In the end, it's all the same
It's time to bring Canada's sewage treatment systems into
the 21st century, says Ontario's environmental chief
The Toronto Star
Canadians have been shaken recently by several high-profile
cases of human pathogens being spread through municipal
water supplies. This has focused our interest sharply
on the quality of our drinking water.
Yet, strangely enough, there has been much less focus
on an obvious related question: What is the quality of
wastewater we return to lakes and rivers? This is strange
because, in the long run, it's all the same water.
Canadians might not be aware of it, but the people who
manage water in Canada all agree our sewage treatment
plants are aging and have not kept up with demands of
rapidly growing populations.
My latest annual report, released yesterday, outlines
the situation in Ontario. However, it's the same story
in many areas of the country.
In the 1970s, a strong public investment in sewage infrastructure
helped achieve some remarkable environmental success stories,
such as the recovery of Lake Erie from severe phosphorus
This success was followed by several decades of benign
neglect. During this time, governments at all levels gave
low priority to the unglamorous tasks of maintaining,
repairing and upgrading sewage plants and pipes.
The rather embarrassing result is that Canada's performance
on this most basic of housekeeping duties has fallen considerably
behind what is being achieved by other leading industrialized
Today, some municipalities, even in Ontario, still rely
on primary sewage treatment that does little more than
settle out solids. Tertiary treatment - the best available
treatment - is much less widespread in Canada than in
European countries such as Germany, Denmark, Finland,
Sweden and Switzerland.
In the older parts of many Canadian towns and cities,
combined sewers are still the norm, an engineering design
dating back to the 19th century. They overflow with every
major rainstorm, sending untreated sewage directly into
local rivers and lakes. Without strategic long-term plans
to separate storm sewers from sanitary sewers, these sewage
overflows will remain perpetual insults to aquatic ecosystems
— and to the users downstream.
The lower Great Lakes and their tributary rivers receive
particularly high flows of sewage effluent from the large
surrounding populations. To illustrate the magnitude of
the challenge, the Grand River in southern Ontario receives
the treated effluent from 26 sewage treatment plants.
But that same river also supplies drinking water to several
The overall pollutant loadings from municipal sewage
treatment plants are very large indeed. They include both
conventional pollutants such as phosphorus and nitrogen,
as well as a wide range of persistent organic pollutants
and toxic metals.
For example, according to Environment Canada, the two
largest contributors of ammonia loadings to Canadian waters
in 1999 were sewage treatment plants serving Toronto and
Ottawa. Researchers are also finding hormones and pharmaceuticals
in sewage, some of which can disrupt the functioning of
animal and human endocrine systems.
It's time to bring our sewage treatment systems into
the 21st century — or, in some cases, into the late 20th
As a start, plant managers can achieve impressive gains
by optimizing plant performance: This means squeezing
better value out of existing plant designs, tweaking existing
equipment and improving monitoring to reduce overall pollutant
Municipalities can work to phase out combined sewers.
They can also put in place progressive sewer use bylaws,
setting limits on the pollutants being poured down drains
by industries and residences.
To be sure, many sewage treatment plants will need upgrades
and significant investments, involving all levels of government.
But the technology has been available for decades. And
our investments in clean water will produce innumerable
As a first step, we need to take an active interest in
the quality of our wastewaters and the state of our sewer
We could be creative about this. I wonder how many Canadian
towns and cities highlight the performance of their sewage
treatment plant and the quality of its effluent on their
municipal Web site. This would not be difficult or expensive,
and it could be quite illuminating.
Most important, we need to agree on our priorities.
Communities require commitment and a long-range perspective
in order to face hard challenges. Successful communities
take on these challenges, because it is the right thing
to do, and because the paybacks are real and long term.
Sewage treatment is one of those challenges.
The benefits will accrue - they'll be seen at the local
bathing beaches, at the nearby fishing spots and, yes,
at the drinking water intakes downstream. In the long
run, it's all the same water