Earle Barnhart and Hilde Maingay, whose nonprofit organization, The Green Center, is the successor to the New Alchemy Institute, is concerned that the “big pipe” solutions being discussed by a town committee are inefficient and expensive ways to reduce nitrogen loading to Falmouth’s coastal ponds.

The husband and wife team have compiled nine options that residents can undertake to eliminate nutrients from wastewater. They suggest that a feasibility study be conducted to see how much nitrogen would be eliminated, and at what cost, under each scenario.
“With a great variety of options available right now, home-based systems can be designed to respond to the specific needs of each individual residence or area of concern, require very little design time or costs, can be installed immediately, and have a great degree of inherent flexibility,” wrote the couple in a five-page handout they e-mailed yesterday to Town Meeting members.

• Residents can reduce their nitrogen contribution by using low-nitrogen and phosphorus-free soaps, cleaners, and detergents.
• Eliminating the use of chemical fertilizers and garbage disposals would also reduce the amount of nitrogen in the waste stream.
• Noting that car exhaust and road runoff is a significant source of nitrogen deposition to estuaries, residents can reduce their mileage or switch to a hybrid vehicle.
• On a townwide level,  Falmouth could collect food waste separately from garbage to make compost, thereby using the nitrogen and other nutrients in food as fertilizer.

For those who think it is too hard to incorporate these tips into their lives, Hilde and Earle are living examples. They own a composting toilet, which they say is inexpensive and easy to maintain. As professional landscapers, they use compost and organic fertilizers, and at home they feed food scraps to their chickens and use plant-based cleaning products.

The Bigger Picture

A large-scale oyster aquaculture project could clean up Falmouth's coastal ponds, create jobs and increase local food production

Drawing from the expertise of farmer and aquaculture researcher Ronald J. Smolowitz and Woods Hole resident Ronald D. Zweig, an aquaculture specialist for the World Bank, Hilde and Earle recommend using oysters as  natural filters for nitrogen, and widening the inlets of coastal ponds to increase tidal exchange.

A centralized sewer system, while effective at removing nitrogen, comes with a high cost and long lead time to design, construct, and operate, the authors wrote. In terms of water and energy consumption, it is also inefficient.

Purifying water for drinking, then polluting it with human waste, and cleaning it again is inefficient. Transporting large volumes of water from a supply source to a pumping station, to homes, to a sewage treatment plant, and finally to a discharge area is inefficient.

A variety of sources contribute nitrogen to groundwater, but a majority leaches from underground septic tanks

If wastewater treatment was viewed as a “closed-loop” system, the nutrients it contains could be recovered, treated, and used as organic fertilizer, say Hilde and Earle.

Composting toilets

A composting toilet: the only difference is the pipe

The waterless composting toilet is one of the options Hilde and Earle propose for further study.

It looks like a regular toilet, without a pipe. A fan ensures that odors are released through a pipe in the roof, requiring as much energy as a 60-watt bulb.

“The lower the technology, the less likely it is to fail,” said Hilde.

“That’s right,” said Earle. “Gravity never breaks down.”

The holding tank of a Clivus composting toilet

Collection requires a basement storage tank for solid waste, which is typically removed four times a year.

Though current health codes require off-site disposal, the sterilized waste could be used as commercial fertilizer or at home for non-food crops.

Urine-diverting & packaging toilets

Another option is a urine-diverting toilet with an optional waterless urinal.

With this technology, naturally sterile urine is collected in a basement storage unit, where it can be collected for fertilizer, or be processed in a septic or sewer system.

Hilde and Earle also propose a few options for using waterless packaging toilets and urinals. These options would require a commercial contractor to collect waste “packets,” which can be sterilized and composted to create fertilizer.

The British-designed "Loowatt" toilet was originally built with the waste disposal needs of developing countries in mind.

Alternatively, the packets may be incinerated, either at home or off-site—not unlike throwing out diapers, Hilde noted.

The waste packets can be used in a bio-gas digester, which produces methane gas while killing off pathogens.

The result is a potent fertilizer suitable for edible crops.

Alternative Cost-Benefits

Based on each of these options, traditional toilets do not necessarily have to be replaced. With each of these options, a home would have to keep its septic tank in order to process the “gray water” from the kitchen and laundry.

They suggest studying the costs and benefits of maintaining the current septic treatment at most homes, with the addition of aquaculture and the widening of coastal inlets.

Jobs, food, and fertilizers could be created from this endeavor, whereby not only the oysters, but also the wastes and the macro-algae that grows around them could be harvested as fertilizer.

“Why don’t we try it  and see how much [nitrogen] is removed by reducing our inputs, then we can go to the next step?” asked Earle.

An Ecological Treatment System

This schematic by Ron Zweig proposes a centralized treatment system based on John Todd's ecological design principles

Another option is to install a centralized treatment plant with ecological principles in mind.

In this design, wastewater is treated with a biogas digester that releases methane, which can be used as energy to run the system– or cook food or heat a home.

The primary-treated water is then filtered through aquatic plants and wetlands, where the nitrates decompose and are consumed by beneficial bacteria. These aquatic plants may be composted, and the treated water can be reused to irrigate trees and non-edible plants.

Recognizing that not all residents would be comfortable installing an alternative toilet in their homes, Hilde noted that it will take serious study, modeling, and public outreach for people to understand that the systems are safe and just as effective as traditional toilets.

“We assume that we’re incapable of handling our own waste. That’s a really bad assumption,” she said.

While we have to take the issue of nitrogen (and other nutrient) pollution seriously, we also need to examine the unintended consequences of sewering the entire coast. What impact will pumping and discharging millions of gallons of water have on the aquifer, not to mention, on CO2 levels in the atmosphere? What are some ways we as residents can reduce our nitrogen output on an individual scale?

Last week, I went to an interesting talk by USGS hydrologist Denis LeBlanc, who described the role of the Sagamore Lens in supplying the Upper Cape’s fresh water.

I’d been skeptical that pumping wastewater all over town to a centralized location for treatment, and possibly discharging it through an outfall pipe off of Nobska Point, would not impact our groundwater levels. But according to Mr. LeBlanc, even at a rate of 3-5 million gallons a day, that kind of discharge is peanuts, compared to the volume of the resource.

Whether or not an outfall pipe is a good idea is still up for debate. Experts, including Mark Rasmussen of the Coalition for Buzzards Bay, say that the strong currents at Nobska would create enough “flushing” to dilute the wastewater (treated to tertiary standards) so that it would not impact marine life or public health. But still– in a world where water is considered to be “blue gold,” is it responsible to discharge it into the ocean? Even if we can’t drink it, couldn’t we reuse it?

Eco-logical design

At a conference at WBNERR last spring, environmental designers presented some very intriguing ideas on how to turn wastewater into a resource.

These weren’t pie-in-the-sky dreamers, or con artists trying to sell you back your own pee as drinking water. These were businessmen who had built their reputation on some common-sense notions: why should you flush your toilet or water your lawn with drinking water? Why should we still be using the 2,000 year-old Roman aquaduct system to sewer our communities?

To the speakers, the saying, “the solution to pollution is dilution” is simply not the case. Instead, they suggested a closed-loop system, in which gray water is continually re-used within a building, with minimal loss.

Patrick Lucey, president of Aqua-Tex, a water management consultancy firm in British Columbia, showed slides of a LEED-certified complex he designed on a working waterfront section of Victoria.

The system is designed to reuse the gray water from sinks and showers and collect rainwater from the roof. The “wastewater” is then treated in a centralized sewage treatment that one might mistake for a luscious garden.

Wastewater from toilets is treated to a standard that could be safely used for doing laundry or watering non-edible plants, Mr. Lucey said.

The system could go several steps further by including a bio-refinery to utilize solid waste and garbage as bio-fuels for heating; co-generation technology to create electricity; and removing nitrogen and phosphorus from effluent for use as fertilizer.

Engineered ecology

Closer to home, projects at the Wrentham Mall and Gilette Stadium in Foxboro (home of the Patriots) have achieved 75-95 % water reuse by employing ecological design principles. If every large public building could do that, we’d go a long way in reducing the 1,200 gallons that Americans consume on average per day (through showers, toilets, laundry, dishwashers, and food production).

Even closer to home, a Woods Hole-based firm, Todd Ecological Design, has set the standard for using nature’s principles to deal with wastewater. In municipalities, golf courses, factories, and campuses worldwide, the EcoMachines designed by Dr. John Todd, one the founders of New Alchemy Institute, use micr0-bacteria, plants, and invertebrates to effectively digest the harmful components of wastewater. Designs often include tropical greenhouse gardens that help make this process possible, even in cold climates.

However, as Falmouth’s wastewater superintendent pointed out after meeting with Jon Todd (Dr. Todd’s son), the EcoMachine cannot get the nitrogen content low enough to meet the limits set by DEP.  In order to prevent further estuarine degradation, some parts of Falmouth need to reduce nitrogen to 3 milligrams per liter– the equivalent of 1.5 drops in a bathtub– which will likely require the services of a modern wastewater treatment plant.

You are what you eat

But there are still possibilities for concerned residents to reduce their nitrogen output. Eating less meat is one idea proposed by Dr. Eric Davidson of the Woods Hole Research Center. While this might be a startling idea to some, consider the fact that the amino acids in animal protein are made up of nitrogen, and to a large extent, are passed out of the body.

If we’re eating meat three times a day, we have a bigger nitrogen footprint. For those who don’t want to be vegetarian, thinking about portion sizes, or whether they’re eating beef, or less nitrogen-demanding pork, chicken, or fish, makes a difference.

-Eric Davidson, sr. scientist, Woods Hole Research Center

Another reason to cut down meat consumption takes a global view: in places like Brazil, rainforest is being cleared at alarming rates in order to create cattle pasture. Cutting forests reduces the earth’s ability to process CO2, and also releases extra greenhouse gases (like NO2) into the atmosphere. So, if not just for the local environment, eating meat (or chosing not to) from these places can make a big difference in terms of climate change.

What else can you do?

Finally, debate over sewering sometimes leaves out small, yet significant components of our community’s total nitrogen output: stormwater and fertilizers. If we could eliminate chemical-based fertilizers from our lawns and gardens, Falmouth could reduce nitrogen in estuaries by at least 10 %. (For info on how to reduce your lawn’s N-footprint, see the Falmouth Friendly Lawns brochure.)

And if the town could install more catch basins to deal with stormwater, less nitrogen (and other pollutants) would flow directly from the roads to sensitive ecosystems. One fun fact to remember as you’re driving in a rainstorm: that first flush of rainwater from the road brings NOx emissions from your tailpipe directly to the nearest water source.

So, a few nuances to consider as we head down the road to figuring out how to create a wastewater design to meet demands of the next century. And we didn’t even get into I/A systems, such as Nitrex or RUCK.

Special thanks to David Dow for putting his two cents in on these issues. As always, we welcome comments, questions, and perspectives.