Beech Branch Outfall: Making the Right Decisions for a Unique Pipe in Rocky Mount, North Carolina

The City of Rocky Mount’s Beech Branch Outfall consists of 27-in. corrugated metal pipe (CMP) with a total length of approximately 25,000 linear feet. This gravity line was installed in 1978 and was well beyond the expected service life for a pipe of this material of construction used in sanitary sewer service. The pipe had experienced several failures, and a comprehensive program was undertaken, which included flow monitoring, modeling, data collection, review of historical data, and surveying, to develop and evaluate rehabilitation and replacement alternatives for this critical asset. Initial inspections performed revealed the CMP was lined with road tar-like material rather than a coal tar epoxy creating some unique challenges to be addressed during design. This paper will explore the data, decisions, findings, and recommendations that lead to successful rehabilitation of the pipe using the cured in place pipe method in 2020.