Atwater, Calif.


Long-running contract delivers ongoing operational efficiencies and energy savings to Northern California project.


The project involved the transition from management-only services to full-service operations, maintenance and management (O&M) of a 6-MGD advanced secondary trickling filter wastewater treatment plant serving the City of Atwater, Town of Winton, Castle Airport and a federal penitentiary. In addition, Veolia North America provides farm management for a land application site growing alfalfa, oats and Sudan hay, with revenue from the sale of the hay being returned directly to the city. The facility is under a regulatory mandate to update to full tertiary capability, and Veolia will operate the new system when it comes online.


  • Institute energy optimization program that replaced five mechanical surface aeration units with three biomixers, which increased mixing and energy efficiency.
  • Assist the city with planning for a proposed design/build/operate (DBO) project to expand treatment plant capacity from 6 MGD to 10 MGD.
  • Revise city's biosolids land application management program and acquire all necessary permits for application to farmlands.
  • Develop site management plans and implement application practices.
  • Conduct pilot study to improve three-species chronic toxicity analytical results.
  • Provide a DBO project for the city's dechlorination system.
  • Provide a $132,000 capital improvement project; install variable frequency drives and an updated SCADA system.


  • Reduced power consumption 35% - saving more than $150,000 during the plant's first year in operation.
  • Eliminated odor complaints, which were frequent prior to Veolia’s involvement.
  • Maintained a strong safety record, with no lost-time accidents since the contract's inception in 1994.
  • ​Achieved repeat honors for Plant Safety and Supervisor-of-the-Year Awards from the California Water Executives Association, as well as numerous commendations from local and state officials.