This project was not forced upon the City by the WDNR. However, standard engineering and life cycle schedules are completed in 20 year increments (NR110.09)(1)(a). A thorough review of the Whitewater facility has not been done since its construction in 1982. Planning for items that have outlived their useful life and preparing the utility for another 32 plus years of service is the responsible thing to do.
Ultimately, we must provide quality service to our customers while maintaining compliance with all regulatory requirements. Those requirements have changed since 1982 and will continue to do so in the future. The heart of most treatment systems is the secondary treatment process. Here in Whitewater that is accomplished using Rotating Biological Contactors or RBCs. Again, these were designed to a 20 year life cycle and units run 24 hours a day, 7 days a week.
We currently have 3 of the 48 RBCs out of service due to shaft failure. Another 6 are out of service due to their proximate location to the failed units. I could develop a list but I feel the point is better addressed by cost. We have received two cost opinions over the years and both have shown the cost to repair our existing system is greater than the cost of replacing it with a different, more flexible, technology. The secondary process and associated equipment is the largest cost component with this project. Additionally, electrical infrastructure, hydraulic constraints and code compliance all account for a large portion of the overall cost. The inclusion of these items was driven by process reliability, permit compliance and safe working conditions.