Health and Safety

CHAPTER 23-28.28

SECTION 23-28.28-9

§ 23-28.28-9 Standards for use of explosives.

(a) All licensees under this chapter, when using any explosives, shall not exceed the standards of distance, amount of charge, maximum earth vibration, and maximum air shock as set forth in the United States department of the interior bureau of mines report of investigators number 8507 which is entitled "Structure Response and Damage Produced by Ground Vibration from Surface Mines Blasting", and any amendment and/or modifications thereof, which standards are incorporated herein by reference.

(b) Blasting limits. No licensee shall use an explosive weight in pounds per delay in excess of the formula of the distance to the nearest structure in feet, divided by the factor of seventy (70), multiplied by itself, [W = (D/70) squared], except when seismograph monitoring as set forth in subsection (c).

(c) Seismograph required. Each licensee shall be required to perform a seismograph test at the nearest structure to the blast prior to and during any blasting that would exceed the limits as set forth in subsection (b).

(d)(1) Seismic limits. At the structure nearest to the blast, the peak particle velocity in any direction at frequencies between 2.5 and 10 Hertz shall not exceed 0.5 inches per second, and at each frequency, f, greater than 10 Hertz, the peak particle velocity shall not exceed 0.05f inches per second up to a maximum of 2 inches per second. In addition, at the nearest structure no air-shock (sound) reading shall exceed one hundred and thirty-four (134) decibels using a 0.1-Hz, high-pass system, or exceed one hundred and thirty-three (133) decibels using a 2-Hz high-pass system or exceed one hundred and twenty-nine (129) decibels using a 5-Hz or 6-Hz high-pass system.

(2) If the licensee is blasting within the allowed limits as dictated under subsection (b), but is found in excess of the seismic limits of this subsection, the licensee shall reduce the amount of explosives per delay, or adjust the operation to comply with the limits as dictated by this subsection.

History of Section.
(P.L. 1979, ch. 313, § 2; P.L. 1994, ch. 120, § 1.)