Lower frequency limit of measuring system maximum level, in Hz (no more than - 3dB) Maximum Level1in dB 0.1 Hz or lower --flat response 2 134 peak.
1Airblast is a flat response from 4 to 125 Hz range, at 2hz airblast the microphone can have an error of no more than -3dB.
2 Only when approved by the Secretary
2 Hz or lower -- flat response 133 peak.
6 Hz or lower -- flat response 129 peak.
C-weighted--slow response 2 105 peak dBC.
Formula | Distance in Feet from |
the Blasting Site to the | |
Nearest Protected | |
Structure | |
W = (D/50)2 | 0 - 300 feet |
W = (D/55)2 | 301 - 5,000 feet |
W = (D/65)2 | 5,001 feet or greater |
W = Weight of explosives in pounds
D = Distance to the nearest structure
Seismograph Measurement | Distance to the |
(peak particle velocity) | Nearest |
Protected Structure | |
1.25 ips | 0 - 300 feet |
1.00 ips | 301 - 5,000 feet |
0.75 ips | 5,001 feet or greater |
Seismographs used to demonstrate compliance with this subsection must be shake-table calibrated annually. A copy of the annual calibration certificate shall be kept filed with the blasting logs and seismograph records and made available for review as required by subdivision 3.5.a of this rule. All seismic monitoring shall follow the ISEE Field Practice Guidelines for Blasting Seismographs, unless otherwise approved in the blasting plan.
All applicants must complete the pre-blast surveyor training provided by the Secretary prior to approval to conduct pre-blast surveys. The Secretary shall not grant approval or re-approval to any person who is a convicted felon. The Secretary may establish a fee for approval and training of pre-blast surveyors.
The Secretary shall issue written documentation of the re-approval to conduct pre-blast surveys to each person who has been re-approved by the Secretary
W. Va. Code R. § 199-1-3