PVSC Old Sludge Storage Tank Rehabilitation

Interior of Old Sludge Storage Tank

PVSC Old Sludge Storage Tank Rehabilitation

Restoration of Existing Storage Tank to Support Plant Operations

Nearly 100 years ago, the Passaic Valley Sewerage Commission constructed a wastewater treatment plant near the banks of the Passaic River and Newark Bay. Over the subsequent century, it has become one of the East Coast’s largest wastewater facilities. It serves 1.5 million residents, 225 significant industrial users, and 5,000 commercial users across 48 municipalities and 5 counties and is designed to treat an annual average flow of 226 million gallons per day and wet weather capacity of 400 MGD. 

PVSC’s treatment facility operates a pure oxygen active sludge plant and treats its sludge using gravity thickeners, thickening centrifuges, Zimpro wet air oxidation, decant tanks, and frame and plate sludge filter presses. In addition to PVSC’s own sludge production of approximately 20 MGD (peak), PVSC accepts and processes merchant sludge from the New York City Department of Environmental Protection, Bergen County Utilities Authority and others. PVSC can receive such visitor sludges delivered via overland trucks or marine vessels such as ships and barges. The marine vessels discharge into a combination of four existing open air storage tanks, two “new sludge storage” tanks and two “old sludge storage” tanks. 

In 2016, PVSC commissioned an existing conditions assessment of several facilities, including the old sludge storage facilities constructed in the 1960s, to determine the need for repairs and replacements of the WWTP’s aging solids handling infrastructure. The OSS tanks showed signs of corrosion and needed to be rehabilitated to ensure future ability to receive sludge. 

The Old Sludge Storage Rehabilitation project restores the 1.6-million-gallon OSS tanks’ use and supports the overall operation of the Zimpro biosolids handling process. Additionally, the project included repairs and upgrades to the OSS stair tower that connects the two OSS tanks and the associated OSPS pumping station. Lastly, the project included the design of a new below-ground force main to interconnect the OSS tanks to an existing interceptor to convey OSPS pump discharge to the primary clarifier influent channel.

We supported PVSC with obtaining funding through the New Jersey Infrastructure Bank. This included preparing an environmental planning document, which the New Jersey Department of Environmental Protection accepted. They also assisted PVSC with obtaining NJDEP approval for the new force main and vault.

Interior of Old Sludge Storage Tank
Passaic Valley Sewerage Commission

Newark, NJ
United States

1.6-MGD Tank


Distinguished Award (2023)
American Council of Engineering Companies of New Jersey