Midwest WWTP Overloaded by Industrial Influent Rescued from Permit Probation by EOSi’s MicroC® 2000

A small midwestern USA municipality owning and operating a 1.5 MGD wastewater treatment plant (WWTP) was treating both municipal and industrial wastewater, including substantial inflow from a local pork-processing facility. The municipality’s WWTP uses oxidation-ditch technology — circular or oval-shaped aeration-activated sludge basins — to achieve biochemical/biological oxygen demand(BOD) removal, nitrification, and denitrification.

An evaluation of the WWTP’s influent wastewater characteristics highlighted a significant shortfall in the BOD loading compared to its ammonia loading. The high ammonia levels in the influent resulted from the WWTP receiving more than 50% of its inflow from a local pork-processing industrial discharger. The WWTP was required to meet strict weekly and monthly average ammonia and pH effluent limits but was frequently exceeding those limits — and endangering their operating permit.