§ 88.135. Blasting: surface blasting requirements.

 (a)  Blasting shall be conducted between sunrise and sunset.

 (b)  The Department may specify more restrictive time periods, based on other relevant information, according to the need to adequately protect the public.

 (c)  Warning and all-clear signals shall be different in pattern, audible within a range of 1/2 mile from the point of the blast, sounded before and after each blast. Each person within the permit 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 the persons of the meaning of the signals. Each person who conducts blasting incident to surface mining activities shall:

   (1)  Give sufficient warning when a blast is about to be fired, so that a person approaching within 500 feet of the blast area may be warned of the danger and be given ample time to retreat a safe distance from the blast area.

   (2)  Erect signs at least 500 feet from the blast areas reading: ‘‘BLAST AREA—SHUT OFF ALL TWO-WAY RADIOS’’ when electric blasting operations are located near highways or other public ways. The letters of these signs shall be not less than four inches in height on a contrasting background.

   (3)  Place at all 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 safety resumed.

 (e)  In all blasting operations, a scaled distance of 50 or numerically greater may be used to determine the maximum charge weight per delay interval of 8 milliseconds or greater without the use of seismic instrumentation.

 (f)  Blasting operations shall meet the following requirements:

   (1)  Public highways and all entrances to the operation shall be barricaded and guarded by the operator when the highways and entrances to the operations are located within 1,000 feet of any point where a blast is about to be fired.

   (2)  When a blast is about to be fired within 200 feet of a pipeline, the operator shall exercise necessary caution for the protection of the pipeline. The operator shall notify the owner of the line of his intention to blast, giving a description of the precautionary measures that will be taken under §  211.62 (relating to blasting in the vicinity of utility lines).

   (3)  No blasting may be done within the confines of an area of 300 feet of a public building or occupied dwelling unless prior written consent of the property owner has been obtained.

   (4)  Flyrock, including blasted material traveling along the ground, may not be cast from the blasting vicinity more than 1/2 the distance to the nearest dwelling or other occupied structure and in no case beyond the line of property owned or leased by the permittee, or beyond the area of regulated access required under subsection (d).

   (5)  Notwithstanding other regulations, no blasting, whether of overburden or of coal, may be done or performed in a manner and under such circumstances or conditions that eject debris into the air, as 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 in a manner to prevent injury to persons, damage to public or private property outside the permit area, adverse impacts on any underground mine, or availability of groundwaters or surface waters and shall be prohibited in all cases where the effect of the blasting is liable to change the course or channel of any stream.

 (h)  In all blasting operations, the maximum peak particle velocity may not exceed 2 inches per second at the location of any dwelling, public building, school, church or commercial or institutional building. Peak particle velocities shall be recorded in three mutually perpendicular directions—longitudinal, transverse and vertical. 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 blasts, or other factors. The sound pressure level may not exceed 130 dB linear at a frequency 6 Hz or lower.

 (i)  The maximum peak particle velocity limitation of this section do not apply at the following locations:

   (1)  At structures owned by the person conducting the mining activity, and not leased to another party.

   (2)  At structures owned by the person conducting the mining activity, and leased to another party, if a writter waiver by the lessee is submitted to the Department prior to the blasting.

 (j)  Where seismographs are not used to monitor peak velocity, the maximum weight of explosives to be detonated within any 8 millisecond period may be determined by formula W = (D/50² ) where W = the maximum weight of explosives, in pounds, that can be detonated in any 8 millisecond period, or greater and D = the distance, in feet, from the blast to the nearest dwelling, school, church or commercial institutional building.

 (k)  Where a seismograph is used to monitor the peak particle velocity a seismograph record shall be obtained for each blast.

 (l)  The use of a formula to determine maximum weight of explosives per delay for blasting operations at a particular site, may be approved by the Department if the peak particle velocity of 2 inches per second would not be exceeded.

 (m)  The Department may require a seismograph record of any or all blasts and may specify the location at which the measurements are taken.

   The provisions of this §  88.135 adopted December 19, 1980, 10 Pa.B. 4789, effective July 31, 1982, 12 Pa.B. 2382; amended March 30, 1984, 14 Pa.B. 1143, effective August 10, 1985, 15 Pa.B. 2872; amended January 4, 1985, effective immediately upon the approval by the Secretary of the United States Department of the Interior and publication thereof in the Pennsylvania Bulletin, 15 Pa.B. 13. Immediately preceding text appears at serial pages (92589) to (92592).

   This section cited in 25 Pa. Code §  88.82 (relating to signs and markers); and 25 Pa. Code §  88.493 (relating to minimum environmental protection performance standards).