Wastewater Recycling in Los Angeles

Hyperion in Los Angeles. CC BY-SA 4.0, Bettinafilms

The April issue of the ASCE magazine features a short article on Los Angeles’s Hyperion Water Reclamation Plant (WRP). The plant is among the largest, most advanced facilities of its kind in the U.S. and presently processes over 80% of the city’s water, but the city recently revealed plans to recycle all wastewater by 2035.

In an interview with the ASCE, Paul Liu, a managing water utility engineer in the Water Resources Division of the Los Angeles Department of Water and Power (LADWP) says, “Ultimately, however much water LADWP injects into the underground aquifer, the department can extract that same amount out of the ground to offset our imported purchased water. That’s the beauty of the system.” Recycled water requires microfiltration and reverse osmosis to prevent seawater imposition. Advanced future treatment might also include a membrane bioreactor and ultraviolet and advanced oxidation processes to make sure the water is safe to drink.

This ambitious idea would cost an estimated $8 billion but would benefit the city greatly in its attempts to be more environmentally friendly and cost-beneficial in the long term. Currently, Los Angeles imports the vast majority of its annual water supply from other parts of California, the Sierra Nevada Mountains, or the Colorado River. If plans go smoothly, the city should greatly reduce its dependence on importing water from outside regions in a few years.

By recycling wastewater and cutting import costs, Los Angeles is taking steps to contribute to a better environment and waste less water. Hopefully we see more cities follow suit!