30 CFR § 75.1107-7 Water spray devices; capacity; water supply; minimum requirements.
(a) Where water spray devices are used on unattended underground
equipment the rate of flow shall be at least 0.25 gallon per minute per
square foot over the top surface area of the equipment and the supply of
water shall be adequate to provide the required flow of water for 10
minutes.
(b) Where water spray devices are used for inundating attended
underground equipment the rate of flow shall be at least 0.18 gallon per
minute per square foot over the top surface area of the equipment (excluding
conveyors, cutters, and gathering heads), and the supply of water shall be
adequate to provide the required flow of water for 10 minutes.
(c) Where water is used for internal injection on attended equipment
the total quantity of water shall be at least 4.5 gallons times the number of
hazardous locations; however, the total minimum amount of water shall not be
less than the following: