Blog Post

Orange County Recycles the Backwash

GRSStarting today, the Orange County Water District will put into operation the world’s largest sewer water treatment plant for reclaiming drinking water. The $481 million groundwater replenishment system will supplement the Southern California county’s potable water by processing some 70 million gallons of municipal sewage each day through the use of reverse osmosis, which involves forcing water through a semipermeable membrane to remove solutes.

This is the first potable water reuse program of its type in the U.S., according to the New York Times, but many other water-constrained cities have been considering such a technology for over a decade. The NYT reports that the Orange County plant has already had visitors from all over the world. While certainly not the sexiest of cleantech ventures, sewage water reclamation might prove necessary to save our valuable water resources.

Water treatment plants have discharged cleaned water into drinking supplies, such as rivers, for years, but using sewage treatment plants to explicitly increase water supplies has been more controversial. However, the Goreangab Water Reclamation Plant in the Namibian capital of Windhoek has been recycling sewage water directly back into drinking water for decades. The Goreangab system uses a series of activated carbon and ozone washes to purify the water. When the plant was revamped in 2002, reverse osmosis was ruled too expensive.

Reverse osmosis is currently used all over the world in desalination plants, including Israel, China and Spain. The process involves forcing the dirty water through a membrane at high pressure, and at a high cost of energy.

Reverse Osmosis

Water technology is certainly the sector we blog about the least here. While many agree that the global appetite for more clean water technology will certainly grow, investment has been hesitant to follow. It will likely be places like Israel, whose venture capital record and high-tech infrastructure, together with a desperate need for water technology, will fuel innovation and investment in water.

It isn’t just VCs who have cold feet about emerging water technologies. “Toilet-to-tap” programs, as critics call them, are extremely unpopular with the public, often getting voted down or vetoed. Perhaps the public and the venture capitalist community need a modern day Jake Gittes.

While VCs cite untested technologies and uncertain business models, the need for water is great. Large-scale projects like Orange County’s may open up the floodgates for water investment.

14 Responses to “Orange County Recycles the Backwash”

  1. It is promising to see Americans wake up to the ever-growing water crisis. We need to see more models of gray water usage and recycling of water! Most people take their taps for granted and use them like their is no shortage of water – or maybe they just can’t deny themselves the convenience of letting the faucet flow.

    1.1 billion people lack safe drinking water around the globe. Many walk on average 6K just to fetch a few liters. Where Americans use an average of 100 gallons of water per day, people in Africa use about 5!

    There are many ways to support the global water crisis as well as our local issues. For more information, contact [email protected]