The Air Pollution regulation administered by the Ministry of the Environment enforces compliance to the standards set in the Ontario law. The law is phased in, with portions taking effect in 2010, 2013, and 2020 that apply to different types of facilities. By 2020, all facilities are required to comply with the law.
The first phase of the law, which started in 2010, requires all fossil fuel power generating facilities - excluding those less than 25 MW in capacity - to comply with the regulations. Coal-fired plants are included in that definition. Other coal product manufacturing facilities are required to comply by the 2013 phase. Also included in the 2013 phase are waste treatment and disposal facilities, which includes biomass and biogas facilities.
The law sets the standards for dispersion models to assess compliance, as well as contaminant limits. Most of the standards developed under the law are based on the ministry's Ambient Air Quality Criteria (AAQCs). AAQCs are effect-based concentration levels with variable averaging times (e.g., 24 hours, 1 hour, 10 minutes). The effects considered include health, odor, vegetation, soiling, visibility and corrosion.