Recycled Water: employs the same principles as the hydrologic cycles but with vastly greater efficiency and results in a much more pure end product. There are multiple methods used to treat water so that it can be reused however each method has multiple phases.
- The first phases where the water is typically taken from the sewage or wastewater facility and solids are removed (naturally this occurs in rivers).
- Then the second phase is when microorganisms are added which eat smaller particles. Once the organisms consume material they will fall to the bottom leaving the cleaner water to rise to the surface.
- Phase three the water goes through a filtration process where the water percolates through layers of fine anthracite coal, sand and gravel (similar to underground seepage which occurs in aquifers).
- Phase four disinfectants and chlorine is added to kill germs. (Water is ready for industrial and commercial use)
- Phase five microfiltratson process: the water is pressurized through pipes containing straw-like fibers with pores that are 5,000 times smaller than a pinhole
- Phase six reverse osmosis: water is pressurized at about 2000 pounds per square inch through tightly wound layers of membranes with pores that are 5 million times smaller than a pinhole. This eliminates virtually all impurities.
Examples of different efforts of water recycling:
- South Bay Water Recycling program, which distributes recycled wastewater to more than 400 customers in the San Jose area
- Irvine Ranch Water District’s ground-breaking dual water system, which supplies recycled water to commercial high rises for use in flushing toilets and urinals
- West Basin Municipal Water District that distributes recycled water to more than 210 customers
- Monterey County Water Recycling Projects, which provide recycled water for agricultural irrigation to help ease demands on an over-drafted groundwater aquifer
- Padre Dam Water Recycling Facility, which was expanded to recycle 2 million gallons/day for turf irrigation at parks, golf courses and other commercial and industrial facilities.
- In San Diego, 16 water agencies are collectively using over 32,300 acre-feet of recycled water annually to meet the region’s water supply demand
- City of Carlsbad’s new recycled water treatment and distribution system that will deliver approximately 3,000 acre-feet per year of recycled water to customers located in that seaside community.
- Otay Water District is constructing a distribution system to deliver an estimated 5,000 acre-feet per year of recycled water by 2030 purchased from the City of San Diego’s South Bay Water Recycling Plant.
- Orange County Water District and the Orange County Sanitation District came together to take highly treated wastewater previously discharged into the ocean and subjects it to further treatment, including microfiltration, reverse osmosis and ultraviolet disinfection. The purified water is pumped to spreading ponds near the Santa Ana River for percolation into the groundwater basin, with some injected along the coast as a barrier to seawater intrusion.
- The Replenish system produces 70 million gallons per day or up to 25.5 billion gallons of water per year (enough to meet the needs of 500,000 people)