The rapid growth of microbreweries or craft breweries has done much to support the claim that Michigan is “The Great Beer State.” Today, the craft beer craze has moved Michigan up to fifth nationally for the number of breweries, microbreweries and brew pubs, according to the Michigan Brewers Guild.
While small brewers enjoy an economic boost from customers thirsting for more, some communities are facing new challenges trying to get a handle on whether they can treat the beer-making byproducts that get discharged into the sewers. In some cases, treatment plants are suffering hangovers from one of the newest rising stars on the industrial block.
Just how much beer can your wastewater treatment plant drink before it pukes? It’s a question few village, township or city officials thought they’d concern themselves with. But some are.
A LOT OF BOD COMES FROM BREWERS WASTE PRODUCTS
Beer manufacturers don’t enjoy talking wastewater, but it’s a big part of doing business. Between two and seven barrels of wastewater are generated for every barrel of finished product. Approximately 70 percent of the water utilized during the brewing process becomes a wastewater byproduct.
Wastewater generated at a brewery can be high in Biological Oxygen Demand (BOD) from bottling side spillage or can include solids like spent grain, yeast and sedimentation waste. Residential wastewater has a BOD around 250 milligrams/liter. A brewery can have a BOD of 1,000-4,000 mg/L or about 4 times the strength of residential waste.