Lee County needed to increase detention time of chloramine-treated finished water at its Corkscrew Water Treatment Plant in order to meet CT disinfection requirements. The County’s Utilities Division chose Globaltech to design and implement the necessary water storage improvements. As part of the project, Globaltech provided value engineering options to reduce cost and improve operational flexibility.

During the construction phase, we installed a new, 4.0 MG, CROM prestressed concrete storage tank along with a new 36” DIP finished water pipe connecting the transfer pumps to the new tank. We provided baffles in the new 4.0 MG tank and in an existing 2.0 MG tank. We also installed new clearwell and transfer pumps and modified the existing transfer pump system. Finally, we provided new instrumentation to interface with one of three existing Allen-Bradley Control Logix PLC’s in Citect format.

Project Achievements / Benefits

Globaltech’s value engineering recommendations saved the County money and gave them more operational flexibility. For example:

• A parallel 18” finished water (FW) pipe was installed in lieu of replacing the existing 24” FW with a 36” FW main.
• Polypropylene baffle curtains were installed instead of concrete baffle walls in the new 4.0 MG ground storage tank and existing 2.0 MG ground storage tank. Polypropylene curtains are NSF approved and are more economical, easier, and faster to install.
• Perforated storage tank inlets were installed to increase baffling factor and to lower the number of baffles in both the new and existing storage tanks. Perforated inlet pipe provides dispersion of water in the storage tank and increases contact time. It also allows the storage tanks to operate in series without the addition of a costly new inlet pipe.