Sept. 7, 2023 Air Quality alert

On Thursday September 7, 2023, an air quality sensor on the North I-25 Berthoud to Johnstown Project located at the northeast corner of I-25 and CO 56 measured higher than normal particulates (particulate matter, PM10). CDOT suspects sources influencing the high monitored values are vehicle traffic from a dirt road adjacent to the sensor. The daily average monitored Air Quality Index (AQI) was 103, which indicates people in sensitive groups may experience health effects, but the general public is not likely to be affected.  Other air quality sensors on the project measured good to moderate AQI levels. Further information in interpreting AQI values may be obtained online at https://www.airnow.gov/sites/default/files/2018-04/aqi_brochure_02_14_0.pdf.  CDOT continues to implement air quality impact mitigation measures on the project to reduce particulate emissions.