Nonattainment is geek speak for some air quality monitor in the area is above the standard, so EPA usually hits the whole county or "air basin" where it's located with that designation. Triggers a mass of paperwork, regulations, and other lawyers full employment stuff, but a few small pots of money also go with it.

Railroads generally are considered Good overall for air quality, but they do have their dark sides - especially exhaust from old diesels.