North Carolina Administrative Code › Title 15A - Environmental Quality › Chapter 18 - ENVIRONMENTAL HEALTH › Subchapter C - WATER SUPPLIES › Section .0400 - WATER SUPPLY DESIGN CRITERIA › Section 18C .0406 - DISTRIBUTION SYSTEMS

Current through Register Vol. 39, No. 2, July 15, 2024
(a) Water Pipe
				  Materials. Water pipes shall be cast iron, ductile iron, reinforced concrete,
				  plastic, or other material designed for potable water system service and shall
				  meet AWWA standards, section C, or be certified as meeting the specifications
				  of ANSI/NSF Standard 61 Drinking Water System Components - Health Effects,
				  which is incorporated by reference including any subsequent amendments and
				  editions. Copies of AWWA standards may be obtained for public inspection as set
				  forth in Rule .0503 of this Subchapter. Copies of ANSI/NSF Standard 61 may be
				  obtained for public inspection as set forth in Rule .1537 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.
(b) Cross-Connections. No person shall
				  construct, maintain, or operate a physical arrangement whereby a public water
				  system has a cross-connection without the use of proper backflow protection.
(1) 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 any physical connection between an approved supply and unapproved
				  supply unless authorized in an emergency by the Department or its
				  representative.
(2) Service
				  Connection Relation to Plumbing Code. No supplier of water shall provide a
				  service connection to any plumbing system that does not comply with the North
				  Carolina State Building Code, Volume II, and all applicable local plumbing
				  codes. Where required, the supplier of water shall install or require to be
				  installed an appropriate testable backflow prevention assembly prior to making
				  the service connection. Design of backflow prevention assemblies for service
				  connections shall not require Department review.
(3) Connections Requiring Departmental
				  Review. Connections between a public water system and the connection types in
				  Parts (A) through (D) of this Subparagraph shall require review and approval by
				  the Department prior to making the connection. Installation of a testable
				  backflow prevention assembly or air gap shall be required if the connection is
				  non-potable or unapproved. Engineering plans and specifications shall be
				  submitted in accordance with Section .0300 of this Subchapter.
(A) Any regulated public water
				  system;
(B) any community
				  non-regulated public water system. Before providing a connection, a supplier of
				  water shall ensure that the construction of the non-regulated public water
				  system either was approved in accordance with Rule .0301(a) of this Subchapter
				  or that backflow prevention is provided in accordance with this Rule;
(C) non-potable water treatment processes
				  within a potable water treatment plant; and
(D) all cross-connections between potable
				  water supplies and non-potable or unprotected supplies that are not
				  specifically addressed in this Rule or AWWA M-14 Backflow Prevention and Cross
				  Connection Control.
(4)
				  Backflow Prevention Not Addressed by the Plumbing Code. The following
				  requirements shall apply to backflow prevention not addressed by the plumbing
				  code.
(A) Testable backflow prevention
				  assemblies shall meet American Society of Sanitary Engineering (ASSE) standards
				  and carry an ASSE seal, be on the University of Southern California approval
				  list for testable backflow prevention assemblies, or be on the North Carolina
				  State Plumbing Code approval list for approved testable backflow prevention
				  assemblies.
(B) For each identified
				  water treatment process-related hazard, the supplier of water shall provide the
				  appropriate backflow prevention assembly or method to protect the water supply
				  and water treatment employees, in accordance with AWWA M-14 Backflow Prevention
				  and Cross Connection Control.
(C)
				  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. No supplier of water shall permit the filling of such special use
				  tanks or tankers except at locations so equipped.
(D) A supplier of water shall not authorize
				  for construction or other temporary, non-emergency use connections to hydrants
				  that are not equipped with an approved air gap or an installed reduced pressure
				  principle backflow prevention assembly.
(E) If 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:
(i) If 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 with an air gap.
(ii) If
				  the reservoir or tank is filled entirely by water from a public water supply
				  and:
(I) a covered ground reservoir or covered
				  elevated tank is used, an approved reduced pressure back-flow preventer or an
				  approved double check valve assembly shall be used; or
(II) an uncovered ground reservoir or
				  uncovered elevated tank is used, an air gap shall be required.
(F) Installation. The
				  following installation requirements shall be met, where applicable.
(i) Backflow prevention assemblies shall be
				  installed in accordance with manufacturers' recommendations and specifications
				  and shall not be modified in the field.
(ii) Back-flow prevention assemblies shall be
				  located and installed in such a manner as to function as designed; be
				  accessible for testing, maintenance, and inspection; and include all necessary
				  test cocks and drains for testing. Valves shall be installed in the line at
				  both ends of the back-flow prevention device to provide for replacement and
				  maintenance.
(iii) Bypass lines
				  parallel to a backflow prevention assembly shall have an approved backflow
				  prevention assembly installed that is equal to that on the main line.
(iv) Reduced pressure principle assemblies
				  shall be installed above ground or below ground in a vault with positive
				  gravity drainage to atmosphere employing a drain of sufficient size to handle
				  the full flow of discharge from a discharging assembly, 12-inch minimum
				  clearance from vault walls and floor, and in accordance with manufacturer's
				  recommendations. A reduced pressure principle assembly may be installed as
				  protection for either a high-health or low-health hazard.
(v) Double check valve assemblies shall be
				  installed either vertically or horizontal and above ground or below ground in a
				  vault with positive gravity drainage to the atmosphere. A double check valve
				  assembly shall be installed as protection for a low-health hazard
				  only.
(vi) Pressure vacuum breaker
				  assemblies shall be installed only where there is no possibility of a pressure
				  higher than the supply pressure caused by a pump, elevated tank, boiler, air or
				  steam pressure, or any other means which may cause backflow, and in accordance
				  with manufacturer's recommendations. A pressure vacuum breaker shall be
				  installed as protection for a high-health or low-health hazard that is subject
				  to backsiphonage only and with no backpressure.
(5) Interconnection to a public water system
				  shall be subject to the approval of the supplier of water and shall not be made
				  until authorized by the supplier of water.
(6) A community or non-transient
				  non-community public water system with five or more testable backflow
				  prevention assemblies protecting the distribution system, as required pursuant
				  to this Rule, shall maintain the following records beginning on January 1,
				  2020:
(A) records of the location, type,
				  installation date, size, and the associated degree of hazard of backflow
				  prevention devices whose failure would create a high-health hazard;
(B) a description of specific ongoing plans,
				  actions, or schedules to inventory existing backflow prevention devices under
				  Part (b)(5)(A) of this Rule and to identify and address all uncontrolled
				  cross-connection hazards;
(C) final
				  results of all backflow prevention assembly field testing and air gap
				  inspections; and
(D) review of new
				  service connections and existing service connections during a change of the
				  account owner to ensure all required backflow prevention devices are properly
				  installed and tested.
(E) a
				  supplier of water which contracts with a third-party to implement any part of
				  their cross-connection program may allow records required by this Paragraph to
				  be maintained on the premises of the third-party, as long as the records are
				  available on demand by the supplier of water.
(F) program records under Part (C) of this
				  Subparagraph shall be maintained for a minimum of four years. Remaining records
				  referred to in this Paragraph shall be maintained while still current or in
				  use.
(7) Each supplier
				  of water shall notify the Department of any known incident of backflow into the
				  public water system that creates a risk of contamination as soon as practical
				  upon discovery of the incident but no later than the end of the next business
				  day. If requested by the Department, the supplier of water shall submit a
				  written report of the incident describing the nature and severity of the
				  backflow, the actions taken by the supplier of water in response to the
				  incident, and the action plan intended to prevent such incidents in the
				  future.