Believe it or not, this is not such a new idea. In 1998, NASA announced it had built a human waste reclamation bioreactor designed for use in the International Space Station and a manned Mars mission. The system cost $250 million and has been working since May 2009, cutting back the need for resupplying the space station so often.
In 2000, Los Angeles actually completed a sewage reclamation plant, the Donald C. Tillman Water Reclamation Plant in Van Nuys, capable of providing drinking water to 120,000 homes. Public outcry, a mayoral race and a secession threat from the San Fernando Valley changed the political climate and DWP abandoned the plan.
Despite public outcry then, the Orange County Sanitation District persisted and now, as the largest reclamation plant in the world, supplies more than 130 million gallons a day of treated wastewater which is then reclaimed and reused, producing enough new water for nearly 850,000 residents in north and central Orange County.
Working as a Joint Powers Authority, the Las Virgenes Metropolitan Water District and Triunfo Sanitation District has announced plans to soon break ground for an advanced water treatment plant that would turn reclaimed sewer water into drinking water.
The prolonged drought, advances in water-purification technology and an assertive public relations campaign may bring people to their senses about water treated and recycled from “toilet to tap,” the unappealing moniker that replaced the official name, direct-to-potable reuse for drinking water,” and stuck.
The concept is that the same purification that takes place when water moves through the earth, lakes or other natural features can be replicated in a man-made system. These initiatives have multiple benefits, such as reducing our unsustainable reliance on imported water and reusing and recycling surplus water that is normally discharged into creeks, rivers and eventually the ocean, and filtering out not just the “yuck factor” but unwanted drugs, viruses and such that are flushed down the drain.
The process is pretty straightforward.
The preliminary stage screens out all the trash and grit and moves to the primary stage where “solids” are removed. The secondary stage introduces microbes that feed on organic matter and then enters the tertiary treatment process at Tillman reclamation plant in Van Nuys where a sand filter removes finer particles, chlorine is added and then removed. The resulting tertiary water is safe enough for freeway landscaping and artificial snow and even for food crops.
FYI, this tertiary water is used to water the Japanese Garden that grows right next to the Tillman plant, as well as to recharge the Los Angeles River.
The final process sends this water through reverse osmosis and/or microfiltration and then through hollow polypro fibers, where bacteria and many viruses are removed. The water is then forced through thin filtering membranes at high pressure which removes dissolved chemicals, pharmaceuticals and more viruses. Ultimately, the water is zapped with ultraviolet light, an effective low-tech method, and peroxide to remove dangerous trace organic compounds such as by-products of rocket fuel manufacturing and industrial solvents.
Some concerns were keeping enough water in Malibu Creek to support steelhead trout; strict testing of reclaimed water for super-viruses; and that the water has lost minerals in the process. LVMWD officials noted the concerns, allaying one: reclaimed water will be stored in the Las Virgenes reservoir where it will pick up those minerals over time.
