California City Upgrades Water Treatment Plant to Ease the Burden on Its Water Table

A growing demand for water is taking a heavy toll on the water table under the central California city of Visalia. To ease this burden, the city is upgrading its wastewater treatment plant, which will increase the amount of water that can be recycled and help reduce the need for pumping groundwater. The upgraded plant will feature GE’s (USA) membrane bioreactor (MBR) technology and will be the largest MBR plant in California when it enters service in 2013.

Currently, the treated water from the wastewater plant is discharged into a nearby stream, Mill Creek. Water discharge requirements limit the flow to 20 million gallons per day (mgd) on average, which is 2 mgd below the rated capacity of the existing treatment plant.

The upgrade of the plant’s wastewater treatment processes with the GE MBR technology will include de-nitrification of the plant’s effluent and a substantial improvement in water quality, enabling the city to divert water for local recycling. This will expand both the plant capacity and the city’s range of recycled water applications.

“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.”

Under a contract with Visalia, GE will supply MBR technology featuring ZeeWeed* reinforced, hollow-fiber membranes, which have been proven in more than two decades of wastewater treatment and water reuse. ZeeWeed (ZW) 500 technology is an advanced filtration technology that separates particles, bacteria and viruses from water or wastewater. Nearly 1,000 plants worldwide use this technology to produce superior quality drinking water and to meet or exceed stringent wastewater treatment and water reuse standards.

ZW500 MBR technology is certified under ecomagination, GE’s corporate-wide commitment to address challenges such as the need for cleaner, more efficient sources of energy, reduced emissions and abundant sources of clean water.