A Colorado wastewater treatment plant is planning to use a byproduct of the brewing process to reduce nitrogen levels in the water it treats.
The city of Boulder wants to use weak wort, the sugar water left over after sugar is extracted from grains, as a new food source for the bacteria that help clean the wastewater. Talks are being held with local company Avery Brewing Co. for the delivery of thousands of gallons of the product each week.
Wastewater process optimization specialist Cole Sigmon told Colorado's 9News that the brewery waste would help speed up the process, making it more efficient and potentially saving the city more than $50,000 each year.
Under the plans, Boulder will build a 6,000-gallon holding tank and pump system at Avery's new brewery at a cost of about $25,000. It will transport the sugar water by road from the brewery to the wastewater facility.
According to the Boulder Daily Camera, the plans have been developed with support from a grant of more than $1 million that was awarded to Boulder's Wastewater Treatment Facility by the U.S. Environmental Protection Agency and the Colorado Department of Public Health and Environment in 2013 to help reduce nitrogen discharge levels.
Some of this money was used to conduct full-scale tests, which showed that when the microorganisms fed on the weak wort it resulted in the successful removal of additional nitrogen from the wastewater.
Boulder spokesman Nick Grossman said that using weak wort is the most sustainable and cost-effective solution that the city has identified.
If the arrangement with Avery Brewing goes ahead, city officials estimate that the project will reduce nitrogen compounds by an additional 20 to 30 percentage points.
