The Iona Upgrade Must Aim Higher Than “Just Good Enough”
Metro Vancouver once promised tertiary treatment at the Iona Island Wastewater Treatment Plant—the gold standard for protecting the Salish Sea. Now, that promise is slipping away. In a move framed as “cost-saving,” the region is backtracking from tertiary to a “just good enough” secondary treatment, a step that risks decades more of pollution pouring into one of B.C.’s most vital and inhabited marine ecosystems.
But first let’s talk about what is happening right now. Imagine that every time you turned on a tap, you were contributing—however unknowingly—to pollution of the Salish Sea. That’s essentially what’s happening today in Metro Vancouver, because the region’s main wastewater facility only filters out the most obvious contaminants. The Iona Island Wastewater Treatment Plant, serving roughly 850,000 people, currently treats it to a primary level only, allowing nutrients, microplastics, pharmaceuticals, heavy metals and more to pass through into our marine ecosystem.
The Status Quo Is No Longer Acceptable
The Iona plant was built in 1963 and, despite multiple renovations, still performs only the most basic treatment. It handles some 200 billion litres of wastewater per year—roughly 40% of the region’s load—and discharges its effluent via a 7-km outflow pipe into the Salish Sea near the Fraser estuary.
That effluent is not innocuous. Wastewater contains a complex “cocktail” of chemicals: nutrients (nitrogen, phosphorus), microplastics, heavy metals, industrial compounds, pharmaceuticals, pathogens, and more. Primary treatment removes large solids and some organic matter (at best 50–60%) but does not meaningfully reduce most of these harmful compounds. These pollutants are implicated in declines of local marine species including Pacific salmon, and are a chronic threat to the health and reproduction of Southern Resident orcas, harming local economies and affecting the well-being of coastal communities.
A Major Redesign: Metro Vancouver’s New Proposal
Metro Vancouver is under obligation to meet provincial and federal regulatory standards, and given the pressures from population growth, a major redesign can’t wait indefinitely. Beginning in 2024, planners have been exploring new configurations for the Iona upgrade that balance environmental goals with cost and ratepayer impacts. In July 2025, the Metro Vancouver Board held a special workshop to review an alternative phased approach. That alternative was formally adopted by the Board in October 2025, shifting the project to a two-phase delivery model.
Key features of the adopted alternative:
- Incremental addition of secondary treatment at the existing plant to improve effluent sooner
- Rehabilitation of the current plant, with full replacement deferred to later
- Focusing on components necessary to meet secondary treatment compliance by 2039
- Deferment of sub-projects not essential for that compliance
- A revised cost estimate of roughly $6 billion (versus ~$9.9 billion under the original scope)
Metro Vancouver frames this as a more “affordable, feasible” path, claiming it allows the region to deliver regulatory compliance while moderating rate impacts.
BUT…..
Critics warn that this approach could lock the region into years of underperformance, delaying the adoption of tertiary treatment—the only level capable of removing the most harmful pollutants that primary and even secondary systems cannot effectively manage.
Documents presented to the Board reveal that the long-term costs of deferral could be immense. Metro Vancouver staff estimate that completing the remaining work later could add up to $7.7 billion, bringing the total project cost to approximately $14.3 billion—far exceeding the original estimate. As Vancouver City Councillor and Board Director Sarah Kirby-Yung cautioned, “This is essentially saving money now and kicking the can down the road.”
Compounding the concern, the scaled-back plan would meet only partial compliance with provincial wastewater regulations, forcing Metro Vancouver to negotiate with the B.C. government to lower its environmental standards. It would also raise only select parts of the facility—such as doors, roads, and control systems—leaving the main treatment plant exposed to sea-level rise. In addition, two-thirds of planned ecological restoration projects around Iona Island would be postponed, while the lack of seismic upgrades means the existing plant could function at only half capacity in the event of a major earthquake.
And what Metro Vancouver does not say is that pollutants can accumulate in shellfish and fish, posing risks to human health and traditional food harvesting. They also contribute to algal blooms and degraded water quality that make swimming, boating, and other recreation unsafe. Over time, this contamination undermines tourism, fisheries, and the broader blue economy that rely on clean, healthy marine ecosystems.
All this leaves as with a question, is it really an “affordable, feasible” path?
Why Tertiary Treatment Must Be the Benchmark
The merit of tertiary treatment is clear, and other cities globally already require it. Tertiary approaches filter or otherwise remove residual nutrients, metals, microplastics, and trace organic compounds—all of which are poorly addressed (or not at all) by primary or secondary systems.
Georgia Strait Alliance has been vocal for years about this matter: now is the time to demand that Metro Vancouver build the Iona upgrade with tertiary capacity from the start, not as an afterthought. If we stop at secondary, we’ll continue to discharge pollutants that stress ecosystems, undermine fisheries and tourism, and continue to weaken our social license for environmental leadership. Worse, it puts future generations into a bind, making retrofits much more expensive.
What’s at Stake & What You Can Do
Our Salish Sea marine environment is fragile, and persistent exposure to pollutants continues to undermine its resilience. Metro Vancouver has previously committed to tertiary treatment, and maintaining that commitment is essential for public trust and credibility. While delaying advanced treatment may appear more affordable in the short term, retrofits and ecological remediation will ultimately come at a much higher cost—both financially and environmentally. Given the scale and consequence of the Iona upgrade, meaningful public engagement and oversight are vital to ensure that the decisions made today truly protect the health of our ecosystems and communities for generations to come.
At Georgia Strait Alliance, we’ll continue monitoring the decision process, pushing for transparency, and advocating for a path to tertiary treatment. But this isn’t just our struggle—it’s yours too: your community, your sea, your future. You can join us in contacting Metro Vancouver decision-makers, submitting your views to:
- Mike Hurley, Metro Vancouver Board Chair (mayor@burnaby.ca)
- John McEwen, Metro Vancouver Board Vice Chair (john.mcewen@anmore.com)
- Malcolm Brodie, Liquid Waste Committee Chair (mayorea@richmond.ca)
- Liquid Waste Committee (lwmp@metrovancouver.org)
- Iona Island Wastewater Treatment Plant Projects ( ionawwtp@metrovancouver.org)
Raise your voice and share this blog to mobilize others who care about the Salish Sea. Metro Vancouver’s decisions today will shape our coast for decades—let’s make sure they choose a future defined by clean water, not compromise.