Beer breweries are increasing in popularity throughout the U.S. and can pose complications for treatment plants receiving their wastewater. Recently, a wastewater plant in Montana realized it’s not such a bad thing after all and took advantage of the waste supply from a local brewery.

In 2016, Havre, Montana’s wastewater treatment plant upgraded to a biological nutrient removal (BNR) system, but the upgrades weren’t enough to remove sufficient amounts of phosphorus. To improve the plant more, facility superintendent Drue Newfield began to research more about phosphorus accumulating organisms and specifically their need for volatile fatty acids (VFAs). “We were told we don’t have much VFAs in our distribution,” says Newfield. “It’s not long enough to decay and extract them.”

He learned that if he could hold enough biomass and allow it to settle out in anaerobic conditions, he could extract VFAs, which could then be fermented and become food for the systems bacteria. That told Newfield that he needed a food source, so out of curiosity he contacted Michael Garrity, owner of Triple Dog Brewery about experimenting with some of the breweries waste.

Garrity opened Triple Dog Brewery six years ago and had known Newfield from a previous job with the city. “He told me about his ideas at the plant and after he told me how things work, and with my knowledge of fermentation, I thought, why the heck aren’t we doing this?” says Garrity. “We started with the yeast slurry, the liquid form. That kind of worked a little bit, but it would fluctuate.” Newfield knew he needed more. “I asked him about his used barley,” he says. “What I was looking for was a pre-fermented carbon source that would possibly have those VFAs in it.”

Promising results 

Newfield introduced the barely into the system immediately saw results. “Within a few days I saw the phosphorus drop in the affluent,” he says. The first barley introduction took place three years ago. 

Since then, Newfield and his team have been troubleshooting and experimenting with the barley to dial in the best results. They tested various strategies like adding the barely in different locations throughout the process and altering the amount of barely used before finding a combination that worked. “I did experiment with dumping it in front of the bar screens,” says Newfield. “What happened was my grit trailer was filling up twice a week instead of once.” 

The fix for that was easy. Now, the grain is dumped directly into the raw stream after the pretreatment and bar screens. The barley goes right into the wet well where it can spend the longest amount of time for the biomass to feed on it. A 16-gallon bucket of barley is added every morning, and it was trial and error testing that helped the team figure that out. 

“We cut that in half for a little while, and I watched my phosphorus go from 0.2 to over a 1.0 mg/L in a couple days,” says Newfield. “As soon as we went back to a full 16-gallon bucket, we went right back down to the 0.2–0.3 mg/L area.” Newfield also saw improvements in oxygen uptake rate after feeding barely. “A higher oxygen uptake rate on your sludge means it hasn’t finished digestion,” says Newfield. “A lower value for that rate means it has finished its job.” 

With the decrease in oxygen uptake rate, he has seen much more efficient settling and decant. What used to take up to a half of a day to settle now only takes a matter of minutes.

Significant savings

In addition to the water quality improvements, the plant has had significant cost savings. Prior to utilizing barley, the plant spent approximately $16,000 annually on alum to feed the system. For the past two years since the routine introduction of the brewery grain, Newfield and his team have not had to add a drop of alum. Aside from no longer purchasing alum, the plant was previously told it needed various upgrades and specifically the addition of a third clarifier which was quoted at roughly $250,000 to $300,000. Before the plant relied on two clarifiers but was insufficient at handling the sludge. Not only has settling improved so much that the third clarifier is no longer needed, but the plant even has the option now to shut down the second clarifier. 

“Settling works so much better than it did before,” says Newfield. “Now I am down to one clarifier and have a spare.” 

 Havre’s innovative use of barley helped the plant meet and exceed Environmental Protection Agency standards and was awarded honorable mention by the EPA for its innovative ways at the end of last year. “We’re excited that this is working. Why can’t we take this national, or worldwide?” says Garrity. “It’s a great example of how a personal business and government can work together to make a difference in the world.” 

With breweries number increasing throughout the U.S., using their waste barely could be a great option for treatment plants. Newfield said he is happy to talk with other plants about his experience and share any knowledge to help people get started.

Contact Newfield at the Havre Wastewater Treatment Plant for questions at cohwwtp@itstriangle.com, or 406-265-9031.