Holyoke Combined Sewer Overflow Facility and Wastewater Treatment Plant Upgrades

Holyoke’s state-of-the-art project brought the city into compliance

Holyoke, Massachusetts is an older industrial city with limited resources and aging wastewater infrastructure located along the Connecticut River. It has over 16 combined sewer overflow (CSO) discharge locations into the Connecticut River. The Connecticut River is the largest river in New England and flows 410 miles from the Canadian border to the Long Island Sound. The river provides tremendous natural resources and is renowned for its shad fishery,boating, and other recreational uses. A significant portion of the more than 500 million gallons per year of combined sewer overflows into the river came from CSO outfall No. 9 in Holyoke. The high bacteria levels from the untreated CSO discharge affected water quality 15 to 30 miles downstream of the discharge. The city was under a consent order from the EPA to abate both dry and wet weather overflows such that CSO outfall No. 9 would not be permitted more than four untreated overflows per year.

The City of Holyoke needed an innovative technical solution and project delivery method to build a new 103 MGD CSO treatment facility on budget and on schedule. In addition, significant repairs and upgrades were needed at the city’s wastewater treatment plant including headworks, dewatering, aeration, and odor control systems. The city decided to combine the new CSO treatment facility and the wastewater plant upgrades into a single design-build project valued at $24 million. The city obtained special permission through the Massachusetts legislature to conduct the project using the design-build operate delivery method. Although the city only received one bid, they were able to successfully negotiate a contract with AECOM.

Both the CSO treatment facility and the new wastewater plant upgrades were completed ahead of schedule, under budget, and with minimal project changes. The state-of-the-art CSO treatment facility brought the city into compliance and will keep millions of gallons per year of untreated sewage from polluting the Connecticut River. In its first year of operation the CSO facility captured and treated approximately 480 million gallons of combined storm water and wastewater.