B.C. Air Quality

Agricultural Burning

Agricultural burning is carried out to clear the land for planting, and control pests, disease and weeds. These activities cause smoky conditions and elevated levels of particulate matter (PM2.5 and PM10). Materials typically burned are:

  • brush, stumps and roots;
  • grass stubble, mainly by grass seed growers in the Creston Valley;
  • orchard prunings (e.g., fruit trees and grape vines), mainly in the Okanagan;
  • diseased crop material;
  • spoiled hay and straw;
  • orchard replacement waste (orchards are commonly replaced by vineyards); and
  • plastics (see below: Burning Agricultural Plastics).


Agricultural open burning of weeds, foliage, leaves, crops or stubble is exempt from the current Open Burning Smoke Control Regulation. However, open burning of piled land-clearing debris, as well as orchard prunings, must be in compliance with the regulation.

The Ministry of Environment is reviewing and revising this regulation. See Proposed Changes to the Open Burning Smoke Control Regulation.

In some cases, agricultural debris burning can cause significant smoke problems because the debris is often not left to season (dry) before it is burned. Also, some of the material sent up in smoke could be turned into a valuable product, such as compost, manufactured products and wood chips. Investment Agriculture, the B.C. Agriculture Council, and various local and regional governments fund chipping programs aimed at reducing burning and mitigating cost to the agriculture industry.

Agricultural burning must meet the requirements of other laws, such as the Wildfire Act and Wildfire Regulation, and laws set by local fire departments and local governments. Where these are more stringent, they apply over provincial regulations.

Burning Agricultural Plastics

Agricultural plastics are also burned as a disposal method. This practice, which releases very toxic emissions, is illegal. "Ag-plastics" are prohibited materials under the Open Burning Smoke Control Regulation. They include:

  • film plastics, e.g., mulch and greenhouse film, silage and other bags;
  • rigid plastics, e.g., plant containers and irrigation tubing; and
  • twine, e.g., ranch and greenhouse twine.

The Regional District of Okanagan-Similkameen (RDOS) began a pilot ag-plastic recycling program in 2006, which is continuing today. For more details, see the Agricultural Plastic Recycling Pilot Project: Practicing Safe Plastic Management (PDF: 3.3 MB/2 pages), on the RDOS's Air Quality website.

Also, take a look at "Better Ways to Dispose of Agricultural Plastics" — on page 11 of the BC Lung Association's State of the Air Report 2007 in British Columbia (PDF: 2 MB/16 pages).

Outdoor Wood-Fired Hydronic Heaters

Outdoor wood-fired hydronic heaters (boilers) are used in agriculture to heat greenhouses. These commercial heating units can release a good deal of smoke because the combustion process tends to be inefficient.

The province is introducing limits on emissions from wood-fired agricultural boilers that will require greenhouses and other agricultural boiler users to monitor and report on their emissions regularly. In B.C., pollution standards for agricultural boilers fall under the Agricultural Waste Control Regulation. The updated standards establish strong, economically viable limits on emissions from wood-fired boilers, ensuring better protection for air quality and safeguarding human health. They will be fully phased in by Sep. 1, 2010. See B.C. Gets Tough on Agricultural Boiler Emissions.

Metro Vancouver recently passed the Boilers and Process Heaters Emission Regulation Bylaw (PDF: 56 KB/9 pages), which regulates wood-fired boilers in greenhouses. The Province's agricultural-boiler standards are substantially harmonized with Metro Vancouver's bylaw. Of the approximately 200 known greenhouses operating across the province, 171 are located in the Lower Mainland, 17 on Vancouver Island, and 12 in the Interior.


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