When the Rio Grande Estates Subdivision’s upgraded wastewater treatment facility opened in 2004, the Lake County (Ohio) Utilities Department had a lot to be excited about – increased efficiency, lower operational costs, and a higher quality effluent. But even more significant was the approval of this technology for small- to mid-sized residential treatment facilities in Ohio.
The new Rio Grande facility, serving 35 residences, utilizes submerged membrane bioreactor (MBR) technology which, until December 2005, was considered an “unproven technology” by the Ohio Environmental Protection Agency (EPA). While MBR had been used in warmer climates, it had not been adapted for Ohio’s cold winter weather.
A Well-Developed Technology
With the support of the Ohio EPA, Burgess & Niple helped the Lake County Utilities Department obtain a research and development grant from the Ohio Water Development Authority (OWDA) to fund the project and, ultimately, develop the first municipal submerged flat plate MBR wastewater treatment facility in Ohio.
The new facility was designed with the membrane cassettes installed in precast concrete tanks below grade and with full covers for both temperature and odor control. The full-scale, 21,500-gallon-per-day MBR plant was installed parallel to the existing facility and placed in service by diverting the flow to the demonstration facility. The existing tanks were kept on standby for the one-year certification test period which ended in December 2005.
The operational and maintenance data collected during the 12-month period demonstrated that the plant successfully met all requirements and was recommended by the Ohio EPA as a well-developed technology.
Following the Ohio EPA approval, MBR technology has attracted statewide interest and is now being used by B&N to upgrade and expand a wastewater treatment plant for the City of Dover, Ohio and has been included in the planning phases for several additional treatment plant designs.
A membrane bioreactor (MBR) is an activated sludge process that uses a physical barrier – the membrane – to filter contaminants from wastewater. Utilizing membranes submerged in the aeration tanks as part of the liquid-solids separation process eliminates the need for both secondary settling tanks and sand filters. Additional benefits include:
In 2006, the Rio Grande project received an Honor Award from the American Council of Engineering Companies of Ohio.