In June 1989 , the Bush administration proposed a bill to amend the Clean Air Act . Working with Senate Majority Leader George J. Mitchell , the administration won passage of the amendments over the opposition of business-aligned members of Congress who feared the impact of tougher regulations . The legislation sought to curb acid rain and smog by requiring decreased emissions of chemicals such as sulfur dioxide . The measure was the first major update to the Clean Air Act since 1977 . Bush also signed the Oil Pollution Act of 1990 in response to the Exxon Valdez oil spill . However , the League of Conservation Voters criticized some of Bush 's other environmental actions , including his opposition to stricter auto-mileage standards
Exxon Valdez oil spill
Exxon Valdez oil spill
Presidency of George H. W. Bush