Look Before You Dig: Use of an Abandoned Gas Main to Install A 7,500 Linear Foot Wastewater Force Main

The Kearny Municipal Utilities Authority undertook a project to provide sewer service to a 3.1 square kilometer (1.2 square mile) urban area in the Town of Kearny, Hudson County, New Jersey. The planned new service area has necessitated construction of a 2.41 kilometer (1.5 mile) long High Density Polyethylene (HDPE) force main and two submersible pumping stations. The force main construction has been completed and its alignment transverses through two interstate highways, key underground utilities and tidal wetlands. The existence and negotiated use of an abandoned gas main for use as a host pipe to install the wastewater force main allowed the project to be constructed at a lower cost and improved construction safety while minimizing environmental and traffic impacts. This paper describes the planning and alternatives analysis that led to the discovery of the abandoned gas main, feasibility investigation and use/easement agreement negotiation. The construction methods along with the time savings, cost advantage and environmental benefits are also described.