EPA Splits Philadelphia-Area Air Quality Oversight Zone Between Three States
Official: 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
Reading: The EPA is redesignating the boundaries of an existing nonattainment area and issuing clean data determinations that continue ozone standard monitoring and compliance requirements without changing the stringency of the ozone standards themselves.
The redrawing follows requests from Maryland and Delaware and affects how ozone pollution is tracked and managed in New Jersey.
In clear language
The EPA is redrawing the air quality monitoring boundaries for a region covering parts of Pennsylvania, New Jersey, Maryland, and Delaware. This change splits what was one oversight area into three separate zones, while keeping the same geographic area covered overall. The redrawing follows requests from Maryland and Delaware and affects how ozone pollution is tracked and managed in New Jersey.
How does this affect you?
Pick the type of resident or organization you most identify with — we'll generate a plain-language breakdown of what changes for you and what you can do about it.
Who does this affect?
- Residents and businesses in New Jersey counties within the Philadelphia-Wilmington-Atlantic City region, particularly in the northern portions of the state
- State and local air quality agencies in New Jersey that must comply with EPA ozone standards
- Companies and industries in NJ subject to ozone pollution regulations
- People with respiratory conditions or sensitivity to ozone pollution in affected NJ areas
What can you do?
- Monitor air quality forecasts for your area using the EPA AirNow website (airnow.gov) to plan outdoor activities on high-ozone days
- Support or participate in local air quality improvement initiatives in your community
- Check whether your county's air quality designation has changed and review any new compliance requirements if you operate a business
Timeline
- Effective: 2026-07-06
- Effective: 2026-07-06
- Effective: 2026-07-06
- Effective: 2026-07-06
- Effective: 2026-07-06
- Effective: 2026-07-06
- Effective: 2026-07-06
- Effective: 2026-07-06
- Effective: 2026-07-06
- Effective: 2026-07-06
- Effective: 2026-07-06
- Effective: 2026-07-06
- Effective: 2026-07-06
- Effective: 2026-07-06
- Effective: 2026-07-06
- Effective: 2026-07-06
- 2026-07-06: Rule becomes effective
No New Jersey official has a verified action on this policy yet.
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