Air Pollution

Pursuant to a congressional request, GAO reviewed the National Acid Precipitation Assessment Program's (NAPAP) progress in developing, applying, and evaluating the Regional Acid Deposition Model (RADM).

GAO found that: (1) although NAPAP completed RADM developmental work 2 years beyond its original target date, the delay did not affect the final assessment, since other portions of the assessment were incomplete and the project became more complicated than initially envisioned; (2) a disagreement between the Environmental Protection Agency (EPA) and the Department of Energy (DOE) over the extent to which the utility industry would adopt clean coal technologies delayed agreement on the emissions projections needed as input for future emissions analyses, resulting in a 10-week delay in the RADM applications schedule; (3) NAPAP officials planned to incorporate RADM-assisted analyses in their assessment, since the model had already undergone significant testing and showed major improvements for regional modelling; (4) unlike earlier models, RADM accounted for such atmospheric complexities as chemical conversion of sulphur and nitrogen dioxides to acidic compounds; (5) RADM should estimate with greater accuracy than previous models the changes in acidic deposition resulting from various levels of emissions reductions; (6) because RADM should depict interactions among different atmospheric pollutants, it should assist policymakers in deciding whether and where to concentrate controls and in avoiding inadvertently worsening one pollution problem while trying to control another; and (7) although the EPA-DOE impasse over future emission estimates caused uncertainty over the inclusion of these studies in the assessment, current congressional proposals to control acidic deposition could proceed without the assessment without risking excessive or unnecessary control actions.