By David Nesseth
While Canada has often held to a scattered approach that aims to merely meet minimum standards for wastewater treatment, a new report suggests it’s time to co-ordinate and strategize for the future before Canada falls further behind other jurisdictions and the number of contaminants in wastewater continues to grow, creating adverse effects on Canada’s public and environmental health.
The March 2018 report, Canada’s Challenges and Opportunities to Address Contaminants in Wastewater, is the result of findings over six months by an expert national panel appointed by the Canadian Water Network and funded by Environment and Climate Change Canada. It showcases seven recommendations for the federal government to get Canadian municipalities not only back on track, but ahead of the game, as much as is possible, when it comes to taking a more ambitious approach to wastewater treatment.
“The panel recommends effective collaboration between the various levels of government and risk-based watershed and sewershed approaches that consider all elements of wastewater management to protect the environment and human health, while recovering some resources along the way,” Susheel Arora, member of the report’s expert panel and Director of Wastewater and Stormwater Services at Halifax Water, told Environmental Science & Engineering Magazine.
Wastewater Systems Effluent Regulations
The challenge in moving forward comes from the fact that many Canadian cities are not only locked in for the long term on their wastewater infrastructure, but an estimated one in four wastewater facilities in Canada will require substantial upgrades to simply meet baseline Wastewater Systems Effluent Regulations. Those upgrades alone, the panel report states, could cost some $5.5 billion. While the report calls for increased action, some Canadian municipalities will have until 2040 to even arrive at those minimum standards.
Arora, however, said that the timelines are “pragmatic” and based on the risk to the receiving environment.
“There are several utilities or municipalities which have been assigned shorter timelines of 2020 or 2030 based on a different level of risk to the receiving environment and human health,” said Arora. “Future-based timelines provide an opportunity for addressing some contaminants of emerging concern through resource recovery, as new technologies prove themselves in the marketplace,” he added.
Canada’s laggardness in embracing wastewater technology has seen it fall well behind the U.S. and European Union in terms of making secondary treatment a minimum acceptable technology. While Canada finally implemented secondary treatment as law in 2015, it has been law in the U.S for 47 years, and in the EU for 27 years.
To encourage progress for Canada municipalities, the panel report suggests that incentives should also play a role in local decisions surrounding wastewater facility upgrades.
“Incentives to achieve results beyond minimum compliance do not necessarily have to be financial in nature,” the panel report states. “Professional accreditation and peer-assessed benchmarking programs demonstrate responsible stewardship and effective management and are excellent motivators for municipalities and utilities.”
But, there are other avenues for change and action, the panel report suggests. The authors illustrate how the City of Brantford in Ontario followed the 2-stage Composite Correction Program developed by the U.S. Environmental Protection Agency. It helped the city identify ways to re-rate design capacity, achieve higher effluent quality and defer significant infrastructure expansion capital costs.
“Optimization of existing wastewater treatment infrastructure can be a cost-effective method to improve performance measures and potentially delay the need for major infrastructure investments,” the panel report states. “Additional benefits [in Brantford] included an increased understanding of treatment capability, improved communication between operations and city staff, confidence in troubleshooting issues, tools to address poor process conditions and the ability to nitrify when conditions were optimal.”
The panel report also touts “co-benefits” as a very real added value consideration for municipalities nervous about investing in their wastewater infrastructure. For example, those $5.5 billion in plant upgrades still on the to-do list for some cities? They’re expected to translate into $16.5 billion in associated benefits, the report states. For example, cities that use wastewater technologies designed to remove conventional contaminants such as biochemical oxygen demand and ammonia get the “co-benefit” of a technology that enhances the removal of trace organic contaminants.
Then, there is the whole new conversation of resource recovery surrounding wastewater treatment plants, where there are opportunities for generating revenues for partial or full cost recovery, such as selling methane back into the grid or commercial fertilizer products. All five of Metro Vancouver’s wastewater treatment plants recover and use biogas to generate heat for their plants, the panel report notes.
“Recouping costs may be attractive at the municipal level, while supporting a circular economy is likely to resonate with the general public,” the panel report states.
Additionally, the panel report notes that direct treatment isn’t always the only option available to municipalities.
“Treatment represents only one element of wastewater management and the effectiveness of other options like source control, sewer separation and the use of non-technology options should also be given strong consideration,” the panel report states.
In terms of a Canadian city that has been a leader in wastewater management, the panel report points to Calgary, which currently collects data on 60 chemical compounds, including flame retardants, hormones, pharmaceuticals and common cleaning agents. The city has also invested in a partnership with the University of Calgary called Advancing Canadian Wastewater Assets to test technology and watershed impact.
Pathogens, nutrients, metals, pharmaceuticals and microplastics are some of the known and emerging contaminants of concern found in wastewater, but the report makes clear that science has not yet been able to establish which ones are the clearest present danger. Instead, the report notes that keeping contaminants out of municipal systems in the first place, commonly called source control, instead of trying to remove them from wastewater, was one of the “top priorities” expressed by the expert panel.
Assessing and restricting certain substances in the marketplace through the Canadian Environmental Protection Act remains a priority, the panel report states, particularly given that many contaminants are only partially treatable by conventional treatment, or expensive to treat. Microbeads and their contribution to microplastic pollution globally have become a high-profile example of source control, as many jurisdictions have been moving to ban the product. In Canada, the sale of shower gels, toothpaste and facial scrubs containing plastic microbeads is set to be banned by July 1, 2018.
“Public education for source control goes a long way in protecting the environment, and the report recommends a holistic watershed and sewershed-based approach, with public education as part of the solution,” said Arora.
Sewer overflows also remain a concern for the expert wastewater panel as weather patterns grow increasingly severe and unpredictable. The panel notes that upgrades to collection systems must stay on pace with other system upgrades to avoid the release of stormwater and raw wastewater when collection system capacity is exceeded during heavy rain. The report gives examples of upstream investments to reduce combined sewer overflows and bypass events, such as separating stormwater and sanitary sewers; reducing inflow and infiltration of stormwater or groundwater into sanitary sewer collection pipes; disconnecting downspouts to sanitary sewers; strategically utilizing existing storm sewer capacity; real-time control; and incorporating overflow surge tanks into systems. The City of Ottawa, for example, has been using real-time controls of overflow equipment and monitoring pipe flow data to maximize the capture of potential overflows. The city has also been building storage facilities to temporarily hold additional flows, and is developing monitoring systems to alert staff of flows at 13 different overflow locations.
Blueprint for action
The report presented the following recommendations to the federal government as a blueprint for Canada to move forward effectively.
- Continue to apply and further develop risk-based approaches Develop an effective risk management approach to deal with the complexity and changing nature of chemical mixtures in wastewater and their observed effects in the environment and on human health. The precautionary principle approach, based on best science and Indigenous knowledge, and inclusive of uncertainty and adaptive management, would be core to this work.
- Improve access to data on wastewater treatment across Canada Establish a coordinated and meaningful national system of collecting, assessing and sharing data on wastewater treatment among municipalities and utilities in Canada. Consider re-establishing something similar to the Municipal Water and Wastewater Survey, with Indigenous input, as well as a nationally accessible database. Effective collaboration between provinces, territories, Indigenous and the federal government is required to build this database.
- Incentivize and reward innovation to go beyond minimum standards Encourage an assessment of new or amended treatment technologies, using research and pilot testing, to generate a menu of solutions to guide investment decisions. This would include a compendium of key examples focused on how co-benefits can be derived from optimization and innovation in wastewater management. These actions would support Canada’s infrastructure program for wastewater system upgrades, including resource recovery.
- Support site-specific approaches based on receiving water quality objectives This would also incentivize jurisdictions to develop source water protection programs that include sewershed protection plans and prioritize options for source control. Recognize where keeping contaminants out of systems is more effective than trying to remove them from wastewater through treatment.
- Implement watershed-based approaches within an integrated approach to water management and governance, including the possibility of water quality trading. In addition to source control, other non-technical opportunities could be considered to address and reduce risk to local communities and the environment.
- Better coordinate research, technology transfer and practice insights to improve the understanding of risks and recognize meaningful co-benefits (e.g., centres of excellence, data dissemination, success/failure case studies, pilot plant studies, coordination of research, process certification). This initiative will be challenging, but is much needed, and must be spearheaded by the federal government and Indigenous governments across Canada.
- Require a future-ready strategic planning document as a condition for immediate and long-term funding, with input from all stakeholders as well as consideration of resource recovery and implementation timelines. This will support the funding of proven and promising technology and the flexibility to choose community-tailored solutions that are appropriate, robust and will have the greatest beneficial impact.
(Source: The May 2018 report, Canada’s Challenges and Opportunities to Address Contaminants in Wastewater, by Canadian Water Network)
David Nesseth is a writer for ES&E Magazine.