Overpeck Valley Relief Sewer

The Bergen County Utilities Authority (BCUA) constructed the existing Overpeck Valley Trunk Sewer (OVTS) in the early 1950s in order to convey sewage from Englewood to the newly constructed BCUA Wastewater Treatment Plant, located in Little Ferry.  The original trunk sewer included 42-, 48- and 60-in reinforced concrete pipe and is approximately 27,000 ft in length.  Over the years, the flows into the sewer have increased and several overflow chambers were constructed to relieve the sewer during peak wet weather conditions.

The BCUA has been mandated by the New Jersey Department of Environmental Protection (NJDEP) by an Administration Court Order to eliminate Overflow 006, which discharges into Overpeck Creek and is located at the extreme upper end of the interceptor system in Englewood.  The BCUA conducted an engineering study that concluded that the most cost effective solution for eliminating the overflow is to construct a parallel relief sewer in order to increase the flow capacity of the interceptor and eliminate the surcharging of the existing sewer.

In September 2004, Hatch Mott MacDonald was selected to provide engineering design, permitting, and construction managements services for the new parallel relief sewer.  The new sewer included approximately 15,000 ft of 72 in sewer, 10,300 ft of 66 in sewer, and 2,700 ft of 42 in sewer.  The project had many engineering challenges including the crossings of the Hackensack River, a major railroad yard, a PSE&G Electric Generating Plant, the New Jersey Turnpike and State Highway Route 46.  In addition, the entire area, which includes the Boroughs of Englewood, Leonia, Palisades Park and Ridgefield, has grown tremendously since the original construction of the trunk sewer.  The growth in the area has added developments and industries in proximity to the original sewer route and create d challenges regarding the selection of available corridors for the new sewer.  Further complicating the project is the existence of a 48 in water main that was constructed several years after the sewer and closely parallels it for over 2 miles.

The construction of the new sewer included pile supports and subaqueous pipe installation for the Hackensack River crossing as well as over 5,000 ft of trenchless construction using microtunneling.  The microtuneling is being used to cross the railroad yard, the New Jersey Turnpike, State Highway 46 and other areas where deep excavation and dewatering would cause havoc with existing utilities and disrupt commerce. In addition, the new route was selected to avoid conflicts and utilizes an adjacent closed landfill and park land in order to limit the disruption to commercial activities.

The new relief sewer will be constructed parallel to the existing 60 in trunk sewer.  The two pipelines are interconnected at eight (8) locations to distribute flow to both the new and existing conduits.  The interconnections are designed so that either pipeline can be taken out of service for maintenance and inspections.