New airport noise map may shrink home-insulation zone

Airport consultants are working on a new noise map around Minneapolis-St. Paul International Airport that will probably mean fewer Southwest Minneapolitans will get home sound-insulation upgrades than earlier forecasts showed.

Consultants from HNTB Inc. will make initial presentations to the Metropolitan Airports Commission (MAC) Planning and Environment Committee April 8 and May 6. Both sessions are 1 p.m. at the airport's 2nd floor meeting room.

HNTB will discuss flight-forecasting data they would use to draw the map, said Roy Fuhrmann, MAC's director of environment. The forecasts consider such things as the number of flights and the type of aircraft flown.

The new noise map should be ready for public review by June or July, said John Nelson, manager of MAC's sound insulation program.

MAC's current noise map was prepared in 1991 and projects 1996 flight patterns. As of January, MAC has insulated 7,177 homes of the 7,852 eligible, Nelson said. It has paid for new doors, windows, insulation and other improvements to lower interior noise by at least 5 decibels.

It expects to finish work on eligible homes by the end of 2004, he said. It also plans to recontact the 292 homeowners that had previously declined upgrades.

MAC had approved a new noise map -- predicting 2005 noise levels based on 2000 flight data -- and submitted it to the Federal Aviation Administration.

Following the Sept. 11, 2001 terrorist attacks and a downturn in flights, the MAC pulled that map and agreed to redo it at the request of the airlines.

The new map will use 2002 data to predict 2007 noise levels, and the contours will shrink in south and southwest Minneapolis, Nelson said.

In part, it will reflect the use of quieter planes, he said. In part it will reflect the opening of the new north-south runway, which will take some traffic away from Minneapolis.

The MAC's new sound-insulation program will expand eligibility to quieter neighborhoods -- out to what computer-generated noise models call the 60 DNL (Day Night Level) line. DNL lines reflect estimated plane noise, adding penalties for night flights.

Eligibility previously stopped at the 65 DNL line.

Insulation upgrades to homes in the newly eligible 60-65 DNL areas would not begin until June