manifold to all of the underground tanks.
Each vapor return pipe shall allow the transfer of gasoline vapors to the tank from which the liquid gasoline is being drawn;
(2)Pipe diameter shall meet manufacturer's specifications. If the manufacturer does not specify diameters, the following minimum pipe diameters apply. If the manufacturer only specifies diameters for part of the system, the following diameters apply for the pipe(s) not specified. All fittings, connectors, and joints shall have an inside diameter equal to the inside diameter of the pipe to which it is attached. The following diameters are specified for the number of nozzles that may be operated at the same time;
(A)Vapor Recovery Dispenser Risers
(i)Three-forths of an inch for vapor recovery dispenser risers returning vapors from one nozzle; or
(ii)One inch for vapor recovery dispenser risers returning vapors from two nozzles;
(B)Vapor Recovery Piping
(i)At least two inches for six or fewer nozzles; or
(ii)At least three inches for more than six nozzles;
(3)All piping and fittings shall be installed in accordance with manufacturer's instructions and specifications. Metal pipe shall be minimum schedule 40 welded or seamless steel per ASTM A-53, "Specification for Pipe, Steel, Black and Hot-Dipped, Zinc-Coated Welded and Seamless Pipe". Fittings shall be 150 pounds cold water screwed malleable iron. Pipe and fittings shall be galvanized and pipe threads shall be zinc-coated. Nonmetallic pipes and fittings shall be U/L listed under nonmetallic primary pipes and fittings for underground flammable liquids (gas and oil equipment directory);
(4)Each vapor return pipe shall slope toward the storage tank with a minimum grade of 1/8 inches per foot. No low points or sags shall exist along the return piping;
(5)All vapor return and vent piping shall be provided with flexible joints or swing joints at each tank connection and at the base of the vent pipe riser where it fastens to a building or other structure;
(6)All vapor return pipe-trenching shall be compacted to 90 percent of the standard proctor according to ASTM D-698 "Laboratory Compaction Characteristics of Soil Using Standard Effort" of the area soil before the pipes are installed and back-filled with sand or other material approved by the pipe manufacturer at least six inches below and above the piping;
(7)The pipes shall not be driven over or in any other way crushed before paving or surfacing;
(8)The vapor return piping or manifolded piping on a vacuum assisted system shall enter a separate opening to the tank from that
connected to the vent pipe or the Stage I piping;
(9)All vapor return piping shall be tagged at the termination point recording the function of the piping. In addition, a record of the installation of the Stage II vapor return piping shall be kept in the facility;
(10)Vent piping shall be constructed of materials in accordance with Subparagraph (3) of this Paragraph;
(11)All vent pipes shall be a minimum of two inches inside diameter or meet the local Fire Codes; and
(12)All vent pipes shall slope toward the underground storage tank with a grade of at least 1/8 inch per linear foot.
(e) Compliance Schedule. Compliance under Paragraph (d) of this Rule by the affected facility shall coincide with the completion of the tank installation or repair. The owner or operator of a facility shall notify the Director within 60 days after the day the facility has exceeded the exemptions under Paragraph (b) of this Rule. Facilities that lose their exemption under Paragraph (b) of this Rule shall comply with this Rule within 18 months after the day the owner or operator of the facility has notified the Director that the facility has exceeded its exemption under Paragraph (b) of this Rule.
(f) Testing Requirements.
(1)Within 30 days after installation of the vapor return piping, the owner or operator of the facility shall submit reports of the following tests to be completed as described in EPA-450/3-91-022b:
(A)Bay Area Source Test Procedure ST-30, Leak Test Procedure, or San Diego Test Procedure TP-91-1, Pressure Decay/Leak Test Procedure, and
(B)Bay Area Source Test Procedure ST-27, Dynamic Back Pressure, or San Diego Test Procedure TP-91-2, Pressure Drop vs Flow/Liquid Blockage Test Procedure.
(2)Testing shall be in accordance with Rule .0912 of this Section.
(3)The owner or operator of the facility shall notify the Regional Office Supervisor by telephone at least five business days before back-filling the trenches and at least 10 business days before the tests given in Subparagraph (1) of this Paragraph are to be performed to allow inspection by the Division.
(4)The owner or operator of the facility and the test contractor shall report all test failures to the Regional Office Supervisor within 24 hours of the failure.
(5)The Director may require the owner or operator of the facility to perform any of the tests in Subparagraph (1) of this Paragraph if there are any modifications or repairs.
22:23 NORTH CAROLINA REGISTER JUNE 2, 2008