Little Ferry WPCF Collection System
There are three categories of municipal collection systems; storm sewers, sanitary sewers and combined sewers. Systems that convey stormwater runoff and other drainage directly to surface waters while excluding sanitary wastes are considered storm sewers. Systems that receive wastewater from residential, commercial or industrial sources along with relatively small amounts of groundwater infiltration or stormwater inflow are considered sanitary sewers. Sewers that convey both sanitary wastes and stormwater are referred to as combined sewers. The operation and maintenance of storm sewers are the responsibility of individual municipalities and are, therefore, beyond the scope of the BCUA’s water pollution control responsibilities. Combined sewers are present in Fort Lee, Hackensack, and Ridgefield Park. While combined sewers are also a municipal responsibility, the BCUA treatment plant does receive discharge from combined sewers.
The BCUA operates a system of gravity sewer lines, pumping stations and forcemains that receive the discharge of wastewater from the individual municipal collection systems and transports the wastewater to the treatment plant in Little Ferry. A gravity sewer is sloped downward so that the wastewater flows toward the treatment plant. When the topography is such that the construction of gravity sewers creates very deep sewer lines, a pumping station is built to lift the sewage to a level that will allow it to once again flow by gravity. Typically, pumped sewage is discharged into a forcemain, which is a pressurized line that eventually feeds into a gravity sewer.
The BCUA does not own or operate the local collection systems. Traditionally, each Bergen County municipality independently constructed its own sanitary sewer system and sewage treatment plant when necessary for public health reasons. As such, many of the municipal collection systems predate the formation of the BCUA in 1947. Generally, the materials and methods used for sewer construction were greatly improved after 1950. Pipes with better and fewer joints were available and became the standard for the industry, making sewers more impermeable. Older systems allow groundwater to enter the sewers, which is referred to as infiltration. It was also standard practice in the past to connect stormwater conveyance systems, such as roof leaders and sump pumps, to the sanitary sewers so that local flooding problems could be alleviated. This is known as inflow. Infiltration and inflow present engineering and regulatory challenges for the BCUA and for many municipalities within the BCUA service area.
The BCUA began constructing its collection system in 1948. The system consists of the trunk and intercepting sewers which convey the wastewater flow from the municipal collection systems to the treatment plant in Little Ferry. Each subsequent construction phase connected additional municipalities to the system. With the completion of the most recent expansion in 1992, the collection system now encompasses approximately 108 miles of sewer lines and nine pumping stations serving all or part of 46 municipalities in Bergen County.
Three separate trunk sewer systems collect and transport wastewater to the BCUA treatment plant. The first trunk sewer constructed by the BCUA was the Overpeck Trunk Sewer which extends from Little Ferry to Tenafly. Interceptor sewers were also constructed which allowed 12 municipalities in the Overpeck Valley to abandon their sewage treatment plants and discharge wastewater to the BCUA. This construction was completed in 1951. The next expansion of the service area occurred through construction of the Hackensack Valley Trunk Sewer. This second stage, completed in 1964, extended from Little Ferry to Westwood and added 16 municipalities to the system. The service area was also expanded to the southwest through the construction of the Southwest Trunk Sewer which extends from Little Ferry to Hasbrouck Heights. This third trunk sewer system was completed in 1972. Additionally, two major subsystems were completed in 1976 extending service to the Pascack Valley and Northern Valley areas of Bergen County. Both of these subsystems discharge to the Hackensack Valley Trunk Sewer.
Measuring the amount of wastewater produced by each municipality is important for both operating and billing purposes. To accomplish this task, the BCUA has constructed 166 metering chambers throughout the service area. The typical BCUA metering chamber is an underground concrete vault that contains a metering device. Metering data is transported via telephone lines to the BCUA’s User Charge Department automatically.
The nine BCUA pumping stations were constructed on the outer reaches of the service area except for the largest station which is located in Harrington Park and serves the Northern Valley region. All BCUA pumping stations are designed to run automatically and do not require personnel on a 24-hour per day basis. Each station contains its own electrical generating facilities in the event that normal power is lost. The pumping stations require periodic cleaning of the wet wells to remove the buildup of grit and other materials that are not removed by the pumps.
The Northern Valley extension of the BCUA collection system circumnavigates the Oradell Reservoir owned by United Water Inc. Five of the nine BCUA pumping stations are located within the reservoir watershed. Since the discharge of wastewater into the reservoir has the potential to contaminate a significant portion of the drinking water supply for Bergen County, the pumping stations, forcemains, and other parts of the collection system located in this region receive proportionally greater attention due to the impact that sewage overflow would have on this system.
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