Nov 30, 2007

From Flushing to Drinking?

Purifying wastewater may become the answer to droughts and water shortages in a California county.

Orange County, Calif., has begun a long process to turn sewage water into drinking water.

Filters, screens, chemicals and ultraviolet light will all be a part of the intense process begun by the Orange County Water District to create what industry experts claim to be the world’s largest plant dedicated to purifying sewer water to increase drinking water supplies. The hope is that this plant will begin a worldwide trend to helping counties deal with drought and water shortages. The plant, known as the Groundwater Replenishment System, costs $481 million.

Other towns are beginning to consider similar ideas: San Diego began testing a similar plan, which increases reservoir water by combining it with recycled sewer water; San Jose, Calif., began studying the idea in September; water managers in southern Florida approved a proposal to increase drinking water supplies; and planners in Texas are considering the idea as well.

“These types of projects you will see springing up all over the place where there are severe water shortages,” Michael R. Markus, general manager of the Orange County district, told The New York Times. Water managers worldwide have visited Markus’ plant, which is designed to process 70 million gal per day.

District managers remind skeptics that the water cannot, per California state law, flow directly into taps. Instead, it will be sent underground, where it will serve dual purposes of blocking seawater and filtering into aquifers.

The public or legislative bodies often reject these types of projects because of their expense and the health concern issues they raise.

Even so, Markus complains that the finished water “is as pure as distilled water” and no more expensive than purchasing water from wholesalers.