Our Process

Treatment Process

The Santa Paula Water Recycling Facility utilizes a membrane bioreactor (MBR) process in which the majority of the treatment occurs in underground tanks. The operations buildings are constructed above the tank structure and contain the process equipment, a laboratory, restrooms, workshop, break rooms and administrative offices.

The facility has the capacity to treat 4.2 million gallons per day (MGD) average dry weather flow (ADWF). It is currently equipped with the membranes needed to treat 3.4 MGD. When it becomes necessary to expand the capacity of the facility in order to accommodate a larger population, additional membranes will be installed into the facility, increasing the rated capacity to 4.2 MGD.

The treatment processes include:

  • Influent Lift Station
  • Screening and Head Works
  • Flow Equalization Tanks
  • Pre-Anoxic Zone
  • Aerobic Zone
  • Post–Anoxic Zone
  • Membrane Separation Tank
  • UV–Disinfection
  • Effluent Storage
  • Effluent Pump Station
  • Percolation Ponds

The solids processes include aerobic digestion and sludge dewatering. All odorous process areas are fully controls with a dual-odor control system.


Water Quality

The effluent is treated to a tertiary level, meeting CA Title 22 requirements and the present requirements of the Regional Board for all constituents amenable to biologic treatment. It is currently disposed in thirteen acres of percolation ponds located to the east of the new facility, however the City is drafting an alternate use plan for the recycled water to reclaim and reuse it, in the process generating an additional revenue stream for the City.

The facility’s water quality results for the month of October 2010:

  Influent Effluent Permit Requirements Effluent Results
BOD 340 10 1.1
TSS 283 10 <1
Total Nitrogen n/a 10 6.0