Congressional adjustments made to the Clean Air Act 10 years ago have reduced acid-rain forming sulfurous emissions from coal-burning power plants. But that doesnt mean the problem has gone away, say the authors of a recently released federal report.
"We're just starting to see the arguable effects of the 1990 amendments," said David Marwick, assistant director of environmental protection issues for the U. S. General Accounting Office (GAO), the independent research arm of Congress that issued the report.
GAO auditors found that utility-generated emissions of sulfur dioxide decreased 17 percent between 1990 and 1998, while nitrogen oxide emissions went down by 8 percent during the same time period. Sulfur dioxide and nitrogen oxide are the two chief culprits of the acid rain problem. In the eastern United States, the focus of the report, sulfate deposits declined by 26 percent and nitrate deposits dropped by only 2 percent.
The 1990 amendments to the Clean Air Act limited emissions and forced utilities to install smokestack `scrubbers' and to use cleaner-burning coal. The revised act specifically addressed sulfur emissions problem by creating a system of pollution allowances that could be traded between utilities.
Utilities may generate the bulk of sulfur dioxide emissions (70 percent), but they contribute relatively little to total nitrogen oxide emissions (30 percent), which is primarily created by automobiles
The small decline in nitrogen oxide emissions was bad news for eastern forests, particularly in the Adirondack mountains of upstate New York. Although sulfate levels declined in 92 percent of Adirondack lakes tested in one study included in the GAO report, nitrates jumped in 48 percent of the lakes.
Marwick said that the rise in nitrate levels, detected in data supplied by the non-profit Adirondack Lakes Survey Corporation, was the most "unexpected" finding of the report. It suggests that power plants and automobiles are churning nitrates into the air faster than plants and soils can absorb them, forcing nitrates to collect in lakes.
"Unless steps are taken soon to dramatically reduce nitrogen oxide emissions, the recovery of Adirondack lakes could take decades or even centuries," the report's authors warned.
Studies of the mid-Appalachian area, and of the southern Blue Ridge mountains, in the GAO report showed similar patterns of acid deposition the process by which a compound is delivered into an ecosystem. But the report says that recovery would take longer in the Adirondacks because of their longer exposure to pollution and the relative thinness of soil in the range's watersheds.
Allegations by state and national officials from northeastern states that emissions from utilities in the South and Midwest are partly to blame for their environmental problems have drawn attention to the campaign to stop acid rain and improve air quality in recent months.
The GAO report also included U.S. Environmental Protection Agency data on sulfur dioxide emissions allowances used by utilities participating in the first phase of the Acid Rain Program, which began in 1995.
Under the program, utilities may sell off unused sulfur pollution allowances to other utilities or hold them for future use.
Auditors were asked to determine the extent to which utilities in 11 midwestern states used sulfur dioxide allowances originally assigned to utilities in their states, compared with allowances that originated in other states, particularly mid-Atlantic and northeastern states, during 1995 through 1998." The targeted states were Illinois, Indiana, Iowa, Kansas, Kentucky, Michigan, Minnesota, Missouri, Ohio, West Virginia and Wisconsin.
The auditors found that from 1995 to 1998, utilities in these states relied on allowances bought from out-of-state utilities 19 percent of the time, the same rate of reliance on out-of-state allowances found among northeastern utilities.
Less than four percent 538,000 -- of the total number of allowances used by midwestern utilities were purchased from northeastern utilities. Allowances cover one ton of sulfur dioxide and cost about $150 apiece.
That finding appears to undermine the basic principle behind a bill passed last week by the New York legislature. The measure penalizes New York utilities that sell allowances to power plants in Illinois, Indiana, Kentucky, Michigan, North Carolina, Ohio, Tennessee, Virginia, Wisconsin, and West Virginia and prohibits sales to plants in Delaware, Maryland, New Jersey and Pennsylvania.
A May 7 Op-Ed piece in the Cleveland The Plain Dealer called New York's action "a blast of hot air" that would merely "invite a long battle over the move's constitutionality. And it would do little to reduce air pollution."
Other observers argue that the measure is likelier to send a message to Congress that further reduction in acceptable emissions levels is needed if it is to have any significant effect on pollution. "This week's action in Albany is important symbolically and may yield modest practical benefits. But the only sure way to get the kind of reduction needed to protect the Adirondacks is to impose a far stricter nationwide cap on sulfur emissions," the editors of The New York Times editorialized on May 9.
The New York bill does not address nitrogen oxide emissions, but legislation in Congress would establish a nitrogen oxide allowances program similar to the sulfur dioxide allowances established in 1990.
A copy of the GAO report is available in the March 2000 Month in Review at the GAO website.