1. Air pollution is different from water--spreads out in 3 dimensions--rivers stay in the riverbank. 2. I guess the EPA could do better--likely fewer *people* affected by the Animas river debacle, but across a much larger geographic area.
You’re right…but the vast majority of people live in the Cities. I live only 25 miles from Boston…but the air quality in my very wooded neighborhood is significantly better then Boston.