From Sewage, Added Water for Drinking

FOUNTAIN VALLEY, Calif. — It used to be so final: flush the toilet, and waste be gone.

But on Nov. 30, for millions of people here in Orange County, pulling the lever will be the start of a long, intense process to purify the sewage into drinking water — after a hard scrubbing with filters, screens, chemicals and ultraviolet light and the passage of time underground.

On that Friday, the Orange County Water District will turn on what industry experts say is the world’s largest plant devoted to purifying sewer water to increase drinking water supplies. They and others hope it serves as a model for authorities worldwide facing persistent drought, predicted water shortages and projected growth.

The process, called by proponents “indirect potable water reuse” and “toilet to tap” by the wary, is getting a close look in several cities.

The San Diego City Council approved a pilot plan in October to bolster a drinking water reservoir with recycled sewer water. The mayor vetoed the proposal as costly and unlikely to win public acceptance, but the Council will consider overriding it in early December.

Water officials in the San Jose area announced a study of the issue in September, water managers in South Florida approved a plan in November calling for abundant use of recycled wastewater in the coming years in part to help restock drinking water supplies, and planners in Texas are giving it serious consideration.

“These types of projects you will see springing up all over the place where there are severe water shortages,” said Michael R. Markus, the general manager of the Orange County district, whose plant, which will process 70 million gallons a day, has already been visited by water managers from across the globe.

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