§ 13-20. Blasting records.
(a)
All users of explosives shall keep daily records for a period of three (3) years of all blasting performed on a form or forms prescribed by the Director of the Public Works Department which shall be made available at reasonable times and hours at a location approved by the Director for inspection by him or her or his or her designee and signed copies of such records shall be furnished to the Director within seven (7) days from the date of the actual blast.
(b)
The minimum data to be shown on such record shall be:
(1)
Name and location of blasting site.
(2)
Date and time of firing.
(3)
Arrangements and spacing of charges.
(4)
The amount of explosive for each blast or delay series.
(5)
Delay interval.
(6)
Name of person in charge of loading and firing.
(7)
County user permit number, and signature and title of person making report.
(c)
(1) Records of instrument readings taken as required by Section 13-18 shall be analyzed by an independent recognized seismologist or vibration engineer and shall be reported by him or her to the Director of Public Works with full and complete details within thirty (30) days from the date of the actual blast or upon demand. This seismologist or vibration engineer shall be qualified in blast monitoring and shall have documented prior experience within this field.
(2)
All original records will be the property of the blasting company with a copy certified by a seismologist or vibration engineer furnished to the Director of Public Works.
(d)
Unless otherwise authorized by the Director, all instruments used for compliance with this chapter shall meet the following minimum specifications:
(1)
Seismic frequency range: 2 to 200HZ ( 3HZ)
(2)
Acoustic frequency range: 2 to 200HZ ( 1db)
(3)
Velocity range: 0.02 to 4.0 inches/second
(4)
Sound range: 110 to 140 db linear
(5)
Transducers: Three mutually perpendicular axis
(6)
Recording: Provide time history of waveform.
(7)
Each instrument shall be calibrated annually, preferably on a shake table, and such calibration certified except for instruments which are certified as self-calibrating.
(e)
A copy of preblast inspection documentation as required by Section 13-15(b) and (c) shall be forwarded, in its entirety, to the Director upon demand.
(Ord. No. 96-45, § 1, 3-19-96)