California approves rules for turning sewage waste into safe, drinkable water

California approves rules for turning sewage waste into safe, drinkable water

By Ashmeeta Subra  January 16th, 2024

It might not sound appealing off the cuff, but the conversion of sewage waste into drinking water could help address long-term drought and water shortages.


The California State Water Resources Control Board voted unanimously to approve sewage waste conversion, allowing wastewater treatment for direct use in households, businesses, and other larger systems – a crucial move in times of drought. Until now, recycled water could only be mixed into aquifers or utilised for irrigation and various non-potable purposes.

“A city produces wastewater during a drought and having that source available to augment other (drinking water) supplies can be critical,” Darrin Polhemus, deputy director of the Division of Drinking Water at the Water Resources Control Board, told CalMatters.

The expected cost of the water would be higher than imported water, but it promises a more local, sustainable, and reliable supply for California amid ongoing climate change challenges. Texas and Colorado have already established regulations for making wastewater potable, while Arizona and Florida are developing similar rules.

The treated wastewater, often dubbed ‘toilet-to-tap’, requires extensive steps overseen by 63 pages of detailed rules and thorough monitoring to ensure effective treatment. The treatment process involves ozone exposure, bacterial treatment, carbon filtration, reverse osmosis, UV light exposure, mineral restoration, and the regular treatment undergone by all drinking water at the final stage.

In consideration of potential safety concerns and health risks, Board Chair E. Joaquin Esquivel has directed staff to update the board on monitoring, contaminants, and other issues within the upcoming year.

In 2022, Governor Gavin Newsom pushed for increased use of the state’s recycled water, aiming for a nine per cent increase by 2030 and more than double by 2040. By 2032, the project is expected to produce about 115 million gallons of recycled water daily, sufficient for 385,000 households in Southern California. The majority will be used to replenish groundwater while a portion will be added to drinking water sources upstream of Metropolitan’s treatment plant for imported water.

Planet Ark does not take responsibility for the accuracy of the original information and encourages readers to check the references before using this information for their own purposes.


Positive Actions

Ashmeeta Subra

With background in international relations and marketing communications, Ashmeeta is excited to use her skills to encourage positive environmental actions through Planet Ark. She believes that by taking small actions, we can help make a big difference and be good stewards of our planet. Outside of work, she loves spending time in nature and enjoying downtime at the beach.

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