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State of Environment Reporting
 Status
of Water Quality
Water
Quality Index 1998-1999
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Water
Quality
Index
Definitions:
- Excellent:
Conditions
very
close
to
natural
or
pristine.
All
uses
are
protected
and
none
are
threatened
or
impaired.
- Good:
Conditions
rarely
depart
from
natural
or
desirable
levels.
All
uses
are
protected,
with
only
minor
threats
or
impairment.
- Fair:
Conditions
sometimes
depart
from
natural
or
desirable
levels.
Most
uses
are
protected,
but
a
few
are
threatened
or
impaired.
- Borderline:
Conditions
often
depart
from
natural
or
desirable
levels.
Several
uses
are
threatened
or
impaired.
- Poor:
Conditions
usually
depart
from
natural
or
desirable
levels.
Most
uses
are
threatened,
impaired
or
even
lost.
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SOURCE:
Ministry of Water, Land and Air Protection, 2001. NOTES: The ratings
are derived from a Provincial Water Quality Index (WQI), which measures
the impact of pollutants on water quality. Since the WQI is based
on sampling in areas where there are likely to be water quality
concerns, the results may indicate a poorer status than if a random
sampling of all water bodies in the province was considered. Individual
indices are determined by the number of water quality objectives
not met and the frequency and amount by which these objectives are
exceeded. Most of the thousands of water bodies in the province
are not monitored. Data for the WQI were taken from 33 water bodies
(including fresh surface streams, rivers and lakes, and marine areas)
and were based on the overall WQI for 1998 and 1999.
Status
of Water Quality
- The
Water Quality Index ranks water quality
against objectives set for each water
body. Objectives are set by the Province
by considering the users of the water
(humans and other organisms) and waste
streams entering the water body.
- Of
the 33 water bodies monitored, 17 were
rated Good or Excellent.
- Fourteen
water bodies were rated as Fair, indicating
some impairment of uses and the need for
actions to prevent further impairment.
The main problem is pollution from non-point
sources (such as agriculture and urban
runoff), followed by impacts from mining
and dams.
- Tsolum
River and Christina Lake both received
a Borderline rating. Borderline water
quality in Tsolum River is a result of
copper loading from an abandoned mine.
In Christina Lake, high spring phosphorus
loading is likely due to a series of wet
years causing high run-off and elevating
the level of phosphorus in many interior
water bodies.
- No
water bodies were rated as Poor.
- The
number of water bodies monitored for the
attainment of water quality objectives
has decreased from 124 in 1995 to 33 in
1999.
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