Recycled Water Quality
Prior to delivering recycled water for non-potable uses, the wastewater treatment facility will upgrade their system to produce recycled water that meets California Division of Drinking Water’s Title 22 requirements for unrestricted reuse and that protects the Refinery’s assets.
This recycled water project is expected to include the following:
Recycled water that meets Title 22 standards for non-potable use is being safely and successfully used in numerous communities for many purposes. The following lists some of the growing list of recycled water applications:
The Treatment Process
After entering the plant, wastewater from homes and businesses undergoes a carefully regulated purification and disinfection process to produce tertiary-treated recycled water. This means the wastewater that comes into the treatment plant is put through a multi-step treatment process before being distributed to customers for industrial or irrigation purposes:
Primary Sedimentation
Incoming wastewater slowly flows through the primary sedimentation tanks where settling and skimming removes solids and floating grease and sediment.
Biological Treatment
Next, the wastewater passes through a series of fixed film reactors, aeration basins and secondary clarifiers.
Here naturally occurring microorganisms consume the dissolved organics, causing the microorganisms to fatten and grow heavy, making them easier to remove.
Biological treatment removes approximately 90 to 95% of the remaining solids and biodegradable material from the wastewater.
Filtration and Disinfection
Finally, filtration removes any remaining solids and a disinfectant, such as chlorine, is used to destroy bacteria, viruses and other pathogens. Higher levels of disinfection are applied to water that is to be used for landscape irrigation or industrial processing.
Treatment Performance Monitoring
The recycled water system is vigilantly monitored to ensure that water quality standards are continually being met. The water is tested at every stage of treatment with physical, chemical, and bacteriological testing performed daily. Local and regional authorities also annually monitor water quality and distribution systems.
This recycled water project is expected to include the following:
- Ammonia removal, phosphate reduction, , tertiary treatment, and disinfection upgrades at the City’s wastewater treatment facility
- Chloride control in the recycled water for protection of the Refinery’s cooling towers from corrosion
- Recycled water delivery through purple pipes that are completely separate from drinking water pipes
- Routine inspections to ensure no cross-connection between drinking water pipes and recycled water pipes has occurred
- A sophisticated computerized control system and a staff of state-certified system operators to routinely monitor operations and performance of the water recycling plant and water distribution system
Recycled water that meets Title 22 standards for non-potable use is being safely and successfully used in numerous communities for many purposes. The following lists some of the growing list of recycled water applications:
- Industrial/commercial – cooling towers, boilers, street sweeping, toilet flushing, fire suppression
- Urban irrigation – parks, playgrounds, school fields, golf courses, cemeteries, landscaping
- Agricultural irrigation – grapes, strawberries, lettuce and celery
- Residential irrigation – front and backyard landscaping, common areas
- Wetland enhancement, decorative water features, golf course ponds
- Groundwater recharge/Indirect potable reuse
- Fill stations
The Treatment Process
After entering the plant, wastewater from homes and businesses undergoes a carefully regulated purification and disinfection process to produce tertiary-treated recycled water. This means the wastewater that comes into the treatment plant is put through a multi-step treatment process before being distributed to customers for industrial or irrigation purposes:
Primary Sedimentation
Incoming wastewater slowly flows through the primary sedimentation tanks where settling and skimming removes solids and floating grease and sediment.
Biological Treatment
Next, the wastewater passes through a series of fixed film reactors, aeration basins and secondary clarifiers.
Here naturally occurring microorganisms consume the dissolved organics, causing the microorganisms to fatten and grow heavy, making them easier to remove.
Biological treatment removes approximately 90 to 95% of the remaining solids and biodegradable material from the wastewater.
Filtration and Disinfection
Finally, filtration removes any remaining solids and a disinfectant, such as chlorine, is used to destroy bacteria, viruses and other pathogens. Higher levels of disinfection are applied to water that is to be used for landscape irrigation or industrial processing.
Treatment Performance Monitoring
The recycled water system is vigilantly monitored to ensure that water quality standards are continually being met. The water is tested at every stage of treatment with physical, chemical, and bacteriological testing performed daily. Local and regional authorities also annually monitor water quality and distribution systems.