Los Angeles plant selects innovative water reuse solution

Los Angeles plant selects innovative water reuse solution

As California faces one of the most severe droughts on record, the City of Los Angeles Terminal Island Water Reclamation Plant has commissioned Xylem to deliver a unique water reuse solution to help increase the supply of purified, recycled water in Los Angeles. The solution will include Xylem’s Wedeco MiPRO photo Advanced Oxidation Process (AOP).

On May 5, California’s state water board approved emergency drought regulations that aim to slash water use in urban areas by 25 percent. The measures call for cities and water agencies to reduce water usage by 8 to 36 percent. In response, the Terminal Island Water Reclamation Plant’s recycled water solution will provide 12 million gallons of highly purified water per day to reduce dependency on imported potable water supplies.

The Terminal Island Water Reclamation Plant treats wastewater from more than 100 businesses in the heavily industrialized Los Angeles harbor area and from 130,000 residents. The plant purifies tertiary effluent, producing potable water used to recharge the stressed drinking water aquifers – particularly important in the face of the ongoing drought.

“Los Angeles Sanitation is pleased to partner with Xylem as we continue to identify ways to increase recycled water capacity at our water reclamation plants,” commented Traci Minamide, Chief Operating Officer. “This effort will allow us to contribute more to groundwater recharge in the face of a historic drought. The innovative technology – advanced oxidation process – aids in our commitment as environmental stewards to protect our most precious resource.”

Protecting groundwater and supplying industries

Xylem’s Wedeco MiPRO photo AOP solution will ensure that the Terminal Island Water Reclamation Plant complies with California’s stringent groundwater recharge regulations for indirect potable reuse in the safest, most cost-effective way possible. It will protect groundwater against increased salinity due to seawater intrusion, as well as supply recycled water to local industries.

The solution will be installed as a final barrier against pathogens and contaminants that cannot be removed by other technologies. The MiPRO photo system is part of an expansion of the plant at the Advanced Water Purification Facility, which includes microfiltration and reverse osmosis prior to AOP. The customized solution, validated through extensive pilot-scale testing at the plant, will be the first greenfield AOP design using ultraviolet (UV) light with chlorine for indirect potable reuse.

A breakthrough in water reuse technology

“This application of UV with chlorine as an AOP process is a significant breakthrough in treatment to make water reuse more sustainable and cost-effective,” said Keel Robinson, North America Water Reuse Leader for Xylem. “The use of UV with chlorine for AOP will enable the Terminal Island Water Reclamation Plant to utilize their existing chlorination facility without having to add any new chemicals, and it will significantly reduce the life-cycle cost relative to the other types of AOP, such as UV with hydrogen peroxide.”

Additionally, Xylem will be supplying a Sanitaire aeration system to the Terminal Island Water Reclamation Plant for enhancing the performance of the existing wastewater biological treatment system. The Sanitaire fine bubble aeration grids will consist of Silver Series II membrane disc diffusers and ceramic disc diffusers to enhance oxygen transfer, reduce energy costs, and improve the quality of the water feeding the Advanced Water Purification Facility. Xylem has now provided fine bubble diffused aeration to all the Los Angeles Sanitation’s wastewater treatment plants.

by Simon