In the battle to prevent further pollution of the Vineyard’s ponds, Island officials are eying a new way of disposing human waste: cutting-edge toilets.

With a majority of the water contamination on the Island tied to septic systems, the Chilmark conservation commission is taking a look at eco-toilets, specifically urine-diverting toilets, as a way to cut down on nitrogen levels in Chilmark Pond. 

“Eighty per cent of the nitrogen pollution that we experience is because of on-site wastewater systems, and the majority of the nutrients entering those on-site systems are entering in the form of urine,” said Brian Horsley, the project assistant at the Massachusetts Alternative Septic System Test Center, in an interview last week. 

Urine-diverting toilets show promise, but have drawbacks.

Ray Ewing

Urine-diverting toilets show promise, but have drawbacks.

Ray Ewing

The commission invited Mr. Horsley to the Vineyard last month for a forum in conjunction with the Abel’s Hill Association. There, Mr. Horsley highlighted efforts around installing eco-toilets in Falmouth which stop the nitrogen source from ever entering the pond, while also creating a potential new fertilizing source. 

Eco-toilets come in various forms. Composting toilets don’t use water and treat human waste by composting it. Micro-flush toilets use less water, which leads to less water contamination further down the line. Urine-diverting toilets divide urine from solid waste in the toilet bowl, and the urine can then be processed separately to be used as a fertilizer product before it even goes into the septic system. 

The Island’s interest in these types of toilets is growing, according to Chilmark conservation commission chair Sarah Khedouri, especially for those who live by Chilmark Pond, which has seen high levels of nitrogen for more than a decade. 

“We’re starting to see these algae blooms appearing earlier and earlier in the summer and lasting longer and longer,” she said. 

The toilets also are a cost-effective way to combat the problem, according to Mr. Horsley. While innovative/alternate (I/A) septic systems cost around $50,000 per parcel, one urine-diverting toilet costs around $10,000. 

“We are advocates for those [septic] systems, but we’re also aware that they’re very expensive. That’s also going to drive up the cost of living,” he said. “It’s crazy to me that we aren’t more willing to look at alternatives, given the expense and the severity of water pollution that we’re experiencing.”

The Alternative Septic System Test Center is a research center through Barnstable County where scientists conduct studies, research and testing in wastewater. The center allows for research and development, product testing and outreach. 

Mr. Horsley himself has been passionate about the potential of eco-toilets as one part of a multi-pronged approach to combat the high nitrogen levels. He has been working in Falmouth for almost three years to incorporate urine-diverting toilets into the town’s watershed plan. Right now, he is eyeing 25 toilet systems across four watersheds. 

Urine-diverting toilets typically have a collection basin in the bowl that catches the urine and drains it to a storage tank. A service company can then collect the stored waste to dispose of it or convert it to fertilizer. 

There is a hitch to the new idea, though. Right now, the state doesn’t have regulations that allow the new toilets to be installed. While composting toilets are in the state’s Title 5 code, which addresses septic systems, urine-diversion is nowhere to be found.  

“The Department of Environmental Protection (DEP) is even struggling with just defining what it is in terms of their regulations. Is it wastewater? Is it septage? Is it biosolid?” Mr. Horsley said. “They’re trying to basically find a home for urine diversion systems to be approved within their existing regulations.” 

To be truly effective at reducing nitrogen, the toilets also have to be used at scale, and the maintenance can be off-putting for some homeowners.

Chilmark Pond has had some of the worst water quality on the Vineyard.

Ray Ewing

Chilmark Pond has had some of the worst water quality on the Vineyard.

Ray Ewing

Mr. Horsley has been working with the state to develop the necessary guidelines and permits needed. Ideally, he would be able to begin the project in Falmouth early 2026. 

Cleaning up the Vineyard’s ponds have been a priority for years, but diverting the source has been hard, especially for the up-Island towns that are too spread out for sewers. 

Earlier this year, the Chilmark Pond Foundation put a sonic wave-emitting buoy to prevent cyanobacteria blooms, the bright blue-green tell-tale signs of degradation, from forming. 

In 2023, Tisbury changed the town's wastewater regulations to require properties in the Lagoon Pond and Lake Tashmoo watersheds to install I/A septic systems effective January 2024.  

These measures were taken after the state DEP declared towns on Cape Cod must create and implement plans to reduce nitrogen pollution and improve water quality. 

While those regulations didn’t include Martha’s Vineyard, Ms. Khedouri said they’re on the way. 

“The scientific reports say our estuaries, our great ponds are in real trouble as far as environmental pollution,” she said. “There’s a certain awareness at the town level that there might be state regulations coming down, and there’s a desire to be ready and do something about it.” 

Ms. Khedouri is optimistic about how these toilets could be used as another source of helping the health of the Island’s ponds and water systems. 

“What’s fascinating about this approach is [that] we could just stop it all the source,” she said.