The water we drink and use now is the same water from the age of the dinosaurs and the pyramid builders. Water is transferred over and over again from the oceans to the atmosphere and dropped back to land again. This is called the water cycle. You might say that Mother Nature envisioned water to be reusable.
With climate change, climate variability, population growth in arid regions and environmental needs for water resources, nature’s water cycle doesn’t always provide water where it’s needed. So, we must use technology to mimic the water cycle’s groundwater filtration process to produce the water that we all rely upon.
Recycled water is water that was used and disposed of to a wastewater treatment plant, but is then put through several different treatment processes to clean it to a very high level. Then, it is redistributed for use.
Recycled water has been used in communities throughout California and the United States for almost 100 years. There are technologies that can clean recycled water to such a high standard that it is even more pure than any other water source – it is essentially distilled water.
Reusing water allows localities to have a water source that is independent of outside influences, such as the climate, water demands by other cities or regions, and judicial rulings. It is dependable, locally controlled and beneficial to the environment. In Oxnard’s case, recycled water will decrease the city’s dependence on imported water and provide a reliable, sustainable source of local water. It takes less energy to produce recycled water at Oxnard’s Advanced Water Purification Facility (AWPF) than to import water from Northern California.
The City of Oxnard’s AWPF, is a highly innovative wastewater purification plant designed to deliver recycled water that is safe, clean and clear.
Water produced from the AWPF undergoes one of the world’s most highly developed purification processes, one that is used successfully in several locations.
Treated wastewater from the Oxnard Wastewater Treatment Plant that is usually sent to the ocean is instead further purified using three advanced treatment steps: microfiltration, reverse osmosis, and advanced oxidation with ultraviolet light and hydrogen peroxide.
- Microfiltration (MF) – A low-pressure membrane filtration process where pressure is applied to push water through a filter with pores that are 5,000 times smaller than a pinhole to strain suspended particles, bacteria and other materials out of the water. The filtered water is then ready for the next treatment step.
MF is used in commercial industries to process food, fruit juices and soda beverages; in computer chip manufacturing; and to sterilize medicines that cannot be heated.
- Reverse Osmosis (RO) – A high-pressure membrane filtration process that forces water through tightly wound layers of thin, plastic sheets. Although water can pass through, most minerals cannot. RO filters out contaminants, viruses, salts and other materials from the water.
RO is also commonly used for desalting brackish groundwater, in kidney dialysis and in the beverage industry. Many bottled water companies use reverse osmosis because of its proven purifying capability.
- Advanced Oxidation with ultraviolet light and hydrogen peroxide (AOP) Advanced Oxidation (AO) with ultraviolet light (UV) and hydrogen peroxide, often called the Advanced Oxidation Process (AOP) – Disinfection is provided by UV, a high intensity light similar to extremely concentrated sunlight. UV converts hydrogen peroxide into a disinfectant that destroys any microorganisms and organic materials that might remain in the water after the previous two steps of treatment. This process provides extra assurance that no unwanted contaminants will remain in the purified water.
UV is used by hospitals and dental offices to sterilize instruments.
This three-step, multiple barrier process at the AWPF creates an ultra-pure quality water that can be used to meet any future water supply needs in Oxnard.
The resulting high-quality recycled water is distributed through its own separate pipeline system specifically built for this purpose. The recycled water pipeline is identifiable by special purple pipes and connections. Initial uses of recycled water include: irrigation of parks, medians, golf courses and athletic fields; watering of agriculture crops; and process water for local industries.
The City of Oxnard has the responsibility to provide a safe, secure environment to live and work in today and in the future. A reliable water supply is part of that responsibility. With great foresight, more than a decade ago the city began plans for securing additional local water supplies to prevent shortages in the future. Recycled water is one way to increase our local sources and provide a sustainable water supply for the Oxnard Plain.