9420.pdf

The status of treatment for plants discharging to sewer was reviewed for those located
in the GVS&DD (Figure 5.3). The individual discharge permits require treatment of the
effluent prior to discharge to sewer. The level of treatment ranges from the use of grease
and sand interceptors to screening (30 % and 80 % of all plants, respectively).
Approximately 10 % of these facilities use a combination of the two forms of treatment.
The screen sizes used in plants discharging to the GVS&DD is not specified in the permit.
A summary of MOELP, GVRD or City of Vancouver discharge permit requirements is
presented in Table 5.1. Contaminant discharge concentration limits are generally
600 mg/L for TSS and 1000 mg/L for BOD for plants discharging to the GVRD, but to
date have not been enforced. MOELP permits for the discharge of process water from
fish processing plants generally do not contain BOD or TSS limits, and contain statements
such as the requirement that the effluent quality should be equivalent to or better than
typical fish processing plant effluent. For the purpose of calculating permit fees (which
are based on the TSS and BOD loading of the effluent), effluents are assumed to exhibit
a TSS concentration and BOD of 70 mg/L and 100 mg/L, respectively. Effluent
concentrations generally exceed these assumed values. However, permit fees are
determined by multiplying the assumed concentrations by the product of the maximum
permitted daily discharge flow, by the number of days per year, by the unit fee for each
parameter. Therefore, permit fees are also to be paid for days during which no
processing takes place. It is probable that permit fees would be in the same order of
magnitude should they be paid on actual concentrations (i.e. organic load, hydraulic load
and days of operation per year).
A summary of fish processing effluent discharge regulations in selected European
jurisdictions is presented in Table 5.2. Experts from the Danish Institute for Fisheries
Technology and Aquiculture, however, expressed the opinion that the lowest BOD level
that industry could achieve is 100 -150 mg/L. They also recognized that the set limit of
15 mg/L BOD is not economically achievable by fish processors using currently available
technology (NovaTec, 1993a).
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5.1.2 Water Consumption and Wastewater Management
Wastewater management practices in place at fish processing facilities in the Pacific
Northwest’ (B. C., Alaska, Washington, and Oregon) range from grinding and discharging
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