US districts fight saline intrusion with reused water

Two California water districts announced an agreement on 18 April 2009 to transfer and use recycled wastewater as a barrier against saline intrusion into groundwater, replacing 5.5 billion gallons (20.8 million m³) of drinking water per year previously used for this purpose.

The Water Replenishment District of Southern California (WRD) will be supplied by the West Basin Municipal Water District (WBMWD) with the extra 25% of reused water to make the seawater barrier 100% recycled water, avoiding the costly import of drinking water from northern California.

“The project is a great example of public agency partnerships and cooperation that bring value and benefit to the communities we serve. Without this agreement between WRD and West Basin, this project would not be built,” said Albert Robles, president of the WRD board.

West Basin will expand its Edward C Little Water Recycling Facility (WRF) for the fifth time to produce the additional purified water for the recycled water barrier. The facility has been expanded four times in the past to provide reused water to more than 200 sites throughout the South Bay.

WRD has been a partner with West Basin since the first phase was built. The Edward C Little WRF takes wastewater that would otherwise be sent to the ocean and, through advanced water purification technologies, makes five types of “designer” waters. It is the only facility in the world to do so.

The five types are:

  • Tertiary Water (Title 22): for a wide variety of industrial and irrigation uses;
  • Nitrified Water: for industrial cooling towers;
  • Softened Reverse Osmosis Water: Secondary treated wastewater purified by microfiltration, followed by reverse osmosis and disinfection for groundwater recharge;
  • Pure Reverse Osmosis Water: for refinery low-pressure boiler feed water;
  • Ultra-Pure Reverse Osmosis Water: for refinery high-pressure boiler feed water.

  • Comments

    Login on register to comment

    Login Register

    Related content

    Related supplier content

    Get the newsletter