Section En 511.14 - Leakage Surveys and Inspections(a) For purposes of this section, "business districts" means the principle business areas in the urban portion of a community.(b) The presence of certain factors shall indicate the presence of a business district, as follows:(1) The general public regularly congregates in this area for economic, industrial, religious, educational, health or recreational purposes;(2) The majority of the buildings on either side of the street are utilized for commercial, industrial, religious, educational, health or recreational purposes;(3) Gas facilities are under continuous paving that extends either from the center line of the thoroughfare to the building wall or from the storage tank to the building wall; or(4) Other locations or sites in the urban portion of a community which contain a similar density and/or mix of buildings and services as provided in (1) through (3) above.(c) Each LPG operator and landfill gas operator shall conduct periodic leakage surveys in accordance with this section.(d) Each LPG operator and landfill gas operator shall include a plan for periodic leakage surveys in its operating and maintenance plan.(e) Each LPG operator shall conduct a leakage survey upon a change in gas supplier.(f) Each LPG operator and landfill gas operator shall conduct periodic leakage surveys in business districts and outside business districts in intervals as required by 49 C.F.R. § 192.706 or § 192.723.(g) Each LPG operator shall conduct periodic leakage surveys by:(1) Performing a pressure drop test according to Appendix D of NFPA 54, as adopted by En 511.02(a); or(2) Utilizing a combustible gas indicator meter or equivalent testing procedures.(h) Each landfill gas operator shall conduct periodic leakage surveys by utilizing a combustible gas indicator meter or equivalent testing procedures.(i) The type and scope of the leakage control program shall be determined by the nature of the operations, such as liquid petroleum distribution systems and the local conditions, but it shall meet the minimum requirements set forth in this section.(j) Each LPG operator and landfill gas operator shall follow procedures for classification and control of flammable gas leaks approved by the department's enforcement division.(k) When investigating a leak, if it is determined that the perimeter of a leak area extends to a building wall, the investigation shall continue into the building unless public safety or identifiable exigent circumstances prohibit entry.(l) The LPG operator or landfill gas operator shall establish a leak repair priority based on its evaluation of the location and the magnitude of a leak.(m) Each LPG operator and landfill gas operator shall assign a classification of leaks as follows:(1) Class I shall be a leak that represents an existing or probable hazard to persons or property, and requires immediate repair within 24 hours or continuous action until the conditions are no longer hazardous;(2) Class II shall be a leak that is recognized as being non-hazardous at the time of detection, but requires scheduled repair within 6 months or before the end of the calendar year based on probable future hazard; and(3) Class III shall be a leak that is non-hazardous at the time of detection and can be reasonably expected to remain non-hazardous.(n) In making a determination as to whether to classify a leak as Class I, II or III, an LPG operator or landfill gas operator shall comply with leak classification and leakage control procedures set forth in the 1999 ASME Guide for Gas Transmission and Distribution Piping Systems, Guide Material Appendix G-11A, Tables 3a, 3b and 3c, substituting the term "class" for "grade."(o) Each LPG operator and landfill gas operator shall conduct a follow-up inspection as follows:(1) The perimeter of the leak area shall be checked with a combustible gas indicator (CGI); and(2) Where there is residual gas in the ground after the repair of a Class I leak, the LPG operator shall conduct a follow-up inspection as soon as practical after allowing the soil atmosphere to vent and stabilize, but in no case later than one month following the repair.(p) In the case of leak repairs other than Class I, the need for a follow-up inspection shall be determined by qualified personnel of the LPG operator or landfill gas operator.N.H. Admin. Code § En 511.14
Derived from Number 45, Filed November 9, 2023, Proposed by #13796, Effective 10/25/2023, Expires 10/25/2033.