City of Yellowknife Sewage Lagoon Planning Study

The City of Yellowknife currently uses a natural lagoon and wetland system to treat municipal wastewater; however, the system cannot accommodate existing and future wastewater volumes. In this study, the City will evaluate options to improve performance to comply with existing effluent discharge criteria as well as future guidelines. Each option will be evaluated based on capital costs, operating costs during the lifecycle, treatment efficiency, power usage, ease of use by operators, and impact on the receiving environment. The study will determine the most feasible option for maintaining the required retention time for sewage treatment (therefore eliminating premature discharges of effluent into the natural watercourse) and for consistently meeting or exceeding the anticipated more stringent effluent guidelines prior to releasing waters into the watershed. Options will be based on a twenty-year planning horizon, which will incorporate considerations for future demand and population growth. A secondary objective of the study is to complete the detailed design of the preferred option and prepare the associated water board submission for compliance, which also includes a stakeholder and public consultation component. It is anticipated that the implementation of the preferred option for wastewater treatment in the City of Yellowknife will meet the wastewater treatment needs of the municipality and ensure the long-term protection of Great Slave Lake.