North Carolina Administrative Code › Title 21 - OCCUPATIONAL LICENSING BOARDS AND COMMISSIONS › Chapter 23 - IRRIGATION CONTRACTORS' › Section .0500 - IRRIGATION SYSTEM INSTALLATION MINIMUM STANDARDS › Section 23 .0505 - TRENCHING AND PIPING

Current through Register Vol. 39, No. 2, July 15, 2024
(a) All portions of
				an irrigation system that do not meet the standards in this Rule shall be noted
				on the record drawing.
(b) An
				irrigation contractor shall install an irrigation system without trenching
				across the established root systems of existing trees and shrubs.
(c) Notwithstanding the requirement in
				Paragraph (b) of this Rule, when the irrigation contractor finds that it is
				necessary to trench into the root zone of an established plant in order to
				provide adequate irrigation to the surrounding area, he shall dig the trench in
				such a way as to minimize the effect on the roots (for example, by digging the
				trench in a straight line towards the base of the tree or shrub such that, if
				the line of the trench were extended, it would intersect with the base of the
				tree or shrub).
(d) An irrigation
				contractor shall cut damaged roots cleanly at right angles.
(e) Piping in irrigation systems shall be
				selected so that the flow velocity will not exceed five feet per second for
				polyvinyl chloride (PVC), polyethylene (PE), and high density polyethylene
				(HDPE) pipe and seven feet per second for metal pipe.
(f) The main line and lateral line piping
				shall be installed to provide a minimum of 12 inches between the top of the
				pipe and the finished grade. However, if a utility, man-made structure, or
				roots create an obstacle that makes the 12 inch depth coverage requirement
				impractical, the piping shall be installed at a minimum of 6 inches between the
				top of the pipe and the finished grade.
(g) The bottom of the trench shall be smooth
				and level and provide a flat bed on which to rest the pipe.
(h) The irrigation contractor shall clean
				backfill material of any debris that may damage the pipe.
(i) When swing joints are used, the depth of
				the pipe shall allow the swing joint to operate as designed.
(j) All trenches and holes created during
				installation of an irrigation system shall be backfilled and compacted to the
				final grade. The trench shall be compacted in lifts no greater than six inches
				to insure proper compaction.
(k)
				All PVC connections installed in irrigation systems shall be prepared according
				to the manufacturer's recommendations (e.g. priming and glue
				application).
(l) The irrigation
				contractor shall use the manufacturer's approved lubricant when assembling bell
				and gasket and pipe and fittings.
(m) The irrigation contractor shall use
				Teflon tape on all threaded fittings, wrapping the tape around the pipe three
				times to insure a proper seal.
(n)
				When the irrigation system uses reclaimed water, the irrigation contractor
				shall use purple pipe or mark the pipe with purple tape placed above all piping
				in the system. Tape shall be within six inches of the top of the pipe. The
				irrigation contractor shall use purple valve box covers and purple quick
				coupler flaps and place an eight inch by eight inch sign with purple background
				stating "RECLAIMED WATER-DO NOT DRINK," and "AGUA DE RECUPERION-NO
				BEBER."
Authority
				  G.S.
				  89G-5(15);
				  89G-5(16);
Eff. July 1, 2011;
Amended Eff. April 1, 2015;
Readopted Eff. January 1, 2016;
Amended Eff. November 1,
				  2016.