City of Colton - Design Wastewater Treatment Plant Upgrades and Expansion

LEE + RO has completed several projects for the City of Colton, including their Wastewater Treatment Plant Centrifuge project, Plant 2 Condition Assessment, and the Prado Booster Pump Station Upgrades (currently under construction). Their wastewater treatment plant (WWTP) consists of three treatment plants:

1. Plant No. 1 was constructed in 1949 - Conventional Activated Sludge system that was removed from service in 2004 and demolished in 2020
2. Plant No. 2 constructed in 1971 is expected to be removed from service soon, and
3. Plant No. 3 constructed in 2000 is an Extended Aeration Activated Sludge system

Combined, the WWTP has a capacity of 10.4 million gallons per day (MGD). The plant provides secondary treatment, nutrient removal, solids removal and solids digestion utilizing conventional and extended aeration, anaerobic digestion, solids dewatering and drying.

The WWTP has been in service for over 50 years and many of the components are at the end of their useful service life and require upgrade or replacement. With the City currently planning to remove Plant No. 2 from service, Plant No. 3’s expansion is necessary to accommodate the projected future flows.

LEE + RO’s designs will ensure that the City’s goals to increase the efficiency and reliability of the WWTP, replace outdated equipment and facilities, upgrade treatment processes, and increase WWTP capacity will be achieved. The project scope includes new construction and improvements to existing major process components.