(a) All blasting shall be conducted between sunrise and sunset.

1. (1) The Department may specify more restrictive time periods, based upon public requests or other relevant information, according to the need to adequately protect the public from adverse noise.

2. (2) Blasting may, however, be conducted between sunset and sun rise if:

   1. (A) A blast that has been prepared during the afternoon must be delayed due to the occurrence of an unavoidable hazardous condition and cannot be delayed until the next day because a potential safety hazard could result that cannot be adequately mitigated;
   2. (B) A complete written report of blasting at night is filed by the operator with the Department not later than three days after the night blasting. The report shall include the reasons for the delay in blasting, including why the blast could not be held over to the next day, when the blast was actually conducted, the warnings signs given, and a copy of the blast report required by Section 460:10-31-10.

(c) Access to an area possibly subject to flyrock from blasting shall be regulated 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 operator has reasonably determined:

1. (1) That no unusual circumstances, such as imminent slides or undetonated charges, exist; and
2. (2) That access to and travel in or through the area can be safely resumed.

(d) Except where lesser distances are approved by the Department, based upon a pre-blasting survey, seismic investigation, or other appropriate investigation, blasting shall not be conducted within:

1. (1) 300 feet of any building used as a dwelling, school, church, hospital, or nursing facility; or
2. (2) 500 feet of facilities including, but not limited to, disposal wells, petroleum or gas - storage facilities, municipal water-storage facilities, fluid transmission pipelines, gas or oil collection lines, or water and sewerage lines.
3. (3) Any mining operation actively mining on the effective date of these regulations which conducts blasting activities closer than the above distances is exempt from the provisions of (d) (1) and (d) (2) of this Section with regard to the structures or facilities to which these blasting operations take place.

(h) If blasting is conducted to prevent adverse impacts on any underground mine and changes in the course, channel, or availability of ground or surface water outside the permit area, then the maximum peak particle velocity limitation shall not apply at the following locations:

1. (1) At structures owned by the operator and not leased to another party; and
2. (2) At structures owned by the operator and leased to another party, if a writtenwaiver by the lessee is submitted to the Department prior to blasting.

(j) The maximum weight of explosives to be detonated within any 8-millisecond period may be determined by the formula W=(d/60)2 square where W = the maximum weight of explosives, in pounds, that can be detonated in any 8-millisecond period, and D = the distance, in the feet, from the blast to the nearest dwelling, school, church, or commercial or institutional building. For distances between 300 or 5,000 feet, using ANFO or the equivalent solution of the equation results in the following maximum weights:

1. (1) For distance of 300 feet, maximum weight is 25 pounds.
2. (2) For distance of 350 feet, maximum weight is 34 pounds.
3. (3) For distance of 400 feet, maximum weight is 44 pounds.
4. (4) For distance of 500 feet, maximum weight is 69 pounds.
5. (5) For distance of 600 feet, maximum weight is100 pounds.
6. (6) For distance of 700 feet, maximum weight is 136 pounds.
7. (7) For distance of 800 feet, maximum weight is 178 pounds.
8. (8) For distance of 900 feet, maximum weight is 225 pounds.
9. (9) For distance of 1000 feet, maximum weight is 278 pounds.
10. (10) For distance of 1,100 feet, maximum weight is 336 pounds.
11. (11) For distance of 1,200 feet, maximum weight is 400 pounds.
12. (12) For distance of 1,300 feet, maximum weight is 469 pounds.
13. (13) For distance of 1,400 feet, maximum weight is 544 pounds.
14. (14) For distance of 1,500 feet, maximum weight is 625 pounds.
15. (15) For distance of 1,600 feet, maximum weight is 711 pounds.
16. (16) For distance of 1,700 feet, maximum weight is 803 pounds.
17. (17) For distance of 1,800 feet, maximum weight is 900 pounds.
18. (18) For distance of 1,900 feet, maximum weight is 1,002 pounds.
19. (19) For distance of 2,000 feet, maximum weight is 1,111 pounds.
20. (20) For distance of 2,500 feet, maximum weight is 1,736 pounds.
21. (21) For distance of 3,000 feet, maximum weight is 2,500 pounds.
22. (22) For distance of 3,500 feet, maximum weight is 3,403 pounds.
23. (23) For distance of 4,000 feet, maximum weight is 4,444 pounds.
24. (24) For distance of 4,500 feet, maximum weight is 5,625 pounds.
25. (25) For distance of 5,000 feet, maximum weight is 6,944 pounds.

(l) Frequency level. The lower frequency limit Maximum level, of measuring system, in dB in Hz(+/-3 dB) must be the following:

1. (1) 0.1 Hz or lower-flat response must be 134 peak.
2. (2) 2 Hz or lower-flat response must be 133 peak.
3. (3) 6 Hz or lower-flat response must be 129 peak.
4. (4) C-weighted-slow response must be105 peak dBC.