People living along Interstate Hwy. 35W in Burnsville could have two more noise walls by 2015.
Two of the walls already line either side of the freeway south of Burnsville Parkway. The next set are planned to be built north of 162nd Street -- extending 1,148 feet along Buck Hill Road on the west side of the freeway and Kenrick Avenue and 964 feet along Maple Island Road on the east. Together the walls will cost about $1 million.
Since 1997, when the noise wall program began, the Minnesota Department of Transportation (MnDOT) has spent more than $30 million -- about $2 million a year -- to build 35 of the 20-foot-high wooden walls in the metro area: in Eagan, Edina, St. Louis Park, Blaine, Oakdale, Woodbury, Plymouth, New Hope and Lino Lakes, among other locations. Cities are required to contribute 10 percent of the cost.
The goal is always a 10 decibel reduction, meaning the sound of the traffic is half as loud for those behind the wall, said Peter Wasko, noise specialist for the department. "We certainly want to provide a substantial change in what those noise levels are."
Locations for the walls are determined by the number of people who would benefit from the noise relief and how much the noise would be reduced. The priority list is updated every five years; more than 280 locations remain on the list, Wasko said.
At this location in Burnsville about 12 residences on the west side and 13 on the east side would receive the largest benefit of the noise barrier. Traffic noise ranges from the upper 60 to mid 70 decibel levels without the wall and drops to the mid 60s with the walls, Wasko said.
The change must be greater than 3 decibels for the average human ear to detect a change in outdoor noise, Wasko said. "A 5 decibel change is clearly noticeable and a 10 decibel change would sound half as loud," he said.
Residents who live near the chosen locations always have the option to veto the walls. A few cities have turned them down because they block the view, Wasko said. But typically they are welcomed. Edina residents along Hwy. 100 so urgently wanted the noise barriers that they helped pay for them themselves.
Burnsville residents were invited to an informational meeting about the walls last Thursday. They have two weeks to return a mailed postcard to MnDOT to register their opinion. The walls would be built in 2015.
The Burnsville location will have a high benefit for the cost and the City Council has agreed to make the 10 percent contribution if the residents want them, said city engineer Ryan Peterson.
The city would use some of its state gas tax allocation to cover its share, Peterson said.
Laurie Blake 952-746-3287