Final Report Says Recycling Water Is Not So Expensive
The San Diego Public Utilities Department today presents its final report on water recycling and estimates it would cost no more to recycle water than to import it.
The report will be presented the San Diego City Council’s Natural Resources and Culture Committee.
Turning wastewater into drinking water could provide a large, reliable source of water for San Diego. But water recycling has been politically controversial because some people think reusing wastewater is distasteful.
It's also been seen as expensive: about twice the cost of importing water from outside the region.
But the final report on San Diego's Water Purification Demonstration Project now claims the future cost of recycled and imported water would be about the same, around $1,000 per acre foot.
The report indicates recycling water does save some money by reducing the need for imported water and by cutting the volume of wastewater the city must handle and treat before it's pumped out to sea.
Today, between 80 and 90 percent of San Diego water is imported from northern California or the Colorado River.
Turning wastewater into drinking water involves an intense purification process. Water is forced through very fine filters in the process called "reverse osmosis." Any remaining contaminants in the water are then blasted with UV light, and mixed with hydrogen peroxide.
The City of San Diego’s Public Utilities Department built a test plant, the “demonstration project,” to start the process of water recycling. If the city chooses to go ahead, it would build a permanent plant that would treat wastewater and pump it into the San Vicente Reservoir, where it would mix with the city’s larger water supply.
A permanent water recycling plant would cost an estimated $369 million.