Sewage treatment wasted--the Victoria (BC, Canada) example.

A previous Editorial (Chapman, 2006) provided the background for issues regarding sewage discharged by the City of Victoria (British Columbia, Canada) and environs (the Capital Regional District, CRD). In brief, the sewage receives preliminary screening to remove solids larger than 6 mm prior to discharge more than 1 km offshore in roughly 60 m deep, well-mixed marine waters with strong tidal currents. Despite scientific evidence that there are no major environmental or human health impacts, this discharge of ‘untreated’ sewage has been a constant irritation to the city’s US neighbours and to environmental groups, has resulted in a large number of lay opinions in the popular media (radio, television, newspapers, magazines), and finally resulted (July 2006) in the British Columbia Minister of the Environment directing the CRD to move to secondary sewage treatment. Prior to this direction, an independent expert scientific review had been completed under the auspices of the Society of Environmental Toxicology and Chemistry (SETAC; Stubblefield et al., 2006). This independent review made an important point that appears to have been overlooked by the Minister and others in favour of secondary treatment. Specifically, stormwater, sanitary and combined overflows, and other discharges, particularly into the surface waters in Victoria’s harbours, present more pressing environmental issues than the current offshore submarine sewage discharges. But there was no opportunity to properly discuss and evaluate the SETAC review; the CRD’s plan to review the SETAC report over a 5month period, with public input, prior to deciding how to proceed was obviated by the Minister’s direction, which was handed down just two days after the release of the SETAC report. The SETAC review, previous assessments, and subsequent expert opinion by local medical health officers have all confirmed that there are no major human health concerns associated with the sewage discharge. Granted, gastrointestinal illness and/or ear infections could conceivably occur if individuals were in offshore waters when, during certain periods in the fall and winter, excessive rainfall entering the drainage system can cause the sewage plume to surface. But this would not be a common occurrence to say the least, and the risks would be far smaller than those posed by the combined-overflows problem specified above. The SETAC review also confirmed that the outfalls were not causing major adverse environmental effects. The review specifically stated ‘‘There is no reason to believe that serious human health effects or severe ecological consequences not yet in evidence will arise in future” but, not unreasonably, the reviewers admitted that they could not predict future risks due to emerging contaminants of concern (‘‘the larger problem is with estimating the likelihood of events that have not yet, and might never, occur”).