Acid rain: what we know, what we did, what we will do.

Abstract

This paper reviews the involvement of the Canadian province of Ontario in the acid rain issue. Ontario is a major producer of acid gas emissions and suffers significant environmental consequences because of acid rain. The province's substantial contribution to the scientific understanding of acid rain is summarized with emphasis on the extent and origins of the deposition it receives, the impact on the aquatic environment, and the impact on the terrestrial environment. This paper discusses the history of the government's success at reducing acid gas emissions through the 1970's when legislators set out to enhance local or "ambient" air quality, the first legislation to require SO2 reductions from companies already in compliance with ambient air quality legislation, and the current Countdown Acid Rain program which reduces SO2 emission limits by 67%. The process used to establish the tough new limits while reasonably anticipating the development of SO2 control technologies is detailed along with the specific requirements of the major emitters controlled by the regulations. Projections confirm that while the Countdown reductions will bring about significant reductions in deposition, adequate environmental protection in Canada cannot be achieved without some comparable U.S. acid gas abatement effort.