The head of the US Environmental Protection Agency's air office is leaving the agency, according to a marketscreener.com report. The departure ends a tenure that coincided with the Trump administration's multi-year rollback of Clean Air Act regulations.

The Office of Air and Radiation (OAR) is EPA's largest program office. It administers the National Ambient Air Quality Standards, the Title V operating permit program, the Section 112 hazardous air pollutant program, federal motor vehicle emissions and greenhouse gas standards, and New Source Review preconstruction permits for major stationary sources. The portfolio reaches every power plant, refinery, cement kiln and large manufacturing facility in the country.

For the waste and recycling industry, the air office's work shows up on two recurring tracks:

• Section 111 emission guidelines for municipal solid waste landfills and waste-to-energy units
• New Source Review applicability on major modifications to materials recovery facilities and scrap metal shredders that cross major-source emission thresholds

What does a leadership exit change in practice?

A departure at the assistant administrator level does not automatically pause or rescind the rulemakings already on the books. It changes who signs off on the next cycle of proposals and final rules, and typically triggers a quiet reshuffling across the air office's program divisions.

The regulated community watches these transitions for signals on:

• the speed at which EPA completes review of pending reconsideration petitions
• whether the air office accelerates, pauses, or withdraws pending proposed rules
• how the office balances court-ordered deadlines against its discretionary agenda

What this means for the rulemaking pipeline

The air office's workload over the past four years has included revisions to the Obama-era Clean Power Plan, the Mercury and Air Toxics Standards, the New Source Review program, and the federal vehicle greenhouse gas standards. The Biden EPA's stated priority has been reviewing and revising or rescinding the Trump-era air rules, and a leadership change of this kind is the kind of personnel move the regulated community tracks for early signals on the agency's working agenda.

Litigation deadlines in the D.C. Circuit and the Supreme Court's West Virginia v. EPA ruling have forced the agency to either finalize replacement standards or face automatic vacaturs on several of those dockets.

What the recycling and waste sector is tracking

For solid waste and recycling operators, the immediate concern is continuity in the air permitting pipeline. Title V renewals and New Source Review permits for materials recovery facilities and waste-to-energy expansions do not stop during a leadership transition, but unresolved policy questions tend to migrate up the chain of command.

Those questions include the future of the Section 111 emission guidelines for landfills and the scope of major-source determinations for materials recovery facilities that handle mixed paper, plastics, and metal scrap.

The milestone that decides what happens next

The regulatory milestone that decides what happens next is the timing of a Senate-confirmed successor. Assistant administrators for the air office have historically taken months to install. Until that person is in place, career staff will continue to process permits and technical work, but the policy direction of the rulemaking pipeline remains unsettled, and the regulated community will be reading the next Federal Register notices for the signatures that follow.