Commonwealth was hired to investigate and provide solutions to an underperforming wastewater treatment system for their oxidation ditches, which was also impacting performance in their clarifiers requiring frequent use of water on-site for maintenance needs. The analysis showed the current system was not capable of adjusting to the difference in loading between summer and winter considers for this lake community.
To expedite the improvements, the Owner elected to utilize the Guaranteed Savings approach whereby a Contractor (Provider) is selected, and then a Guaranteed Maximum Price is established. Kokosing Construction Company was selected to implement improvements to address performance issues and aging infrastructure throughout the wastewater treatment facility.
The work modified the oxidation ditches to improve flow movement, eliminated four high-horsepower mixers, installation of a new blower and aeration system, and made miscellaneous improvements to the grit pumping system, grit classifier, and influent gate. Within 24 hours of being online, the improved performance was visibly noticeable in the clarifier. This approach saved months on the schedule, and through the process, the Owner was able to apply and be awarded a NIPSCO rebate for approximately $90,000. The Owner elected to perform additional work at a cost higher than project savings. The difference was added to the contract.