Boulder's Avery Brewing Co. is working with the city to use brewing waste to filter wastewater. 

The city of Boulder is teaming up with Colorado craft brewer Avery Brewing Co. as part of an effort to meet new federal clean water standards.

It turns out a byproduct of the brewing process -- a sugar-water called weak wort -- can help remove nitrogen from wastewater. Avery, which just expanded its operation in Boulder, is working with the city. 

Boulder wastewater manager Chris Douville said right now the city is removing about half the nitrogen in wastewater. Douville would like to get that number up to 70 or 75 percent, with help from the beer byproduct.

"We just can’t get there without some kind of supplemental product, and this waste product is one that we’ve identified that has a very high probability for us," Douville said.

It could be sometime next year before the city is set up to use the brewery byproduct. Stricter federal clean water regulations take effect in 2017.

"We are doing what we need to do to stay ahead of when the actual regulation would go into effect," Douville said.

The Daily Camera has more details: 

The potential arrangement developed as a result of a grant Boulder's Wastewater Treatment Facility received in 2013.

The Environmental Protection Agency and the Colorado Department of Public Health and Environment awarded the Boulder facility more than $1 million in grant money to reduce nitrogen discharge levels as a means of protecting aquatic wildlife and improving drinking water quality.

Boulder is not the only Colorado city working with industry to clean up its wastewater. Colorado Springs has arranged with a local dairy to supply a different byproduct that also helps remove nitrogen.