NYCDEP Newtown Creek Wastewater Treatment Plant Secondary Treatment Upgrade

Client: New York City Department of Environmental Protection
Location: New York, NY

The largest of New York City’s wastewater treatment plants, the Newtown Creek Wastewater Treatment Plant underwent a $5 billion upgrade to further improve effluent quality and increasewet weather treatment capacity from 620 million gallons per day (mgd) to 700 mgd. Hazen, as part of a Joint Venture, provided the City with program management, facility planning, design services and operations assistance.

The original facility commissioned in 1967 consisted of raw influent screening and grit tanks followed by two batteries of modified aeration tanks, followed by sedimentation tanks and chlorine disinfection. The original facilities occupied 32 acres. The plant upgrade increased the site footprint to 54 acres to provide space for a third secondary treatment battery and other new facilities.

The Master Plan for the Newtown Creek WWTP Plant Upgrade included 23 unique construction projects which were executed by 50 individual construction contracts. The contracts were carefully staged and coordinated to ensure plant compliance with interim permit limits while minimizing the program schedule and costs.

An aerial photograph taken in 2009 shows construction of the new South Battery over the footprint of the old one. Once the new North and Central Batteries were fully operational, the increased treatment capacity allowed the existing South Battery to be completely, rather than gradually, demolished in order to expedite construction.

An aerial photograph taken in October 2010 shows construction of the Central Residuals Building (CRB). The CRB includes ⅜” bar screens for secondary screening of influent wastewater to protect the Aeration Tanks. The Waste Activated Sludge (WAS) from the Final Settling Tanks passes through ½” bar screens in the CRB on its way to the thickening centrifuges. The CRB also provides a common location for the processing and disposal of residuals generated by plant processes, including screenings, skimmings, and grit.

An aerial photograph taken in January 2014 shows the upgraded Newtown Creek WWTP. The state-of-the-art design alternative reduced the originally proposed design costs by nearly 37% and saved the City approximately $800 million in 1996 ($1.2 billion in 2014) while significantly reducing the construction schedule to meet consent order milestones.

Project Outcomes and Benefits

  • Project was completed 2 years ahead of schedule.
  • Innovative design approach resulted in over $1 billion dollars in overall savings.
  • Upgraded process has consistently exceeded permit requirements for 90% removal of Carbonaceous Biological Oxygen and Suspended Solids.
  • Extensive field sampling was performed to characterize influent wastewater characteristics and develop a calibrated BioWinTM model to optimize performance
  • Weekly microscopic analysis of Mixed Liquor Suspended Solids samples to identify process issues before they manifest.
  • Extensive operational assistance and troubleshooting to assist with issues ranging from controlling sludge bulking and struvite accumulation to optimizing centrifuge and disinfection system performance and maximizing digester gas production and maintaining treatment during construction shutdowns
  • Operations costs reduced due to implementation of automation for process control.

In order to maintain plant operation and permit compliance while working on a congested site in the middle of a highly urbanized area, a unique treatment process of high-rate, step-feed activated sludge without primary sedimentation was designed, pilot-tested and installed. The plant’s headworks were upgraded with new coarse and fine screens and grit removal facilities to protect the aeration tanks.

The plant’s extensive upgrade included coarse (1-inch) and fine (3/8-inch) bar screens, optimized operator interfaces for improved system control, expanded electrical power capacity, replaced transformers, new disinfection systems, new digesters and centrifuges, upgraded pumping stations, and new aeration and sedimentation basins and sludge storage tanks, central residuals building, new aeration tanks, and additional odor minimization work.

For more information on this project, or to discuss a similar project in your area, contact Chris Portner at cportner@hazenandsawyer.com