Trenton, NJ — Trenton Water Works (TWW) today announced that it has issued a request for proposals from engineering firms to assess the design and construction of its $9 million filtration plant raw water intake and recommend improvements to its current design, hydraulic performance, and support systems.
“Based on operational data, inspections, and expert consultations, TWW has found no evidence that operator actions caused the intake’s reduced performance; rather, cold-weather conditions exposed design limitations that were not anticipated in the current configuration,” said Sean Semple, Director of the city's Department of Water and Sewer, which operates Trenton Water Works. “The independent assessment will evaluate whether the intake’s design assumptions adequately accounted for frazil ice, supercooled river conditions, and seasonal biological loading.”
Bid No. CC2026-03, re-advertised on December 15, seeks proposals from engineering firms with experience with river-based surface water intakes operating in similar climates and environments. Bidding firms must also have the capacity to provide comprehensive services for the evaluation of and design improvements to the water filtration plant's raw water intake system, a physical structure submerged in the Delaware River that pulls untreated water from the river for treatment, screening out large debris such as fish, tree branches, leaves, and other organic matter. The city's deadline for submitting proposals is January 9, 2026.
Last winter, the current design of the raw water intake, which TWW rehabilitated in 2021-2023, including its compressed air blow-off system, was not very resilient to frazil ice buildup, and it was necessary to bypass the structure to pump water into the plant using high-capacity diesel pumps for several weeks. The newly constructed raw water intake was designed by the engineering and development consultancy Mott MacDonald Group and replaced a concrete structure in service since 1954.
"Plant operators have seen reduced hydraulic capacity in the current intake system during peak winter months when pockets of the Delaware River around the plant are supercool, and the growth of aquatic vegetation during summer months, which will require engineering-informed changes to the intake's design to overcome Mother Nature's challenges," added Semple. "We've been doing a lot of work over the last several months to address the intake's hydraulic performance, including using divers to examine the structure, cleaning out its intake channels of sediment and debris, evaluating the capacity of the compressed air blow-off system, and operating protocols."
To ensure system reliability and performance during extreme cold, TWW issued a Water Conservation Advisory on December 18, asking customers and residents in its five-municipality service area—Trenton, Hamilton Township, Ewing Township, Lawrence Township, and Hopewell Township—to voluntarily conserve water until further notice. TWW mailed the notice to all of its customers, and it is available online at trentonwaterworks.org.
"Cold weather impacts the performance of our water infrastructure, but our filtration plant operators, distribution system technicians, and distribution repair teams are ready to address any operational issues," said Semple.
To report water main breaks, toppled-over fire hydrants, service line leaks, and other water emergencies, customers and residents can call TWW's 24/7 hotline at (609) 989-3222.
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