1. (1) Unexploded charges.

   1. (a) Drilling cannot begin:

      1. (i) When there is danger of drilling into a charged or misfired hole.
      2. (ii) Until all remaining butts of old holes are examined for unexploded charges.
   2. (b) Unexploded charges must be refired before work proceeds.

2. (2) Distance limits during drilling. Blasters cannot load or use explosives closer than:

   1. (a) The length of the steel being used for drilling; or
   2. (b) Within fifty feet of drilling operations, whichever is greater.

3. (3) Prior to loading drill holes.

   1. (a) Holes must be checked prior to loading to determine depth and conditions.
   2. (b) Drill holes that have contained explosives or blasting agents cannot be deepened.
   3. (c) Drill holes must be large enough to allow unobstructed or free insertion of explosive cartridges.

4. (4) Enlarging or springing a drill hole.

   1. (a) A drill hole cannot be sprung when it is near a loaded hole.

   2. (b) A minimum of two hours must pass after a charge has exploded in a drill hole that was enlarged or "sprung," before loading another charge of explosives into the hole.

      Note:

      You do not have to wait two hours if the sprung hole is thoroughly wet down with water before it is loaded.

   3. (c) Flashlight batteries cannot be used as a power source for springing holes.

[Statutory Authority: RCW 49.17.010, 49.17.040, 49.17.050, and 49.17.060. WSR 17-16-132, § 296-52-67080, filed 8/1/17, effective 9/1/17; WSR 05-08-110, § 296-52-67080, filed 4/5/05, effective 6/1/05. Statutory Authority: RCW 49.17.010, [49.17].040, and [49.17].050. WSR 02-03-125, § 296-52-67080, filed 1/23/02, effective 3/1/02.]