Faced with an aging water treatment plant and polluted water from ten nearby breweries disrupting treatment operations, the small town of Havre, Montana came up with a solution to use beer to its advantage. Engineering consultant Coralyn Revis figured out a plan to use the beer water runoff from local breweries, which is rich in yeast, hops, and sugar, to feed microbes used during the water treatment process.
Used barley from beer-making operations was used as a substitute for an aluminum-sulfate solution in the water filtration process and saved the city $1 million in upgrades to the water treatment plant.
So how does it work? 10 gallons of waste barley mash is added to the water treatment process as an external source of carbon and volatile fatty acid supplement. Aside from saving the city money, the water discharge into the local Milk River also now has better nutrient levels and lower ammonia toxicity.
The Environmental Protection Agency praised the project as a successful joint effort between government operations and local business to benefit water quality, improve public health, and boost the economy.