Code of practice for managing particulate matter emissions in the potash sector: executive summary

Official title: Code of practice for the management of PM_2.5 emissions in the potash sector in Canada

Executive summary

Federal, provincial and territorial environment ministers are taking action to better protect human health and the environment by endorsing and implementing the new Air Quality Management System (AQMS). The AQMS includes Canadian Ambient Air Quality Standards for fine particulate matter (PM_2.5) and ground-level ozone, base level industrial emissions requirements (BLIERs) and local air zone management by the provincial/territorial jurisdictions. For the potash sector, a qualitative BLIER (in the form of a code of practice) was developed for fine particulate matter with a mean aerodynamic diameter of less than 2.5 microns (PM_2.5).

The overall objective of the code is to identify and promote best practices in the Canadian potash sector with respect to PM_2.5 emissions. The code was developed by Environment and Climate Change Canada in consultation with potash industry representatives and the provinces of Saskatchewan and New Brunswick. Information on best management practices was drawn from various sources such as consulting reports, literature and environmental codes by provinces/territories, Environment and Climate Change Canada and the United States Environmental Protection Agency (U.S. EPA), as well as from individual potash companies and technical journals.

There are currently ten potash facilities operating in Canada: all situated in Saskatchewan. An eleventh facility, located in New Brunswick, was placed on care and maintenance in January 2016. Potash mining in Canada is carried out by means of two distinct methods, conventional underground mining and solution mining. Conventional mining is the process of tunneling below the earth and removing ore deposits from the mine’s walls, and transporting it to the surface for wet processing. Solution mining is an alternative method where unsaturated brine is injected into the underground ore deposit through wells to dissolve potassium chloride (KCl), which is then pumped to the surface for processing. In both cases the ore must be dried, screened, and often compacted to produce marketable products. Nine of Canada’s potash facilities are conventional mines, and two are solution mines.

The major processing activities of the sector, drying and compacting, are the primary sources of PM_2.5 emissions. They represent about 80% of sector emissions. The remaining 20% are from the fugitive, loadout, and mine exhaust emissions. Table S-1 lists the 15 recommendations designed to limit PM_2.5 emissions from these sources.

The code describes the sector’s mining and processing activities in Section 2. Section 3 elaborates on the PM_2.5 emissions produced by these activities. The recommended work practices intended to control and minimize these emissions are set out in Section 4. Finally, Section 5 outlines a strategy for implementing the code, along with recommendations for reviewing, reporting, and recordkeeping.

This code is designed to be used by the potash industry, or by regulatory agencies and the general public as a source of technical and policy guidance. However, it does not negate any regulatory requirements.

The code does not require an existing facility to make major technological changes, but rather implement and enhance monitoring and maintenance of its existing abatement equipment. Finally, the recommendations in this code should be incorporated into the initial design stages of new facilities to control and minimize PM_2.5 emissions.

^a Environmental management practices are referred to in Environment Canada’s Environmental Code of Practice for Metal Mines, 2009. Many of these practices can also be applied to the potash mining industry.