When designing a brewery, waste management is often an afterthought. Selecting the proper equipment, from cooling systems to fermentation vessels, is no easy task. Inventory logistics, labor concerns and market research all need attention. Nevertheless, taking time to consider waste management is a crucial step in managing wort and producing beer. With a properly designed waste management system in place, breweries can avoid costly production delays, potential fines from local, state or federal environmental agencies and what may be every brewer’s worst nightmare — product contamination.
It was with these concerns in mind that a successful brewery collaborated with ClearBlu Environmental, a full-service design-build firm that specializes in applying sustainable technologies to process wastewater treatment and reclamation. Because their business was growing rapidly, the brewery wanted to expand operations in Texas. An efficient treatment system was required to process the wastewater generated by the brewery.
ClearBlu Environmental designed the pretreatment system, which included screening, settling and pH balancing, as well as the pond design, aeration system, bacterial treatment and final-stage flow monitoring. It was determined that three lift stations would need to be installed, with two pumps to operate in each lift station.
With any brewery, the wastewater contained solids that could erode or clog the pumps, reducing pump reliability and risking operational delays. That wasn’t all. The technical challenges at this brewery included acidic wastewater with a pH of 4, and high-temperature wastewater over 140°F.
The engineers realized the proper submersible pumps would be critical to help ensure the waste management system could maintain sanitation requirements. They consulted with Industrial Flow Solutions, a supplier of pumps and fluid management systems. What they learned about pumps applies to any brewery wastewater system. Managers should consider the following:
- Solids handling
- Corrosion resistance
- Chemical compatibility
- High temperatures
Solids used in the brewing process, such as spent grains, hops, flavoring agents and yeast, can flood into the waste stream during the mashing and lautering process. These soft solids also get rinsed into drains during cleaning and sanitation.
In small quantities, these solids can be harmless. But the adhesive properties of protein and carbohydrate chains extracted during the mashing process often cause these spent grains to clump together, forming dough balls. These dough balls are especially prominent when using unmalted grains (e.g., flaked wheat and oats), which are extremely popular in modern beer styles. Dough balls have emergent properties from their singular counterparts and can range from very elastic to very hard and form in various sizes.
Dough balls create unfavorable conditions for submersible pumps not designed for solids handling. They can clog strainers and obstruct impellers, hindering proper pump operation that can lead to pump failure. And when a pump fails, flooded waste streams and putrefaction of the waste in the sump can lead to product contamination and an unhappy group of customers. Pump failures also occur when other solids from the brewing process make their way into the waste stream. In a brewery, it’s common to see packaging materials (e.g., bottle fragments, bottle caps, cans, plastics) and other debris like hair nets, gloves, and pallet chunks in the sump pit, as well.