Though it's not a glamorous topic, it's time for folks
(since we all need water) to think about ...
"While we live, our bodies are moving particles of the
earth, joined inextricably both to the soil and to the
bodies of other living things."
by Wendell Barry
Every single time a conventional toilet is flushed, about
40 pounds of potable water is dirtied ... usually in the
process of carrying away less than a pound of
human excrement. Furthermore, each day, the average U.S.
citizen pushes the "out of sight, out of mind" handle seven
times, and in a year, 13,000 gallons of fresh H 2 0 rush
off ... to dispose of enough nitrogen, phosphorus, and
potassium to fertilize a 50' X 50' garden!
Of course, there's no question that the modern porcelain
"throne" (and the effective sanitization facilities to
which it's connected) has played a major role in reducing
disease in the twentieth century. But as we approach the
year 2000, the price of sewage treatment as we know it
threatens to become higher than we can afford to pay ... in
terms of both dollars and human health.
Today, about 70% of all U.S. households are connected to
centralized waste treatment facilities. And on the average,
those plants represent between $500 and $600 of capital
per individual served. In fact, sewage treatment
is one of the largest public works projects ever undertaken
... having absorbed more than $35 billion to date, and
estimated to require another $115 billion by the turn of
the century. Worse yet, despite that incredible
outlay, serious questions about the long-term health
effects of the use of the residues left after treatment
have yet to be answered.
The remaining 30% of U.S. households are served by personal
disposal facilities ... usually a septic tank and drainage
field. When working correctly, these systems don't result
in direct runoff to streams—nor do they add to
public indebtedness—but they have been
singled out as the largest source of ground-water
contamination (see the article on page 26 for more about
the problems that face our underground water supplies).
So when the numerous liabilities of the Thomas Crapper
water closet (yes, that is the name of the man who
developed the flush toilet) are consideredfrom water
consumption to pollution and from outright treatment cost
to the waste of valuable organic matter-there's little
doubt that the commode must change dramatically ... and
The following article describes several approaches that can
be used to reduce water consumption for waste disposal
and—in a few cases—turn that waste into useful
products. While some of these techniques do a more thorough
job of protecting the environment than others, any one of
them would be a significant improvement over the
conventional high-volume toilet.
As many people know, there's no reason why five
gallons of water must be wasted to flush a conventional
toilet. With bricks (or water-filled plastic bottles)
placed up right at each end inside the tank,
adequate flushing pressure—which is a function of the
level in the reservoir-can be maintained while less water
is consumed. Commercial dams that can be inserted around
the outlet from the tank serve roughly the same purpose.
These simple methods can cut the water used in flushing by
Another worthwhile approach is to tune to each situation
the amount of liquid that's flushed. Two-stage valves can
be manipulated to discharge a much smaller amount of water
when there are only liquids to be disposed of. You'll be
glad to know, too, that none of these "remedies"
requires a cash outlay of more than $ 10 ... a sum that the
water savings provided by such devices should pay back in
If you're in the market for a new toiletor if you feel so
strongly about the wasteful nature of your present throne
that you're willing to replace it—one option
is to purchase a low-volume conventional water closet.
Almost all bathroom fixture manufacturers are now offering
what they call "water-saving toilets". Be wary, though ...
the best of these products can get by with as little as a
gallon of water per cycle, but many of them still dispatch
as much as three and a half gallons per flush.
Furthermore, when compared with composting
toilets—which use no water and recycle the
waste-low-volume commodes don't rate high on the
environmental chart ... but using one or two gallons per
flush certainly does compare favorably with
wasting five. (Besides, these conventional—looking
thrones are more likely to meet with approval from building
inspectors and future buyers of your home than are
Water use in liquid-driven disposal systems can be reduced
to less than a gallon per cycle if some other force in
addition to gravity is employed to help drive the
water down. The two most common approach are positive and
negative pressure... wherein the system is either placed in
a partial vacuum or is pushed by compressed a Since such
setups require an auxilia power source (either a vacuum
pump or compressor) to get the job done, thoug they're
comparatively expensive and do require some source of
(usually electric energy. At present, they're most commonly
used in large, multiresidence buildin where the hardware
can be centralized.
NONRECYCLING WATERLESS TOILETS
In areas that have no central sewage trea ment and severe
soil and ground-water lim tations on septic tanks and
drainage field ... chemical, incineration, oil, and on-site
treatment facilities are the options most often selected.
Many people have probably encountere the basic chemical
toilet in the form of po table outhouses ... the units that
usually give off a sweet "chemical" odor. Whateve form they
take, though, such toilets are really nothing more than
sanitary holding tanks, and no processing of the content
takes place within the device.
Incineration toilets, on the other had use either gas or
electric heat to turn wast to ash. They yield a sterilized
effluent that's considerably reduced in volume, but do
require a lot of energy.
Oil systems carry waste to a central holding tank ... using
a medium that won't mix with the products being disposed
off. The mineral-based oil then floats to the top of the
contents of the holding tank and is picked up and pumped
back to the fixture for reuse. Residential models
will hold year's worth of waste for a family of
four. .. after which the holding tank must pumped out and
the waste trucked off for proper disposal.
On-site processing systems (of which the septic tank with
drainage field is one example) don't necessarily save
water, but neither do they burden community sewage
treatment plants. One version relies on aerobic processing,
and resembles a wella-erated septic tank but employs a
different biological process. A system is also available,
on a limited basis, that recycles all of the water used in
a household ... and though it's rather expensive at this
time and requires semiannual maintenance by skilled
technicians, it may become more practical and affordable in
years to come.
WATERLESS WASTE RECYCLERS
Human waste can be broken down by natural biological
processes that, if properly maintained, render it safe and
useful for fertilization of certain types of plants. The
mechanism by which decomposition takes place is roughly the
same as that which cuts in a garden compost pile, and
consists of bacteria that thrive in an environment well
supplied with air. Both biological action and-to some
extent—the heat generated by it are responsible for
the sterilization of the waste.
Very generally, composting waste disposal systems can be
divided into two types: privies (where the waste is removed
periodically for composting in a separate bin) and toilets
(where most of the biological action takes place within the
receiving chamber). In addition, though composting privies
are often located separate from the residential
structure and frequently don't bear much physical
resemblance to the conventional toilet, they are distinct
from the traditional outhouse (in which the little
decomposition that does take place is anaerobic).
In use and maintenance, a composting toilet or privy
requires more care than do most of the other alternatives
we've mentioned. For one thing, material that's rich in
carbon (vegetable matter) must be added, with each use, to
balance the nitrogen present in human waste (a 30:1 C-to-N
ratio is ideal for decomposition). The contents may also
have to be stirred occasionally, and-once every year or
so-some totally decomposed matter can be removed.
Studies have shown that the residue left by a properly
functioning composter has very few remaining
pathogens. Nonetheless, the potential for disease from
incorrectly processed human waste should not be ignored. To
date, few experts recommend that the humus from a composter
be used to fertilize anything other than
ornamental plants, and it's quite likely that
local health regulations will prohibit any
above-surface disposal. In time, though, the confidence of'
health experts may increase, and the state of technology
and its application may improve enough to allow more
fruitful use of decomposed human waste.
Commercial composting toilets are for the most part very
well engineered and backed by caring people. Still, the
prices of such units may exceed many folks' budgets ...
particularly because some sort of system to dispose of gray
water (liquid from sinks, bathtubs, etc.) will have to be
in addition to the commode, to handle that liquid
waste. The accompanying commentaries are from people who've
built their own composting toilets ... often, at least in
part, to avoid the expense of buying a commercial unit.
Zandy Clark is one of the foremost designers of
do-it-yourself composting toilets and privies, and the
model he's presenting takes a unique approach to solving
the all-too-frequent problem of excess liq uid. And Kathy
Dahl, in her report, mentions that difficulty and relates
her solution. We hope you'll profit from
both of these individuals' expertise-through-
EDITOR'S NOTE: If you're seriously considering using or
building an alternative waste disposal system, you'll want
to take advantage of the top-notch written material that's
available. For an overall guide through the wonders of
waste disposal, you'll want to read Goodbye to the Flush
Toilet edited by Carol Hupping Stoner (Rodale Press,
$10.95) and/or The Toilet Papers by Sim Van der Ryn (Capra
Press, $5.95). Also, for just about everything you can
imagine wanting to know about the proper use of gray water,
look into Residential Water Re-Use by Murray Milne, which
can be purchased for $10 from the Director's Office, Dept.
TMEN, Water Resources Center, University of California,
Davis, California 95616.