Connect with Us
Seeking science in the sewage
The debate over sewage treatment has raged in the Capital Region District for the last two decades, and with each passing year, the distinction between political and environmental motives behind the proposed $783-million project grows more difficult to separate.
University of Victoria Earth and Ocean Sciences professor Jay Cullen recently led a Café Scientifique talk titled: "Victoria’s Sewage Treatment: a Brief History of Slime."
The discussion was a part of a free, informal series aimed at bridging the science-to-public gap – something that has been notably missing when it comes to the highly politicized debate over whether or not Greater Victoria truly needs to change its ways of streaming sewage into the Strait of Juan de Fuca.
“The CRD operates a world-class program to determine the impact of the effluent on the health of the marine environment and the potential impact on public health,” said Cullen, whose research is focused on metal chemistry in sea water. “For the most part, the impact of the effluent on the marine environment, and certainly on public health, is minimal.”
Cullen admits the effluent does have some measurable impact on the marine environment. It causes changes in the invertebrates that live in the sediments around the outfalls, reduces species richness and is the source of a greater abundance of organisms able to tolerate high levels organic loading. But the impacts, Cullen said, are reversible and confined to about 200 metres from the outfalls themselves.
Cullen agreed to lead the talk based on the false assertions he’s recognized within the CRD: one being that the effluent has no impact whatsoever. The other: that the impact is a devastating environmental disaster in progress.
“The truth is that neither of those points of view are likely true,” he said. “There is an impact and the question should be, whenever you generate some sort of waste, there is an impact on the environment. The impact right now seems relatively minor compared to what one might predict the impact would be on the terrestrial environment in terms of energy use and land use, moving toward more land-based treatment.”
Acknowledging that a land-based treatment system will not eliminate all chemicals flushed into the marine environment should be among the next steps of action for the region, regardless of whether or not one big-ticket liquid waste treatment plant goes through, Cullen said.
“The public has a perception that if this plant is built, that some of the high profile problems in the marine environment, like PCBs (polychlorinated biphenyls) or flame retardants in our resident killer whales will magically go away. The scientific evidence shows that’s not true,” he said. “We should be clear about what we’d like to gain from doing this and why we’re doing it.”
The Ministry of Environment decided to push forward with liquid waste treatment in 2006, following the release of the scientific and technical review of the CRD's core area liquid waste management plan – a report administered by the Society of Environmental Toxicology and Chemistry (SETAC), written by seven experts in environmental toxicology, engineering and health.
“Initially this edict from the Minister of Environment in 2006 suggested that the weight of environmental evidence suggested we had to do the treatment. A careful reading of the evidence that exists, by most marine scientists locally, suggests that’s not the case,” Cullen said.
“If we were going to rank initiatives to improve the health of the marine environments, treating Victoria’s sewage would be pretty low down the list of things we’d like to see improvements in.”
Former chair and current member of the CRD’s core area liquid waste management committee, Saanich Coun. Judy Brownoff vehemently disagrees with Cullen. Brownoff, while readily admitting to her lack of education in science, has done her homework and followed the available literature on wastewater, dating back to the early 1990s in the CRD.
For Brownoff, the environmental risk of continuing to discharge of chemicals into the strait via raw sewage remains too great to ignore any longer.
“I think if you asked a federal scientist or a provincial scientist or a retired scientist, they’d all tell you different things,” Brownoff said. “All scientists have different viewpoints of different things. For me, I don’t known how you can say that when the chemicals attach to solids – which we know they will – it’s OK to put them out in the ocean and float anywhere they want and attach to the food chain.”
With two-thirds funding committed from the provincial and federal governments, and laws mandating sewage treatment, Brownoff says the time for is now.
According to CRD data, the volume of effluent pollutants piped into the water off Victoria is 10 times more than the limit set by the province of B.C. Currently, the effluent discharge is 250 milligrams per litre of carbonaceous biochemical oxygen demand (BOD) and total suspended solids (TSS), or 10 times more than the provincial regulation of 25 mg per litre or less.
“Many of these anthropogenic chemicals are showing up in sea mammals, for example when they analyze the flesh of sea mammals,” said Jack Hull, interim project director of the core area wastewater treatment program. “Obviously they’re coming from somewhere. If we’re dumping those things in the ocean, we’re contributing to those problems and if we’re dumping these contaminants, we don’t really know the consequences. For some we do; for others we don’t.
“(Contaminants) have been shown to affect the reproductive cycle of mammals. Those things just don’t disappear. Fish swimming through that water at an outfall are ingesting these contaminants.”
The SETAC report itself, often quoted by sewage treatment opponents to the lack of definitive research on the marine environment off Victoria, says the region can't dump sewage into the Strait of Juan de Fuca forever.
The SETAC report, along with a plethora of information on chemical levels at outfalls, fact sheets, surveys and other reports dating back to the creation of the core area liquid waste management plan in 2003, are available at wastewatermadeclear.ca.