SECTION 460:10-31-9. Seismographic measurements

(a)   Where a seismograph is used to monitor the velocity of ground motion and the peak particle velocity limit of 1 inch per second is not exceeded, the equation in Section 460:10-31-8(j) need not be used. If that equation is not used by the operator, a seismograph record shall be obtained for each shot.

(b)   The use of a modified equation to determine maximum weight of explosives per delay for blasting operations at a particular site, may be approved by the Department, on receipt of a petition accompanied by reports including seismograph records of test blasting on the site. In no case shall the Department approve the use of a modified equation where the peak particle velocity of 1 inch per second required in Section 460:10-31-8(g) would be exceeded.

(c)   The Department may require a seismograph record of any or all blasts and may specify the location at which such measurements are taken.