Preparing for Population Growth While Improving Effluent Water Quality 

The Wolcott Wastewater Treatment Plant expansion allows for the Unified Government of Wyandotte County/Kansas City to offload their existing Plant 20 while protecting the water quality of the Kansas River. Expansion of treatment capacity will help to address population growth and improve effluent quality for compliance with a phased total maximum daily load and National Pollutant Discharge Elimination System nutrient removal permit requirements. 

The new Wolcott plant is our first aerobic granular sludge treatment facility — and the first of its kind in Kansas. 

The Wolcott WWTP expansion is being constructed in phases. The milestone for phase I was completed in 2022 and includes a new greenfield 2 MGD plant, with improvements designed to accommodate an expansion to 4 MGD within approximately 10 years. It is anticipated the ultimate capacity can reach 18 MGD at buildout. The initial plant improvements have the capacity to treat current average day flows from both the existing Plant 20 and Pump Station 50 service areas, as well as the projected growth likely to occur within the next several years. 

The new plant consists of the following new facilities: administration and maintenance buildings, screening and grit removal, secondary treatment, tertiary filtration, UV disinfection, and new solids handling and thickening facilities. AquaNereda® AGS was selected as the preferred alternative for secondary treatment. HDR, the owner and the construction manager toured similar-sized Nereda facilities in Europe to gain insights on design features and operational considerations to incorporate into the WWTP design.  

The new plant was constructed through a construction manager at risk form of alternative delivery. We led design workshops and have assisted UG in the procurement of the CMAR. We have also been engaged with UG staff at all levels including management, operations, legal and purchasing to ensure all parties understood each step of the CMAR process, from the development of the request for qualification and request for proposal to the interview and selection process.