Air Pollution

GAO followed up on the Environmental Protection Agency's (EPA) response to GAO's July 1990 recommendations on the effectiveness of EPA's motor vehicle testing program. (See GAO/RCED-90-128). EPA agreesoverall with GAO's recommendations, some of which have been addressed by the Clean Air Act Amendments of 1990. Under this legislation, EPA can require states to deny vehicle registrations to owners who have not complied with recalls. EPA has also begun to address GAO's other recommendations, but several years will be required for comprehensive implementation. For example, changes to EPA's process for certifying that vehicles meet emission standards will not be effective until 1995. While EPA's acknowledgement of the problems and the agency's initial steps are positive, it is also clear that EPA, the auto manufacturers, and the states will need to continue working on vehicle compliance with emission standards over the useful life of the vehicle.

GAO found that: (1) EPA indicated overall agreement with the GAO recommendations; (2) the Clean Air Act Amendments of 1990 addressed some of the recommendations, by requiring states with enhanced inspection/maintenance programs to assess and report program effectiveness to EPA every 2 years and requiring EPA to issue guidance on recall requirements within one year; (3) EPA has proposed actions to include the use of actual data from in-use vehicles to determine emissions systems' deterioration rates, but EPA will need time to study alternative procedures and automobile manufacturers will need sufficient lead time to prepare for changes in the certification process; (4) EPA plans to allocate $140,000 to test in-use vehicles during the current program year, to increase the number of engine families tested, and test a sample of vehicles from the vehicle population for which it has little or no direct knowledge of the level of compliance; (5) EPA is preparing detailed guidance on recall requirements as part of the inspection/maintenance programs for states with enhanced nonattainment areas; and (6) EPA now requires all states with inspection/maintenance programs to report operating data annually.