The Division of Air Quality will conduct a public hearing (Docket #2026-R-A-0007) on a proposed State Implementation Plan (SIP) revision. Public comment period open through Nov. 12, 2026.

On February 7, 2024, and December 11, 2024, the Environmental Protection Agency (EPA) promulgated a revised annual primary fine particulate matter (PM_2.5) and secondary sulfur dioxide (SO₂) National Ambient Air Quality Standards (NAAQS), respectively. The EPA changed the annual primary PM_2.5 NAAQS from 12.0 micrograms per cubic meter (µg/m³) to 9.0 µg/m³ and the secondary SO₂ NAAQS from 0.5 parts per million as a 3-hour average, not to be exceeded more than once in a year, to an annual standard with a level of 10 parts per billion, averaged over 3 years.

The Clean Air Act requires states to submit an infrastructure plan within three years after the promulgation of a revised or new NAAQS. Infrastructure plans address how states will implement, maintain, and enforce the 2024 annual primary PM_2.5 and secondary SO₂ NAAQS. This proposed infrastructure plan demonstrates that Delaware has the legal and programmatic infrastructure in place to enforce the 2024 PM_2.5 and SO₂ standards.

To view the proposed SIP revisions visit regulations.delaware.gov/register/current_issue beginning Oct. 1, 2026. For any questions or to view the proposed SIP revisions in person, by appointment-only, contact Jasmine Steward, at Division of Air Quality, 100 W Water St, Dover, Delaware, 19904, or via phone 302-739-9402 or by email at Jasmine.Steward@delaware.gov.

Those wishing to offer verbal comments the hearing must pre-register no later than noon on Oct. 28, 2026, at de.gov/dnreccomments or by telephone at 302-739-9034.

The Department will accept public comment through Nov. 12, 2026. Comments will be accepted in written form via email to DNRECHearingComments@delaware.gov, using the online form at de.gov/dnreccomments, or by U.S. mail to the address on this page.

Public Hearing Officer: Theresa Smith
DNREC Office of the Secretary
89 Kings Highway
Dover, DE 19901