759.05 BLASTING OPERATIONS.
(a) Blasting operations shall be conducted only under the supervision of a qualified blaster. A qualified blaster and at least one other person shall be physically present at the detonation of a blast. Only the qualified blaster may detonate or give the command to detonate a blast.
(b) Blasting Schedule; Written Schedule. Written notice of the exact time and place of the use of explosives shall be given to both the Safety Director or his/her designee and seismologist at least forty-eight hours before such explosives are used. It shall be the duty of the seismologist to attend all such use of explosives on the date and at the time and place, and to notify the permit holder or licensee of any alternative date and time in the event the same is necessary to be rescheduled. The seismologist shall issue written reports on each and every blasting event to the Safety Director or his/her designee and the permit holder, licensee and/or contractor, which reports shall include comments upon compliance with regulations and standards herein established. These reports shall be filed with the Safety Director or his/her designee within twenty-four hours after each blasting event, or at the latest, prior to the next blasting event, if same occurs prior to the expiration of twenty-four hours.
(c) Hours of Blasting. No blasting operations shall be conducted within the corporate limits except on weekdays, which are not otherwise legal holidays or Sundays, and only then between the hours of 9:00 a.m. and 4:30 p.m., provided, however, that in the event the Safety Director or his/her designee agree that an emergency situation exists, such hours and times of blasting may be specifically varied to counteract such emergency.
(d) Blasting Access Control and Warnings. The permit holder shall conspicuously place signs reading "Blasting Area" along the perimeter of any blasting area when the perimeter is within 100 feet of any public road and/or right of way, as well as at the edge of all blasting areas along access and haul roads within the permit area.
For each blast, the qualified blaster conducting the blast shall define the limits of the blasting area where danger of flyrock exists. The permit holder shall be responsible for controlling access to the blasting area to prevent the presence of unauthorized persons at least ten minutes before each blast and until the qualified blaster has determined that no unusual post-blast hazards exist and access to and travel within the blasting area can safely resume.
(e) Ground Vibration Specifications. Blasting operations shall be so conducted that ground vibrations measured at the nearest structure or building, supporting towers and appurtenances, do not exceed a peak particle velocity on any of the three mutually perpendicular planes of motion, i.e., vertical, longitudinal or transverse.
The blasting shall be conducted so that the low frequency ground vibration does not exceed Modified Figure B-1, Bureau of Mines, RI 8507, set forth below:
(See Code Book for illustration)
(f) Air Blast Effects. No air blast shall exceed the maximum limits of 133 decibels at no more than two Hertz flat response at any dwelling, public or commercial building, school, church or community or institutional building. All air blast measuring systems shall have at least a flat frequency response range from two Hertz to 200 Hertz.
(g) Fly Rock Control. "Fly rock" shall be considered as any rock, mud and/or debris which may travel the air or along the ground as a result of blasting. Fly rock shall be controlled by the permit holder by the use of approved blasting matting in such a manner so as to prevent "flyrock" from occurring as a result of any blast.
(Ord. 1990-177. Passed 12-26-90.)