In high water table conditions, what installation precaution helps prevent the UST from floating?

• A. Use tie-down straps or deadman anchors
• B. Lay the tank flat on its side
• C. Paint the tank bright colors
• D. Install in a hillside

Answer: (A)

When groundwater is high, the tank can become buoyant and try to float upward because water surrounding the tank reduces its effective weight. The way to prevent this is to add downward restraint that holds the tank in place regardless of buoyant forces. Tie-down straps or deadman anchors do exactly that: they anchor the tank to a stable in-ground or foundation point, absorbing the upward buoyant force from the surrounding saturated soil and water. Properly installed restraints, with appropriate materials and tension, keep the UST fixed in place and prevent flotation.

The other options don’t address buoyancy: laying the tank on its side does not stop upward movement and can create other installation problems; painting the tank doesn’t affect anchorage or buoyancy; installing on a hillside doesn’t inherently prevent flotation.