30 CFR § 56.4202
Fire hydrants
July 29, 2020
If fire hydrants are part of the mine's firefighting system, the hydrants shall be provided with—
(a) Uniform fittings or readily available adapters for onsite firefighting equipment;
(b) Readily available wrenches or keys to open the valves; and
(c) Readily available adapters capable of connecting hydrant fittings to the hose equipment of any firefighting organization relied upon by the mine.