US 17 ACE Basin – Segments 1 & 2A Design-Build

US 17 in Beaufort and Colleton Counties, SC, was one of nation’s most dangerous two-lane roads. The South Carolina Department of Transportation (SCDOT) sought to widen the roadway and construct new bridges in order to improve its safety, while preserving the pristine estuary of the beautiful ACE Basin. As the lead designer of the winning design-build team, Davis & Floyd performed project management as well as prepared roadway, drainage, and bridge design for three bridges. Davis & Floyd also provided environmental services and utility coordination for the US 17 ACE Basin project.

The Davis & Floyd team captured all the NEPA and Environmental Permit Commitment in the 1st ever Environmental Compliance Plan (ECP). The ECP was presented in environmental partnering sessions and preconstruction conference. The ECP was used as a tool to conduct monthly Environmental Compliance Audits that included the Wetland Permit, land disturbance inspections, SW3P inspections, potential cultural resources, potential Threatened and Endangered Species, and Beaufort County Tree Ordinance and Burning Ordinance Requirements. Our team addressed specific environmental issues, including:

  • Monitored critical wetlands
  • Tracked mitigation credits
  • Modified the wetland permit
  • Permitted 6 Borrow Pits and set up guidance to maintain compliance with pit dewatering and reclamation
  • Obtained land disturbance permits and developed an overall site-specific construction and industrial stormwater pollution prevention plan
  • Developed and implemented an Eagle Management Zone Plan that created a buffer to control construction noises around a nesting pair of bald eagles (two eaglets were born and reared during the project)
  • Conducted asbestos surveys for building demolition to ensure proper abatement, demolition, and building material solid waste disposal
  • Developed and ensured compliance with dust control plan, Spill Prevention Plan (SPCC), and commitments for Hazardous Waste Sites
  • Supervised underground tank removals and properly abandoned groundwater monitoring wells as well as replaced groundwater monitoring wells
  • Permitted and completed compliance audits at the Pug Mill site

Environmentally sensitive to this scenic area, the design-build team explored every opportunity to save as many grand oak trees as possible, including using a 100′-wide natural median; guardrails to protect motorists traveling in proximity to retained trees; and a 10′-wide, Americans with Disabilities Act (ADA) compliant, multi-purpose path. To minimize impacts to wildlife, two former drainage box culverts were retained to provide a safe crossing for animals (critter crossings).


  • NEPA and Environmental Permitting
  • Environmental Compliance Plan
  • Environmental Compliance Audits
  • Wetland Permitting
  • Land Disturbance Inspections
  • SW3P inspections
  • Environmental Services & Design