ARIZONA MINING PERMITTING GUIDE - AZGS Document Repository

Above-Ground Fuel Storage - Continued
Arizona Mining Permitting Guide
SUPPORTS, FOUNDATIONS, AND ANCHORAGE:
Tanks at grade shall rest on foundations made of concrete, masonry, piling or protected steel.
(UFC 79.505, 29, C.F.R. 1910.106(b)(5)(i) and (iv))
Tank foundations shall be designed to minimize corrosion and the possibility of uneven
settling of the tank. (UFC 79.505)
Tanks above grade shall be securely supported. Their foundations shall be of concrete,
masonry or protected steel. (If steel is more than 12 inches high.) (UFC 79,505(b))
Where a tank is located in an area that is subject to flooding, consult 29 C.F.R. 1910.106 (vi).
In General, each horizontal tank so located that more than 70 percent of its storage capacity
will be submerged during flood stage, shall be anchored, attached to a foundation of concrete
or of steel and concrete of sufficient weight to provide adequate load for the tank when filled
with flammable liquid and submerged by flood waters to the established flood stage, or
adequately secured by other means. (29 C.F.R. 1910.106 (vi)(d)).
DRAINAGE & DIKES FOR ABOVE-GROUND TANKS:
The area surrounding a tank or group of tanks shall be provided with drainage or shall be
diked to prevent accidental discharge of liquid from entering adjacent tanks, adjoining
property or reaching water-ways. (UFC 79.507 (a))
Drainage:
Where protection of adjacent tanks, adjoining property or waterways is by means of a natural
or man-made drainage system, such system shall comply with the following:
Drainage shall be provided at a slope of not less than one percent away from the tank toward
an impounding basin or an approved means of disposal having a capacity greater than that of
the largest tank served. This termination area and the route of the drainage system shall be so
located that a fire occurring in the drainage system will not seriously endanger tanks or
adjoining property. (UFC 79.507 (b))
Dikes:
The volumetric capacity of the diked area shall be not less than the greatest amount of liquid
that can be released from the largest tank within the diked area. The capacity of the diked area
enclosing more than one tank, shall be calculated by deducting the volume of the tanks other
than the largest tank below the height of the dike. (UFC 79.507 (c) (1))
Walls of the diked area shall be of earth, steel, concrete, or solid masonry, all to be designed
to be liquid tight and to withstand a full hydrostatic head. Earthen walls three feet or more in
height shall have a flat section at the top of not less than two feet wide. The minimum
distance between tank and toe of the interior dike walls shall be at least five feet. (UFC 79.507
(c) (2))
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