Waste Not, Want Not: The Future of Toilets
by Lloyd Alter, Toronto on 07.24.08
Turning waste into fertilizer in Boston
We have written before about the need to change our waste water system that mixes black and gray water and flushes it away; commenters were not impressed and wrote "Composting toilets are NEVER going to make it into the main stream market. Debating it is silly." But the debate is happening anyways; Rebecca Tuhus-Dubrow writes an excellent article in the Boston Globe on the subject.
"IN A WORLD of rapidly diminishing resources, there's one we tend to overlook. It's easy to produce and extremely abundant. But instead of viewing it as an embarrassment of riches, we're more likely to see it as just an embarrassment.
This neglected treasure is human waste. Urine is rich in nitrogen, potassium, and phosphorus, the three main ingredients in artificial fertilizer. Feces contains these nutrients, too, in smaller doses, and the methane it produces can be harnessed as biogas, a green energy source."
She describes the awful numbers: "Annually, each of us produces about 13 gallons of feces and 130 gallons of urine, which is instantly diluted into the 4,000 gallons we use to flush it. This large quantity of contaminated liquid further mixes with "greywater," the water from the laundry, shower, and sink, tripling or quadrupling the amount of water that must be treated as sewage in energy-intensive plants. In effect, the system takes a relatively small amount of pathogenic material - primarily the feces - and taints enormous amounts of water with it. Especially in regions struggling with freshwater scarcity, many observers have come to see this system as highly inefficient. "It's a totally insane idea," says Arno Rosemarin.[ the research and communications manager at the Stockholm Environment Institute]
We are also throwing away valuable phosphorus with our urine, a key fertilizer. "Don't mix what God separates," says one researcher. In Sweden, toilets are being installed to divert urine, which can be used as fertilizer with almost no treatment. Pilot projects have been started where vacuum toilets suck waste away for use in biogas plats to generate energy.
"There are, however, obstacles to widespread implementation of unorthodox toilets. Space limitations make compost toilets infeasible in most urban areas. Vacuum toilets require a different plumbing system. And there may be psychological barriers to changing habits in the bathroom." ::Boston Globe May require stupid free registration
But we have to start looking at these habits and changes in our plumbing systems. Ten years ago nobody handled their garbage; it all went in one can and some guy in green overalls took it away. Then we learned to separate our recyclables, and in many areas learned the often yucky task of separating our compostables.
We treat our body waste the same way, putting everything into a single pipe, mixing it with industrial waste and pumping it to some distant unknown location. We may have to change our ways and learn how to separate and recycle this as well.
TreeHugger on Composting Toilets
Thinking about Crap: Should Houses Have Composting Toilets ...
Composting toilets: Ready for Prime Time?
TreeHugger Tips: How-to Manage Humanure Composting
TreeHugger Tips: Hacking a Composting Toilet
Composting Toilets Work, Even in Antarctica
The Hot Poop on Alternative Toilets
TreeHugger On Phosphorus
P is for Phosphorus (As Well As Human Urine)
I.P. Freely - On The Organic Cabbages
Treehugger on Separating Toilets
Hot Poop on Composting Toilets: Separett
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It would be tough to implement, but it's a great idea. Especially when you look at the last paragraph talking about recycling solid waste.
use the existing sewage treatment plants to remove the solids from the waste stream - then use the "Anything Into Oil" process to produce diesel fuel - you also get the minerals & methane to power the process - no one has to change out their toilets - only the sewage treatment plants have to update - of course an added bonus is that sewage treatment plants can become a revenue generating source as opposed to just an expense we all get charged for to use
I'm a homebuilder and have used a sawdust toilet (based on instructions from "Humanure Handbook" by Joseph Jenkins) on my jobsites when I don't have a local health or code enforcement guy looking over my shoulder. Pretty simple and if done properly, pretty safe. I've always composted the contents of the buckets in my "not for the food garden" compost pile. Never had a smell issue w/ either the toilet or the compost pile. Swabbing out the bucket w/ soapy water is minor inconvenience for 5 min. tops.
Also have a customer who's been using a "Biolet 20 Deluxe" toilet for 3 months & so far so good. Also the county parks in our area (St.Charles, MO,USA) all have large commercial composting toilets and have had some as long as 5 years now.
So things are slowly changing but the pace is gonna pick up when local governments in dessert areas have exhausted all other water saving measures. Also water quality issues in our streams and rivers are starting to drive this issue also. So get over it all you "Fecofobes" out there.
There are already sewage treatment plants in this country that turn solid waste into compost for farming and return the water to a potable state. So what is this article about?
As Dialtone said, there is no reason to change out anyones toilets.
We just need to push our local governments and utilities to make the changes that will ultimately put an end to this waste of resources.
The problem with retrofitting existing waste treatment plants is the complete reorganization they would need to do this effectively.
Diluting wastes with flush water so they will flow through pipes adds a great deal of cost and effort to clean all that water up again.
The Deer ISland plant (nice photo) was purpose built to generate methane to assist its process, and is a large part of why Boston Harbor's water quality is now vastly improved.
Even with sewage plants that convert waste to fuel/compost/unicorns there are still solid reasons to switch to lower impact options. For example the post mentions the 4000 gallons of water that we flush down with our 143 gallons of waste.
We use energy to treat that water, we use energy to pump that water, and ultimately even with good treatment plants we just dump that water (there are a few municipalities with graywater systems, I know). Why not skip a bunch of steps and a bunch of wasted resoureces and compost closer to (or in the) home?
How are most U.S. areas treating composting toilets as far as ordinances go? I know that in many areas even greywater systems are pretty much prohibited. My wife and I are starting to plan our retirement home and these are some of the systems we're looking at to save resources.
Partial solutions to this problem should be possible, and would help a great deal.
It's been well-proven that you cannot re-plumb a city, but with urbanization accelerating, there are opportunities to change how plumbing works in new buildings, and when new neighborhoods begin to become dense, there may be some opportunity to change the wastewater infrastructure as well.
You probably won't get people to separate their bodily wastes except where they already do: Men use urinals when available, and those fixtures account for maybe 1/3rd of the urine in a given blackwater stream.
The problem I have with greywater systems is that they are never entirely grey, especially where young children are involved. At the end of the day you have to treat them like blackwater anyway. But if you can get a pure blackwater stream (no paint thinner, no antibiotic hand soap, no laundry detergent), you might be able to do some really interesting things with that.
No sense debating it? Never say never. It's a hard sell, but everybody poops. We need to deal with it responsibly.
I don't know about some of these numbers. I think the math is off. Given the average size and regularity of my bowel movements I'm making alot more than 13 gallons of feces per year. Per month maybe!
A small start could be found in stadium urinals at land grant universities.
I am in desperate need of information to make personal Bio toilets for a small community in Zambia Africa. We want to imrove our living standards and benitfit from the gas to be used , and a compost system we have heard about too. advice or brochours on how to make thewse toilets will be very welcome.