Regional Recycled Water Advanced Purification Center: Phase I
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A Look Inside How It Works
The demonstration plant uses an innovative three-step purification process. The first step involves membrane bioreactors; the second step is reverse osmosis; and the third step is ultraviolet disinfection and advanced oxidation.
What makes our purification process innovative is how and when MBRs are used. They have been used in the wastewater industry for decades but are relatively new for purifying water for reuse. Initial pilot studies by Metropolitan and the Sanitation Districts found that MBRs may be a cost-effective first step in the purification process for water reuse. Once approved by state regulators using data from our demonstration plant, this innovative technology could be applied across California and even globally to increase the efficiency of other water recycling programs.
The Purification Process
Membrane bioreactors use biological processes and membrane filters to clean water.
Air is added to biological process tanks to create an environment where helpful microorganisms can thrive. These microorganisms effectively remove organic material and nitrogen compounds, such as ammonia and nitrate, from the water.
The water also flows through tanks where thousands of straw-shaped membranes with tiny openings filter and remove microscopic materials, including microorganisms and other particles. Many of the microorganisms and particles removed through this process are smaller than 1/100 of a grain of sand.
Reverse osmosis is often considered the core step in the water purification process, as it effectively eliminates more than 99% of all impurities. Water leaving the MBRs is pressurized through a series of pumps and pushed through tightly wound membranes. RO membranes selectively allow water molecules to pass through, while blocking the passage of microscopic materials such as bacteria, pharmaceuticals and salts.
Reverse osmosis is commonly used to remove salt in desalination projects, as well as in the commercial production of bottled water.
Ultraviolet Light/Advanced Oxidation
Ultraviolet light is a powerful disinfectant used to inactivate viruses in water. When UV light is combined with a strong oxidant such as hydrogen peroxide or sodium hypochlorite, extremely reactive molecules are created. These molecules effectively remove any trace chemical compounds that may persist through the first two phases of water purification. The combination of the UV light and a strong oxidant is referred to as the Advanced Oxidation Process. This is a final refining step that ensures the purified water is safe and meets or exceeds all water quality standards.
The Los Angeles County Sanitation Districts’ Whittier Narrows Water Reclamation becomes the first plant in the U.S. designed to recycle water and recharge groundwater basins.
Metropolitan launches the Local Resources Program, which provides financial incentives for local projects like recycling, groundwater recovery and desalination and encourages what will become more than 100 different projects throughout the Southland to date.
Metropolitan initiates discussion and technical studies with Sanitation Districts for what is named the Regional Recycled Water Program.
Pilot studies on purification technologies and feasibility studies begin and conclude in 2016.
Demonstration plant construction starts.
The demonstration plant comes online.
Metropolitan’s board approves a four-year environmental planning phase.
Metropolitan and the Sanitation Districts complete the first phase of testing at the demonstration plant.
Pure Water Southern California becomes the official name of the program. Other milestones include $80 million in funding from the State of California and the launch of the program’s environmental review process.
Partner agencies will consider the Environmental Impact Report in decision making, and construction could start as early as 2025.
Select Pure Water Southern California facilities may be online.
Operations are scheduled to begin.
Innovation at Work
Pure Water Southern California is novel in its proposed purification process and in its regional scale, but the concept of recycling water is not new and has been widely recognized as proven technology. Several countries worldwide and many communities across Southern California, including some in Los Angeles, Orange and San Bernardino counties, use recycled water to replenish groundwater basins that eventually supply water for drinking and other applications.
Click on the to explore various innovative programs in development and operation throughout our region.
The City of San Diego is constructing a new water recycling plant and associated facilities to produce 30 million gallons of purified water daily. This is the first phase in its multi-year Pure Water Program that will provide one-third of the City’s water supply by 2035.
The Edward C. Little Water Recycling Facility purifies water from the City of Los Angeles' Hyperion Wastewater Treatment Plant and produces water for irrigation water, industrial use, and adding to groundwater to prevent seawater intrusion.
The Groundwater Replenishment System is the world's largest advanced water purification system. The system produces 100 million gallons of purified water daily to help refill groundwater basins. It is currently undergoing an expansion to 130 million gallons daily.
The Albert Robles Center purifies and recycles approximately 14.8 million gallons of water daily, which is used for groundwater replenishment. The Center is a multipurpose and multi-benefit site which includes an Advanced Water Treatment Facility, a fully digital Learning Center, and a water-efficient Demonstration Garden.
Pure Water Oceanside is an advanced water purification program that purifies recycled water to create a new, local source of drinking water. Between 3 to 5 million gallons of drinking water is created each day, enough to provide 32% of the City of Oceanside’s water supply.
Recycled water makes up more than one-third of Eastern Municipal Water District’s water supply portfolio. Recycled water is used for agriculture, irrigation and industrial use. EMWD is also planning to produce purified recycled water for groundwater replenishment through its Purified Water Replenishment program.
The City of Oxnard’s Advanced Water Purification Facility produces recycled water for irrigation of parks, medians, golf courses and athletic fields; watering of agriculture crops; and process water for local industries. The City plans to expand its facility and use recycled water for groundwater replenishment.
IEUA receives and cleans more than 50 million gallons per day of wastewater, which is then used for agriculture, municipal irrigation, industrial uses, and for groundwater replenishment. IEUA is also planning to provide additional purified recycled water for groundwater replenishment by 2028.
The East County Advanced Water Purification Program will create a new drinking water supply utilizing state-of-the-art technology to recycle the region’s wastewater. The project is under construction and scheduled to be online in 2025.
The Los Angeles County Sanitation Districts began replenishing groundwater with recycled water in 1962 at their Whittier Narrows Water Reclamation Plant. Recycling has since expanded to 10 treatment plants and they have recycled over 1 trillion gallons.
Environmental Review Documents and Resources
Awards & Recognitions