Regulatory Roundup

In early July, EPA proposed revisions to the public participation requirements tied to New Source Review (NSR) permitting, the process states use to approve construction or modification of stationary emission sources like power plants and industrial facilities. Under the Clean Air Act, states submit implementation plans to EPA that spell out how minor NSR permitting will work, including how much public comment and hearing process is required before a permit is approved.

The proposed change would let state and local air quality agencies decide for themselves how much public participation is necessary for individual minor permits and minor modifications, rather than following a more standardized federal requirement. EPA's stated rationale is reducing administrative burden on the agencies that process these permits.

Why it matters for monitoring programs: agencies and facilities that regularly go through minor NSR permitting may see faster or lighter-weight approval processes if this rule finalizes, but it also means permitting timelines and public comment expectations could start to vary more by state. Programs operating across multiple states may want to watch for divergence in local requirements.

Public comments on the proposal are open through August 21, 2026.

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When EPA tightens a National Ambient Air Quality Standard (NAAQS), like it did for PM2.5 in 2024, the agency is legally required to designate which regions across the country meet the new standard ("attainment") and which don't ("nonattainment") within a set timeframe. Those designations determine which areas face stricter permitting, control requirements, and monitoring obligations going forward.

In mid-2026, a coalition of state and local governments along with environmental and public health groups sued EPA, arguing the agency had failed to complete these designations within the legally required window following the 2024 PM2.5 standard. In July 2026, a federal district court agreed, ruling that EPA had not fulfilled its non-discretionary duty under the Clean Air Act to issue timely attainment designations.

Why it matters for monitoring programs: this ruling increases pressure on EPA to finalize designations, which means more regions could be reclassified as nonattainment in the near term. Facilities and agencies in areas that may shift status should expect closer scrutiny of monitoring data and compliance planning once designations are finalized.

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Throughout 2026, EPA leadership has continued to prioritize reconsidering several Biden-era vehicle emissions rules, including tighter emission restrictions for light- and medium-duty vehicles and nitrogen oxide reduction requirements for heavy-duty engines under the Clean Trucks Plan. Both sets of rules apply to model years 2027 and later, and EPA has floated keeping current standards in place for an additional two years while it reconsiders them.

Separately, EPA has continued working to formally rescind the 2009 greenhouse gas endangerment finding, the scientific and legal finding that underlies many federal rules regulating greenhouse gas emissions from vehicles. That effort has faced legal challenges from environmental advocacy groups.

Why it matters for monitoring programs: these actions center on vehicle emissions rather than ambient air monitoring directly, but shifts of this scale in EPA's regulatory priorities can affect state-level funding, staffing, and attention available for ambient monitoring programs more broadly. Worth watching for downstream effects even though nothing here directly changes sampling or reporting requirements yet.

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