Who: University of Guelph. Project lead: Dr. Wenxi Liao, co-lead: Dr. David McCarthy, co-PIs: Dr. Shadman Khan, Dr. Marc Habash, Dr. Jacqueline Goordial.Why: Northern communities across Canada's Arctic rely heavily on simple sewage lagoons that have limited wastewater treatment capacity. Conventional wastewater treatment plants are often impractical in these regions due to extreme cold conditions. Nature-based biofilters have demonstrated effective removal of nutrients, pathogens, and emerging contaminants in cold regions. However, more research is needed to adapt these systems using local plant species and suitable filter materials so that they are environmentally compatible, culturally appropriate, and resilient to Canada’s Arctic conditions. What: This project will develop and optimize low-cost, scalable, and climate-adapted biofilters for wastewater treatment in Canada’s Arctic, while protecting native plant species and enhancing ecosystem services. The project is important for Northern communities because it offers an effective, affordable, and locally relevant wastewater treatment solution that is informed by local knowledge and community input.Approximately six pilot-scale biofilter systems near the triplex at CHARS to evaluate wastewater treatment performance and plant health under Arctic conditions from 2027 to early 2028. Wastewater will be pumped from the triplex sewage holding tank into a temporary storage tank and then to the biofilters for treatment. Treated effluent will drain from each biofilter into a separate collection container. After effluent samples have been collected, the remaining treated effluent will be pumped back into the sewage holding tank in the triplex. Therefore, no wastewater or treated wastewater will be discharge to the ground in the experiment.Wastewater treatment assessments will be conducted only when the graduate students are present at CHARS. During these periods, the students will closely supervise the biofilters to ensure safe operation and promptly address any issues. Wastewater will not be introduced into the biofilters when the students are not on site. During unattended periods, the biofilters will be irrigated with tap water, as needed, to support plant survival and growth.Native Arctic plant species, such as mastodon flower and Arctic willow, will be collected locally under the appropriate permit and transplanted into the biofilters. Fewer than 20 plants in total will be collected.The biofilters will be instrumented with environmental and water quality sensors, including soil moisture, turbidity, pH, and electrical conductivity sensors, to continuously monitor system performance. Sensors and biofilters will be monitored graduate students and CHARS staff.The project will involve a collaborative research team, CHARS staff, and local community partners. All biofilters and sensors will be removed at the end of the project in early 2028. Personnel and research materials will be transported using existing commercial airline services and CHARS facilities. No vehicles will be required to support on-site research activities.Where: The field demonstration is proposed to take place at CHARS in Cambridge Bay, Nunavut. When: The field deployment and monitoring of biofilters is planned between March 2027 to March 2028. The biofilters and equipment will be disassembled around June 2028.