New Source Review Permitting Improvement Act

The bill would amend three sections of the Clean Air Act to narrow when changes at industrial stationary sources — such as power plants, refineries, and factories — trigger New Source Review (NSR) permitting, the preconstruction permit process that applies when a facility makes a major modification. Under the bill, a change would count as a "modification" only if the maximum hourly emission rate achievable after the change exceeds the highest hourly rate achieved during any hour in the preceding 10 years. Changes designed to reduce air pollutant emissions per unit of production, or to restore, maintain, or improve operational reliability or safety, would be excluded from the modification definition — unless EPA determines the resulting increase in the maximum achievable hourly emission rate would cause an adverse effect on human health or the environment.

The bill would also limit preconstruction permit requirements to situations involving physical construction of the discrete parts of an emissions unit, not other costly, site-altering, or permanent on-site activities. These narrowed definitions apply both in attainment areas and in nonattainment areas (areas that do not meet federal air quality standards). A rule-of-construction provision would ensure the bill cannot be read to expand what counts as a modification beyond current law's scope.

Operators of major stationary sources subject to NSR permitting — including electric power plants, petroleum refineries, chemical manufacturers, and other large industrial facilities — who would face fewer triggering events for preconstruction permits. EPA's permitting staff would need to make new adverse-effect determinations for certain safety and reliability projects. Communities near major emitting facilities would be affected by how the new emission thresholds are applied in practice.

For industrial facility operators, the 10-year hourly emission baseline and the reliability/safety project exemption could significantly reduce the frequency and cost of NSR permit proceedings, allowing routine operational changes and equipment upgrades to proceed without lengthy preconstruction review. For communities and environmental regulators, the scope of EPA's health-and-environment override determines whether emission increases from previously exempt projects still receive scrutiny.

The bill is largely self-executing through amended statutory definitions. The key discretionary element is EPA's authority to determine, for a change otherwise exempt as a pollution-reduction or reliability/safety project, that the increase in maximum achievable hourly emission rate would cause an adverse effect on human health or the environment — triggering modification status despite the exemption. The bill does not specify rulemaking timelines, but EPA would likely need to issue guidance or rulemaking to implement the 10-year hourly baseline methodology and the adverse-effects determination standard consistently across NSR permit applications.