ARIZONA MINING PERMITTING GUIDE - AZGS Document Repository

Above-Ground Fuel Storage - Continued
Arizona Mining Permitting Guide
Maximum height of the dikes walls shall be six feet, unless otherwise approved by the
Arizona State Mine Inspector. (UFC 79.507 (c) (3))
Each diked area containing two or more tanks shall be subdivided by drainage channels
leading to an impounding basin or by intermediate curbs or spill dikes in order to prevent
spills from endangering adjacent tanks within the diked area. Tanks storing class III liquids do
not require special drainage. (UFC 79.507 (c) (5))
Provisions shall be made for draining or removing excess water from a drainage system or
diked area. Such drains shall not discharge to adjoining property, natural water courses, public
sewers or public drainage channels unless the drain is so designed as to prevent the release of
flammable or combustible liquids. (UFC 79.507 (d))
TANK VALVES:
Each connection to an above-ground tank located below normal liquid level or through which
a liquid can normally flow, shall be provided with an internal or external control valve located
as close as practicable to the shell of the tank. All valves at tanks to be impact-type valving.
(UFC Sec 79.508 (a))
Fuel lines shall be equipped with valves to cut off fuel at the source and shall be located and
maintained to minimize fire hazards. (R11-1-306)
VENTING & TANK CONNECTIONS:
Storage tanks shall be vented or otherwise constructed to prevent development of pressure or
vacuum as a result of filling, emptying, or atmospheric temperature changes. (30 C.F.R.
56.4430(a))
Every aboveground storage tank shall have some form of construction or device that will
relieve excessive internal pressure caused by exposure fires. (29 C.F.R. 1910.106 (2)(iv))
Normal vents shall be sized in accordance with nationally recognized engineering standards
or shall be at least as large as the filling or withdrawal connection, whichever is larger, but in
no case less than one and one quarter inch nominal inside diameter. (UFC 79.509 (a))
Vent pipe outlet shall be located so that the vapors are released at a safe point outside of
buildings and not less than 12 feet above the adjacent ground level. Vent outlets shall be
located so that flammable vapors will not be trapped by eaves or other obstructions and shall
be at least five feet from building openings or property lines. (29 C.F.R. 1910.106 (iv))
Filling and emptying connections shall be properly identified. (29 C.F.R.
1910.106(b)(2)(vii)(f))
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