Revisions of the Nonattainment Designation for the 2008 and 2015 Ozone Standards and Clean Data Determinations for the 2008 and 2015 Ozone Standards: Cecil County, MD and New Castle County, DE
Key claim: The EPA is revising the Philadelphia-Wilmington-Atlantic City ozone nonattainment area into three distinct areas and issuing clean data determinations for Maryland and Delaware under both the 2008 and 2015 ozone NAAQS.
Abstract
(Rule · Environmental Protection Agency) The Environmental Protection Agency (EPA) is approving two separate requests from Maryland and Delaware to revise the designation for the Philadelphia-Wilmington-Atlantic City, PA-NJ-MD-DE nonattainment area for the 2008 primary and secondary ozone national ambient air quality standards (NAAQS) and the 2015 primary and secondary ozone NAAQS. Due to the concurrent requests from Maryland and Delaware, the EPA is revising the Philadelphia-Wilmington-Atlantic City, PA-NJ-MD-DE nonattainment area boundary into three distinct nonattainment areas that together cover the identical geographic area of the existing area. The EPA is also issuing clean data determinations (CDDs) for the revised Maryland and Delaware nonattainment areas for both the 2008 and 2015 ozone NAAQS. The EPA is taking this action pursuant to Clean Air Act (CAA) sections 107, 110, 172, and 182.
Why this matters
Redrawing the multi-state Philadelphia-area ozone boundary and issuing clean data determinations shifts which counties face nonattainment-triggered permitting burdens (like stricter New Source Review) and suspends certain SIP planning obligations for the affected Maryland and Delaware counties. It illustrates how boundary revisions and monitoring data can materially change regulatory costs for industry and states even without changing the underlying NAAQS.