HDD Matches Installation Method to Long and Difficult Pipe Crossing in Macon, GA

Abstract

The Macon Water Authority (MWA), in Macon, GA, needed to replace an existing undersized force main pipeline immediately adjacent and into the Rocky Creek Wastewater Treatment Facility (WWTF). This force main needed to be increased in size to adequately convey flow from the south side of the service area into the WWTF. Complicating the proposed installation in the area of the required upsized force main is Rocky Creek proper and surrounding wetlands, both of which would have to be traversed for a successful installation. Carter & Sloope (C&S), the design engineer for the overall project, recognized that horizontal directional drilling (HDD) could be a viable solution to the complexities of the proposed crossing, as well as a way to minimize the environmental impacts of the pipeline installation on the wetlands and creek. Due to the significant scope and complexity of this project, C&S recognized the need to utilize HDD contractors and pipe materials that have demonstrated successful installation in similar applications. They employed a pre-qualification process to assure that properly qualified HDD contractors and materials were used. Mears Group, Inc. was selected for the HDD portion of the project and elected to install the entire ≈4,200 LF HDD length, with 24-inch DR-18 Fusible PVC pipe. This project represents the largest HDD installation that C&S and MWA have been involved with to date. The success of this project was the result of a ‘team first’ construction effort, traversing landowner concerns, alignment adjustments, layout and fusion requirements, and general constructability issues with a crossing of this length and size.