Edgewater Forcemain Installed within a Railroad Tunnel

ntroduction The Bergen County Utilities Authority (BCUA) Serves a population of 536,000 residents in Forty-Six Municipalities in Northeast Bergen County, where they manage solid waste and operate two wastewater treatment plants in Little Ferry and Edgewater, New Jersey. In 2007 the BCUA acquired the River Road Wastewater Treatment Plant (WWTP) from the Borough of Edgewater. This facility has a capacity of 6mgd and serves Edgewater and portions of Fort Lee, Cliffside Park and North Bergen. The NJDPES Permit for the facility required additional treatment for copper, zinc and ammonia. This would require upgrades to WWTP and extension of the facility's outfall by 1,000 linear feet into the Hudson River. The BCUA determined that these investments were not cost effective and very difficult to permit. The BCUA decided after exhaustive analysis to convert the Edgewater WWTP to a pumping station and convey the effluent to the Little Ferry WWTP. The flow will be carried by twin 24-inch forcemains and a 54-inch gravity sewer for a distance of 17,000 linear feet Description of Project The project has been split into four contracts based upon construction methods including the conversation of WWTP to a Pumping Station, 8,570 linear feet of twin 24-inch high density polyethene (HDPE) fusion welded force mains, 3,055 linear feet of Horizontal Directional Drill and 5,300 linear feet of 54-inch diameter gravity sewer split between 3,350 linear feet of open cut and 1,890 linear feet of open cut (Refer to Figure 1) Figure 1 - Alignment of Edgewater Forcemain and Gravity Sewer The first contract consists of 8,570 near feet of twin 24-inch diameter HDPE fusion welded forcemains. This Contract includes the connection to the new pumping station, 1,500 linear feet of open cut along River Road and 1,500 linear feet through an active high rise construction site. The most interesting aspect of this contract is the reach of the forcemains was installed through an abandoned Railroad Tunnel The tunnel measures approximately 5,000 linear feet in length with a depth of 200-feet. It was originally constructed as a rock cut with virtually no liner in 1890's to supply coal for ocean going ships. The tracks were removed in the early 1990's The tunnel is currently owned by the New York Susquehanna and Western Railroad. The tunnel contains other utilities such as a High Bridge High Voltage Electrical Transmission Line to Manhattan and a Hess Oil Line and a PSE&G gas main. Conclusion This abstract presents a brief overview of the project. The final paper will discuss the unique construction techniques used to install the forcemain in the tunnel, the restrictions required by construction within an active private construction site and steps the BCUA took to mitigate these hurdles. The final paper will also present the technical aspects of the project including the design of the forcemain, safety issues encountered during construction in the tunnel.