This metric is the number of days per year that the “air quality index” (AQI) was categorized as “Moderate” or “Unsafe for Sensitive Groups” (USG) for at least one pollutant at one monitoring site based on the National Ambient Air Quality Standards (NAAQS) for ozone and fine particulate matter (PM2.5). Each calendar day with poor air quality is counted once regardless of how many sites or pollutants meet the criteria on that day. Monitors for ozone are located in Bennington, Rutland, and Underhill; monitors for PM2.5 are located at these sites as well as in Burlington. The Rutland ozone monitor was installed in 2016, therefore years prior to 2016 may have had a few more days of poor air quality than are reported here. Air quality in the USG range exceeds the federal air quality standards (is worse than the standard); Moderate air quality still poses some risk to sensitive populations and can have additional environmental and visibility impacts. Current year is calendar year 2017. The target number of days with poor air quality is zero.