Project GREENline, Wastewater System Expansion, Mt. Pleasant, SC
Designed as a 2-year project to improve flow within MPW's wastewater transmission network, Project GREENline was awarded to Chandler Construction Services, Inc. in early 2003. The project included the installation of 12-inch, 24-inch and 36-inch diameter gravity sewer and 16" forcemain in a heavily congested area along Highway 17N in Mt. Pleasant, SC.

After the project was awarded, Chandler proposed several modifications which significantly reduced potential problems with traffic disruption and minimized impacts to archeological and environmental-sensitive areas.

Special construction challenges included saving 'grand' oaks and protecting more than 100 other trees, hand tunneling under hardscape, consulting with sweet grass basket vendors along the project route, respecting historic Christ Church Cemetery, completing a dozen road crossings, and working under 23 kV overhead electric lines. A 120-foot long, 54-inch diameter and 350-foot long, 60-inch diameter closed-face directional bore were constructed on grade.

Average cuts were greater than 12 feet and the entire three mile length of the project required extensive dewatering. A 30-foot wide construction easement which narrowed to 12 feet in some areas was secured from the South Carolina DOT, local agencies, private residences and business owners. The entire site was restored to pre-construction conditions and impacted trees were mitigated in accordance with county and town requirements.

Pipe laying and tie-ins were completed in January 2004. The wastewater transmission system was permitted and placed in operation more than 7 months ahead of schedule.