9420.pdf

which are permitted to grind and discharge their waste (see Section 5.1.1), as no BOD
data is available for this waste stream. Subgroups within this total were also calculated.
The subgroups considered were:
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direct discharge to marine waters;
direct discharge to the Fraser River;
direct discharge to municipal sewers.
The BOD loading estimate for effluents discharged to marine waters was calculated in the
following way: The largest processors discharging to marine waters (accounting for
approximately 95 % of the sum of the permitted daily discharge flows) were contacted to
obtain the total amount of fish handled by these processors in 1993. (Production data
were provided by the plants on a voluntary basis.) This amount was then multiplied by
the mass loading estimate, and added to the BOD loading due to surimi processing. The
latter was estimated separately based on effluent concentration and flow data, as surimi
processing typically results in effluent with higher BOD than other fish processing.
The loading estimates for discharges to the Fraser River and discharges from all B.C. fish
processing facilities were determined in an analogous manner, whereas the loading froml
plants discharging to a sewer system was assumed to account for the balance of the total
estimated 1993 loading. The breakdown of the estimated 1993 BOD load is shown in
Table 3.10.
The estimated 1993 BOD loads were compared to population equivalents based on a perperson-per-day
BOD equivalent of 100 grams BOD (see Table 3.10). Based on these
assumptions, the estimated 1993 BOD load from all fish processing plants in BC
excluding surimi processing had a population equivalent of approximately 30,000 people.
If surimi processing is included in the calculation (including a BOD loading estimate for
Ucluelet Seafood Processors, a surimi processing plant which did not process surimi in
1993) the population equivalent is approximately 50,000 people. It should be pointed out
that the comparison was carried out assuming an even landing through the year. In
reality, the monthly population equivalent loading would be considerably higher during the
peak processing months (peak loading) and lower during the off-peak period. Although
only peak loadings are of environmental concern at a specific site, assessment of
environmental impacts on receiving environment was beyond the scope of this report.
Annual loading averages were selected for use for comparative purposes.
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