Havre, Montana fed a brewery's spent barley to its sewage bacteria, dodging a $1M upgrade

NPR reported that brewery waste can throw off the microbes sewage plants use to remove nitrogen and phosphorus, but if used in the right spot and amount it helps the process. In Havre, Montana, about three years before the 2020 report, wastewater plant manager Drue Newfield approached Triple Dog Brewing owner Michael Garrity with the idea of feeding the plant's bacteria leftover barley. If it worked, the town of 10,000 could avoid spending about $1 million on an upgrade to meet tougher clean water standards.

Each morning since, a bucket of the brewery's spent barley goes into the water at the plant's application point. The team spent the first two years troubleshooting how much barley to add and what conditions the bacteria needed. Without the free barley the plant would have had to buy a chemical called alum.

Newfield says the alum saved is at least $16,000 a year, and the barley may have prevented an upgrade costing millions.

Wastewater bacteria remove nitrate better when given a carbon source alongside it.

The brewery's spent barley is free and would otherwise be a disposal problem.

A small town's single plant manager and single brewer could agree on it face to face.

Tighter clean-water standards raised the cost of doing nothing to roughly $1 million.

One operation's waste can be another's input, but only after months of tuning the dose, timing and conditions.

The US EPA gave Havre an honorable mention in late 2019. Several Montana towns showed interest and a Boston plant manager called Newfield. A pilot in Bozeman found the chemistry worked but moving the liquid brewery waste there was too expensive for now.