15A NCAC 18C .0406 DISTRIBUTION SYSTEMS
(a) Water Pipe Materials. Distribution mains shall be cast iron, ductile iron, asbestos‑cement, reinforced concrete, plastic, or other material designed for potable water system service and shall be the appropriate AWWA standards, section C, or NSF Standards No. 14 and No. 15 that is hereby incorporated by reference including any subsequent amendments and editions. Copies are available for public inspection as set forth in Rule .0102 of this Subchapter. The pressure rating class of the pipe shall be in excess of the maximum design pressure within that section of the water distribution system. The quality of pipe to be used shall be stated in the project specifications.
(1) No potable water supply shall be connected by any means to another source of water supply or to a storage facility unless such connection has been previously approved by the Department. No connection shall be made to any plumbing system that does not comply with the North Carolina State Building Code, volume II, or any applicable local plumbing code.
(2) No person shall introduce any water into the distribution system of a public water supply through any means other than from a source of supply duly approved by the Department or its representatives, or make a physical connection between an approved supply and unapproved supply unless authorized in an emergency by the Department or its representative.
(3) In cases where storage capacity is used only for non‑potable purposes and there is installed either an elevated or ground tank or a ground reservoir, the following precautions shall be taken:
(A) When the reservoir or tank is filled from a supply other than a public water supply and the public water supply is used as a supplemental supply, the pipeline from the public water supply shall be installed in such a manner that the water will be discharged over the top or rim of the reservoir or tank. There shall be a complete physical break between the outlet end of the fill pipe and the top or overflow rim of the tank of at least twice the inside diameter of the inlet pipe.
(B) When the reservoir or tank is filled entirely by water from a public water supply:
(i) If a covered ground reservoir or covered elevated tank is used, an approved reduced pressure back‑flow preventor or an approved double check valve assembly may be used. The back‑flow prevention device shall be installed in such a manner as to afford adequate protection, be easily accessible, and include all necessary pressure gauges and drains for testing. Gate valves shall be installed in the line at both ends of the back‑flow prevention device.
(ii) If an uncovered ground reservoir or uncovered elevated tank is used, a complete physical break shall be provided between the reservoir or elevated tank and the public supply. The physical break between the inlet pipe and the top or overflow rim of the reservoir shall be at least twice the diameter of the inlet pipe.
(4) All cross‑connections between potable water supplies and non‑potable or unprotected supplies that are not specifically covered in the categories in this Paragraph will be considered special problems and the protective devices required shall be determined by the Department on the basis of the degree of health hazard involved.
(5) Persons desiring to install non‑potable water supplies in conjunction with a public water supply shall submit detailed plans and specifications in triplicate showing the non‑potable water supply and its relation to the potable water supply to the Department in accordance with Rule .0302(a) of this Subchapter.
(6) Any such interconnection to a potable water system is subject to the approval of the water supplier and shall not be made until authorized by the water supplier in addition to the Department.
(7) No person shall fill special use tanks or tankers containing pesticides, fertilizers, other toxic chemicals, or their residues from a public water system except at a location equipped with an over‑the‑rim free discharge of water or a reduced pressure backflow preventer properly installed on the public water supply that has been approved by the Department. No supplier of water shall permit the filling of such special use tanks or tankers except at locations so equipped.
History Note: Authority G.S. 130A‑315; 130A‑317; P.L. 93‑523;
Eff. January 1, 1977;
Readopted Eff. December 5, 1977;
Amended Eff. April 1, 2014; September 1, 1990; December 1, 1988; June 30, 1980.