Emission Reduction Credits (NNSR Offsets)

Current understanding

To be populated as evidence accumulates.

2026-11-05 — Air Plan Revisions; Arizona; Maricopa County Air Quality Department; New Source Review; Emission Reduction Credits: cross-connection with emissions-standards: Maricopa County’s approved SIP revision links reductions from on-road vehicle retrofits and replacements to industrial offset compliance through emission reduction credits, rather than changes to direct emission limits. (novelty: 2)
2026-10-08 — Air Quality Plan; Arizona; Maricopa County Air Quality Department; New Source Review; Emission Reduction Credits-Rule 204: EPA proposed approval (Nov 2025) of Maricopa County, AZ Rule 204 would create an ERC-generating pathway from retrofitting or replacing off-road engine fleets, with the resulting credits usable as NNSR offsets by major stationary sources expanding in the nonattainment area. (novelty: 2)