February 13, 2007
Kamloops Daily News

Conscientious Canadians wouldn't throw plastics into the
newspaper recycling bin but we don't think twice about
mixing human waste when we flush the toilet.

It's not a subject that most people talk about over coffee
but human wastes are not equal. Urine is sterile when it
leaves the body, unlike feces. It consists mainly of water,
a bit of proteins and salts.

Urine seems relatively innocuous but a little bit can create
a big problem at the sewage treatment plant. Despite making
up only 1 per cent of the volume of waste water, urine
contributes about 80 per cent of the nitrogen and 45 per
cent of all the phosphate in waste water.

If urine were removed at the source, sewage would be less
expensive to treat. The chemicals in urine are good
fertilizers but we need fertilizers on land, not in water.
In water, they promote algae growth that chokes out natural
fish and plant life.

It's time to shine some light on the way we treat sewage.
Typical sewage consists of a dissimilar mix of recyclables;
urine (yellow water), solid human waste (black water), water
from household sinks and baths (grey water) and sometimes
storm sewer runoff. Before it can leave the treatment
plant, it must be cleaned sufficiently to be discharged into
a river.

The first step is to remove large objects such as condoms,
tampons, dead goldfish, toys, false teeth and the random
assortment of detritus that people surreptitiously slip down
the drain.

The remainder flows into containers that allow material to
float or sink. The next step involves aeration where
bacteria go to work digesting as much as possible. Methane
gas produced can be burned to produce electricity but in
Kamloops it's vented and the pulp mill is often blamed for
the smell.

Then alum has to be added to remove phosphates from urine
that the aeration stage couldn't get rid of. The sludge is
transferred to drying beds and the water is chlorinated.
The dry sludge is mixture of so many different materials
that it's hard to dispose of.

Urine recycling is not new. Some parts of Europe have been
removing urine from sewage by separation toilets. These
toilets divert urine away from the drain.

Urine-diversion toilets don't look any different than
ordinary ones with one exception. The toilet has two waste
pipes, one in front to collect the urine and another larger
one in back.

When the user sits on the toilet, urine is collected with a
small amount of water and sent to a storage tank. The catch
is that men will have to sit to pee which is more of a
cultural problem than a practical one. One lingering
opinion is that real men pee while standing up while only
sissies sit. For those men who can't bear this perceived
indignity, the toilet can be designed with a target drain
for peeing while standing.

The Netherlands is conducting urine separation trials.
Small-scale urine separation has been practiced for
centuries in the textile dyeing blacksmithing industries.

The urine from all these projects can be sprayed directly
onto fields or sent to treatment plants where phosphate is
precipitated out as a fertilizer.

Energy is saved in two ways. The urine phosphates replace
those previously mined and the treatment of sewage without
urine is cheaper. True, there is an added cost of trucking
the urine to a central plant for processing but this could
be reduced by curbside recycling.

This will require some getting used to. Kamloopsians are
just getting used to curbside recycling of materials. We
need to overcome the impression that sewage is
unmentionable. European surveys indicate that consumers
would be happy to buy vegetables fertilized with processed
urine.

The future of sewers can be seen through the evolution of
landfills which used to be considered as refuse dumps. Not
long ago, recyclable goods were buried. Now, enlightened
Kamloopsians are part of the solution, not the problem.

Sewers remain out of sight and out of mind. They are called
sanitary sewers in name only. The British are less
delicate; calling them "foul sewers."

It takes effort and planning to get useful stuff out of our
landfills. The sooner we start sorting the stuff we dump
down our drains, the better.

As the planet runs out of clean water, we need to re-think
this ancient subterranean system.

David Charbonneau is the owner of Trio Technical.
He can be reached at dcharbonneau13@shaw.ca

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