Newtown Creek is the largest of New York City’s fourteen Wastewater Treatment Plants, processing up to 310 million gallons per day (MGD), and up to 720 MGD during wet weather flow. The Central Residuals Building (CRB) removes all non-biological matter from the wastewater, and was the last major project in a $5 billion dollar overall plant upgrade. To meet a state mandate, the client imposed contractual milestones to complete construction within two years. The CM coordinated with four contractors, an onsite design team, and the DEP operations staff to achieve these milestones. The greatest project challenge was commissioning the new secondary screens, which required intercepting the entire plant flow through four 96” diameter conduits and redirecting it through twelve 3/8” bar screens. The screens had to be brought online without interrupting plant flow. Prior to startup, the screens and all related systems needed to be fully tested and deemed reliable. There was a “point of no return” during the startup sequence, where all flow had to pass through the new screens and failure would be catastrophic. The automation system, which controls the number of screens in service, could not be tested prior to commissioning. The CM provided 24/7 coverage to monitor startup until the automation proved reliable.
New York State’s Wicks Law requires separate prime contracts for general, electrical, HVAC and plumbing contracts. This multiple prime requirement, combined with the aggressively scheduled contractual milestones, placed pressure on the CM to monitor the schedule very closely and take action when needed. The CM team took the initiative to use 4D modeling software that combined the existing 3D model with the CPM schedule for multiple purposes. This allowed the CM to work with contractors for conflict mitigation, find improved sequencing of complicated operational startups to save months in construction time, provide client with visual aids during construction, and ultimately achieve all of the milestone requirements. Seeing the success of the 4D model approach, the client will utilize 4D modeling in future large scale projects. In an area sometimes overlooked at great cost, the CM team performed detailed code compliance reviews for Department of Buildings (DOB) and Fire Department (FDNY) requirements throughout the course of construction. This unique approach to review the physical work in place specific to code compliance prior to inspections, enabled us to discover issues not evident on plans, and allowed sufficient time to take corrective action in order to pass inspections without violations or schedule delay.
“Through effective and pro-active management techniques, such as utilizing 4D Modeling, facilitating project partnering sessions, and anticipating potential project pitfalls, the CM drove and motivated the four prime contractors to achieve and exceed anticipated NC-41 project schedules and goals.”
Nat J. Federici, PE
NYC Department of Environmental Protection, Bureau of Engineering Design and Construction