Air Pollution

To help cut motor vehicle emissions, a major source of urban pollution, the Environmental Protection Agency (EPA) established a policy in 1978 for state inspection and maintenance programs. Because emissions were not reduced to levels set by EPA, Congress passed legislation in 1990 requiring the upgrading of inspection and maintenance programs in the most seriously polluted parts of the country. EPA proposed a regulation in July 1992 that will require more stringent tail pipe exhaust emission tests, including the IM240 test, a move that could have a tremendous economic impact on the inspection and repair industries. Because of many unresolved issues related to the IM240 test--ranging from doubts about the reliability of test results to difficulties in getting repairs done to vehicles diagnosed with emission problems--GAO questions why EPA did not look into alternative tests before issuing its proposed regulation. Studies by various groups suggest that another test option may yield results similar to the IM240 test but at a lower cost and possibly less inconvenience to the public. Although EPA has just begun to study this other option, when the study results will be available to the states is unclear. EPA said that it had proposed allowing states until November 1993 to settle on a specific inspection and maintenance test procedure, but this time frame is not clearly stated in EPA's proposed regulation. It is important for EPA to complete its study on alternatives to the IM240 test before then. Otherwise, states may end up adopting test procedures that may not be the most cost effective and most convenient approach for motorists.

GAO found that: (1) there are drawbacks to the IM240 test procedure for both the identification and repair of out-of-compliance vehicles which could hamper the test procedure's effectiveness; (2) over 25 percent of the vehicles that EPA tested using the IM240 test failed an initial test but passed a second emissions test, even though no repairs were made; (3) vehicles that fail the IM240 test may be more difficult to repair because of trouble in diagnosing the cause of emission problems, mechanics not being trained in emission repairs for high-technology vehicles, and the inability of repair shops to afford IM240 equipment to replicate emission tests and determine whether repairs were effective; (4) EPA has suggested to states that they could use an alternative to IM240 if the alternative were an effective substitute, but states are reluctant to evaluate another option due to lack of expertise or resources; and (5) some state officials believe the proposed EPA inspection and maintenance (I&M) regulation is ambiguous about when EPA is proposing to allow states with seriously polluted areas to make a commitment to a specific I&M test procedure.

Recommendations

Our recommendations from this work are listed below with a Contact for more information. Status will change from "In process" to "Open," "Closed - implemented," or "Closed - not implemented" based on our follow up work.

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