In a given week, we produce about 35,000 gallons of beer. A result of that, aside from the pretty fucking awesome end product, is between 90,000 to 138,000 gallons of wastewater.

Admittedly, there are few of us who kick back with a beer and think about how a brewery our size handles such a large amount of wastewater. It’s an important consideration, though, since that water eventually makes its way down two Maryland rivers and into the Chesapeake Bay.

So we asked Matt Brophy, our VP of brewing operations, to put on his Bill Nye the Science guy hat and explain the process to us. He made our heads spin with big words and acronyms, but we eventually caught on.

Wastewater is first transferred from the brewhouse, cellar, and packaging area to an outside pumping station that catches large particles (primarily spent grain and yeast residue). Each day, a local farmer picks up these nutrient-rich leftovers, which are then applied to farm fields to enrich the soil for the next season.

Then, the water is treated to reduce biological oxygen demand or BOD. Throughout the wastewater treatment process, we constantly monitor the performance of the plant ensuring that we are achieving our goal of BOD reduction.

From there, it’s transferred into an aeration tank where (you guessed it) the wastewater is constantly aerated to maintain microorganism growth. According to Brophy, we love bugs. These microorganisms help evaporate things like ethanol, which contributes to the overall BOD load. Just like brewers create the proper environment in wort for yeast, we provide the best conditions in the aeration tank for a vast variety of microorganisms to go to town.

After the aeration tank, it goes through a weir, which monitors the amount of wastewater going through the system, and into a clarifier. In the clarifier, any remaining particles are removed. (Eventually, those particles build up in a sludge at the bottom of the tank. Mmm, sludge. That’s actually transferred back into the aeration tank to keep those bugs happy.)

The wastewater’s last stop here at the brewery is a fixed media tank that acts as a holding vessel until it’s pumped (through a series of pipes) to the Frederick County municipal Waste Water Treatment Plant (WWTP).

And there’s your science lesson for the day, boys and girls. We hope you enjoyed getting wasted here at Flying Dog Brewery.