All blasting operations shall be conducted as follows:
A. Compliance with this chapter and all applicable laws. No person shall conduct any blasting operations in unincorporated Pima County except as permitted under this chapter. Storage, transportation and blasting procedures shall comply with this chapter, all applicable federal, state and local laws, ordinances and regulations.
B. Blasting contractor to remain on-site.
1. The approved blasting contractor shall:
a. Personally supervise all aspects of the blasting operation.
b. Be physically present at the blasting site area when the explosive materials are loaded into the ground and remain in attendance until the blasting operation is completed.
2. There shall be no change in the blasting contractor for blasting operations for which a blasting permit has been issued without the express approval of the county engineer.
C. Blasting site supervision. Before a blast is initiated, the blasting contractor shall make sure that surplus explosives are in a safe place, that persons and vehicles are at a safe distance or under sufficient cover, and that a loud warning signal has been sounded.
D. Blue-staking. Prior to conducting any blasting operations, the contractor shall request that the blasting area be blue-staked.
E. Notices.
1. Notice of blasting operations shall be provided to:
a. Any and all utility companies servicing the blasting area. A copy of the blasting plan shall be given sufficiently in advance to enable the companies to advise the contractor of any precautions that should be taken to protect their facilities from damage. Notice of specific blasts shall be given a minimum of 24 hours prior to conducting the blasting operation.
b. The owner and occupant of each structure within a 500-foot radius of the blasting site. The notification must be given not less than twenty-four hours nor more than one week prior to any blasting operation and shall be in a form approved by the county engineer.
c. Pima County sheriff's department bomb squad, the Pima County sheriff's department communications, and the Pima County department of transportation field engineering twenty-four hours prior to blasting.
d. The fire chief of the fire district within which the blasting site is located and of any fire district within 500 feet of the blasting site twenty-four hours prior to a scheduled blasting operation.
2. The minimum notice periods established by this chapter may be reduced to a lesser period if the county engineer determines that special circumstances warrant such reduction in time.
3. The blasting contractor shall erect special signs to warn the public of ongoing blasting operations. Signs shall be located and maintained so as to be clearly visible to the public during all critical blasting operations.
F. Hours of operations. Blasting operations shall be conducted on weekdays, between the hours of 8:00 a.m. and 5:00 p.m., but in no event later than one-half hour before sunset. No blasting operations shall be conducted at any time on Saturday, Sunday, or legal holiday, except under extraordinary circumstances and by special written permission of the county engineer.
G. Loading of explosives. Explosives shall not be loaded into the ground until a valid blasting permit, issued by the Pima County, is available on site.
H. Precautions against accidental detonation. The following are required as precautions against accidental detonation of explosives:
1. The posting of signs reading, "BLASTING ZONE 1000 FEET" and "TURN OFF 2-WAY RADIOS" on all roads within 1,000 feet of blasting operations where electric detonators are used.
2. Blasting operations shall not be conducted during the approach and progress of an electrical storm.
3. The blasting contractor shall periodically check for electricity or stray currents in areas where it is likely that such conditions may exceed safe limits for blasting operations.
4. Except for the lighting of the safety fuse for blasting operations, smoking, the carrying of matches, or the use of matches, lighters, spark producing devices or the presence of any open flame are prohibited within 50 feet of where explosive materials are being stored or used.
I. Use of a blasting mat and flagmen. The county engineer may require use of a blasting mat if blasting occurs within close proximity to a structure or installation, such as a road or railway that could be damaged by rocks or other projectiles. Where blasting occurs close to a road or railway, flagmen shall be stationed at the time of the blast at a sufficient distance from the blasting operation to halt approaching vehicles.
J. Seismic and air blast monitoring. Seismic and air blast monitoring shall be conducted and recorded in the blasting log for each blast.
1. For blasts occurring farther than 500 feet from the nearest structure, the blasting contractor may conduct the required monitoring.
2. For blasts occurring within 500 feet of any structure, the seismic and air-blast monitoring shall be conducted by an independent testing agency approved by the county engineer.
K. Blasting log. An accurate blasting log shall be maintained by the blasting contractor.
1. The log shall contain the following information:
a. The blasting plan.
b. The county permit number.
c. The location of the blasting operation.
d. The date and time of each blasting occurrence.
e. The seismic and air blast readings received.
f. The name of the individual who conducted the seismic monitoring.
g. The type of explosive, pounds of explosive per delay, drill hole layout, depths and diameters of drill holes, timing and delay pattern, anticipated peak particle velocities, and scaled distance.
h. Any and all known damage or injury that occurred as a result of the blast. If no known damage or injury occurred, the log shall so state.
i. Any other pertinent information required by the county engineer.
2. A current copy of the blasting log shall be available at the blast site, and at the blasting contractor's office. If the blasting contractor does not have a local office, the blasting log shall be kept at the office of the general contractor for the project.
3. A copy of the blasting log shall be submitted to the county engineer
a. After each blast, if the blast site is within 500 feet of any structure as identified on the blasting plan. No succeeding blasting shall occur without the permission of the county engineer. Subsequent blasting shall not proceed until compliance with all requirements of this ordinance are demonstrated in the submitted log. Failure to submit the daily blasting log is cause for the revocation of the blasting permit.
b. Within seven calendar days after the end of blasting operation, the expiration of the blasting permit, or when requested by the county engineer. Failure to submit the blasting log within the required time frame may result in the revocation or suspension of the approved blasting contractor certification.
L. Scaled distance. The following scaled distances shall apply when structures are within 500 feet of the proposed blast:
Maximum | Minimum | Scaled Distance |
500 | 300 | 75 |
300 | 100 | 100 |
100 | — | express approval of the county engineer |
M. No blasting within 100 feet of a structure. Notwithstanding any other provision of this chapter, no blasting shall occur within 100 feet of a residence without the specific permission of the county engineer.
N. No intoxicants. No person under the influence of intoxicants, narcotics or controlled substances shall handle or use explosive materials in any manner.
O. Transportation of explosives. Explosives shall be transported to the blasting site in a magazine which meet federal requirements for a type 2 explosives storage facility.
P. One-day supply of explosive materials on-site
1. No more than a one-day supply of explosives shall be brought on to the blasting site. One-day supply of explosive materials means: the quantity required to conduct one-day blasting operations only.
2. No explosive materials, including blasting wires and caps, shall be permitted to be stored overnight on the blasting site.
3. Explosive materials shall not be left undetonated in the ground overnight.
Q. On-site storage. Explosive materials shall be stored in type 3 magazine(s) also known as a "day-box" as required under federal explosives storage requirements.
1. Detonators shall not be stored with high explosives. Explosives and detonating devices shall be stored in magazines separated by an earth revetment.
2. Explosive material storage shall be located a minimum of a 300-foot radius from the site of the blast.
3. At no time shall the explosive materials be left unattended. The blasting contractor shall have, at all times, an unobstructed view of the on-site explosive material storage, and shall ensure that the storage magazine is locked and not accessible to unauthorized persons.
R. Post blast survey.
1. After a blast, all wires and or nonelectric leads shall be carefully traced and a search made for any unexploded explosive materials.
2. All misfires shall be investigated by the blasting contractor who shall determine a safe method of disposal.
(Ord. 1997-58 § 1, 1997)