Flint Hills Refinery 421 Air Monitoring Station, Inver Grove Heights, Minnesota

Flint Hills Refinery 421 is an air monitoring station located in Inver Grove Heights, Minnesota, United States. The facility is part of the broader environmental monitoring infrastructure overseen by the Minnesota Pollution Control Agency, Division of Air Quality. As a stationary monitoring site, it contributes to the national network of air quality surveillance that tracks criteria pollutants and other atmospheric parameters. The station operates under the regulatory framework of the US EPA's Air Quality System (AQS), which sets standards for ambient air monitoring. While specific technical specifications such as the number of parameters measured are not detailed, typical stations in this network monitor pollutants like ozone, particulate matter, carbon monoxide, sulfur dioxide, and nitrogen dioxide. The site's location in an industrial and urban area suggests a focus on capturing emissions from refining and transportation sources. This monitoring station plays a key role in assessing air quality in the Minneapolis-Saint Paul metropolitan region. Data collected supports public health advisories, regulatory compliance, and long-term trend analysis. The station's operational status ensures continuous reporting, contributing to the state's ability to meet National Ambient Air Quality Standards (NAAQS) and provide communities with reliable environmental information.

The station is situated in Dakota County, part of the Twin Cities metropolitan area, which has a mix of industrial, residential, and transportation sources. Air monitoring in this region focuses on criteria pollutants such as PM2.5, ozone, and nitrogen dioxide, which are influenced by refinery operations, vehicle emissions, and seasonal weather patterns. The site's representativeness is important for understanding local exposure and regional transport of pollutants.