Federal grant of $3.6 million funds seismic retrofits on eight Interior Alaska bridges

The Federal Highway Administration has given the Alaska Department of Transportation and Public Facilities $3.64 million to earthquake-proof eight highway bridges. When the department put the work out to bid in April, its own engineers estimated the job at $5 million to $10 million, which leaves the grant covering somewhere between 36 and 73 percent of the cost. The records posted to USAspending don't say where the rest comes from.

The bridges are river crossings on the roads through the Copper River basin and into the Interior. On the Edgerton Highway, the Copper River bridge at Chitina and the Tonsina River bridge. On the Old Richardson, the Klutina River bridge at Copper Center. On the Parks, the Tanana River bridge at Nenana and the North Slough crossing beside it. On the Richardson, the Tanana River bridge at Big Delta, the Little Salcha River bridge and a second Klutina River span.

Alaska accounts for 11 percent of the world's recorded earthquakes and seven of the 10 largest ever recorded in the United States, according to the Alaska Seismic Hazards Safety Commission.

The bid documents call for construction to finish by Oct. 31, 2027. The grant itself runs through April 2029. The retrofits are part of a two-phase state seismic program that, according to a 2012 Alaska bridge report, goes after the bridge weaknesses posing the most risk that can be fixed for the least money.