The Wastewater plant was built and operated by Preble County in 1976. After the bonds for the construction were satisfied, operation of the wastewater treatment plant (WWTP) and collection system were turned over to the Lakengren Water Authority in 1998.
The most significant upgrades made to the WWTP have been the switch from chlorine injection to ultraviolet radiation as the means of finale disinfection of the effluent. This was completed in 1994 while Preble County operated the sewer system.
The most recent improvements have been the reconstruction of the four radial clarifiers. This included the rebuilding of the operating heads, including all new bearings and seals and replacement of all the old galvanized steel components with new stainless steel components. All of the concrete tanks were pressure washed, inspected and epoxy coated.
Other than minor upgrades to pumping equipment, flow meters and other minor systems, the plant exists today much like when it was originally designed and built.
In 2015, Ohio EPA renewed our National Pollutant Discharge Elimination System permit (NPDES Permit). Effective January 1st, the limit on the amount of Nitrogen, Ammonia (NH3) we were allowed to discharge will be reduced by 60%.
The WWTP in its current configuration would not be able to maintain compliance without modification.
The Lakengren Water Authority (LWA) retained the engineering services of Mote and Associates to evaluate the WWTP and recommend a solution.
It was determined that the only way to meet the requirements of the new discharge permit was to modify the WWTP with the addition of new processes that would be better suited to our situation.
After evaluating different treatment techniques and processes, it was determined that an orbal (oxidation ditch) design would be best suited to our needs.
Along with the nitrogen removal requirement, we are addressing phosphorous removal, improving sludge processing and upgrading the electrical system which includes the installation of backup power generation.
It is expected that these modifications and improvements should serve the needs of the Lakengren Community for the next 50 years or more.
Article provided by:
General Manager, Lakengren Water Authority