Creston’s wastewater treatment facility treats both domestic and industrial effluent. The Columbia Brewery, which feeds its wastewater to the town, underwent major expansions that significantly increased its wastewater flows. Creston was not equipped to treat the volume of wastewater generated by the brewery. Town officials were eager to solve the problem, especially since the brewery was Creston’s largest employer. Creston needed a simple, efficient, low-maintenance wastewater treatment system.
After an investigation by the town’s consultant, it was concluded that anaerobic pretreatment would be the best way to upgrade and expand capacity. Following a competitive bid process, the Town of Creston chose the low-rate anaerobic ADI-BVF® reactor to treat brewery septage, as well as domestic and waste-activated sludge. Brewery effluent is diverted and treated separately in a bulk volume fermenter that acts like a large septic tank.
ADI Systems supplied and installed a 5.4 MG (20,460 m3) lined basin anaerobic BVF® reactor for the Town of Creston. The system is designed for a wastewater flow of 0.8 mgd (3,040 m3/d). The reactor has a geomembrane cover which helps to maintain proper temperature, collect biogas, and control odor. Biogas produced from the anaerobic digestion process is burned in a hot water boiler to provide heating for the reactor. Final effluent flows to an existing aeration system for polishing.
The BVF reactor has stopped overloading at Creston’s wastewater treatment plant and allowed the town to meet final effluent discharge limits. The chemical oxygen demand (COD), biochemical oxygen demand (BOD), and suspended solids removals average 90, 90, and 86%, respectively.
Settled sludge is periodically “vacuumed” into a pressure tank and injected into nearby fields from approximately 6 inches (15 cm) below the surface. This process benefits a local farmer by significantly cutting fertilizer costs. The farmer discs the soil in preparation for planting and says the sludge has excellent soil-building capabilities.
The wastewater treatment system ADI Systems provided is very user-friendly. A software interface allows plant operators and ADI Systems to work together to monitor plant performance and make process changes despite being thousands of miles apart.