Regardless of what you may have heard, 526 completion is moving forward.  The Mark Clark Extension project team is currently pursuing the Final Environmental Impact Statement (FEIS). They are also working on additional environmental studies, a settlement community study, mitigation for parks, a traffic analysis to support a phased approach and updating the U.S. Army Corps of Engineers and U.S. Coast Guard permits for phased construction in addition to finalizing the financial assessment. Over the next two years, the team will work to finish the EIS and other studies.

Funding will need to be revisited within the next year to stay on track with the approval timeline.

The SCDOT is recommending a phasing approach. They have found that there are challenges for projects of this size.  The phased approach is less risky for contractors and will ensure market competitiveness. Phase 1 will extend the Mark Clark from West Ashley to Johns Island for an estimated $1.35B. Phase 2 will extend the Mark Clark from Johns Island to James Island for an estimated $702M.

While many were shocked to see the new billion-dollar figure to finish the project, this is just an estimate and, as Secretary Hall stated, it is a “highly speculative” figure. The original cost estimate of $725 million was done in 2014 based on construction in 2019. The updated $2.35B estimate for Phase 1 and 2 is based on a 2028-2035 construction for both phases. The new estimate also includes anticipated project delay costs and 2-3 years of litigation. The sooner the project is started, the lower the cost will be.

Please see below for a breakdown of the cost increases:

• Base material costs/quantities + labor increases: +$700M
• Mobilization increases: +$59M
• Bridge structure/construction complexity: +$63M
• Additional sound barriers: +$8M
• Traffic control/lighting cost: +$11M
• Misc. Unit price and quantity increases: +$57M
• Additional Contingencies: +$76M
• Project delay costs: +$112M

SCDOT’s next steps will be to have an industry review of the cost estimate. They are already in contact with industry groups to initiate this. They will need authorization from the County, the State Infrastructure Bank (SIB) and the Joint Bond Review Committee (JBRC) to proceed with $150.2M in work to get the project ready for construction bids:

• Preliminary Engineering $8.2M
• Right of Way Acquisition $126M
• Tidal Mitigation $16M

Currently, the SIB and County agreement calls for splitting these costs 50/50. SCDOT is committed to working with the County and SIB to identify a reasonable funding plan for the project and an amendment to the original agreement if needed.

The County did not take any action following the Secretary’s presentation to the County Council on May 5, but Councilmembers had an opportunity to ask questions and provide their comments.

On April 26, the Charleston City Council unanimously adopted a resolution encouraging the completion of the Mark Clark.

The Chamber remains committed to completing the Mark Clark Extension. We encourage all stakeholders to make a plan, go after the necessary funds and complete the project. This is a crucial investment into our region’s future.