The National Research Council released a new report Tuesday that says an additional 12 billion gallons of American wastewater could be safely reclaimed on a daily basis.
That's enough to provide water to 6 percent of the U.S. each day.
The study reviewed the risk of exposure to microbes and 24 chemical contaminants in reclaimed drinking water compared to that of existing supplies that already have a small amount of treated sewage.
The research concluded that the health risks are comparable or even lower.
The study was partly sponsored by Southern California water agencies, which are trying to safeguard tight water supplies for a growing population.
The Associated Press contributed to this report.