Image courtesy of McCarthy

By NOLAN POINTER

LAWRENCE, Kan. – The Kansas River Wastewater Treatment Plant modernization is now complete.

McCarthy Building Companies served as general contractor for the project and Black & Veatch was engineer of record.

The $74.3 million project represents a comprehensive upgrade of the plant that has served Lawrence since 1956 and processes approximately 80 percent of the city’s daily wastewater.

The landmark project — Lawrence’s second-largest funded wastewater infrastructure investment — replaced aging infrastructure and integrated modern treatment systems to extend the operational life of the facility and help ensure the city meets state water quality standards well into the future.

The Kansas River Wastewater Treatment Plant processes roughly eight million gallons of wastewater per day before discharging treated water into the Kansas River. The plant’s age and increasingly stringent regulatory requirements made a comprehensive upgrade necessary. The facility now meets updated National Pollutant Discharge Elimination System permit standards set by the Kansas Dept. of Health and Environment.

The project fundamentally transformed how the plant treats and discharges water. Key improvements include:

• Advanced Nutrient Removal: Four aeration basins were converted to biological nutrient removal basins — a more sophisticated biological treatment process that significantly reduces the nitrogen and phosphorus discharged into the Kansas River.
• UV Disinfection: A chlorine contact basin was converted to an ultraviolet disinfection system, replacing chemical treatment with a cleaner, more environmentally sustainable alternative.
• New Control Facility: A new SCADA facility gives plant operators real-time monitoring and control across all plant systems, improving operational efficiency and the ability to respond quickly to changing conditions.
• Electrical and Infrastructure Upgrades: More than 10 major motor control centers and switchboards were replaced and electrical systems fully modernized, significantly extending the plant’s useful life.

Delivered using the Construction Manager at Risk method, the project represents the City of Lawrence’s first application of CMAR delivery on a wastewater project. McCarthy’s involvement began in the design phase, enabling early collaboration with the owner and design team to identify constructability challenges, structure the procurement strategy and develop solutions before construction began in May 2023.

Among the project’s most complex challenges was keeping the plant fully operational throughout construction. McCarthy developed more than 130 detailed operational sequencing plans to ensure that construction activity never disrupted plant operations.

The construction team recorded zero recordable safety incidents across more than 252,000 hours of construction work — a reflection of the team’s commitment to the safety of workers, plant staff and the surrounding community.