Farewell to "Flush and Forget"
by Lester Brown, Washington, D.C on 10.29.07
The toilet. What a remarkably civilized invention. But it is flawed, as I discuss in Plan B 2.0 (free online).
The current engineering concept for dealing with human waste is to use vast quantities of water to wash it away, preferably into a sewer system where it will be treated before being discharged into the local river. This “flush and forget” system is expensive and water-intensive, disrupts the nutrient cycle, and is a major source of disease in developing countries.
Water-based sewage systems take nutrients originating in the soil and typically dump them into rivers, lakes, or the sea. Not only are the nutrients lost from agriculture, but the nutrient overload has led to the death of many rivers and to the formation of some 200 dead zones in ocean coastal regions.
Sunita Narain of the Centre for Science and Environment in India argues convincingly that a water-based disposal system with sewage treatment facilities is neither environmentally nor economically viable for India. She notes that an Indian family of five, producing 250 liters of excrement in a year and using a water flush toilet, requires 150,000 liters of water to wash away its wastes.
As currently designed, India’s sewer system is actually a pathogen-dispersal system. It takes a small quantity of contaminated material and uses it to make vast quantities of water unfit for human use, often simply discharging it into nearby rivers or streams.
India’s government, like that of many other developing countries, is hopelessly chasing the goal of universal water-based sewage systems and sewage treatment facilities—unable to close the huge gap between services needed and provided, but unwilling to admit that it is not an economically viable option.
This dispersal of pathogens is a huge public health challenge. Worldwide, poor sanitation and personal hygiene claim 2.7 million lives per year, second only to the 5.9 million claimed by hunger and malnutrition.
Fortunately, there is a low-cost alternative: the composting toilet. This is a simple, waterless, odorless toilet linked to a small compost facility. Table waste can also be incorporated into the composter. The dry composting converts human fecal material into a soil-like humus, which is essentially odorless and is scarcely 10 percent of the original volume. These compost facilities need to be emptied every year or so, depending on design and size. Vendors periodically collect the humus and can market it as a soil supplement.
This technology reduces residential water use, thus cutting water bills and lowering the energy needed to pump and purify water. As a bonus, it also reduces garbage flow if table waste is incorporated, eliminates the sewage water disposal problem, and restores the nutrient cycle.
The U.S. Environmental Protection Agency now lists several brands of dry toilets approved for use. Pioneered in Sweden, these toilets work well under widely varying conditions, including Swedish apartment buildings, U.S. private residences, and Chinese villages.
Two household appliances, toilets and showers, together account for over half of indoor water use. Whereas traditional flush toilets used 6 gallons (or 22.7 liters) per flush, the legal U.S. maximum for new toilets is 1.6 gallons (6 liters). An Australian-produced toilet with a dual-flush two-button technology uses only 1 gallon for a liquid waste flush and 1.6 gallons for a solid waste flush. Shifting from a showerhead flowing at 5 gallons per minute to a 2.5 gallons-per-minute model cuts water use nearly in half. With washing machines, a horizontal axis design developed in Europe uses 40 percent less than the traditional top-loading models. In addition, this European model now being marketed internationally also uses less energy.
For cities, the most effective single step to raise water productivity is to adopt a comprehensive water treatment/recycling system, reusing the same water continuously. With this system, only a small percentage of water is lost to evaporation each time it cycles through. Given the technologies that are available today, it is quite possible to recycle urban water supplies comprehensively, largely removing cities as a claimant on scarce water resources.
The existing water-based waste disposal economy is not viable. There are too many households, factories, and feedlots to simply try and wash waste away on our crowded planet. To do so is ecologically mindless and outdated—an approach that belongs to an age when there were many fewer people and far less economic activity.
For more on this subject, see Chapter 11, “Designing Sustainable Cities,” in Plan B 2.0, available for free downloading.
See also: ::Should Houses Have Composting Toilets?, ::Composting toilets: Ready for Prime Time?, ::The Governor General on Composting Toilets
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Do you have a list of the dry toilets approved by the EPA and/or links to their websites, or just additional info about them?
I'm redoing part of my house (which includes a bathroom) and I definitely want to look into these toilets before blindly putting another wasteful appliance into my home.
Thank you.
Clivus Multrum is the iconic composting toilet, but there are about half a dozen manufacturers.
The simple adage 'if it's yellow, it's mellow' can lead to enormous water savings without any new, expensive equipment or arguments with your local plumbing inspector and health department.
If I understand correctly, Clivus' are aerobically digesting types and will not kill off all pathogens, while bio-digesting toilets are anaeorbically based and will leave a sterile compost.
Bio-digesters also will produce methane which can be burned for fuel. Methane is a more potent greenhouse gas than CO2, so burning this byproduct to supplant other fuels carries multiple benefits.
If your needs match up, a waterless urinal is also an excellent way to save water without inconvenience. Likely not possible in every home, but in an office, church or restaurant the savings are tremendous.
There are also 'package unit' residentially sized waste treatment systems that do an excellent job of treating wastes. They are often cost competitive with septic fields, particularly where additional engineering for raised septic beds or other techniques must be used to contend with poor soil conditions.
Flush plumbing has a history of over 3,000 years. Improvements are happening more rapidly, but the real breakthroughs are likely in non-flush, non-centralized approaches.
Thank you Ross. Your attitude gives me hope.
http://www.epa.gov/NE/assistance/ceitts/wastewater/techs/techcarousel.html
Here's a link to one composting toilet. Looks pretty expensive.
I remember watching a show on TV about a place, I think it was called the bunny ranch. They had a dry toilet where they just covered their business in saw dust and some other stuff, then when the bucket filled up they took it out to the composting area for that stuff only. After sitting for a year or something it was good to use.
I have constructed my own compost toilet, it is very easy to do!
I used the wonderful 'Humanure Handbook' by Joe Jenkins as my bible, I reccommend it to any budding composting toilet user/maker.
Simply, put a few handfuls of partly composted sawdust (can be mixed with leafmould) on top of your 'deposit' and when your container is full (I use a plastic brewing bucket) go and tip it on your compost heap. It's that simple!
I compost my humanure seperately to my food wastes, leave the material for 3 or 4 years, and use it for 'permanent plantings' such as raspberries, fruit trees, etc, NOT salad carrots, radishes... this is just a precaution.
This simple compost toilet saves water and builds soil, conserves nutrients and helps the overloaded sewerage works cope, as well as helping to grow delicious fruit!
Go buy that book, set up a commode or better, change your life and you won't feel guilty every time you go to the loo!
Or you can just pee in the sink, like me.
For anyone interested, I suggest reading...
The Humanure Handbook: A Guide to Composting Human Manure
Particularly...
Chapter 8: The Sawdust Toilet
A couple things.
The US EPA does not actually approve systems for use. There are various agencies that do, depending on where you are located (eg. NSF, CSA, SWAN, etc.).
Composting toilets are popular in Sweden, but were not really pioneered there as far as I can tell. There were actually composting toilets for sale in the US as far back as about 1880 (well before Sweden). Other countries that seem to use Compost toilets a lot include Canada, the US, Norway, Finland, Australia and NZ.
Other than that, good story! Everyone should use a CT!
An installed anaerobic digester/composting toilet system has been installed at the Leslie Science center in Ann Arbor at its eco-house, , but as I understand it current reg.s prevent the reuse of methane from the recovery system, and that water can be distilled from the system as well. There are flow tables for grey water reuse for gardening as well. The unfortunate situation is as a city enterprise it is under promoted and lacking in its utilization as a teaching facility/structure
I just wonder what would happen if a person or small group requested time before a town board to suggest a town-wide revolution toward composting toilets as an alternative to building more sewage treatment capacity. Vested interests in traditional operation and construction, recipients of federal matching funds would explode in the media poo pooing the idea as primative or unsanitary. Any ideas about how an effective strategy could lead to change? I'm sincerely looking for resources and suggestions at beretco.op@gmail.com.
Also, consider how right now municipalities are dumping sewerage sludge (mixed with commercial waste) on farmland as an alternative to river dumping. It winds up on open land and farmland here in North Carolina. I wonder if it's more hazardous than composted material and if viruses (even prions) can survive in there.
Also, aren't medication residues also a consideration?
Could have been more truthful than inciteful. The typical older U.S. toilet only use 3 gallons per flush, not the 6 gallons you report. Many 1.5 gal. toilets take 2 to 3 flushes to properly dispose (flush) the waste away.