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MWH filter plant

Filter plant: 1660-pounds-per-day (ppd) ozone capacity

It’s no secret that California’s inland communities have been experiencing severe drought conditions, especially in recent years. In a Water Online article, authored by California Region Reuse Leader Melanie Holmer and Global Practice Leader Kati Bell, the use of ozone-biologically active filtration (ozone-BAF), could be one cost-effective means of bringing potable reuse to inland communities that cannot implement the Full Advanced Treatment (FAT) process. The proposed treatment alternative could “provide a constant source to augment water supplies in these locations.”

California currently allows indirect potable reuse (IPR) by groundwater replenishment using FAT, which includes microfiltration, RO and UV advanced oxidation. The challenge of RO is that it “produces a concentrate waste stream that cannot easily be disposed because of its salinity, toxicity, and high concentrations of trace chemical contaminants.” Coastal treatment facilities have the means to dilute and dispose of this toxic waste stream through ocean outfalls; however, inland California communities do not have this disposal option, effectively eliminating their ability to reap the benefits of potable reuse. With recent research showing that ozone-BAF can provide water that is protective of human health at a cost that is less than half of FAT, ozone-BAF is an enticing alternative for inland communities to leverage potable reuse while addressing the issues of water quality, cost, and reliability of water supplies.

For more on this promising new filtration method, read “Ozone-Biologically Active Filtration For Potable Reuse In California’s Inland Communities: Benefits And Barriers.”