The Latest Poop on Falmouth Nitrogen


President and Senior Scientist Dr. Eric A. Davidson

Falmouth Massachusetts is one of the few communities in the country and in the world where citizens get together in their living rooms and patios to talk about nitrogen.  I cut my scientist’s teeth on nitrogen studies and, throughout my career, I have studied how humans have altered the nitrogen cycle, with both good and bad outcomes.  So it made my day to be invited to a gathering of nonscientists who wanted to talk about nitrogen.  The impetus in our community is the well-justified fear that our property taxes are going to increase substantially because our town will have to build a sewer system to treat our wastes.  Nitrogen and phosphorus are leaching out of our septic systems and into the coastal bays and estuaries, where these nutrients promote unwanted growth of algae to the detriment of shellfish habitat and water quality.  Dead algae washes up onto shore and stinks as it decomposes, which is neither good for our own enjoyment living at the coast nor good for the tourist industry upon which our local economy depends.  Not surprisingly, our citizens are educating themselves about nitrogen.

The hosts for this meeting, Hilde Maingay and Earle Barnhart, provide a shining example, not only for organizing a meeting like this, but also for demonstrating a viable alternative to town-wide sewering.  Their lovely home has a perfectly normal looking bathroom, but the toilet is a little unusual when you look under the lid.  Their composting toilet is modern, odorless, trouble-free, and safe.  It turns a waste problem into a resource.  Of course, it will take a lot of education and outreach to get a large number of people comfortable with anything but the standard flusher that we’ve grown up with.  County health agent, George Heufelder, noted at the meeting that there have been no local takers for a no-interest loan program for homeowners to replace failing septic systems with composting toilets.  It is not the technology that keeps us from moving in this direction, he noted, but rather human attitudes, including inertia, skepticism, and fear of the unknown.  On the other hand, fear of increasing taxes is also strong, so minds may be opening about cheaper alternatives to traditional sewering.

Even the septic systems that have not failed and that are in compliance with the Massachusetts Title V code are only good for protecting us from pathogens, because they do little to reduce nutrient pollution of groundwater and estuaries.  We need technologies that people are willing to use and that will lead us away from septic systems towards alternatives that eliminate or reduce nutrient pollution of groundwater, rivers, and estuaries.

The Woods Hole Research Center currently hosts the North American Center for the International Nitrogen Initiative (, and we have been leading scientific assessments of the impacts and potential solutions of too much nitrogen in the environment.  In addition to our science, we are also acting locally, by installing and managing our own denitrification system.  During the last year, this system converted 75% of the nitrogen in our waste water into harmless dinitrogen gas.  This is yet another tool in the local tool box for how to keep nitrogen out of the estuaries.

My guess is that Falmouth and many other communities on Cape Cod and elsewhere, where septic systems are often more common than municipal sewage treatment, will seek out a combination of solutions to this growing problem.  Some neighborhoods will be sewered and some will find alternative solutions such as small-scale denitrification systems or composting toilets.  One thing is for sure – this problem won’t go away until we find a solution, which will require science, technology, money, and probably some changes in human behavior.  Whether or not you want to know about nitrogen, is it a regular occurrence in daily life.