Tom Lunn, Columbia Power & Water Systems
Jonathan Hardin, Columbia Power & Water Systems
Andrew Bohon, Inflo Design Group
The Middle Tennessee region has seen significant growth over the last several years with development from the greater Nashville metropolitan area extending south into Maury County. Columbia Power and Water Systems (CPWS) is in the midst of their Long Term Water Supply Program (LTWSP), which began with an initial planning study in 2016, to address these growing water demands and vastly improve the reliability of the existing system. The LTWSP has already completed two design and construction projects to increase the reliability of the existing water treatment plant and provide additional finished water pumping capacity (the Early Action Pump Project completed in 2020 and the Phase I Improvement Project completed in 2021). The Phase II design, a new 12 MGD membrane treatment train plant expansion is currently underway with final design anticipated in early 2025. A recent evaluation determined that the CPWS water demands jumped from an expected compound annual growth rate (CAGR) of 3.0-3.5% annually to over 7% annually for the past 2 years. While the Phase II project was originally slated to include improvements to the existing plant, these improvements are now required much sooner to provide more efficiency and reliability from the existing conventional filtration treatment train. Beginning in late 2023, Project Teal commenced to identify which plant improvements were most critical to allow the plant to reliably and consistently treat it’s rated capacity of 20 MGD. A team of plant operators, design engineers, and CPWS’s CMAR combined forces to develop a plan for accelerating the design and construction of these improvements. The initial Teal project list consisted of over 25 separate improvements projects. These items were evaluated based on cost, lead times, impact to the treatment process, potential process interruptions required for construction, and risk associated with delay. Following this initial prioritization, the projects were organized into deliverables packages for both the TDEC and CMAR to allow time for regulatory review and approval and development of a Guaranteed Maximum Price for construction to move forward. In order to meet the necessary timelines, all aspects of the schedule were accelerated which required constant communication and full cooperation of the team, as well as regular coordination with the engineers designing the Phase II plant expansion. Project Management for Project Teal has been critical to maintain progress on all of the separate projects and parallel reviews and submittals. It is anticipated that the Project Teal design will be complete by Spring 2024 with some construction activities beginning by later summer of 2024. The presentation on this project will include lessons learned through the design completion and a status update on construction progress.