Questions or concerns regarding a business's compliance with COVID-19 requirements may be directed to the Covid Compliance hotline at 1 (844) VC-OPENS / (844) 826-7367 or email

The Simi Valley Public Library, Senior Center, and Cultural Arts Center remain closed to the public.

 For the most current COVID-19 case numbers and more, visit I En Español

Operations: Collection & Treatment

Press Enter to show all options, press Tab go to next option
Plant PhotoDepartment of Public Works

Director: Ron Fuchiwaki

Wastewater Treatment Plant
Location: 600 West Los Angeles Avenue
Simi Valley, CA 93065
(805) 583-6440


The Sanitation Division has two Operations Sections:

  • Collections Section
  • Treatment Section

Collections Section - Sewer System

The Collections Section operates, maintains, and monitors the sewer system to assure sewage is safely and properly conveyed from nearly 40,000 lateral connections to the City's Water Quality Control Plant.

Sewer System Management Plans are state-mandated requirements for California’s public collection system agencies that own or operate sanitary sewer systems greater than one mile in length. The purpose of these plans is to:

  • Facilitate proper funding and management of sanitary sewer systems.
  • Reduce sanitary sewer overflows.
  • Protect public health and the environment.
  • Improve the overall maintenance and operation of sewer systems and sewage lift stations.

Please download the 2019 Sewer System Management Plan (SSMP) for additional information,

The City of Simi Valley Sewer Lateral Policy
Lateral Diagram; definition of private sewer lateral; Building to public sewer main/Building connection; Public sewer main; lower lateral; upper lateral; Public right-of-way; private property

Most property owners are unaware that they own the upper and lower sewer lateral line connection from the house/building to the public sewer main. It is the responsibility of the property owner to properly maintain the private sewer lateral line to prevent blockage, misalignment, or deterioration. If a property owner believes the roots from a City owned tree may have caused damage to a properly maintained sewer lateral they must contact the City for inspection prior to repairing the sewer lateral to be considered for reimbursement. Tree roots are generally not able to penetrate a properly maintained sewer lateral line without a preexisting entryway. Inferior materials, poor installation or lack of maintenance may cause the sewer lateral line or seals to decay, disintegrate, deteriorate, loosen joints, and develop fissures that create an entry point for tree roots.

Please download the City of Simi Valley Sewer Lateral Policy  for additional information.

Treatment Section - Water Quality Control Plant

The Treatment Section operates, maintains, and monitors the Water Quality Control Plant.

The City of Simi Valley’s Water Quality Control Plant treats approximately 10 million gallons of wastewater each day to protect public health and safety and to comply with State and Federal regulations.  The wastewater comes from a variety of sources, including discharges from local businesses and industries, with the majority of discharge coming from residential properties. 

The Water Quality Control Plant (Treatment Plant) is located on 33 acres at the western end of Simi Valley. The Treatment Plant is an activated sludge plant using the latest methods for biological nutrient removal. After meeting stringent State permit requirements, treated water is discharged to the Arroyo Simi.  The entire treatment system is continuously monitored via a state-of-the-art SCADA computer system.  Prior to discharge, a portion of the effluent water is reclaimed and used for dust control and irrigation at the Simi Valley Landfill.

To learn how the City cleans water take a virtual tour of the Water Quality Control Plant.

Chlorine Contact Tanks


Free viewers are required for some of the attached documents.
They can be downloaded by clicking on the icons below.

Acrobat Reader Download Acrobat Reader Flash Player Download Flash Player Windows Media Player Download Windows Media Player Microsoft Silverlight Download Microsoft Silverlight Word Viewer Download Word Viewer Excel Viewer Download Excel Viewer PowerPoint Viewer Download PowerPoint Viewer