HDD for Water Main and Interconnections in North Charleston, SC
Weston & Sampson was selected by Charleston Water System (CWS) to provide rapid design services for over 20,000 feet of 24” water transmission main along with several other shorter sections of various sizes of interconnections in a rapidly developing area of North Charleston. The project was performed in close coordination with local economic development efforts and to strengthen the CWS transmission system north of Charleston International Airport. This project was significant in that Weston & Sampson was selected to provide engineering services for this ROADWISE project that was already under construction. Rapid collaboration between Charleston County, South Carolina Department of Transportation (SCDOT), North Charleston Public Works, Charleston Water System, the US Army Corps Of Engineers, Ocean & Coastal Resource Management (OCRM), and South Carolina Department of Health and Environmental Control (SCDHEC) led to a very compressed design and permitting phase to meet the construction timeline. Our unique ability to effectively coordinate communication between several municipal entities, regulatory agencies, and contractors helped to make the design and permitting process successful. The project included crossing of a navigable waterway and sensitive wetland areas. Weston & Sampson evaluated construction methods and recommended, based upon the length and geology that the crossing be completed using Horizontal Directional Drilling, to install just over 1000 linear feet of 30” High Density Polyethylene pipe. The crossing plans included boring profiles, geology, staging areas, rig side layout as well as pipe side and fusion staging areas were provided for bidding while adjacent road and bridge construction were closely coordinated. The project has been completed and in service since September 2011.
Phase 2 of the project included the design of a 24” DIP water main extension also to be installed in conjunction with a City of North Charleston economic development project. We provided surveying, conceptual planning, permitting, final design, and construction administration for 6,400 linear feet of 24” water main constructed in two divisions. The project included two 42” steel casing jack & bores under a 200-foot wide railroad right-of-way and a 90-foot wide road right-of-way.