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WATER:
Municipal Sewage
Treatment
Municipal
sewage is a major
source of water
pollution, posing
a threat to both
human health
and aquatic environments.
In addition to
human excrement,
sewage contains
hundreds of  chemicals
and other toxic
pollutants from
households, businesses
and industrial
operations. Both
untreated (raw)
and inadequately
treated sewage
cause water pollution.
Coastal areas
in both eastern
and western Canada
are closed for
fishing, swimming
and shellfish
harvesting because
of unsafe levels
of faecal coliform
bacteria.
Canada’s
OECD Ranking
The percentage
of the population
served by public
sewage treatment
in Canada is
78%, placing
Canada 9th out
of 28 OECD countries.
The OECD average
is 60%. The nations
with a higher
percentage of
their population
served by public
sewage treatment
than Canada include
the Netherlands,
Switzerland,
Sweden, Germany,
Luxembourg, Denmark,
the United Kingdom
and New Zealand.
Another
12% of Canadians
are connected
to public sewage
networks but
are not served
by any form of
sewage treatment.
In other words,
their sewage
enters a pipe,
but is never
treated before
being returned
to the environment.
A further 9%
of Canadians
are not served
by public sewage
treatment, but
may have private
treatment services,
such as septic
tanks.
When
the figures are
looked at more
closely to examine
the quality of
sewage treatment
being provided,
Canada’s
performance is
less impressive.
There are three
levels of sewage
treatment –
primary, secondary
and tertiary
– which
provide progressively
more effective
treatment. In
Canada, only
33% of the population
is served by
tertiary treatment,
the best available
treatment, while
19% still have
access to only
crude primary
treatment, the
least effective
form of sewage
treatment. In
contrast, in
countries like
Germany, Denmark,
Finland, Sweden
and Switzerland,
over 70% of the
population is
served by tertiary
treatment.
Environment
Canada cautions
that “Statistics
on the population
served by treatment
facilities may
not provide the
entire picture,
however. In most
Canadian cities,
wastewater bypasses
sewage treatment
during heavy
rainfalls, combining
with storm water
in sewer outflows.”13
The
Trend
The percentage
of Canadians
served by sewage
treatment has
been steadily
rising, from
64% in 1980 to
78% in 1997.
Much remains
to be done, as
over 90 Canadian
municipalities
still discharge
raw, untreated
sewage, including
three provincial
capitals (Victoria,
Halifax and St.
John’s).14
Raw sewage from
these three large
cities still
goes straight
into the ocean.
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