Thunderchild First Nation - Turtle Lake Site 115C Sewage Lagoon Operations

Thunderchild First Nation is proposed to operate a new lagoon as a two-cell facultative lagoon with a third separate cell to facilitate evaporation of the water treatment plant's concentrate stream (waste from the reverse osmosis system).  The WTP process waste will be isolated to its own cell but will have the ability to be mixed into the storage cell of the lagoon, if required to dilute any residual biological loading.  However, this is intended to be operated as an evaporative cell only.  The primary cell of the facultative lagoon will only receive sewage from the truck dump pad shown on the plans, the access road and truck dump will require keyed access to the facility through the chain link fence gates.  Sewage hauling from the 19 Thunderchild 115C homes' septic tanks will be trucked similar to the current arrangement, but be deposited at the proposed lagoon site at the dump structure.  The primary cell provides primary treatment of the truck hauled sewage with aerobic bacteria processes.  These processes use oxygen from wind and from photosynthesis of algae to break down the organic components of the sewage.  After primary treatment, the wastewater transfers to the secondary (storage) cell to be stored until it is ready to be released on an annual or bi-annual basis.  This storage cell is designed to hold 220 days of treated wastewater at the 20 year design threshold, accounting for population and water usage growth.  All three lagoon and waste pond cells are lined with a fused high density polyethylene (HDPE) liner to ensure no untreated sewage will leach from the cells.  An under-liner weeping tile underdrain network will allow for monitoring of the liner integrity.  Once treated effluent is ready for release, typically in spring and / or fall, a valve will be opened to release the storage cell through the effluent structure and into an undeveloped tertiary storage wetland to the northeast.  Treated effluent would either be evaporated from this wetland or slowly mix with the surrounding environment.  Note that this released effluent is treated and regulated components will be tested during each release to ensure it meets the Provincial guidelines for biochemical oxygen demand (BOD), carbonaceous biochemical oxygen demand (CBOD), total suspended solids (TSS), total chlorine residual and unionized ammonia.  The 220 days of storage allows for sufficient storage through winter months, should there be a longer winter after the prior fall release. 

Latest update

April 26, 2024 - Indigenous Services Canada issued its notice of determination Notice of Determination for the Thunderchild First Nation - Turtle Lake Site 115C Sewage Lagoon ( 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 for the Thunderchild First Nation - Turtle Lake Site 115C Sewage Lagoon - April 26, 2024
1 Notice of Intent -Start of Public Comment Period - March 25, 2024


Indigenous Services Canada
Alvin Hamilton Building, 1783 Hamilton Street
Regina, Saskatchewan S4P 2B6
Telephone: 306-581-3134

  • Location

    • Thunderchild First Nation (Saskatchewan)
  • Nature of Activity

    • Waste Management
  • Assessment Status

  • Start Date

  • Proponent

    Thunderchild 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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