“MY wastewater?!?”, you might be thinking. It’s true. Anything that runs down the drains of your sinks, showers, washing machines, dishwashers and toilets becomes wastewater. Personal and industrial use of items that contain complex, and sometimes harmful, chemicals means that wastewater contains a myriad of compounds including plastics, heavy metals, nutrients like phosphorus and nitrogen, sulphides, soaps, pharmaceuticals, pathogens, food waste, fats, oils and human waste.
Iona Island Wastewater Treatment Plant outflow enters the Salish Sea through this seven-kilometre-long pipe. Source: Obabika.
How do these pollutants end up in the Salish Sea? Pipes direct anything that flows from where you live to your municipality’s sewer system, where it joins runoff from rain and snow – called stormwater. The resulting mixture then flows to your region’s wastewater treatment plant to be processed, and the filtered product – now called outflow – is discharged into local waters. If you live in Vancouver or Burnaby, your wastewater is likely treated at the region’s largest plant, Iona Island, which processes over 200 billion litres of water each year and pumps outflow into the Strait of Georgia, at the mouth of the Fraser River, via a seven-kilometre-long pipe.
Pollutants contained in wastewater treatment plant outflow can negatively impact marine ecosystems. Locally, pollution in the Salish Sea is putting Pacific salmon at risk and causing immune and endocrine system dysfunction in endangered Southern Resident orcas. The good news is that the technology to remove these compounds from wastewater is available.
You might ask “what if we just stopped using things that contain these pollutants?” The use of these chemicals can be unnecessary, as in the case of some cosmetics, but in many instances it is essential, as in the case of pharmaceuticals. In addition to source control where we can, the real solution to the problem is effective and targeted wastewater treatment, which can prevent these toxins from harming the environment into which wastewater outflow is directed.
Wastewater can be treated using a variety of methods, which are organized according to the degree to which they remove these compounds.
Primary treatment uses mechanical methods to remove materials that settle or float. Larger solids can be removed via screens, while smaller particles are skimmed or can be removed via a settling process. Only fifty to sixty percent of solids are removed at this level of treatment.
Secondary treatment is the minimum federal standard in Canada. In addition to using the methods above, it uses biological processes to remove suspended solids and dissolved matter. Bacteria and chlorine can be used to remove organic material and small particles. Ninety percent of solids are removed at this level of treatment.
Tertiary treatment employs the methods above and filters the most harmful contaminants. Tertiary treatment can disinfect wastewater from viruses and pathogens, making it safe to discharge near places like beaches. Nitrogen, phosphorus and persistent organic pollutants can also be eliminated, in addition to over ninety-nine percent of microplastics.
In Europe tertiary treatment is the norm and many Canadian municipalities treat wastewater at a tertiary level. Sadly, Metro Vancouver’s Iona Island Plant only treats wastewater at the primary level, but an upgrade is currently being planned. It is imperative that tertiary
The Iona Island Wastewater Treatment Plant. Source: Obabika.
treatment technology be installed during this upgrade to prevent harmful toxins from entering the Salish Sea via the Plant’s outflow.
Is it really possible? With your help, yes! The Iona Island Plant upgrade is currently at an early stage, meaning the inclusion of tertiary treatment could still be approved. To make this happen, we need municipal, provincial and federal governments to fund the installation of tertiary treatment technology, ideally as soon as possible.
What’s the catch? Put simply, the hard costs of tertiary treatment exceed that of secondary. That said, only treating wastewater to the secondary level means wastewater will continue to pollute the Salish Sea and harm its inhabitants, like salmon and Southern Resident orcas. Included in the cost of secondary treatment should be the cost of the loss of Salish Sea ecosystem function, economic impact on the region’s booming ecotourism sector and fisheries and the future cost for the cleanup of marine contaminants.
Beginning tertiary wastewater treatment at the Iona Island Plant as soon as possible will prevent the above environmental costs and protect the health of the Salish Sea, its surrounding communities and inhabitants. Show your support for a healthy and vibrant Salish Sea by sending a letter to the government now – together we can reduce the harm caused by undertreating our wastewater.
Show your support for the inclusion of tertiary wastewater treatment at the Iona Island Plant by taking action here!