npr:

As America’s craft beer industry continues to boom, the waste it generates can pose challenges for sewer systems. But if it’s used in the right spot, in the right amount, it’s potentially beneficial and can actually save wastewater treatment plants money.

In Bozeman, Mont., the Water Reclamation Facility treats more than 6 million gallons of water every day from sinks, showers, toilets — really anything that goes down a drain. That includes liquid waste from more than 10 breweries in this city of nearly 50,000.

Because it’s rich in yeast, hops and sugar, brewery waste can throw off the microbes that wastewater plants rely on to remove nitrogen and phosphorus. The two nutrients can cause algae blooms in rivers and kill off fish.