The search for a solution to the sewage treatment issue has lost sight of what it should be looking for; here’s a reminder.
IN MID-AUGUST, Victoria architectural firm D’Ambrosio Architecture + Urbanism released drawings of a design created by “an international team” for a wall around a sewage treatment plant on McLoughlin Point at the entrance to Victoria’s harbour. Writing in the past tense, as though the idea might have already been superceded by some better one, the firm stated: “The architectural strategy embraced the industrial nature of the facility. It consisted of a series of 184 concrete columns forming a palisade around the process and operation buildings. The buildings housing operational and administrative functions engage the columns, creating a visually calm and collected interface between the industrial facility and the sensitive harbour waterfront.”
Aside from obscuring the plant, the 184 sturdy concrete columns in D’Ambrosio’s design don’t suggest any utilitarian purpose. Instead they seem to be there simply to memorialize something big: A war, perhaps, or some other sad outcome of human misjudgement. Considering the evidence challenging the wisdom of moving the region’s marine-based treatment system to land, D’Ambrosio’s vision is, intentionally or not, one of the most honest public statements made about the treatment project so far.
Later in this story I’m going to follow D’Ambrosio’s lead and be creative, but in a different direction. Rather than artful, I’m going to be practical and answer these questions: What’s wrong with the current marine-based treatment system, and how can we fix that?
First though, I want to tell you about one of the great strengths of the current system, a very progressive approach to wastewater treatment that obviously has much potential but will likely be one of the first casualties of land-based secondary treatment: the CRD’s Regional Source Control Program. The best way for me to describe its potential is to show you what it has achieved since 2003.
Back in 2004, the Sierra Legal Defence Fund (now called Ecojustice) petitioned the federal government “to effectively address the pollution of the marine environment by persistent organic pollutants including PCBs.” Ecojustice targeted Victoria’s outfalls in their petition and named ten different contaminants it identified as “harmful”: Polychlorinated biphenols (PCBs), oil and grease, mercury, lead, silver, cadmium, copper, zinc, polycyclic aromatic hydrocarbons (PAHs) and “halogenated compounds.”
For each contaminant, Ecojustice provided an estimate of the amount being discharged over a two-year period. It based its numbers on CRD data obtained through an FOI, but some of those numbers now seem unsupportable—either too high or too low—based on data since made public by the CRD.
Using data collected by CRD scientists between 2003 and 2014 for the substances named in Ecojustice’s petition, reductions can be estimated: The discharge of oil and grease has been reduced by 93 percent, mercury by 95 percent, silver by 94 percent, cadmium by 72 percent, lead by 62 percent, and PAHs by 28 percent. Although there are several halogenated compounds found in the CRD’s effluent, consider the case of pentachlorophenol, once commonly used by homeowners in Victoria as an insecticide and a wood preservative. In 2004, PCP was detected in 100 percent of the CRD’s samples. By 2014, the CRD could no longer detect PCP in the effluent.
What about PCBs? Ecojustice took a single sample from each outfall in both 2001 and 2003 and included those in its 2004 petition. That 2001 figure was 2100 grams per year and was well-used in campaigns to discredit the marine-based, source-controlled system. In 2015, DFO scientist Sophie Johannessen published a peer-reviewed study that estimated the annual discharge of PCBs at 340 grams per year. Based on those numbers, there has been an 83 percent reduction in the amount of PCBs being discharged, even while the residential population using the outfalls increased.
The 95 percent reduction in mercury since 2004 is the strongest affirmation of the potential of source-controlled treatment. Victoria’s effluent now has even less mercury per litre than the Annacis Island secondary treatment plant on the Fraser River. But Victoria has done this without the immense cost of land-based secondary treatment or any of the environmental risks associated with land-based disposal of the chemically-contaminated biosolids that Annacis Island and other secondary treatment plants produce.
CRD scientist Chris Lowe, who has overseen the region’s wastewater monitoring program for many years, credits the reductions to the Regional Source Control Program and to reductions in the general use of certain materials in our culture. Digital photography has largely replaced silver-based photography, for instance.
To put the current level of chemical contamination from Victoria’s wastewater in some perspective, I compared the CRD’s 2014 data for the substances Ecojustice identified as “harmful” with Health Canada’s current Drinking Water Guidelines for those substances. That’s right, I compared Victoria’s sewage with Canada’s drinking water. The result is surprising (see table below).
Health Canada’s Guidelines specify an upper limit for the allowable concentration of contaminants for water to be safe for humans to drink. For example, the concentration of mercury allowed in Canadian drinking water is .001 milligram per litre. That turns out to be 100 times higher than the average concentration of mercury in the sewage that passed through the Macaulay Point outfall during 2014. Health Canada allows 25 times more cadmium and twice as much lead in drinking water than can be found in Victoria’s sewage.
Not all of the contaminants targeted by Ecojustice are limited by Health Canada’s Guidelines. For example, copper and zinc are considered beneficial to human health and the Guidelines set no health-related limits for these. The US EPA’s National Primary Drinking Water Regulations, however, has established a limit for copper in America’s drinking water. That level is 10 times higher than the level of copper currently found in Victoria’s wastewater.
Similarly, Health Canada’s Guidelines don’t give an allowable limit for polychlorinated biphenols (PCBs), but the EPA does. It allows PCBs in drinking water at a concentration that’s 50 to 60 times higher than is currently found in the effluent passing through Victoria’s two marine outfalls.
Two of the contaminants on Ecojustice’s list, copper and zinc, both of which come mainly from deteriorating domestic water supply pipes and fittings, have seen only minor reductions since 2004. Does the failure of source control to limit the amount of copper and zinc warrant the investment of billions in public resources over the life of a land-based treatment system?
Ecojustice might think it does, but environmental protection policy in jurisdictions around North America doesn’t reflect that view. Let me tell you about copper, zinc and “the initial dilution zone.”
While both copper and zinc are considered essential for human health, they are potentially harmful to aquatic life even at low concentrations. To protect organisms against such contaminants in wastewater discharged to bodies of water, the BC Ministry of Environment has developed “Water Quality Objectives” that are orders of magnitude more stringent than Health Canada’s Drinking Water Guidelines. These objectives must be met, but the undiluted effluent from secondary and tertiary treatment plants simply can’t meet them. In fact, sewage treatment is known to increase the amount of dissolved copper, which makes copper even more immediately available to cause harm to aquatic organisms. None of BC’s secondary treatment plants meet the Province’s standard for either copper or zinc. For example, Vancouver’s Annacis Island secondary treatment plant—located right on the migration route of Fraser River sockeye—exceeds BC’s water quality objectives by factors of 4 and 10 for zinc and copper respectively. How does the Province get around this conundrum?
It does that by incorporating into its environmental regulations what’s known in wastewater treatment policy as “the initial dilution zone.” What is that? It’s an imperfect place, a volume of water where conditions are moving from not-so-good to better. The BC Environmental Protection Branch, responsible for overseeing the appropriate implementation of BC Water Quality Objectives, states: “Objectives do not apply within an initial dilution zone, which is the initial portion of the larger effluent mixing zone. The extent of initial dilution zones is defined on a site-specific basis, with due regard to water uses, aquatic life, including migratory fish, and other waste discharges.”
In other words, the effluent inside an outfall isn’t required to meet water quality objectives. It doesn’t have to meet the objectives a second or two after being discharged, either. It’s allowed a certain distance away from the outfall—usually 100 metres—to become diluted enough that it effectively meets the regulation water quality objectives. Notice that all of this is determined on a “site-specific” basis. Once the effect of the initial dilution zone is taken into count, the CRD’s discharge of copper and zinc meets the Province’s stringent water quality objectives just as well as Annacis Island’s secondary treatment plant does.
Why does the Province take this approach? The Environmental Protection Branch’s explanation is blunt: “If initial dilution zones did not exist, it would mean that effluent quality would have to meet water quality objectives, which would be costly and impractical.”
Costly and impractical. Say those words a few times, roll them around your mind and try to get a feel for why the Province, the US EPA and every other jurisdiction in North America—except one—has adopted the initial dilution zone (aka “mixing zone, “zone of initial dilution,” etc) as a fundamental policy tool for making practical decisions about environmental protection and wastewater. That one exception, of course, is Environment Canada’s Wastewater Systems Effluent Regulations, brought into being by Stephen Harper’s government.
Those regulations judged that Victoria’s effluent, before being discharged into the initial dilution zone, had too high a concentration of “suspended solids,” which, to translate as accurately as possible, means “digested food.” Obviously, “food” is not one of the substances that can be successfully source controlled by the CRD. As contaminants go, this one is all appearance and no cause for concern. According to marine scientists, the amount of digested food Victorians discharge to the ocean does not constitute an environmental risk. DFO’s Johannessen put it in context in her 2015 study: The discharge of digested food from the two outfalls represents .03 percent—that’s three one-hundredths of one percent—of the total suspended solids discharged by all sources to the Strait of Georgia and the Strait of Juan de Fuca. Yet that’s the only factor Environment Canada’s regulation used to push Victoria in the costly and impractical direction it’s now headed. There’s the appearance that something necessary has been done, but there’s no evidence that there is a problem that needed fixing.
The CRD’s highly-effective source control program will likely be one of the first victims of Environment Canada’s unhelpful regulation. The serious financial burden of a land-based secondary treatment system will inevitably result in a quest for cost-saving measures at the CRD. Other communities with secondary sewage treatment don’t have advanced source control programs, so why should Victoria? Chop.
Victoria’s unique approach to wastewater treatment—reducing contaminants by keeping them out of the environment in the first place—is a challenge for many to understand and appreciate. It has remained Victoria’s big secret. Why? Because the CRD has done a terrible job of communicating its successes to the community, and media here have largely ignored the story. The CRD’s unwillingness to toot its horn has likely reduced the impact of the program over what would have been possible with a better-funded, more broadly understood and supported initiative. That dearth of communication also applies to the marine-based treatment system’s strengths and weaknesses and its ability to protect public health.
IN A 2008 EDITORIAL in the scientific journal Marine Pollution Bulletin, nine Victoria and Vancouver marine scientists refuted the basis on which then-Environment Minister Barry Penner had ordered Victoria to abandon its carefully-engineered and smoothly operating marine-based treatment system. The scientists noted, “The concept of natural sewage treatment has been criticized in the media, but in fact waste treatment is well recognized as a useful ecosystem service contributing to human well-being. The focus of environmental protection is changing to preserving such ecosystem services to the benefit of both human beings and the natural environment. It makes no sense to replace a natural ecosystem service with a human creation that is energy inefficient and has other harmful environmental consequences.”
Let me remind you, briefly, how Victoria’s “natural treatment system” works. Many people know there are screening and settling plants at Clover Point and Macaulay Point where a lot of solids are removed, but they don’t seem to know what happens out in the Strait of Juan de Fuca.
The plants on the points remove from the wastewater anything solid that’s larger than 6 millimetres in diameter, which is roughly the size of a pea. Oil and grease are scrapped off in the settling tanks and the remaining effluent—99.9 percent water—flows by gravity down a pipe to the outfall. The outfalls consist of a pipe sitting on the seabed leading to a specially-engineered section called a diffuser. Located 55 to 60 metres below the surface, the diffuser has carefully spaced and oriented ports that direct the effluent upwards. Macaulay Point’s diffuser is 135 metres long and about 1700 metres from the nearest shoreline. Clover Point’s diffuser is 196 metres long and 1100 metres from the nearest shore. The ends of both outfalls are capped and the effluent is forced out of 28 small ports at Macaulay and 37 ports at Clover. It’s not “dumped,” as the Times Colonist relentlessly claims.
At Clover Point, the effluent is dispersed from 37 small jets into a 200-metre-wide by 60-metre-high wall of cold, turbulent, highly-oxygenated salt water that’s travelling at speeds of up to one metre per second, depending on the strength of the tides. At that speed, as much as 12,000 cubic metres of water passes over the diffuser in a single second, quickly diluting the effluent and beginning the physical process of killing off bacterial contaminants. Victoria’s treatment system harnesses a tremendous source of renewable energy—almost twice the peak spring flow of the Fraser River—to do that work. DFO’s Johannessen describes the turbulent river of water off Clover Point as “like a giant washing machine.”
The “plume,” as the rising effluent is known, is washed in the direction of the current. CRD monitoring of the plume shows it seldom reaches the surface of the water (four times in 2014), and then only during periods of intense winter or spring rains. But the top of the plume is generally trapped five metres or more below the surface. At that depth, while bacteria are rapidly dying as a result of the harsh physical conditions, there’s little possibility of contact with humans. The testimony from knowledgeable, local experts about the efficacy of this approach to killing bacteria is unequivocal: Six past and current public health officers—Dr Richard Stanwick, Dr John Millar, Dr Shaun Peck, Dr Brian Emerson, Dr Brian Allen and Dr Kelly Barnard—have stated: “There is no measurable public health risk from Victoria’s current method of offshore liquid waste disposal.”
In spite of their assurance, though, there are some pertinent questions about what might happen in the future as the region’s population grows and there’s more sewage. Would the plume break through to the surface more frequently? And what happens when the tides change? Doesn’t the current passing over the diffuser slow down, stop, and then change direction? Then what happens to the plume at slack tide? Does the rapid rate of dilution stop?
I’ve spoken with many local engineers, scientists and interested residents over the past several years about these questions, and they’ve provided all sorts of creative solutions. I’ve knit some of what they’ve told me into what follows.
According to these experts, there’s a way of improving the physical characteristics of the outfalls’ plumes that would make Victoria’s treatment system even more effective at dispersing chemical and biological contaminants and extend its life far into the future. The improvements become possible if a completely different problem—contamination of near-shore waters by the release of sewage during significant rainstorms—is solved first. Let me take you through these ideas, starting with solving a real problem for $50 million.
The nine local marine scientists who wrote the editorial in Marine Pollution Bulletin in support of Victoria’s “natural sewage treatment” system noted that, prior to Penner’s 2006 order to the CRD, “an independent expert scientific review had been completed under the auspices of the Society of Environmental Toxicology and Chemistry (SETAC). 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.”
None of those “more pressing environmental issues” have been addressed, and that has created bizarre and unpredictable results.
In March of this year, Washington State Representative Jeff Morris and 36 of his fellow legislators threatened an economic boycott of Victoria. The incident that triggered their outrage was an article in the Times Colonist about what’s called a “combined sewer overflow,” or CSO. Morris thought the paper’s story was about Victoria’s deep-water marine outfalls, but it wasn’t. It was about a very ordinary problem, common even in Morris’ 40th District. During heavy rainfalls, sewage collection systems that don’t have enough hydraulic capacity—the ability to absorb liquid—spill the excess through short beach outfalls into near-shore waters. When such events occur in Victoria, there’s a big fuss in the TC as CRD officials warn residents of the possibility of contamination of beaches. It’s common to blame these spills on the two deep-water marine outfalls, but there’s no connection. CSOs are a problem unto themselves, and land-based treatment plans developed by the CRD so far would only address a fraction of the problem.
Seattle is currently fixing a much worse CSO problem than Victoria’s, partly by increasing the hydraulic capacity of the Murray Basin collection system. That involves building a big storage tank that can absorb surges in the amount of liquid in the sewers during storms. Once a storm has passed, and liquid levels in the collection system have dropped, the contents of the tank can be slowly released, and a CSO is avoided.
The CRD’s McLoughlin Point plan included building such a tank in Gordon Head—the so-called Arbutus attenuation tank. Construction of that tank would have allowed the CRD to put a screen on one of three remaining unscreened beach outfalls on the East Coast Interceptor. Unscreened beach outfalls have given Morris and Mr Floatie much material to work with—“floatables” is the usual euphemism—in their misleading campaigns against Victoria’s marine-based treatment system. But only increasing the hydraulic capacity of the collection system will eliminate floatables, Mr Floatie and Representative Morris from the region’s politics. The cost of accomplishing that can be estimated from the projected cost of the Arbutus attenuation tank project.
The CRD and its consultants predicted the Arbutus tank would cost $9.5 million and its construction would eliminate all overflows in the East Coast Interceptor portion of the system for all downpours up to a “one-in-five-year storm event.” That’s the CSO standard required by the Province. To bring the whole system up to that standard would require a total of five Arbutus-like tanks scattered strategically around the core area. The total capital cost of such an increase in hydraulic capacity would be in the neighbourhood of $50 million. Imagine if the CRD decided to listen to the scientists and actually solved the CSO problem.
Doing that would also allow improvement of the marine-based treatment system. Here’s how that would work.
Those tanks, if used only to absorb downpours and eliminate CSOs, would be empty almost all of the time. According to the CRD, over a six-year period the region experienced 160 CSOs. This means that having the capacity to reduce CSOs down to the Province’s standard would result in storage tanks that would be empty about 90 percent of the time. During that time, they could safely be used for another purpose: controlling the outfall plumes. Let me describe how that would work.
The volume of liquid flowing to the outfalls as a result of human activity varies through a 24-hour period in a pattern that’s very predictable. See the oscillating line in the graph above, which shows how the flow to the outfalls varies over eight days. The consistent pattern of our daily use of sinks, showers, bathtubs and toilets results in a peak flow around breakfast, after which it falls off until mid-afternoon and then rises to another peak just before we go to bed. The flow falls to a minimum while we sleep, and then the cycle repeats itself.
Imagine if we could even-out the flow so that’s it’s more or less constant throughout the day (indicated by the red line in the graph above). That would reduce the maximum flow from the diffusers and that would be like going back several decades in time to when the maximum flow was about 65 percent of what it is today. The plume would then be even less likely to reach the surface.
How could the flow be evened out? The experts say that could be accomplished by using the CSO tanks to hold back some of the flow generated between breakfast and bedtime and then letting it go in the wee hours of the night.
Those tanks would also allow reducing or pausing the flow of effluent from the diffusers during the period when the tidal current slows, stops and then reverses direction. This would further reduce the likelihood that the plume could break through to the surface. It might also lessen the amount of organic material that’s deposited in the footprint of the initial dilution zone during slack tide.
There could even be bells and whistles: Large tanks full of sewage would contain a lot of thermal energy. The Southeast False Creek Neighbourhood Energy Utility in Vancouver, for example, uses thermal energy captured from sewage to provide space heating and hot water to nearby buildings. Perhaps the False Creek example points to where such tanks could be located: below the car-parking level in new Downtown condominium towers. In exchange for providing that service, or as an inducement to provide it, the City could allow a couple of extra floors on a limited number of new buildings.
These tanks could also act as a catchment for particles of lead, zinc and copper coming from corroding plumbing pipes and fittings upstream, thereby keeping those materials out of the marine environment. It would even be possible to fit the tanks with standard water-oil separators that would further reduce the amount of oil and grease discharged to the Strait of Juan de Fuca, allowing the oil to be recycled.
Why isn’t Victoria going to do this—or something along these lines?
Perhaps Franc D’Ambrosio’s grand vision of 184 decorative concrete columns hints at the answer to that question. His project isn’t meant to be a response to a compelling physical issue. Same with the treatment project. It’s an opportunity for some people to make money and for others to make a name for themselves as architects, political fixers, activists—even as journalists. Mostly it fulfills a promise made ten years ago by former BC Premier Gordon Campbell to former Washington State Governor Christine Gregoire. Whatever the original objective might have been, the actual environmental impact of what will be chosen has since become of little consequence. In fact, knowing the impact has been carefully avoided. Here’s a telling example of how pervasive the avoidance of truth has been on this issue.
Recall that at the beginning of this story I referred to a 2004 petition by Ecojustice to the federal government. The information Ecojustice used to press its campaign against Victoria’s treatment system turned out to be flawed, and in the years since, scientists have confirmed the CRD’s source control program has removed a big chunk of the contaminants. During that time, many local marine scientists publicly questioned the value of land-based treatment and expressed concerns about its associated environmental risks. By late 2012, enough doubts had been raised about the CRD’s direction that a motion was put forward at the CRD calling for “a full environmental study that will assess the comparative environmental impact of the current process and proposed process for disposing of liquid waste before the CRD plans are finalized.”
One might expect that an organization like Ecojustice would have been in full support of a truth-seeking exercise like a comparative environmental assessment. Who wouldn’t want to confirm that the best direction was being taken?
Apparently, Ecojustice didn’t want to know. In a letter sent to CRD directors before they voted on the motion, Ecojustice lawyers implicitly threatened the CRD with legal action under the Species at Risk Act if it approved the call for a comparative environmental impact assessment.
The motion failed.
David Broadland is the publisher of Focus.
Edited by admin