Tirey & Associates, P.C.

Consulting Structural Engineers

Project: Waterville Estates Village District New Water Tank

Location: Campton, New Hampshire

Completion Date: June, 2009

 

A new two cell, 200,000 gallon concrete water tank with attached pumphouse was constructed on top of a narrow ridgeline to provide water for a small community of private homes. The tank is mostly buried in the ground in the middle of a small cul-de-sac, which required ledge removal prior to the tank construction.

 

The tank consists of reinforced, cast-in-place concrete walls and base slab, and a precast concrete plank roof. As with any liquid containing structure, designing for crack control in the concrete is very important. Providing construction phase services which include site visits to inspect reinforcing steel placement, forms and waterstop is critical to help ensure a tight structure. Following construction of the tank walls, each cell of the tank was filled with water to check for liquid tightness using the Hydrostatic Test for Open or Covered Tanks Using Visual Inspection Only method. Upon passage of the leak test and any minor leak repairs, the precast plank roof was placed on the walls with a concrete topping placed on the plank. The top of the tank has a waterproof membrane covering it, thereby preventing surface water from entering the tank and allowing placement of a small layer of soil fill over the tank to make it less conspicuous.