STPFN Wastewater Treatment Plant Upgrade and Expansion Project

The proposed project is to upgrade and expand the wastewater treatment facility for the St. Theresa Point First Nation (STPFN). STPFN is an Indigenous community located in the Island Lake region of Manitoba, approximately 460 kilometers northeast of Winnipeg. The community is accessible year-round by air and via winter road from February to March. The 2021 on-reserve population is 4,062 people (INAC, 2021). Wastewater is collected in the community through trucked and piped sewage services. There are two wastewater treatment plants (WWTPs) currently servicing the community: the North WWTP (UTM coordinates 15 U 378398 m E 5966032 m N and the South WWTP (UTM coordinates 15 U 377642 m E, 5963684 m N). Both WWTPs discharge the treated effluent to Island Lake on the east shore of the community.

Results from a previous feasibility study indicated that both WWTPs have substantial operational issues and are in a state of disrepair, requiring upgrading (Neegan Burnside, 2020). In addition, the sludge drying bed area, located approximately 5 km south of the South WWTP is not being operated as intended and sludge from both WWTPs has not been taken to the sludge drying bed in several years. Raw wastewater from holding tanks has also been periodically dumped into the sludge drying beds, which appear to be overflowing and partially covered with windblown litter from the adjacent community landfill. To address current deficiencies, operational challenges and accommodate the current wastewater flows and future community growth, the North WWTP will be decommissioned and the South WWTP will be upgraded and expanded with additional upgrades made to the wastewater collection system and the sludge drying beds. The upgraded South WWTP currently has an average design capacity of 1,480 m3/day. With the expansion, it will have the capacity to meet 20-year projected flows of an average 2,100 m3/day.


The STPFN wastewater treatment plant upgrade and expansion project (the Project) consists of the repair/upgrade and decommissioning of wastewater infrastructure in the community, including:

  • Constructing a new lift station (North Lift Station) installed approximately 10 m north of the
    North WWTP to service the north catchment area of STPFN and convey wastewater to the South
  • Installing a 250 mm diameter gravity sewer connecting the manhole of the North WWTP (MH
    79) to the North Lift Station.
  • Decommissioning the existing Lift Station #4 and installing a new 200 mm diameter gravity sewer line (approximately 8 m in length) to convey wastewater flowing from the decommissioned lift station #4 to the North Lift Station.
  • Installing a new 200 mm high density polyethylene (HDPE) forcemain (approximately 2.65 km in length) connecting the North Lift Station to existing gravity sewer at Manhole #8.
  • Upgrading, repairing, and expanding the existing South WWTP, including construction of the
    expanded superstructure, new truck dump pad and manhole, installation/repairs to process and
    mechanical equipment, a new 300 mm gravity effluent overflow outfall discharging to rip rap
    east of the superstructure on the shore of Island Lake, and a new 375 mm gravity sewer line
    (approximately 60 m in length) to Manhole #4.
  • Upgrading the sludge drying beds by draining away the liquid and hauling it to the South WWTP,
    allowing sludge to dry, pushing sludge into stockpiles, and re-grading the site to prevent accumulation of rain/snow.
  • Upgrading (widening) and re-surfacing the access road to the sludge drying beds to
    accommodate truck turn around.
  • Decommissioning of the North WWTP.


During operation, the WWTP treatment process produces sludge (56 m3/day at 0.85% solids) and treated wastewater effluent (40 L/s). Sludge will be de-watered using de-watering trailers and approximately 1.73 m3 /day of de-watered sludge will be hauled to the sludge drying beds on a regular basis (approximately every 7 days). Dried sludge will be hauled to the neighboring community landfill site, on an as-needed basis, to be used as interim cover material. Treated wastewater effluent will be discharged to Island Lake on a continuous basis through the existing discharge/outfall structure. General office waste will be sent to the local community waste disposal ground. The effluent will be monitored continuously to confirm it meets the effluent discharge criteria as described in the Wastewater Systems Effluent Regulations (2017). Should a flood event occur, the South WWTP will discharge wastewater overflows to Island Lake via a 300 mm gravity effluent overflow outfall as an emergency measure. During decommissioning of the North WWTP, STPFN may choose to retain the existing WWTP building for a future use as a storage facility. Sewage and liquid wastes from the North WWTP will be hauled to the new truck haul wastewater receiving station while the sludge would be disposed of at the sludge drying beds following dewatering. During decommissioning of Lift Station #4, sewage and liquid wastes will be hauled to the new truck haul wastewater receiving station. The internal infrastructure (piping, valves, pumps, etc.) will be removed and disposed of at the landfill. The control panel will be salvaged and handed over to STPFN to use as parts for the other lift stations in the community.


Latest update

April 19, 2023 – Indigenous Services Canada issued its Notice of Determination and determined that the project is not likely to cause significant adverse environmental effects.


Key documents

Key documents
Document Number Document Title File Date
2 Notice of Determination - April 19, 2023
1 Comment Period on Intent to Make a Determination - September 2, 2021


Indigenous Services Canada
Shelly Johnson, Environmental Specialist
365 Hargrave Street
Winnipeg, Manitoba R3B 3A3
Telephone: 204-984-0709

  • Location

    • St. Theresa Point First Nation (Manitoba)
    • St. Theresa Point First Nation (Manitoba)
  • Nature of Activity

    • Water Management
  • Assessment Status

  • Start Date

  • Proponent

    St. Theresa Point First Nation
  • Authorities

    • Indigenous Services Canada
  • Assessment Type

    Project on federal lands
  • Reference Number


This map is for illustrative purposes. The markers represent the approximate locations based on available data. More than one marker may be identified for a given assessment.


Nearby assessments

...within 200 kilometres
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