Sayisi Dene First Nation Wastewater Treatment Plant and Water Treatment Plant Upgrade Project - 2223

The wastewater upgrades will consist of a new aerated lagoon and SAGR® system to provide wastewater treatment, new gravity sewer, a new wastewater forcemain and lift station to convey wastewater to the lagoon, an access road to the new lagoon, and upgrades to an existing lift station.

Infrastructure:

Existing Lift Station #1

Upgrades are proposed to Lift Station #1. Upgrades will include retrofitting the lift station to allow for sewage truck dumping as well as replacement and upgrade of the existing pumps.

Gravity Sewer

Approximately 200 m of gravity sewer will be constructed including one new manhole. The gravity sewer will convey wastewater from the existing community school to the proposed lift station. It will be connected to existing gravity sewer that previously conveyed wastewater to Lift Station #2 (School Lift Station) which is to be decommissioned as part of this project.

Lift Station

A new lift station is proposed as part of this project. It will be built near the existing community WWTP, which is to be decommissioned as part of this project. It will convey all the community's piped wastewater to the proposed lagoon. It will consist of a below-grade barrel equipped with a duplex pumping system.

Forcemain

A new forcemain will be constructed to convey wastewater from the proposed lift station to the proposed lagoon. It will consist of approximately 930 m of 100 mm diameter HDPE pipe.

Wastewater Treatment Lagoon

A new wastewater treatment lagoon is proposed as part of this project. It will consist of two aerated cells followed by two SAGR® cells. Treatment will also include ultraviolet disinfection (UV). Treated effluent will flow by gravity into Tadoule Lake. It is noted that overhead wires are proposed to run overtop of the aerated cells. This is proposed to mitigate potential additional risks caused by the lagoon in regards to birds disrupting airport operations.

Existing Wastewater Treatment Plant

The community's existing wastewater treatment system will be decommissioned. It will be replaced by a new lagoon. Wastewater currently being pumped and trucked to the WWTP will instead be directed to the new lagoon. The wastewater treatment plant will be removed, and the existing sewage outfall will no longer be used.

Existing Lift Station #2 (School Lift Station)

The community's existing Lift Station #2, which conveys wastewater from the school area to the existing WWTP, will be decommissioned. Gravity sewer will instead convey the school area wastewater to the new lift station.

Activities:

Construction activities will include the construction of linear infrastructure including gravity sewer, forcemain, and an access road. They will also include the construction of a new lagoon. This will include site clearing and grading, along with restoration of the affected areas. Existing Lift Station #1 will be upgraded. Activities will also include the decommissioning of the existing WWTP and the existing School Lift Station #2, which will include restoration of each respective site.