# Chapter 420, § 5: Installation and Maintenance Standards - **operation:** document - **citation:** 65-407 C.M.R. ch. 420, § 5 - **title:** Chapter 420, § 5: Installation and Maintenance Standards - **source type:** regulation - **agency:** Maine Public Utilities Commission - **status:** current - **official:** true - **published on:** 2026-06-30 - **effective on:** 2026-06-30 - **summary:** A. Interruptions of Service - **machine formats:** - **json:** https://regulus.evalyn.ai/document/me-cmr-65-407-420-5.json - **markdown:** https://regulus.evalyn.ai/document/me-cmr-65-407-420-5.md - **app url:** https://regulus.evalyn.ai/document/me-cmr-65-407-420-5 - **source url:** https://www.maine.gov/sos/sites/maine.gov.sos/files/inline-files/407c420-2026-135-AMD.docx **body:** A. Interruptions of Service 1. Operators must use all practicable means to avoid interruptions to service, including maintaining appropriate levels of maintenance and planning for unexpected events. 2. Should interruptions occur, operators must reestablish service within the shortest time practicable consistent with safety. 3. Operators must keep a record of all interruptions to service involving twenty or more customers that include the following: a. The date and time of interruption; b. The approximate number of customers affected; c. The date and time of service restoration; d. The cause of such interruption when known; and e. A description of steps taken to prevent its recurrence. 4. Operators must report to the MPUC unintended service interruptions pursuant to Section 5(A)(3) of this Chapter occurring within a calendar month by the 15th of the following month. 5. When an operator interrupts service to perform work on lines or equipment, such work must be done at a time causing minimum inconvenience to customers consistent with the circumstances. 6. If practicable, operators must notify, three days in advance of scheduled work on lines or equipment that requires an interruption to service, all commercial, institutional or other customers that can reasonably be expected to be seriously affected. B. Operator Qualification (OQ) Program for New Construction Operators must include all pertinent tasks related to new construction as covered tasks in their OQ Program. C. Installation and Maintenance of Meters, Pressure Regulators and Service Piping 1. Location of Meters. Operators must install meters in either of the following locations: a. Outside the building at a location selected by the operator; or b. When an outside location is not feasible, inside the building, preferably in a dry, well-ventilated place not subject to excessive heat, and as near as possible to the point of entrance of the pipe supplying service to the building. 2. Master Meters. Operators must not utilize master meter systems unless all service lines to the buildings served are operated and maintained by an operator in accordance with this Chapter. 3. Protection of Meters and Distribution System Facilities from Damage from Motorized Vehicles or Equipment. Operators must provide adequate protective barriers for gas meters, regulators, and aboveground pipeline facilities located in areas subject to vehicular damage on each side exposed to vehicular traffic. Operators that have above-ground piping and appurtenances at commercial and industrial premises must consider the potential for damage to the gas facilities from equipment used in the operation and maintenance of that facility and provide adequate protection. 4. Protection of Meters and Distribution System Facilities from Snow and Ice Damage. Operators must protect regulators, meters, and other equipment installed in the piping system must from the forces anticipated as a result of accumulated snow or falling snow and/or ice. 5. Accessibility and Location of Pressure Regulators at Meters or Service Piping. Pressure regulators installed by operators at meters or on service piping locations must conform to the following requirements: a. Pressure regulators must be accessible for inspection, testing and adjustment. b. Pressure regulators must be installed with a screened vent pointed down, or under a protective cover that will prevent blockage of the screened vent by rain, snow, ice or debris. c. Vents on pressure regulator~~s~~ installed after July 1, 2011 with over-pressure protection that vent gas to atmosphere must be at least three feet horizontally, or eight feet vertically, away from any existing building opening above the vent, and at least five feet away from any existing source of ignition (e.g., electrical meters, openings into direct-vent (sealed combustion system) appliances, or mechanical ventilation air intakes). Pressure regulators that utilize over-pressure shutoff (OPSO) technology or otherwise effectively eliminate venting gas to atmosphere need not abide by the above distance restrictions. d. Operators must not direct-bury new regulators. All existing buried regulators must be rated by their manufacturer for the application for which they are used and must be vented above grade. 6. Observation of Unsafe Condition of Customer Facilities a. When visiting a customer's premises for any technical service, such as atmospheric corrosion inspections of facilities or connecting or reconnecting a customer service, operators must also observe visible customer piping for atmospheric corrosion or other potential safety issues. b. All operators must include in their O&M Procedures a "Red Tag" hazardous equipment procedure for suspending service to a customer when a hazardous condition is discovered that makes the continued delivery of gas unsafe. c. Operators' Public Awareness Plans must include notification to customers that their piping must be in compliance with NFPA 54 and maintained to prevent atmospheric corrosion. D. Installation and Maintenance of Mains and Service Lines 1. Installation of Plastic Pipe, Warning Tape, and Tracer Wire. To facilitate location of buried plastic pipe, when plastic pipe is installed or replaced, operators must use the following location methods: a. An electrically conductive tracer wire must be installed with new or replaced plastic pipe, including plastic pipe that is inserted into existing buried cast iron pipe as a means of pipe replacement. Tracer wire must not be wrapped around the pipe and contact with the pipe must be minimized but is not prohibited when trenchless technology, including pipe insertion, is used. Tracer wire or other metallic elements installed for pipe locating purposes must be resistant to corrosion damage, either by use of coated 12-gauge copper wire or by other means. b. Continuous gas pipeline warning tape must be installed approximately one foot below finish grade. The warning tape must be yellow, indicate the presence of a gas line, and at least six inches wide. No warning tape is required when pipe is installed by trenchless technology, including pipe insertion. 2. Plastic Pipe Joining and Design a. Each person that joins plastic pipe must be qualified to do so for each joining method at intervals not exceeding 15 months, but at least once each calendar year. b. Each completed joint, regardless of joint type, must be inspected by a person qualified to perform the inspection, and the joint, pipe, or fitting must be marked with the initials or other identifier unique to the individuals who both made and inspected the joint. This person cannot be the person that performed the joining method that is subject to inspection. c. Design of plastic pipe must be in accordance with the design factor specified in 49 C.F.R. §192.121. 3. Minimum Cover and Separation Standards for Mains and Service Lines a. Mains in Public Right-of-Ways. New or replaced mains located in public rights-of-way must be installed with at least 24 inches of cover above the shallowest pipe appurtenance, except where an obstruction, from other utilities or underground structures, prevents that installation depth or when pipe is inserted into existing pipe. This provision does not supersede any minimum cover depth requirements of an authority having permitting jurisdiction over the facilities being installed. b. Service Lines. Service lines must be installed with at least 24 inches of cover above the shallowest appurtenance attached to the service line. Cover may be reduced to 18 inches above the shallowest appurtenance attached to the service line for the connection to a prefabricated riser. c. Separation from Underground Obstructions 1. Where there is interference with underground obstructions, the operator must lay the main or service at a clearance distance of not less than 12 inches away from such obstructions unless the operator provides adequate shielding to protect the gas pipeline and the other facilities. 2. Operators must avoid where possible any interfering structure which provides a space in which an explosive atmosphere might accumulate in the event of a leak and must give preference to crossing over rather than under such structures. d. Shallow Installations due to Underground Obstructions. When an operator has installed a main or service with less than 24 inches of cover, the operator must protect the main or service with shielding that conforms with gas industry standards both in respect to material and manner of installation. This provision does not supersede any minimum cover depth requirements of an authority having permitting jurisdiction over the facilities being installed. 4. Material Tracking a. Operators must utilize a Geospatial Information System (GIS), or other comparable method to accurately track the location, by GPS coordinates, of all materials utilized for the installation and maintenance of mains and service lines that are permanently affixed to or installed with the mains or service lines. b. The materials to be tracked by the operator include but are not limited to: pipe, valves, fittings, steel pipeline girth welds, and any other appurtenances. c. The information tracked by the operator must include but is not limited to: material description; manufacturer; date of manufacture; batch, lot, and/or heat numbers; maximum design pressure and/or minimum yield strength; and identification of the individual(s) who made any plastic pipe joints and/or steel welds. E. Accessibility and Operability of Pipeline System Valves 1. Pipeline Valves Each pipeline valve installed on a main must be in an accessible location and the operator must mark and maintain the pipeline valve's GPS coordinates and triangulation on a pipeline system drawing. Operators must ensure that current maps are easily accessible to operating personnel. 2. Distribution Line Valves a. Operators must maintain each valve installed on a main that has been designated by the operator as a critical valve to be readily accessible to facilitate its operation. b. Each valve installed on a main that has been designated by the operator as a critical valve must be inspected and partially operated at least once each calendar year at intervals not to exceed 15 months. Operators must take prompt remedial action to correct any critical valve found inoperable, unless the operator designates an alternative critical valve. c. Operators must inspect and partially operate each valve installed on a main that is not a critical valve at least once every five calendar years at intervals not to exceed 66 months. Operators must take remedial action to correct any non-critical valve found inoperable, or document on valve records and maps that the valve is inoperable. d. Operators must inspect and partially operate each valve installed on a service line where there is not a valve at the service riser or where it is not practical to access the service riser valve in an emergency at least once every five calendar years at intervals not to exceed 66 months. e. Operators may designate any valve that the operator does not intend to utilize (e.g., a valve installed on a main to facilitate construction) as a "non-operational valve." In so designating, the operator must document the valve as a non-operational valve on valve records and maps. Non-operational valves so designated and documented by an operator are not subject to the inspection, operation, or remediation requirements of this Section. f. Operators that do not have an MPUC-approved isolation zone plan must install sufficient distribution valves on mains to isolate looped portions of a pipeline system and minimize outages to no more than 500 customers but no more than the number that the operator has sufficient technical resources, including mutual aid, to relight within eight hours. The relight interval begins immediately upon restoration of sufficient system function to support reconnection of service load. e. If an operator installs a valve in a buried box or enclosure, the operator must install the box or enclosure to avoid transmitting external loads to the main and service line(s). 3. Valve Boxes. Operators must maintain all valve boxes associated with critical valves so as to avoid being paved over or filled with debris that prevents access to the valve or degrades valve operability. 4. Valves at Regulator Stations a. Each regulator station controlling flow or pressure of gas in a distribution system must have a valve installed on the inlet piping at a distance from the regulator station sufficient to permit operation of the valve during an emergency that might preclude access to the station. b. All regulator stations constructed after July 1, 2011, must have exterior shutoff valves or a sectionalizing valve installed on all lines entering and leaving regulator stations for use in an emergency to stop gas flow. Such valves must be installed at a readily accessible location where they can be operated in an emergency. c. Exterior shutoff valves, for stations installed after July 1, 2011, must be located a minimum of 40 feet from the regulator station if inlet pressure to the station is 100 psig or less. Valves must be located a minimum of 100 feet from the regulator station if inlet pressure is more than 100 psig. The above minimum separation distances do not apply to stations where achieving the minimum separation distances is not practicable and where an automated fire-valve is installed at the inlet to the station. d. A check valve may be used in lieu of an exterior shutoff valve on downstream piping if located a minimum of 40 feet from the regulator station. e. The exterior shutoff valve may be a sectionalizing valve. - **truncated:** false - **body characters:** 14302