Summerville/N. Charleston, SC
In the northwest area of Charleston within Dorchester and Charleston counties, SEC installed approximately 73,000 linear feet (almost 14 miles) of 12” pipeline in the wet and sandy ground conditions of the low country. During the project, 38 acres were cleared and 25,000 timber mats were placed across the route in addition to other environmental measures after clearing and then grading the ROW. The crews encountered a lot of groundwater and used trench boxes to ensure safe excavations. The project included 32,600 feet of horizontal directional drilling. SEC completed these drills in 136 days with no state reportable inadvertent returns or safety incidents. The longest drill was 4,184’ and SEC used (2) rigs to perform the intersect method. This method of installation was chosen by SEC, to mitigate possible inadvertent returns. The drill was completed without incident. SEC also chose to drill approximately 12,000’ of wetlands to help reduce the disturbance caused by trenching through the wetlands. Two HDDs required containment and testing of drilling fluids, being inside the boundaries of an old phosphate mining area, Runnymeade Plantation Phosphate Mine & Bulow Mining Complex. SEC was commended on the quick response time for unplanned challenges with both installation and environmental challenges. Forty percent of the project took place in wetlands and sensitive environmental areas. Wetland ROW was restricted to 30’, there were no off ROW incidents. SEC successfully executed work within all wetlands with minimal environmental impact. Planning ahead of these sensitive areas, ensuring equipment was fueled prior to reaching the wetland, all ECD’s in place and maintained, & topsoil segregation.