"Reaction blocking" means the strategic placement of a block of concrete between a fitting and undisturbed soil at the side or bottom of a pipe trench, to prevent the movement of pipes, tees, crosses, valves, bends, hydrants and other appurtenances of a water system from forces that result when water is under pressure and in motion.
Nev. Admin. Code § 445A.66305
NRS 445A.860