MAC Facts: MSP 2021 Annual Noise Contour

Each year, the Metropolitan Airports Commission (MAC) assesses aircraft noise from the Minneapolis-St. Paul International Airport (MSP) and publishes the findings in an Annual Noise Contour Report. The 2021 Annual Noise Contour Report marks the 15th year that the MAC has prepared this report for MSP. Per the terms of the amended Consent Decree, the MSP 2021 Annual Noise Contour Report is now available. 

MSP made progress in 2021 to continue its recovery from the on-going impacts of the COVID-19 pandemic. There were 303,884 operations at MSP in 2021, as reported by the Federal Aviation Administration (FAA). While this does represent about a 20 percent increase from 2020, operations remain about 25 percent below operations in 2019.  

Nighttime activity also increased over 2020, from an average of 34 operations a night in 2020 to an average of 41 operations nightly in 2021. More information about 2021 operations was reported in the MAC Facts: 2021 - MSP Year in Review.  

The number of aircraft operations (takeoffs and landings) is a prominent factor in noise contour calculation. With an increase in operations, there was an increase in aircraft noise exposure from flight activity at MSP in 2021 compared to 2020.  

The 2021 Actual Noise Contours increased in size compared to the 2020 Actual Noise Contours but remain smaller than the 2019 contours. The contours expanded along all arrival and departure lobes (the shape of the contours that extend out from the runways) around the airport. The most substantial increase occurred south of the airport in Bloomington where the end of the 60 dB DNL Runway 17 departure lobe extends back to the Minnesota River Valley. The return of departures to Runway 17 caused this area to grow, yet it remains contracted compared to the 2019 contour. 

The 2021 Actual 65 decibel (dB) Day-Night Average Sound Level (DNL) Contour encompasses 3,353 acres. This represents an increase of nearly 866 acres, or 35 percent, from the 2020 Actual Contour. The 2021 Actual 60 dB DNL Contour encompasses approximately 8,572 acres, an increase of 1,985 acres, or 30 percent, from the 2020 Actual Contour. The 2021 65 DNL Contour remains more than 1,000 acres smaller than the 2019 65 DNL Contour while the 2021 60 DNL Contour is more than 2,500 acres smaller than the 2019 60 DNL Contour. 

Because the total number of operations at MSP in 2021 (303,884) was just over half the number forecasted in 2007 (582,366), the actual 2021 60 dB DNL contour is approximately 45 percent smaller than the 2007 Forecast Contour and the 2021 65 dB DNL contour is approximately 54 percent smaller than the 2007 Forecast Contour. The contraction of the contours from the 2007 Forecast to the 2021 Actual Contour scenarios is driven primarily by the reduction in average daily operations and secondarily by the advancements in noise reduction technology on modern aircraft.  There were 763 fewer average operations per day in 2021 compared to what was forecasted in 2007.  

The 2021 Actual Contour does not qualify any additional homes for mitigation as outlined by the terms of the 2017-2024 Program. 2020 was the last year that homes could become eligible under the terms of the program and therefore eligibility has ended for this program. Homes that became eligible for the 2019, 2020 and 2021 programs will be able to participate before the program sunsets in 2024. A list of homes that were previously eligible for mitigation in 2017 – 2021 is available here or check your address on the interactive map at customers.macnoms.com/mitigation. More information is available on the MAC website here.

The MAC has invested over $511 million throughout the life of the program.