One of the first of its kind in the nation, the new 60 million gallon per day (mgd) Biological Chemically Enhanced Primary Treatment (BioCEPT) facility was designed for the City of Akron, Ohio’s Water Reclamation Facility (WRF). BioCEPT is a high rate, wet weather treatment process where microorganisms are used to stabilize untreated wet weather wastewater. This groundbreaking solution increased the WRF’s treatment capacity during wet weather events and is part of an overall strategy to reduce combined sewer overflows to the Cuyahoga River.
A Biological Contact Zone, in combination with traditional Chemically Enhanced Primary Treatment (CEPT) treatment, achieves equivalent secondary wastewater treatment during peak flow (storm) events. Activated sludge from the WRF’s traditional secondary treatment process is combined with the excess wet-weather flow to provide biological treatment. Biological treatment is followed by chemically enhanced settling. Prior to completion of BioCEPT, the WRF had a secondary treatment capacity of 220 mgd. Sustained flows above 220 mgd would flow through a storm retention tank and overflow to the disinfection system and ultimately flow to the Cuyahoga River. Now peak flows of up to 280 mgd to the WRF will receive secondary or equivalent secondary treatment.
There were numerous, highly complex components of this project design. The facility was constructed through the heart of the WRF while the plant remained fully operational. Poor soil required the design and construction of an anchoring system to hold the tank down as it is empty most of the time and groundwater can be close to the surface causing significant uplift pressure. Additionally, locally manufactured tipping buckets, water cannons, a non-potable water system, and a sophisticated pumping system were required to be able to clean the tanks effectively and pump the solids to appropriate treatment units in the WRF.
Completed and operational in December 2021, the new BioCEPT facility is meeting the City’s effluent limits. The innovative project was completed and fully operational ahead of the required USEPA Consent Decree schedule while remaining under budget. There was an estimated $39 million in capital savings from the original Consent Decree required project by providing a simpler, non-proprietary design and incorporating equalization and treatment in the same facility.
This solution could help improve standard wastewater treatment processes nationwide.
The Akron Water Reclamation Facility BioCEPT Improvement project received the 2023 American Council of Engineering Companies (ACEC) of Ohio Engineering Excellence Grand Award.