La. Admin. Code tit. 43 § XV-5361
Current through Register Vol. 50, No. 11, November 20, 2024
Section XV-5361 - Use of Explosives: Control of Adverse EffectsA. General Requirements. Blasting shall be conducted to prevent injury to persons, damage to public or private property outside the permit area, adverse impacts on any underground mine, and change in the course, channel or availability of surface water or ground water outside the permit area.B. Airblast 1. Limits a. Airblast shall not exceed the maximum limits listed below at the location of any dwelling, public building, school, church, community or institutional building outside the permit area, except as provided in §5361 ELower Frequency Limit of Measuring System, in Hz (+/- 3 dB) | Maximum Level (in dB) |
0.1 Hz or lower-flat response 1 | 134 peak |
2 Hz or lower-flat response | 133 peak |
6 Hz or lower-flat response | 129 peak |
C-weighted-slow response n 1 | 105 peak dBC |
1 Only when approved by the office.
b. If necessary to prevent damage, the office shall specify lower maximum allowable airblast levels than those of §5361. B.1.a for use in the vicinity of a specific blasting operation.2. Monitoring a. The operator shall conduct periodic monitoring to ensure compliance with the airblast standards. The office may require airblast measurement of any or all blasts and may specify the locations at which such measurements are taken.b. The measuring systems shall have an upper-end flat-frequency response of at least 200 Hz.C. Flyrock. Flyrock traveling in the air or along the ground shall not be cast from the blasting site: 1. more than one-half the distance to the nearest dwelling or other occupied structure;2. beyond the area of control required under §5359 C; or3. beyond the permit boundary.D. Ground Vibration1. General. In all blasting operations, except as otherwise authorized in §5361 E, the maximum ground vibration shall not exceed the values approved in the blasting plan required under §2707 The maximum ground vibration for protected structures listed in §5361. D.2.a shall be established in accordance with either the maximum peak-particle-velocity limits of §5361. D 2, the scaled-distance equation of §5361. D 3, the blasting-level chart of §5361. D 4, or by the office under §5361. D.5 All structures in the vicinity of the blasting area not listed in §5361. D.2 a, such as water towers, pipelines and other utilities, tunnels, dams, impoundments and underground mines, shall be protected from damage by establishment of a maximum allowable limit on the ground vibration, submitted by the operator in the blasting plan and approved by the office.2. Maximum Peak Particle Velocity a. The maximum ground vibration shall not exceed the following limits at the location of any dwelling, public building, school, church, community or institutional building outside the permit area. Distance (D) from the Blasting Site, in Feet | Maximum Allowable Peak Particle Velocity (V max) for Ground Vibration, in Inches/Second 1 | Scaled Distance Factor to be Applied without Seismic Monitoring 2 (Ds) |
0 to 300 | 1.25 | 50 |
301 to 5,000 | 1.00 | 55 |
5,001 and beyond | 0.75 | 65 |
1 Ground vibration shall be measured as the particle velocity. Particle velocity shall be recorded in three mutually perpendicular directions. The maximum allowable peak particle velocity shall apply to each of the three measurements.
2 Applicable to the scaled-distance equation of §5361. D.3 a
b. A seismographic record shall be provided for each blast. 3. Scaled-Distance Equation a. An operator may use the scaled-distance equation, W = (D/Ds)2, to determine the allowable charge weight of explosives to be detonated in any 8-millisecond period, without seismic monitoring; where W = the maximum weight of explosives, in pounds; D = the distance, in feet, from the blasting site to the nearest protected structure; and Ds = the scaled-distance factor, which may initially be approved by the office using the values for scaled-distance factor listed in §5361. D.2 ab. The development of a modified scaled-distance factor may be authorized by the office on receipt of a written request by the operator, supported by seismographic records of blasting at the minesite. The modified scaled-distance factor shall be determined such that the particle velocity of the predicted ground vibration will not exceed the prescribed maximum allowable peak particle velocity of §5361. D.2 a, at a 95-percent confidence level.4. Blasting-Level Chart a. An operator may use the ground-vibration limits in Figure 1 to determine the maximum allowable ground vibration. Click Here To View Image
Figure 1. Alternative Blasting Level Criteria
(Source: Modified from Figure B-1, Bureau of Mines R18507)
b. If the Figure 1 limits are used, a seismographic record including both particle velocity and vibration-frequency levels shall be provided for each blast. The method for the analysis of the predominant frequency contained in the blasting records shall be approved by the office before application of this alternative-blasting criterion.5. The maximum allowable ground vibration shall be reduced by the office beyond the limits otherwise provided by this Section, if determined necessary to provide damage protection.6. The office may require an operator to conduct seismic monitoring of any or all blasts or may specify the location at which the measurements are taken and the degree of detail necessary in the measurement. E. The maximum airblast and ground-vibration standards of §5361. B and D shall not apply at the following locations: 1. at structures owned by the permittee and not leased to another person; or2. at structures owned by the permittee and leased to another person, if a written waiver by the lessee is submitted to the office before blasting.La. Admin. Code tit. 43, § XV-5361
Promulgated by the Department of Natural Resources, Office of Conservation, LR 5:395 (December 1979), amended LR 14:441 (July 1988), LR 20:447 (April 1994).AUTHORITY NOTE: Promulgated in accordance with R.S. 30:901-932.