit the amount of fertilizer used in landscaping, through education and regulations.

Ms. Caseau said the permeable reactive barrier will not be a single solution to the problem. “It’s not going to be a fix all. It just takes a little piece out of the problem,” she said, adding that the commission is still aiming to control storm water runoff from Five Corners, reduce the amount of fertilizer used on properties abutting coastal ponds and examine the west arm and head of the Lagoon, which she said are showing signs of high nitrogen levels.

Along with Lagoon Pond, she said there are also high levels of nitrogen in Tisbury Great Pond and Edgartown Great Pond. She said the Lagoon was selected by the commission because it is productive for shellfishing and topped the list of urgent needs for nitrogen mitigation. But she said if it is successful, the permeable reactive barrier could be a model for other coastal ponds.

“Our hope is that . . . as soon as we have it in place, it will start working and we will be seeing the algae fade,” Ms. Caseau said. “Other ponds need to do this. If [the barrier] works, hopefully we can expand it into those other areas.”