University of Georgia
With more water going down the drain in Georgia than falling from the sky, University of Georgia experts are working on ways to reuse the hot commodity.
Gray water is used water collected from showers, baths, sinks or washing machines. It’s not safe to drink, but Georgians could still use it to flush toilets, water yards and save money while conserving water, said Frank Henning, a University of Georgia Cooperative Extension watershed agent.
“Gray water is another piece in the puzzle of improving indoor water use efficiency,” he said. “With water shortages, people are trying to find additional water resources. They’re clamoring to know what we can do with gray water.”
Henning is working with UGA faculty members and representatives from north Georgia governments, the Georgia Department of Community Affairs and the Georgia Environmental Protection Division. They are developing code recommendations to guide Georgians on how to install and use gray water recycling systems in their homes safely and legally, particularly to flush toilets. Their work is meant as a model for counties considering code changes.
Using gray water to flush a toilet may not sound like much. But it adds up. According to the American Water Works Association, the average household uses 69 gallons of water a day. About a quarter of that, or 19 gallons, is used to flush toilets. Showers and baths take up 13 gallons, or 19 percent. Leaks waste 10 gallons, or 14 percent, daily.
The gray water advisory group has discussed safety features for recycling systems, such as backflow prevention, purple pipes and dye injection units to separate gray water from drinking water physically and visually. They’ve drawn diagrams to help plumbers install systems correctly, too.
When the drought and subsequent water bans sent gardens and lawns from green to dead, Georgians’ interest in reusing water on their landscapes spiked, said Ernie Earn with the Georgia EPD.
There are already codes in place to use gray water for irrigation systems, Henning said.
Gray water can contain disease-causing microorganisms even after going through a filter and disinfection unit. It can’t be sent through traditional aboveground irrigation systems. But along with used water from the toilet, or black water, it can be released through an underground drip irrigation system that has been approved for onsite wastewater treatment. The Georgia Department of Human Resources has guidelines for installing such systems.
“Installing this type of system may have some additional costs and require some extra effort from the design professionals,” Henning said. “But under current regulations, a subsurface drip irrigation system could be used to treat wastewater and irrigate plants.”
Another way to save water in the home is to install new low-flow toilets, Henning said. They use only one to two gallons of water per flush. Older toilets use five to seven gallons of water per flush.
He also suggests installing low-flow showerheads and fixing leaks.
“A homeowner with low-flow, low-flush and no-leak fixtures could save more than 30 gallons of water per day or nearly 11,000 gallons per year,” Henning said.