Though the new measures would not lower emissions, the EPA claims they will "provide consistency" for meeting current national standards.
The new source performance standards would only apply to new or newly modified facilities. Reforms in the proposal are expected to cost mill owners a combined $390,000 each year for the next five years, the EPA estimates.
The agency first set performance standards for the plants, known as kraft pulp mills, in 1978, but is required by the Clean Air Act to review them at least every eight years. The standard was last updated in 1986.
There are about 99 kraft pulp mills in the United States under EPA regulation.