A new treatment plant in Orange County, Calif., is one of about 15 in the country to recycle wastewater back into the groundwater drinking water supply -- a plan called indirect potable reuse. Two experts answer your questions on water recycling.
Has there been a significant breakthrough in water filtering technology recently? Dean Kamen (inventor of the Segway) came up with a water purification system that generates power. Are any inventions like this in use on large scale?
Cheryl McGovern responds:
The primary role of the U.S. Environmental Protection Agency is to protect human health and the environment through the regulation of water quality at the tap and in the country's surface waters. The agency typically isn't involved in the development of new water filtering technology. However, we believe many people are working on new technologies because there is a great need for more cost-effective treatment processes. Significant progress continues to be made in more energy efficient and effective wastewater treatment equipment. More information about this is available here.
NOTE: As was noted in a 2003 Time magazine article, Kamen's device uses waste heat from an electric generator to distill water -- boil it and condense it. The article notes Kamen has come up with a way to do it using as little energy as possible. While 1,000 watts of heat won't boil much water, Kamen developed a closed system, powered by whatever fuel is at hand, that traps and recycles the energy released when the boiled water vapor recondenses, resulting in a low-power, low-maintenance device that he claims will cost around $1,000 to manufacture and makes 10 gallons of drinkable water per hour.
Shivaji Deshmukh responds:
Technological advances in water treatment have definitely made wastewater purification more affordable and energy efficient. While reverse osmosis has been around since the 1960s, advances in membranes have resulted in treatment that produces higher quality water using less energy in a smaller footprint.
The GWR System is considered a leading example in the field of water purification. The state-of-the-art purification process used with the system can be replicated in other arid coastal regions of the world to address a looming global water crisis. In fact, the GWR System has already been replicated on a smaller scale in Singapore, and other parts of the world such as Australia are looking at GWR System technologies to satisfy their water needs.