Local scientists still question federal sewage regulations

Considerable attention has been paid recently to the numerical values assigned by the federal government.

  • Fri May 13th, 2016 7:00am
  • News

Chris Garrett

Jack Littlepage

Special to the News

Considerable attention has been paid recently to the numerical values assigned by the federal government to the Macaulay Point and Clover Point wastewater outfalls.

The scores for these two locations are 126 and 112, respectively, considerably above 70 and so leading to designation as high risk and requiring secondary treatment by Dec. 31, 2020. A score between 50 and 70 is allegedly medium risk, with a treatment deadline of Dec. 31, 2030. Less than 50 qualifies the discharge as low risk, and comes with a 2040 deadline.

We suggest the methodology and resulting scores are inappropriate and misleading. For both outfalls, 25 points are assigned because of the discharge volume and five because the discharge is into open marine waters. For Macaulay, 96 points come from the combined carbonaceous biological oxygen demand (CBOD) of the wastewater and its suspended solids (SS). For Clover, the number is 82.

Assigning points to the daily outfall volume, without comparison to anything else, makes no sense. Characteristics of the receiving environment should be taken into account. For Victoria, one could compare the discharges with the much larger tidal and estuarine flows in the Salish Sea. The combined outfall flows are approximately one part in 50,000 of the average outflow through Juan de Fuca Strait into the North Pacific.

It’s difficult to see the relevance of this very small fraction. Furthermore, the discharge is over 99 per cent water that is just making its way to the sea. So let’s knock off the 25 points. It’s not the volume of the wastewater that matters, but its contents and environmental impact.

With regard to the contents, the federal regulations focus on CBOD and SS values. CBOD is an index of the amount of dissolved oxygen required for oxidation of the organic matter in the effluent. High CBOD may result in oxygen depletion and dead zones in some receiving environments.

There are no signs of oxygen deficiency resulting from the Capital Regional District (CRD) outfall effluent, due to the strong flows and vigorous mixing of the receiving environment, so we can surely knock off any points associated with the CBOD. This amounts to 44 points at Macaulay, bringing the total score down to 57 and “medium risk.” The score for the Clover Point outfall by these arguments is 49.

We could also argue for a reduction of the SS number. Suspended solids can be a proxy for contaminants that get attached to the particles, but this is a very unfocused way of regulating them. The federal regulations do not address specific individual contaminants such as metals and organic compounds. Detailed analysis of these by CRD scientists and others shows that their effect is minor.

In particular, the excellent source control programs introduced by the CRD and followed by many public-spirited businesses remove many contaminants before they can enter the waste stream. The lack of major industrial activity locally also means that our wastewater presents less of a problem than that in many other places. We could easily argue for a halving of the SS score of 52 for Macaulay, bringing the total down to 31, well into the “low risk” zone. Clover would be lower still at 27.

Thus, even adopting the federal regulations but with site-specific scoring, we could argue for a low risk classification. But really the above discussion just shows how inappropriate the federal approach is.

Everything should be discussed in terms of the site-specific effects on the receiving environment, not some vague hope that potential wastewater effects will be eliminated with largely arbitrary requirements based on end-of-pipe discharge criteria.

Criticisms of the draft regulations by marine scientists at the local DFO Institute of Ocean Science were ignored. The CRD’s own scientists also wrote on two occasions to comment on the lack of site-specific assessments in the draft regulations. While the CRD’s scientists conduct excellent monitoring programs around the outfalls, publish comprehensive reports, and can respond to specific enquiries, the CRD is not proactive in correcting the large amount of misinformation that is propagated in the media.

Overall, it’s mind-boggling that a billion-dollar project continues to be justified on the basis of the inappropriate and easily challenged federal regulations. It is sad that local officials pursue land-based sewage treatment with such meekness and apparent enthusiasm, without at least calling for a moratorium until real or potential problems have been quantified. The tens of millions of dollars that have apparently already been squandered could have been devoted to projects that really would lead to clarification of potential issues and better marine environmental protection.

Throwing more money at land-based treatment without any clear expectation of benefits is tragic.

Chris Garrett and Jack Littlepage are former UVic professors of ocean physics and biological oceanography, respectively. They were featured in a March 25 story in our Sewage in the CRD series.