N.J. Admin. Code § 7:9D-3.4
Current through Register Vol. 56, No. 21, November 4, 2024
Section 7:9D-3.4 - Specific requirements for the decommissioning of Category 4 uncased borings(a) All borings shall be decommissioned within 72 hours of completion.(b) Borings less than 25 feet in depth may be decommissioned by backfilling with cuttings and then tamping in order to restore to the maximum extent possible the natural conditions of the site that existed prior to drilling the borings.(c) All borings 25 feet or greater in depth shall be decommissioned using an approved sealing material in accordance with 7:9D-3.1.(d) The decommissioning of borings installed by direct-push technologies using a pumpable grout mix shall be in accordance with this subchapter, except as follows: 1. The drive casing may be used as a tremie pipe provided the drive point is of the sacrificial type, or the casing is equipped with a grout shoe and is withdrawn as the decommissioning material is pumped into the driven borehole; 2. The direct-push device may be removed and a second casing of equal diameter to the drive casing may be used as a tremie pipe provided the casing is equipped with a sacrificial tip or plug, and is reinserted into the same hole to the boring's original depth;3. If an outer casing is simultaneously driven with the direct-push device and inner drive casing and the cone and inner casing are retrieved, the outer casing may be used as tremie pipe; or4. If the direct-push device and drive casing are retrieved, the borehole may be overdrilled using a hollow stem auger and decommissioned in accordance with this subchapter.(e) The decommissioning of borings greater than or equal to three inches in diameter and 50 feet or less in depth installed by direct-push technologies may use sodium-based bentonite chips and bentonite pellets in accordance with N.J.A.C. 7:9D-3.1(n)2.N.J. Admin. Code § 7:9D-3.4
Amended by 50 N.J.R. 171(a), effective 1/2/2018