The owner or the owner’s blasting contractor shall retain a seismic services consultant to measure and record ground vibration and airblast overpressure levels at specified locations. Such measurements shall be taken every time explosives are detonated during blasting operations. A copy of such measurements shall be filed with the department on a schedule to be established by the department, but not less frequently than once per week. Throughout blasting operations, locations for the monitoring equipment shall be selected by the blasting contractor and the seismic consultant in consultation with the department and subject to department approval. The commissioner may require monitoring of water shock when submarine blasting is conducted.
The limit for ground vibration peak particle velocity is 2.0 ips (50.8 mm/s) for frequencies from 40 Hz to 100 Hz. For frequencies below 40 Hz, vibration limits are 0.75 ips (19.1 mm/s) and 0.5 ips (12.7 mm/s), with graphical data transition lines equivalent to constant displacements. Airblast overpressure shall be limited to 134 dB. Vibration and noise shall not exceed the limits established by the Metropolitan Transit Authority, Department of Environmental Protection, Department of Transportation and Department of Buildings and other agencies responsible for ensuring the structural integrity of affected buildings, structures and infrastructure.
The seismic consultant shall prepare a report of all required measurements and data, acceptance criteria and analysis. In the event that readings exceed the acceptance criteria, the department shall be immediately notified, and the blasting contractor shall propose revised drilling and blasting patterns, charge weight per initiation and other measures to reduce the ground vibration and/or airblast overpressure, as appropriate.