Current through Register Vol. 54, No. 45, November 9, 2024
Section 87.127 - Use of explosives: surface blasting requirements(a) Blasting shall be conducted between sunrise and sunset, at times announced in the blasting schedule, except that mine opening blasting conducted after the second blast, for that mine opening, may be conducted at any time of day or night as necessary to maintain stability of the mine opening to protect the health and safety of mineworkers. For mine opening blasting conducted after the second blast, for that mine opening, the Department may approve ground vibration and airblast limits at a dwelling, public building, school, church or commercial or institutional structure, that are less stringent than those specified in subsection (e) or (m) if consented to, in writing, by the structure owner and lessee, if leased to another party. (b) The Department may specify more restrictive time periods, airblast or ground vibration limits, based on public requests or other relevant information, according to the need to adequately protect the public from the adverse affects of ground vibration, airblast or safety hazards.(c) Warning and all-clear signals shall be different in pattern, audible with a range of 1/2 mile from the point of the blast, sounded before and after each blast. Persons who work within the 1/2 mile of the blasting area shall be notified of the meaning of the signals through appropriate instructions. These instructions shall be periodically delivered or otherwise communicated in a manner which can be reasonably expected to inform these persons of the meaning of the signals. A person who conducts blasting incident to surface mining activities shall:(1) When a blast is about to be fired, give sufficient warning that persons approaching the blast area may be warned of the danger and be given ample time to retreat a safe distance from the blast area.(2) When electric blasting operations are located near highways or other public ways, erect signs at least 500 feet from the blast area reading: BLAST AREA-SHUT OFF ALL TWO-WAY RADIOS. The letters of these signs shall be at least 4 inches in height on a contrasting background.(3) Place at the entrances to the permit area from public roads or highways conspicuous signs which state "Warning. Explosives in Use" which clearly explain the blast warning and all clear signals that are in use and which explain the marking of blasting areas and charged holes within the permit area.(d) Access to an area possibly subject to flyrock from blasting shall be controlled to protect the public and livestock. Access to the area shall be controlled to prevent the presence of livestock or unauthorized personnel during blasting and until an authorized representative of the person who conducts the surface mining activities has reasonably determined:(1) That no unusual circumstances, such as imminent slides or undetonated charges, exist.(2) That access to and travel in or through the area can be safely resumed.(e) Airblast shall be controlled so that it does not exceed the level specified in this subsection at a dwelling, public building, school, church or commercial or institutional structure, unless the structure is located on the permit area when the structure owner and lessee, if leased to another party, have each signed a waiver relieving the operator from meeting the airblast limitations of this subsection. (1) The maximum allowable airblast level is 133 dBL.(2) If necessary to prevent damage, the Department will specify lower maximum allowable airblast levels than those of this subsection for use in the vicinity of a specific blasting operation. The measuring systems used shall have a flat response of at least 200 Hz at the upper end. The Type 1 sound level meter shall use the slow response C- weighted network and shall meet American National Standards Institute (ANSI) S1.4-1971 specifications. The ANSI S1.4-1971 is incorporated by reference.(3) The operator shall conduct periodic monitoring to ensure compliance with the airblast standards. The Department may require an airblast measurement of blasts, and may specify the location of the measurements.(f) Requirements for blasting are as follows: (1) Public highways and entrances to the operation shall be barricaded and guarded by the operator if the highways and entrances to the operations are located within 800 feet of a point where a blast is about to be fired. The operator may use an alternative measure to this requirement if the operator demonstrates, to the Department's satisfaction, that the alternative measure is at least as effective at protecting persons and property from the adverse affects of a blast. Alternative measures are measures such as: (i) Slowing or stopping traffic in coordination with appropriate State or local authorities, including local police.(ii) Using mats to suppress fly rock.(iii) Designing the blast to prevent damage or injury to persons and property located on the public highways or at the operation's entrances by using design elements such as: (A) Orienting the blast so that the direction of relief is away from public highways or operation entrances.(B) Adjusting blast design parameters including: (I) The diameter of holes.(III) The number of holes.(IV) The amount and type of explosive.(V) The burden and spacing.(VI) The amount and type of stemming.(2) When a blast is about to be fired within 200 feet of a pipeline, the operator shall exercise necessary caution as needed for the protection of the pipeline. The operator shall notify the owner of the line of the operator's intention to blast, giving a description of the precautionary measures that will be taken.(3) When blasting is to be done within 1,000 feet of schools or public buildings, it shall be done only during the time approved by the Department. Prior to the blasts, the operator or foreman in charge of the blasting operation shall, within 24 hours prior to the blast, notify persons within this area that a blast is to be detonated. Approval of the method of notification shall be obtained from the Department prior to commencing blasting.(4) Blasting may not be done within the confines of an area of 300 feet of an occupied dwelling unless prior written consent of the property owner has been obtained.(5) Flyrock, including blasted material traveling along the ground, may not be cast from the blasting vicinity more than one-half the distance to the nearest dwelling or other occupied structure and in no case beyond the permit boundary, or beyond the area or regulated access required under subsection (d).(6) Notwithstanding other provisions in this part, no blasting, whether of overburden or of coal, may be done or performed in a manner and under circumstances or conditions to eject debris into the air, to constitute a hazard or danger or do harm or damage to persons or property in the area of the blasting.(g) Blasting shall be conducted to prevent injury to persons, damage to public or private property outside the permit area, adverse impacts on an underground-mine, or availability of groundwaters or surface waters; and shall be prohibited in cases when the effect of the blasting is liable to change the course or channel of a stream.(h) In blasting operations, except as otherwise authorized in this section, the maximum peak particle velocity may not exceed the values approved in the blast plan required by § 87.64 (relating to blasting plan) at the location of a dwelling, public building, school, church, commercial or institutional building or other structure. Peak particle velocities shall be recorded in three mutually perpendicular directions. The maximum peak particle velocity shall be the largest of any of three measurements. The Department may reduce the maximum peak particle velocity allowed, if it determines that a lower standard is required because of density of population or land use, age or type of structure, geology or hydrology of the area, frequency of the vibration or other factors.(i) The maximum peak particle velocity limitation of subsection (h) does not apply at structures located on the permit area when the owner and lessee, if leased to another party, of the structure have each signed a waiver releasing the vibration limit. The waiver shall be clear, knowing and specific. This waiver shall be submitted to the Department prior to the firing of a blast which exceeds the current vibration limit, as stated in this section or the blast plan.(j) When seismographs are not used to monitor peak particle velocity, the maximum weight of explosives to be detonated within an 8 millisecond period may be determined by the formula W = (D/Ds)2 where W equals the maximum weight of explosives, in pounds, that can be detonated in any 8 millisecond period or greater, D equals the distance, in feet, from the blast to the nearest dwelling, school, church, commercial or institutional building and Ds equals the scaled distance factor . The development of a modified scaled-distance factor may be authorized by the Department 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 so that the particle velocity of the predicted ground vibration will not exceed the prescribed maximum allowable peak particle velocity of subsection (n) at a 95% confidence level.(k) When a seismograph is used to monitor the peak particle velocity, a seismograph record shall be obtained for each blast and within 30 calendar days become part of the blast record required in § 87.129 (relating to use of explosives: record of blasting operations). The seismograph record shall be analyzed by an independent party qualified in the analysis of seismic data.(l) The Department may require a seismograph record of blasts and may specify the location at which the measurements are taken.(m) The maximum ground vibration may not exceed the following limits at the location of a dwelling, public building, school, church or community or institutional building: | Distance (D), from the blasting site, in feet | Maximum allow-able peak particle velocity (Vmax) for ground vibration, in inches/second1 | Scaled-distance factor to be applied without seismic monitoring (Ds)2 |
| 0 to 300 | 1.25 | 50 |
| 301 to 5,000 | 1.00 | 55 |
| 5,001 and beyond | .75 | 65 |
1Ground 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.
2Applicable to the scaled-distance equation of subsection (j).
(n) The Department will not permit blasting to be conducted until: (1) Blasting plans, under § 87.64 (relating to blasting plan), are approved by the Department and the approved blasting plan is returned to the operator.(2) Notification of completion of requested preblasting surveys, under § 87.125 (relating to use of explosives: preblasting survey), is received by the Department.(3) Copy of the proof of publication of each blasting schedule, under § 87.126 (relating to use of explosives; public notice of blasting schedule), is received by the Department.(o) An operator may use Figure 1, the blast level chart, to determine the maximum allowable ground vibration. If Figure 1 is used, the operator shall provide a seismograph record including both the particle velocity time-history (wave form) and the particle velocity and vibration frequency levels for each blast. Click to view image
(1) The vibration frequency shall be displayed and analyzed over the frequency range of 1 Hz through 100 Hz.(2) The permittee shall obtain Department approval of the analytical method used to determine the predominant frequency before applying this alternative criterion.The provisions of this §87.127 adopted December 19, 1980, 10 Pa.B. 4789, effective 7/31/1982, 12 Pa.B. 2382; amended July 30, 1982, 12 Pa.B. 2473, effective 7/31/1982, 12 Pa.B. 2382; amended June 15, 1990, 20 Pa.B. 3383, effective 7/27/1991, 21 Pa.B. 3316; amended December 15, 1995, effective 12/16/1995, 25 Pa.B. 5821; amended May 8, 1998, effective 5/9/1998, 28 Pa.B. 2227; amended August 8, 2008, effective 8/9/2008, 38 Pa.B. 4355.The provisions of this §87.127 amended under the Surface Mining Conservation and Reclamation Act (52 P. S. §§ 1396.1-1396.19a); The Clean Streams Law (35 P. S. §§ 691.1-691.1001); and section 1920-A of The Administrative Code of 1929 (71 P. S. § 510-20); amended under section 4.2 of the Surface Mining Conservation and Reclamation Act (52 P. S. § 1396.4b); section 11 of the Noncoal Surface Mining Conservation and Reclamation Act (52 P. S. § 3311); and sections 1917-A and 1920-A of The Administrative Code of 1929 (71 P. S. §§ 510-17 and 510-20).
This section cited in 25 Pa. Code § 87.64 (relating to blasting plan); 25 Pa. Code § 87.76 (relating to surface mining near underground mining); 25 Pa. Code § 87.92 (relating to signs and markers); 25 Pa. Code § 90.43 (relating to blasting plan); 25 Pa. Code § 90.92 (relating to signs and markers); and 25 Pa. Code § 90.148 (relating to blasting).