WATER STORAGE TANKS
4.0 MG Buried Water Storage Tank
Lafayette, CO
J&CA, CTL/Thompson and McLaughlin Water Engineers staff designed a 4.0 MG, underground, post-tensioned concrete water storage tank to service the City of Lafayette. The tank site was only 1.25 acres, only a little bit larger than the sit planned for the Silverthorne tank. Strategic placement of a new tank resulted in significant cost savings and helped strengthen the overall system by simplifying pressure zones. Construction of the tank began in October 1999 and was completed during the spring of 2000; it was part of a series of overall system improvements that also included four pipeline projects. The new tank is an integral part of the entire system and is gravity fed from the water treatment plant. Lafayette has a high pressure zone where water is pumped from the plant to a higher tank. Master planning and tank constructing simplified the system and reduced the amount of pumped water by about 50%. The new system reduces power costs by providing gravity service to large areas of residents. As part of the tank design, connections to the City’s existing water lines were included. During construction in January of 2000, Grimm Construction Company, Inc. placed 540 yards on concrete, which is very difficult to accomplish in a single pour, and it only took four hours to complete.
3.1 MG Fully Buried Water Storage Tank White River N. Water Treatment Plant
Indianapolis, IN
As part of an expansion of their White River North Water Treatment Plant, the Indianapolis Water Company retained J&CA to design a chlorine contact clearwell. This is a rectangular post-tensioned concrete structure with rounded corners. This shape was pioneered by J&CA to provide maximum use of the limited amount of space while at the same time providing the benefits of post-tensioned construction. It has horizontally and vertically post-tensioned walls, and a post-tensioned two-way flat plate mat foundation, designed for six feet of water uplift. In addition, this tank has a post-tensioned two way flat plate roof and is fully buried, with three feet of backfill over the roof to help resist floating in a tank-empty situation. The corners are rounded to a 40-foot inside radius to avoid wall and roof cracking.