Now is the time for the U.S. to update its approach to water treatment, says Bob Perciasepe, U.S. Environmental Protection Agency deputy administrator. “[The challenge] is how to get a 20th-century law—the Clean Water Act—appropriate for 21st-century projects,” he said at the Water Environment Federation’s annual meeting, held on Oct. 3-7 in New Orleans.
When water-quality standards were first developed during the 1960s, problems such as high nitrogen and phosphorous levels as well as pharmaceuticals and other endocrine disruptors were not considered. Perciasepe said that implementing and enforcing Total Maximum Daily Load standards for contaminants are the best way to ensure water quality in impaired waters.
Other conference attendees offered additional water-treatment ideas. “We’ve got to stop thinking about wastewater as a waste and instead think of it as a resource stream,” says Glen Daigger, CH2M Hill’s senior vice president and chief technology officer. For example, many utilities now are using the wastewater treatment process to generate various forms of renewable energy.
One technology uses algae to create biofuels that can be used in place of oil. It also reduces nutrient levels.
Mark Haley, director of the Hopewell (Va.) Regional Wastewater Treatment Facility, says he is growing algae during tertiary treatment using an “algae wheel” developed by Oldcastle Precast as part of a demonstration project at a 50,000- to 60,000-gal-per-day wastewater treatment plant in Hopewell. The wheel provides a growth medium for bacteria, which converts organic carbon into food for algae. Although it is too early to tell how successful the effort will be, Haley says he hopes the algae will reduce nitrogen levels at his facility.
Using algae to create biofuels is an example of a larger trend in which people are starting to look at wastewater as a resource, rather than as something that should be eliminated, Daigger says.