Composting Toilets Eliminate Flush of Good Water

By FRANK CARINI/ecoRI News staff

It’s not quite like going to the bathroom outside, but it’s close.

Composting toilets aren’t the equivalent of an outhouse in your living room and they don’t look that much different than your current commode, but they do save water for drinking and showering.

The average single-family home in the United States uses nearly 70 gallons of water a day, and about 30 percent of that is flushed down the toilet, according to the American Water Works Association.

“People are beginning to question the use of potable water to flush away our wastes,” said Ben Goldberg, who has been selling and installing Phoenix composting toilet systems in private residences, businesses and public facilities across New England since the 1980s. “Treating human waste with conventional septic systems or sewage treatment plants is costly in energy and resources, and contributes to soil and water pollution. As the human population increases, dealing with our waste products becomes more of a challenge. The notion of converting human waste to a usable resource is not a new one.”

The Apeiron Institute for Environmental Living on Hammet Road in Coventry features a composting toilet.

“Composting toilets save an incredible amount of water. You don’t need flush good water literally down the toilet,” Goldberg said. “Asian, European and Latin cultures have been using these methods for centuries. One of the major hurdles to composting toilets in the U.S. is that regulations are geared toward the more conventional flush systems.”

Composting toilet systems — sometimes called biological toilets, dry toilets or waterless toilets — contain and control the composting of excrement and toilet paper. And, unlike a septic system, composting toilets rely on aerobic bacteria and fungi to break down wastes, just as they do in a yard-waste composter.

Systems range if price from less than $1,000 to $7,000 or more, according to Goldberg.

“They work like a compost pile — an indoor compost pile,” he said. “There’s an ecosystem of organisms that decompose the waste. Add some pine shavings after each use and you will have nicely balanced compost.”

Such systems, however, only treat black water — feces and urine — so a separate greywater system, either a septic tank or sewer hookup, is needed to handle dish washing, laundry and bathing. Greywater comprises 50 percent to 80 percent of residential wastewater.

Composting toilets also are difficult to retrofit and are more suitable for new construction. They come in many shapes and sizes depending upon the number of users. They can be homemade or manufactured.

The most important thing when selecting such a toilet, Goldberg said, is to choose a system that adequately meets your needs. Selecting a smaller unit for full time use for a family of 12 will keep you busy emptying under-treated waste, he said. But he noted that smaller systems are terrific for an individual or small family or for weekend or seasonal use.

Larger-storage composting toilets are good choices for continuous year-round use for families or at public facilities, Goldberg said.

A storage tank, where the actual composting takes place, sits in the basement and is usually made of fiberglass or plastic. Wastes are stored and composted within, sometimes for years, virtually eliminating the need for handling partially decomposed waste. Some use small amounts of electricity for venting, some styles use minimal amounts of water, and regular management of most composting toilet systems requires adding carbon-based bulking material such as pine shavings, straw or saw dust.

Most systems are designed to hold waste for 12 to 14 months, after which the composted material can be added to an existing compost pile outside or on flowerbeds, Goldberg said.

“Composting toilets don’t appeal to everyone,” he said. “Taboos still flourish within our culture that prohibit interacting with our waste. Keeping in mind that a century ago, it was considered taboo to go to the bathroom inside the house, we know that taboos can also be transient. (But) in our contemporary world, it’s crucial that we learn to practice conservation of resources and energy.”