California air regulators get new rules for how to count dirty air days
What happened
The US environmental regulators approved new rules for how the Feather River Air Quality Management District in California counts days with too much ozone. This means the district now has a clearer way to show it is meeting federal clean air standards.
Why it matters
The Clean Air Act requires regions to meet specific air quality targets. If a region fails, it can face penalties or lose federal funding. These new rules clarify how the Feather River district measures its progress, which could help it avoid those consequences.
The signal
Watch whether the Feather River district's reported air quality improves in the next few years, or if it continues to struggle with ozone levels.