Victoria’s sewage discharge does not pollute Washington shores, according to guest columnist Brian Burchill.
26 July 2014
The Seattle Times editorial board raised concern about the sewage discharge in a June 17 editorial.Washington Gov. Jay Inslee has written to the British Columbia government demanding an end to the sewage flow, according to an Associated Press news report.
The system’s design is based on “sound scientific evidence” that “sea outfalls allow the sewage effluent to be subjected to the same processes of degradation and oxidation that occur in land-based sewage treatment plants,” according to a 1987 report by Water Research Laboratory.
Such research led the World Health Organization and a British Royal Commission to conclude in 1984 that ocean treatment of sewage is an acceptable, sometimes preferable, practice.
U.S. Congress, overwhelmed with such research and opinion, realized in 1975 that some marine discharges don’t require secondary treatment. Victoria’s is one such discharge. Washington state marine scientists, in a joint study with British Columbia scientists, found no evidence that it fouls our shared waters. They concluded in a 1994 report that “sewage discharges from Victoria have a negligible effect on the shared waters.”
Victoria’s wastewater is treated. Greases and oils are removed, and screening filters out trash items. As per the National Research Council recommendations, a source-control program prevents deleterious substances from going into drains in the first place that, combined with Victoria’s lack of heavy industry, results in concentrations of metals in our discharge being well below EPA standards for drinking water. The million gallons per hour that Victoria discharges is more than 99.9 percent fresh water.
The screens also cause size reduction. Then the final stage of treatment is provided by the ocean, driven by the free, sustainable energy of the tides and currents. The Strait of Juan de Fuca’s strong turbulence and abundance of microbes rapidly disperses the discharge and assimilates it into the marine food chain.
Coliforms from the warm human gut are rapidly reduced, due to the cold seawater and the abundance of predatory microbes, to seawater’s natural background levels, according to a 2000 report in the Canadian Water Resources Journal. These actions, and the high-oxygen content of the strait, prevent Victoria’s discharge from fouling our shared waters.
These rich treatment conditions are continuously replenished by a flow of about 100,000 cubic yards per second that, independent of the tides, sweeps into and back out of the Strait of Juan de Fuca. The inflow presses against Washington state’s north shore until it’s deflected by Whidbey Island.
A small portion sweeps through Puget Sound and rejoins the main flow north to the San Juan Islands. There, the outflow of the Strait of Georgia southward through the islands forces the current to turn back. It flows westward past Victoria, pressing against the south shore of Vancouver Island as it flows to the Pacific.
Hence, Washington’s discharges into Juan de Fuca Strait and Puget Sound — and British Columbia’s discharges into Georgia Strait — flow to Victoria, not the reverse. This current is so strong and persistent that, contrary to popular concern, it’s extremely unlikely for Victoria’s discharge to flow to Washington’s shores. If it ever did, good luck detecting it because it would be infinitesimally dilute and indistinguishable from all of the other discharges.
The suggested study to measure the effect of Victoria’s discharge on U.S. waters would likely be a waste of taxpayers funds. Wisely spent funds have revealed the much more important issue that, even with a 21st-century respect for the environment, the climate-change disaster is still escalating. Infrastructure and land-based treatment systems contribute to the problem.
Given the facts and evidence, not replacing Victoria’s world-class, low-impact system with an unnecessary land-based treatment system would support the U.S. federal administration’s initiatives to reduce climate change, a stance that green Gov. Inslee’s administration ought to seriously consider.
- Brian Burchill is an engineer based in Victoria, B.C.