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Puget Sound

History of US/Canada Collaboration

Transboundary Air Quality
Introduction Air QualityAir Pollutants EmissionsResearchCrossborder Collaboration Crossborder ActivitiesInternational Air ProgramsEPA Region 10

Both the United States and Canada value clean air and are committed to the belief that emissions from one country should not impact another country.

International Cooperative Agreements Timeline
  • 1941: Trail Smelter Arbitration
  • 1970s and 80s: Major efforts during these years led to the development of the US-Canada Air Quality Agreement and related Acid Rain Annex in 1991, and the addition of the Ozone Annex to this Agreement in the year 2000.
  • 1992: Environmental Cooperation Agreement between Washington State and the Province of BC. This Agreement emphasized coordinated action and information sharing on environmental matters of mutual concern including air quality.
  • 1994: Interagency Agreement (PDF, 5 pp., 62KB) between Washington State, the Province of British Columbia, the Greater Vancouver Regional District and the Northwest Clean Air Agency to ensure timely prior consultation on new sources of air pollution, as provided for in the US-Canada Air Quality Agreement.
  • 2000: Environment Canada and the US Environmental Protection Agency signed a Joint Statement of Cooperation on the PSGB Ecosystem. This Statement outlines common goals and objectives, confirms the commitment and leadership of the two federal governments and recognizes the special interests of residents and their governments.
  • 2002: EC and EPA signed the Statement of Intent (PDF, 2 pp., 24KB) for the PSGB International Airshed work. This Statement pledges continued collaborative efforts regarding present and future air quality issues in the PSGB airshed
  • 2003: EC and EPA launched the Canada-US Border Air Quality Strategy to explore mechanisms to address transboundary air quality issues.
  • 2005: EC and EPA released the Border Air Quality Strategy Report, Maintaining Air Quality in a Transboundary Air Basin: Georgia Basin – Puget Sound (PDF, 73 pp., 2.2MB).


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