The City of Visalia, USA, is upgrading its wastewater treatment plant with membrane bioreactor (MBR) technology and will be the largest MBR plant in California when it enters service in 2013.
The project, which will increase the amount of water that can be recycled and help reduce the need for pumping groundwater, will feature GE’s ZeeWeed MBR technology and will include denitrification of the plant’s effluent with a substantial improvement in water quality, enabling the city to divert water for local reuse.
Currently, the treated water from the wastewater plant is discharged into a nearby stream, Mill Creek. Water discharge requirements limit the flow to 20 MGD (75,000 m³/d) on average, which is 2 MGD (7,500 m³/d) below the rated capacity of the existing treatment plant.
The design capacity of the plant will remain at its currently rated level of 22 MGD (83,000 m³/d), but provision will be made for future expansion to 26 MGD (98,000 m³/d)
“The upgrade will provide the city with an additional source of water and will ease the demand on the water table, which we are concerned about reaching lower levels,” said Andrew Benelli, public works director for Visalia. “The treatment plant now will have the capability to provide recycled water for a number of additional uses such as golf courses and agricultural areas.”