Understanding and Assessing Impacts
Planning for a new municipal wastewater treatment system often starts years before the project is executed. The planning and siting phase of constructing a new municipal wastewater treatment system can be organized into five phases:
- Community consultation engagement;
- Reviewing background information;
- Constraint mapping;
- Assessing the site(s); and
- Identifying treatment requirements.
There are specific Northern circumstances that could impact the project timeline and should be taken into consideration when planning. For example, wastewater treatment system planning should consider specific regulatory requirements, the logistics of equipment mobilization, and short construction seasons.
Constraint mapping considers areas of local importance through community consultation and engagement as well as consulting traditional knowledge; proximity to community infrastructures such as airports, houses, and roads; aesthetics such as odour and visibility through community consultation and climactic data; distance to surface water bodies; distance from lagoon base to groundwater table; distance from drinking water intake or watershed; and wildlife presence.
After potential location(s) have been chosen based on a constraint mapping exercise, the location(s) shall be assessed for their physical suitability. This includes assessing historical climate data and future climate projections such as air temperature, precipitation types and amounts by season, prevailing wind speed and direction, degree days, solar radiation, as well as assessing expected climate impacts such as melting permafrost, increased winter and summer precipitation, more frequent extreme weather events, flooding, hydrological changes, and more. The Standard recommends using statistically downscaled global climate models and considering multiple climate scenarios. Hydrological data, topographical data, a geotechnical investigation, a granular material assessment, and a hydrogeological investigation should be undertaken at this stage.