30 CFR § 75.1321 Permits for firing more than 20 boreholes and for use of nonpermissible blasting units.
(a) Applications for permits for firing more than 20 boreholes in a
round and for the use of nonpermissible blasting units shall be submitted in
writing to the District Manager for the district in which the mine is located
and shall contain the following information:
(1) The name and address of the mine;
(2) The active workings in the mine affected by the permit
and the approximate number of boreholes to be fired;
(3) The period of time during which the permit will
apply;
(4) The nature of the development or construction for
which they will be used, e.g., overcasts, undercasts, track grading, roof
brushing or boom holes;
(5) A plan, proposed by the operator designed to protect
miners in the mine from the hazards of methane and other explosive gases
during each multiple shot, e.g., changes in the mine ventilation system,
provisions for auxiliary ventilation and any other safeguards necessary to
minimize such hazards;
(6) A statement of the specific hazards anticipated by the
operator in blasting for overcasts, undercasts, track grading, brushing of
roof, boom holes or other unusual blasting situations such as coalbeds of
abnormal thickness; and
(7) The method to be employed to avoid the dangers
anticipated during development or construction which will ensure the
protection of life and the prevention of injuries to the miners exposed to
such underground blasting.
(b) The District Manager may permit the firing of more than 20
boreholes of permissible explosives in a round where he has determined that
it is necessary to reduce the overall hazard to which miners are exposed
during underground blasting. He may also permit the use of nonpermissible
blasting units if he finds that a permissible blasting unit does not have
adequate blasting capacity and that the use of such permissible units will
create any of the following development or construction hazards:
(1) Exposure to disturbed roof in an adjacent cavity while
scaling and supporting the remaining roof prior to wiring a new series of
boreholes;
(2) Exposure to underburden boreholes where prior rounds
have removed the burden adjacent to a remaining borehole;
(3) Exposure to an unsupported roof while redrilling large
fragmented roof rock following the loss of predrilled boreholes during
earlier blasting operations; or
(4) Any other hazard created by the use of permissible
blasting units during underground development or construction.
(c) Permits shall be issued on a mine-by-mine basis for periods of
time to be specified by the District Manager.
(d) Permits issued under this section shall specify and include as a
condition of their use, any safeguards, in addition to those proposed by the
operator, which the District Manager issuing such permit has determined will
be required to ensure the welfare of the miners employed in the mine at the
time of the blasting permitted.
