A study by DFO scientists found that secondary sewage treatment will have a negligible effect on environmental conditions in our waters.
THE CRD IS POISED to spend upwards of $1 billion on sewage treatment for Victoria in response to new Fisheries Act regulations aimed at protecting fish, yet a recent study led by DFO research scientist Sophie Johannessen says upgrading the level of treatment at two plants in Vancouver and two in Victoria will have a “negligible effect” on environmental conditions in the Strait of Georgia and Juan de Fuca Strait.
Is a mistake of grand proportions about to be made?
Reading between the lines, Johannessen’s peer-reviewed study challenges the narrow basis on which Victoria’s two outfalls were rated “high risk.” Environment Canada’s new regulations provide a laboratory-based formula by which the effluent from sanitary sewers can be assessed using four specific measurements. Municipal treatment plants that don’t meet the formulaic requirements are being forced to upgrade. The regulations do not provide any avenue for evaluating water conditions immediately after the effluent has been discharged from an outfall.
The Johannessen study also raises the profile of one of the contaminants of concern in effluent from all the outfalls considered: polybrominated diphenyl ethers (PBDEs), otherwise known as flame retardants. The study’s authors predict that secondary treatment could significantly reduce the amount of PBDEs being discharged into the Straits “depending on how the sludge is sequestered.” As it turns out, though, this is a big if. So far the CRD hasn’t identified how it would deal with sewage sludge and if current practices for disposing of the sludge elsewhere were used in Victoria, the PBDEs could be recycled through the environment. Johannessen told Focus that unless the CRD found a way to remove the PBDEs from biosolids after treatment, they could eventually make their way to the Strait.
THE NEW FEDERAL Wastewater Systems Effluent Regulations in the Fisheries Act that triggered a high risk rating for Victoria’s two outfalls are unrelated to the PBDE problem. The regulations are only intended to protect fish in the water immediately adjacent to the outfalls from effluent that is “acutely lethal.”
Those regulations require measurement of chlorine, ammonia, total suspended solids, and biochemical oxygen demand at the point at which effluent is discharged from the diffuser ports on the outfalls. In Victoria’s case, it’s the combination of total suspended solids and biochemical oxygen demand that resulted in the outfalls at Macaulay Point and Clover Point being red-lined. The regulations require the effluent to be measured in its most highly concentrated form before it is discharged, and that measurement obviously doesn’t reflect actual conditions a short distance from the outfalls. Nor do the regulations have anything to say about other contaminants in the effluent, such as PBDEs, metals, plastic microbeads, or the thousands of chemicals in all sewage that derive from pharmaceuticals, detergents and other substances. The effect of the Regulations, then, is to protect a fish able to hold its position in the strong tidal currents, with its nose and gills stuck inside one of the outfall’s ports.
Many Victorians will have seen images provided by the CRD that show fish swimming beside—and crabs clambering over—the Macaulay Point outfall, apparently happy to be there. These don’t appear to be conditions lethal to fish.
Macaulay Point outfall
Macaulay Point outfall
That is, the good health of ecosystems near the outfall doesn’t seem to be predicted by the allowable range of total suspended solids and biochemical oxygen demand set out in the regulations.
How could Environment Canada have got this so wrong?
The fundamental inadequacy of Environment Canada’s regulations as a tool for making sound decisions about sewage treatment is captured in a quote from the study: “To predict the likely effects of management action on any point source discharge into the coastal ocean, it is essential to understand both the composition of the effluent and the environmental conditions in the receiving waters.”
While Environment Canada’s regulations consider the former, they completely ignore the latter. In stark contrast, the Johannessen study accounts for the actual differences between physical conditions in the Strait of Georgia or Juan de Fuca Strait and, for example, physical conditions in Lake Ontario or the North Saskatchewan River. The authors state: “In some parts of the world wastewater discharge has led to eutrophication [an excess of nutrients], harmful algal blooms, hypoxia, extinctions of bottom fauna and fish mortality. However, the effects of wastewater discharge are not the same everywhere. For example, phosphates in household wastewater can have dramatic effects on lakes, causing eutrophication and harmful algal blooms, while anthropogenic phosphate has little effect on marine ecosystems, where productivity is more often limited by nitrate. Similarly, wastewater can affect one coastal sea differently from another, depending on processes occurring in the receiving environment. Consequently, management actions that are developed for one area, such as introducing a particular level of wastewater treatment, might not have the anticipated effect when applied to another.”
Johannessen, and one of her co-authors, Rob Macdonald, are both research scientists with DFO’s Institute of Ocean Sciences in Sidney. Both are also adjunct professors at UVic.
Regarding the danger of eutrophication and harmful algal blooms, the authors note, “The nitrogen discharged through all the municipal wastewater outfalls combined represents only approximately one percent of the total influx [of nitrogen from other sources]. In addition, for most of the year in most of the Strait, phytoplankton are limited by light, not by nutrients.” The authors discuss physical conditions particular to the Straits that limit growth of phytoplankton and conclude,“wastewater is unlikely to cause eutrophication or harmful algal blooms in the Strait of Georgia or Juan de Fuca Strait.”
Impacts on the Straits from the discharge of organic carbon from wastewater are also quantified by the authors, who note “the municipal outfalls represent approximately 0.2 percent of the total of the sources. This is negligible in the context of the whole Strait.”
The scientists acknowledge that the discharge of organic carbon does have “local effects in the area immediately surrounding each outfall.” Their description for the Macaulay Point outfall states: “[O]rganic deposition results in a high sediment concentration of organic carbon and greatly elevated sulphides, but no evident oxygen stress within sediments (due to high bottom currents and sandy substrates). Organic biomass appears to be normal relative to background in sediment around the Macaulay outfall.”
The study’s authors note that there is some metal contamination in the Straits but attribute this to past mining activity, noting that core samples from the footprint of the Iona plant outfall show “little indication” of contamination by lead, zinc or copper. Elevated levels of cadmium at some outfall sites are attributed to sulphides in the footprint of the outfalls sequestering dissolved cadmium already in the water.
In terms of biochemical oxygen demand, the study notes that wastewater represents only “one percent” of the demand. “On a basin scale, therefore, municipal wastewater does not add significantly to the pressure on oxygen in the Strait. In the sediment near the outfall, however, the biochemical oxygen demand of the effluent has measurable chemical and biological effects...” Even so, the authors single out the energetic ocean conditions and rapid mixing of the effluent with seawater that exist at the Macaulay and Clover outfalls as mitigating the effect of the effluent’s oxygen demand.
Although the study did not consider various contaminants in wastewater that are present at very low concentrations in the Straits (detergents, pharmaceuticals, fragrances, pathogens, caffeine, etc.), the authors note that most of these substances would be expected to either break down or be consumed within one or two weeks of entering the ocean, after which time anything that remained of them would be exported out of the Straits by the net outflow of water produced by rivers flowing into the Straits. The authors note that secondary treatment could reduce those contaminants but offer no judgment on whether that would benefit the health of the Straits. The concentrations of these materials in local waters are known to be very low—below our ability to detect them.
As mentioned above, the one category of contaminants in sewage that the Johannessen study predicts could be significantly reduced by secondary treatment are PBDEs.
PBDEs are thought to be endocrine disruptors and may produce adverse reproductive, developmental, neurological, and immune effects in both humans and wildlife. There is broad concern that PBDEs, like PCBs, may be bioaccumulative. (See the 2014 US EPA fact sheet for more information on the language scientists are using regarding these effects.) Environment Canada and Health Canada have stated it’s their objective to reduce the concentration of PBDEs in the Canadian environment “to the lowest level possible.” Consequently, the manufacture and use of PBDEs have been banned in Canada.
The Johannessen study notes, “Secondary treatment will decrease the direct input of PBDEs considerably, but it is not designed to break down persistent organic pollutants. Consequently, the effect of increasing the level of treatment will largely be to move PBDEs from marine effluent into sludge that will have to be further managed to prevent its potential re-entry into the aquatic environment.”
This is a critical point. If the only significant environmental benefit of treatment is to divert PBDEs away from the ocean, but our management of sludge and biosolids then allows them back into the environment, what would be the point of spending any public money for that initial diversion?
We can predict the likely fate of CRD biosolids by looking to the Annacis Island secondary treatment plant on the Fraser River that serves metro Vancouver. The data in the study shows the Annacis Island plant removes approximately 80 percent of PDBEs, which, after the sludge is processed in anaerobic biodigesters, end up in biosolids. Those biosolids are, according to Metro Vancouver, used as “cover material at landfills, fertilizer on grasslands and hay fields, for land reclamation at copper and molybdenum mines, as soil for city parks and recreation areas.” Metro Vancouver also notes that “innovative” methods for disposing of biosolids include “deep ocean dumping” and “incineration.”
Consider the possibility of biosolids being used for “landfill cover” at Hartland Landfill, for example. Rainfall would eventually wash the PBDEs into the landfill’s leachate collection pipeline, which feeds into Victoria’s sewer system. The PBDEs would then return to a sewage treatment plant where about 20 percent of them would escape to the ocean. The other 80 percent would then return, via sewage treatment, to become landfill cover at Hartland. Over time the amount of PBDEs circulating through the landfill would increase, as would the flow of PBDEs that escape to the ocean. An investigation of PBDEs in landfill leachate headed by UBC scientist Monica Danon-Schaffer shows some cities in Canada with greatly elevated levels of PBDEs emerging from their landfills.
Similarly, if the biosolids were incinerated, the low temperatures at which municipal incinerators operate would result in the PBDEs passing through the incinerator into the atmosphere, only to be washed out later by rain onto land or water.
For those who hope that gasification of the biosolids would destroy PBDEs, think again. There is only one facility in Canada—the controversial Swan Hills Treatment Centre in Alberta—that is licensed to process such hazardous materials as PBDEs, and it employs very high temperatures relative to municipal incinerators or gasifiers.
What is the CRD’s plan for the biosolids produced by secondary or higher levels of treatment? In 2010 the CRD avoided providing the Province with its plan for biosolids when they submitted, and received approval for, their current wastewater treatment plan for McLoughlin Point. That plan stated that an environmental assessment of the CRD’s biosolids plan had been completed, but an FOI filed by Focus shows the environmental assessment wasn’t actually carried out until 2015. That document simply notes that biosolids “will be used in a beneficial manner consistent with CRD Policy.”
So far, no one knows what that is.
Let’s sum up what we know so far. The only environmental benefit of secondary sewage treatment—according to scientists who have considered the actual in-the-water situation for Victoria—is the opportunity to permanently divert PBDEs away from the ocean. Yet the CRD has not established a plan for how it will dispose of biosolids let alone sequester the PBDEs they would contain.
To explore this further I contacted the study’s lead author, Sophie Johannessen.
Johannessen highlighted the complexity of the PBDEs issue by describing to me a hypothesis she has developed. It’s surprising. Her research suggests that the benthic community—the creatures that live in and on the surface sediments of the ocean bottom— have a lower level of PBDEs at the Macaulay Point outfall than those at the Iona Island outfall, which has a higher level of treatment. Johannessen thinks that’s because there’s more carbon available to eat at Macaulay compared to the amount of PBDEs. In terms of reducing the amount of PBDEs entering the marine food web, less treatment may be better. How could we expect regulators in far away Ottawa to know this?
Johannessen agreed that unless the CRD found a way to remove the PBDEs from biosolids after treatment, they could eventually make their way to the Strait. “Moving persistent contaminants into sludge, which is then spread on land, might actually increase the length of time over which the environment—groundwater, streams and eventually the ocean—is exposed to the contaminants,” she explained. “Source control would be far more effective. For PBDEs, we have already undertaken source control by banning their import or manufacture, although it is going to take a long time for the existing stock of PBDEs in our furniture, toys and electronics to stop draining into the ocean. Source control is likely to be the most effective solution for any trace contaminants, because they do not make up the bulk of the effluent and because they tend not to be destroyed by sewage treatment.”
I asked Johannessen if the CRD’s plan for sewage treatment—ill-defined as it is at the moment—seemed to her to be a good way to spend a billion dollars, especially in light of her finding that the opportunity to remove PBDEs was the only significant environmental effect that might be obtained from sewage treatment. “As a scientist,” she said, “it isn’t for me to say. That’s a political decision.”
Fair enough, but is there anything we could do that would have a more positive effect on the marine ecosystem than upgrading Victoria’s sewage treatment system?
“I think so, yes,” Johannessen said. “We could reduce our greenhouse gas emissions, enact source control for persistent contaminants, and reduce other local pressures on the marine biota.”
How would reducing our emissions help? “Anything that would reduce our greenhouse gas emissions would help to slow the rate of change in the ocean, which would give marine biota more time to adapt to the changes,” Johannessen said. “Reducing carbon dioxide emissions, specifically, would also reduce the rate of ocean acidification, which is considered a major threat to a wide range of marine life, including shellfish.”
What other ocean effects are scientists seeing that are related to climate change? “The local ocean is already changing fast, as a result of global-scale climate change,” Johannessen said. “The temperature of seawater and river water is increasing; the concentration of oxygen in the deep water of Juan de Fuca Strait and the Strait of Georgia is decreasing; the abundance and nutritional content of zooplankton—food for juvenile fish and seabirds—is decreasing; the timing of Fraser River flow—which drives the physical circulation in the Strait—is changing; and the frequency of short-term events such as windstorms and short intense rainstorms is increasing.”
How ironic is it, then, that just as countries around the globe are marshalling the skills and knowledge of their best scientists to find a path to decarbonization, Victorians are poised to trade in their tidal-powered sewage treatment system (Johannessen likens it to “a giant washing machine”) for one that has an immense emissions burden attached? In 2013, for every million dollars of economic activity in Canada, 416 tonnes of CO2 were emitted. So the emissions burden associated with the $1 billion capital cost of this project is on the order of 416,000 tonnes.
Scientists have already made it clear that the current treatment system is not causing harm to the environment. This latest study can also be seen as a warning to all of us that a carelessly-conceived treatment system could end up doing considerably more harm than good.
David Broadland is the publisher of Focus Magazine.
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