Criteria air pollutants are a group of six common air pollutants regulated by the EPA. The EPA developed National Ambient Air Quality Standards (NAAQS) for these pollutants to protect public health and the environment. The six Criteria Pollutants are Ozone (O3), Particulate Matter (PM2.5 and PM10), Carbon Monoxide (CO), Nitrogen Dioxide (NO2), Sulfur Dioxide (SO2) and Lead (Pb).
The Las Vegas Valley (Hydrographic Area 212) is a marginal nonattainment area for the 2015 O3 NAAQS and an attainment area subject to a maintenance plan for the CO and PM10 NAAQS. Hydrographic Areas 164A, 164B, 165, 166, 167, 212, 213, 214, 216, 217, and 218 (excluding the Moapa River Indian Reservation and the Fort Mohave Indian Reservation) are attainment areas subject to a maintenance plan for the 1997 O3 NAAQS. Clark County is in attainment/unclassifiable for the PM2.5, SO2, Pb, NO2 and 2008 O3 NAAQS.
A detailed map of the designated areas within Clark County can be downloaded here.