The map above depicts the U.S. Environmental Protection Agency’s regional offices (which differ from NPCA’s regional breakdown). The emissions data in the linked pages utilize data from EPA’s 2020 ...

The EPA measures regional air quality index (AQI) by how hazardous it is to the general public. Discover the AQI in your city by searching below.

This map shows water systems included in the EPA’s records ... Systems vary from region to region, each with their own water ...