National-Southwire Aluminum Company (NSA) owns and operates a plant that emits fluoride. When its wet scrubbers were turned off as part of its regular maintenance program, NSA discovered no appreciable change in ambient fluoride levels.
Because of the expense of operating the scrubbers and its belief that using the scrubbers did not significantly affect ambient fluoride levels, NSA desired to turn the scrubbers off permanently. Accordingly, NSA sought a determination from the Environmental Protection Agency (EPA) that turning off the scrubbers would not constitute a modification requiring the application of new source performance standards to the plant.
Turning off the scrubbers would result in an increase of more than 1,100 tons per year of fluoride emissions with no decrease in the emission of any other pollutant. This increase was nearly four hundred times the level the EPA had established as inconsequential.
The EPA determined that turning off the scrubbers would constitute a ‘‘new source'' modification. Accordingly, NSA was required either to leave the scrubbers on or to install new pollutant control equipment. Is the EPA correct in its assertion? Explain.