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Wastewater Operations and Maintenance

What We Do

The Plant Operations and Maintenance Section of the Wastewater Division is responsible for the treatment facilities and lift stations. Wastewater treatment plant operators monitor the treatment plant 24 hours a day, 7 days a week to ensure regulatory compliance and maintain process control. The wastewater treatment plant operators are certified Grades I through V, as required by the California Water Resources Control Board, Office of Operator Certification and the maintenance staff are CWEA certified technicians. The maintenance staff is responsible for performing preventative maintenance tasks keeping all of the equipment in excellent working condition. This allows the operations staff to make sure all processes run smoothly. Maintenance staff works closely with the operations staff to resolve issues that may arise as to keep disruptions in the process to a minimum. The treatment process and liftstations contain confined spaces and hazardous chemicals. All of the operations and maintenance staff are trained in confined space entry, and are First Responders that can assist with an emergency involving hazardous chemical releases.


Prior to the year 1910, wastewater from the City of Modesto was discharged without treatment directly into the Tuolumne River at 9th street. In 1910, the City installed a septic tank at the foot of Sutter Avenue with an outfall to the river. In 1919, the City purchased 38 acres of land to build an outfall line at the foot of Sutter Avenue. The tanks overflow was then discharged into the Tuolumne River. In 1928 approximately 12 acres of oxidation and percolation beds were constructed as the first steps in primary treatment of the wastewater.


Frequently Asked Questions

In an Emergency


24- hour emergency line
(209) 577-6200
Non-Emergency Police Dispatch
(209) 522-2470

Contact Us

Wastewater Administration
Primary Plant
1221 Sutter Avenue
Modesto, CA 95351
Directions - Google

Email Us

(209) 577-6200 phone
(209) 577-6345 fax