Updated Monday, November 5, 2012 at 10:58 AM
The new South Park Bridge will be finished a few months late because of difficulty installing one of two huge underwater foundations.
The September 2013 target will be changed to sometime in early 2014, said Jeff Switzer, spokesman for the King County Department of Transportation.
The problem is at the south end, on the South Park side of the Duwamish River, and involves one of the giant concrete abutments partially buried in the riverbed. Hard clay, found 62 feet below the river bottom, had to be removed so workers could sink the structure eight more feet.
The new drawbridge is being built by a joint venture of Kiewit and Massman construction companies, which bid $96 million to win the contract. The project's overall budget is $163 million, including engineering, contingencies and community outreach.
County transportation officials don't yet know whether the delay will cost taxpayers, Switzer said.
The old drawbridge, built in 1929-31, carried 20,000 vehicles a day. Sinking and cracking were visible in its later years until it closed in 2010, isolating the low-income neighborhood and small-business district. Construction on the new bridge began in May 2011.
Demolition of the old bridge begins in a few weeks, so neighbors can expect more construction workers and activity, said Switzer. Parts of the new bridge are finished, including two of the four aerial approach spans near shore, and some road decks.
Ronald Cook, president of R.L. Cook Sales & Supply, said the delay "won't cause any more hardship than we've already seen" to his electrical-supply business. "Everyone's situation is slightly different."
Cook, a board member of the South Park Business Association, said the contractor's plight is understandable.
"It's a situation caused by nature," he said. "Up until this delay here, I think they've been doing a very diligent project, as far as utilizing time, coordinating their materials."
Mike Lindblom: 206-515-5631 or email@example.com.
On Twitter @mikelindblom.
COLIN DILTZ / THE SEATTLE TIMES
Digging through a hard layer of clay to install a riverbed foundation for the new South Park Bridge took more time than expected, and will push completion of the project back a few months.