Changes to the Bluffton Parkway flyover will cost an additional $750,000, which will be covered by the project's $4 million contingency fund, according to the Beaufort County staff.
Designs for the pillars that will support the flyover ramps were finished this fall after load tests were performed, county engineering director Rob McFee has said. The results showed some of the foundations must go deeper to ensure the flyover is safe, McFee said. Those extensions will require more drilling, steel and concrete -- an additional cost of about $482,000.
The final designs call for extensions to 21 of the pillars to ensure stability of the bridge foundations, McFee said. Some will not be lengthened at all, while some will be extended by 18 or 19 feet.
In addition, Palmetto Electric Cooperative must relocate overhead power lines along the eastbound shoulder of U.S. 278, where the eastbound flyover ramp will meet the highway, McFee said. The utility will bury the lines, which is expected to cost $267,000.
McFee reported the additional costs Monday to County Council's Public Facilities Committee. Neither change requires the committee or the full council's approval because they are necessary for the project and are covered by a contingency fund, county attorney Josh Gruber said.
The flyover project, which will cost more than $36 million, includes construction of a 4,200-foot-long bridge segment over the marsh and 4,500 feet of road improvements; it's expected to be completed in October 2015.
The flyover's connection to U.S. 278 will be made as the project nears completion and should not disrupt daytime traffic, McFee said. Crews will piece together the portion of the flyover that will pass over U.S. 278 at night, leaving all four lanes of the highway open during the day, he said.
The committee also discussed a delay in the project to widen S.C. 170 to four lanes from S.C. 46 to U.S. 278. A delay in the permitting process with the state Department of Health and Environmental Control led the project's deadline to be postponed 90 days, until next August, McFee said.
The delay also added about $60,000 in labor costs with contractor Cleland Site Prep, he added.
The state's "review took much longer than anyone anticipated," McFee said. "To compound this matter, they went through an administrative-process change, so we had to submit all this material again on different forms while the contractor was literally ready to go."
Both projects are funded in part by a 1 percent sales tax approved by Beaufort County voters in 2006.
The flyover is also funded by $15 million from the federal government, and the S.C. 170 project is also being funded by a $24.9 million grant from the S.C. State Transportation Infrastructure Bank.
Follow reporter Zach Murdock at twitter.com/IPBG_Zach.