# Chapter 420, § 6: Operation Standards

- **operation:** document
- **citation:** 65-407 C.M.R. ch. 420, § 6
- **title:** Chapter 420, § 6: Operation 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. Operator Qualification (OQ) Program Requirements
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- **app url:** https://regulus.evalyn.ai/document/me-cmr-65-407-420-6
- **source url:** https://www.maine.gov/sos/sites/maine.gov.sos/files/inline-files/407c420-2026-135-AMD.docx
**body:**

A. Operator Qualification (OQ) Program Requirements

  Operators must include in its OQ Program’s written plan:

  1. A provision that all of the operator’s personnel and the employees
  of the operator's contractors who may be joining plastic pipe, by any
  method, or inspecting plastic pipe joints must be qualified (a)
  directly by an employee of the operator who is fully trained and
  qualified; or (b) if an operator utilizes an agency to qualify its
  personnel, all such qualifications must be by the same agency through
  which the operator has adopted their OQ Program written plan. Any
  individual(s) conducting inspections or qualification testing must be
  qualified to join plastic pipe by all methods and have a minimum of
  two years of experience making all joints they are inspecting or for
  which they are qualifying others;

  2. A provision requiring documentation that all qualified personnel
  (employees and contractors) have received training, for all tasks for
  which each person is qualified, prior to being tested for
  qualification. Operators must retain this documentation for as long as
  the individual is performing the covered task, and for five years
  thereafter;

  3. A provision requiring documentation indicating that personnel
  (employees and contractors), qualified for any task by written
  testing, were tested for those tasks by an independent proctor and
  that all tests were corrected by the test proctor or by a computerized
  or online test administrating organization or agency. Operators must
  retain this documentation for as long as the individual is performing
  the covered task, and for five years thereafter. If written testing is
  conducted through a computerized or on-line test administered by the
  Northeast Gas Association or similar organization or agency, then the
  operator must ensure that the test proctor has been qualified by the
  administrator of the test;

  4. A provision requiring documentation indicating that personnel
  (employees and contractors), qualified for any task by hands-on
  testing, were tested individually for those tasks by an independent
  proctor and that all tests were corrected by the test proctor.
  Operators must retain this documentation for as long as the individual
  is performing the covered task, and for five years thereafter;

  5. A provision requiring that. if task testing is computer based, the
  operator have procedures to ensure that the stated individual is the
  person actually taking the test(s) and that the stated individual did
  not receive assistance during the testing. Operators must create
  documentation regarding the above and retain this documentation for as
  long as the individual is performing the covered task, and for five
  years thereafter;

  6. A provision that. for tasks other than joining plastic pipe, the
  operator must perform analysis to verify that the domains and elements
  of all tasks performed by contractor personnel, qualified by an OQ
  Program other than the operator's, equate to the tasks as described in
  the operator's OQ Program. Operators must retain documentation of this
  analysis for as long as the contractor personnel are performing
  covered tasks, and for five years thereafter;

  7. A provision that if the domains and elements of a contractor's task
  do not equate to those contained in the operator's OQ Program or if
  contractor personnel are lacking qualification for necessary tasks,
  the affected personnel must be qualified by the operator or the same
  agency through which the operator has adopted its OQ Program written
  plan; and

  8. A provision that prior to the start of each construction season,
  the operator must provide the Gas Safety Staff with the necessary
  usernames and/or passwords to access any on-line databases used for
  the tracking of qualifications of the operator's employees and
  contractors.

  B. Quality Assurance/Quality Control (QA/QC) Program

  1. Operators must, as part of their compliance with 49 C.F.R. §192.605
  Procedural manual for operations, maintenance, and emergencies,
  include procedures for evaluating the work performed by operator
  personnel to determine the effectiveness and adequacy of the
  procedures used during normal operation and maintenance tasks and to
  modify the procedures when deficiencies are found. Such procedures
  must be set out in a written QA/QC program that promotes gas system
  and related employee and contractor safety through monitoring of field
  work activities performed during the construction, installation,
  operation and maintenance of gas facilities. The operator must also
  develop a construction inspection program for new construction and
  facility repair work done by its employees and by contractors as part
  of its QA/QC program.

  2. A mandatory component of operators' QA/QC Programs must be on-going
  audits of tasks performed with a goal to ensure compliance with the
  operator's written policies, practices, procedures and specifications;
  and with applicable codes. Record keeping accuracy and completeness
  verification audits are also included in this component of the QA/QC
  Program.

  3. The QA/QC audit program must include:

  a. Field Verification Audits of which a representative number are
  conducted after field work is completed for specific tasks.

  b. Performance Audits which consist of various tasks of which a
  representative sample are evaluated during the actual time that the
  work is being performed by the employee or contractor.

  c. Construction Inspections that are frequent enough to encompass most
  of the new facility installation and repairs that are done on the
  operator's system.

  d. Detailed forms incorporating activity checklists prepared to cover
  normally performed work activities for evaluation or inspection of
  specified field work and construction.

  4. When necessary, operators must use QA/QC audit and construction
  inspection findings to implement changes in procedures, training, and
  work practices.

  5. Audits must be conducted by management personnel (e.g.,
  supervisors, engineers) and performed on different employees/crews to
  ensure that all personnel are reviewed and construction work is
  inspected regularly.

  C. Scheduling Permanent Abandonment/Disconnection of Inactive Mains
  and Service Lines

  1. Operators must add and monitor service lines where gas is no longer
  being billed to a customer and which are not cathodically protected
  steel or plastic gas service lines equipped with an excess flow valve,
  according to the operators' DIMP written plans until the lines are
  disconnected and abandoned.

  2. Operators discovering inactive bare steel (unprotected) service
  lines or stubs in the course of leakage surveillance, construction,
  maintenance or inspection of facilities must abandon or replace those
  lines or stubs as follows: If leaking, abandon immediately at the
  main; if not leaking, abandon or replace as soon as practicable but
  not more than six months after discovery.

  3. The operator must indicate in its mapping system any main or
  service line that is abandoned at the time it is abandoned.

  4. The operator must maintain records of any main or service line that
  has been abandoned.

  5. If a building with an active service line is to be demolished and
  is not slated to be replaced the operator must abandon the service
  line must at the main.

  D. Leak Detection

  1. Leakage Surveys and Patrols. Operators must conduct leakage surveys
  and patrols according to the following:

  a. Operators must conduct a risk-based leakage survey program for all
  gas mains with, at a minimum, the requirements as set forth in 49
  C.F.R. §192.723 and 35-A MRSA §4713. As part of their compliance with
  49 C.F.R. §192.605, operators must provide the detail on the survey
  cycles. Operators' DIMP written plans must provide the justification,
  based on data and metrics compiled and reviewed as part of the DIMP
  written plan, for the selection of each survey cycle identified in the
  operators' operations and maintenance procedures. Operators must
  complete a leakage survey of all mains and service lines, including
  meters and meter piping, at a frequency not to exceed 3 calendar
  years.

  b. Operators must conduct a leakage survey of all cast iron main lines
  at least every 30 days between December 1 and April 30.

  c. Operators must conduct a leak survey at buildings used for public
  assembly, including schools, post offices, churches, hospitals,
  nursing homes, theaters, and municipal buildings each year during the
  period March 1 to December 1. This requirement only applies to all
  public assembly buildings having a gas service line. Operators must
  utilize risk-based parameters to identify additional service lines in
  places of public congregation beyond those listed above, that require
  a survey each year from March 1 to December 1. Operators must use
  existing and readily accessible data to identify these risk-based
  parameters which may include service size, delivery pressure, number
  of meters, meter size, or building occupancy

  d. If, when investigating a leak, an operator determines or has
  determined that the perimeter of a leak area extends to a building
  wall, the investigation must continue into the building unless public
  safety or identifiable urgent circumstances prohibit entry.

  e. Once public safety or identifiable urgent circumstances no longer
  prohibit entry, the investigation, as provided in (d) above, must
  continue into the building, if the leak has not yet been resolved
  utilizing a combustible gas indicator.

  2. Leak Detection Equipment Calibration and Maintenance

  Operators must maintain written procedures for the calibration and
  maintenance of leak detection equipment. These procedures must
  consider the type of equipment, frequency of use, manufacturer's
  calibration recommendations, historical performance, age of equipment,
  required maintenance intervals and equipment failure protocols.

  Operators must review these procedures annually and modify the
  procedures to the degree necessary to ensure that leak detection
  equipment used in the field has been properly calibrated and
  maintained.

  E. Leak Classification and Repair

  The purpose of the leak grading system is to determine the degree or
  extent of the potential hazard resulting from gas leakage and to
  prescribe remedial actions. Operators must promptly respond to any
  notification of a gas leak or gas odor or any notification of damage
  to facilities by excavators or other outside sources.

  Operators must ensure that leak grading is made only by those
  individuals who possess training, experience, and knowledge in the
  field of leak classification and investigation. The judgment of these
  individuals, based upon all pertinent information and a complete
  leakage investigation at the scene, must form the basis for the leak
  grade determination.

  1. Leak Response

  a. Operators must establish a leak repair priority based on their
  evaluation of the location and the magnitude of a leak.

  b. Operators must assign a classification of leaks in accordance with
  this subsection;

  c. Operators must immediately notify the fire department of the
  community involved of each Grade 1 leak found to exist in their
  pipeline systems.

  2. Grade 1 Leaks

  a. A Grade 1 leak is a leak that represents an existing or probable
  hazard to persons or property and requires prompt action, immediate
  repair, or continuous action until the conditions are no longer
  hazardous. A Grade 1 leak includes but is not limited to:

  1. Any leak which, in the judgment of operating personnel at the
  scene, is regarded as an immediate hazard;

  2. Escaping gas that has ignited;

  3. Any indication of gas, which has migrated into or under a building,
  or into a conduit or tunnel;

  4. Any reading at the outside wall of a building, or where gas would
  likely migrate to an outside wall of a building;

  5. Any reading of 70% lower explosive limit (LEL) or greater in a
  confined space;

  6. Any reading of 70% LEL or greater in small substructures, other
  than gas associated substructures, from which gas would likely migrate
  to the outside wall of a building; or

  7. Any leak that can be seen, heard, or felt, and which is in a
  location that may endanger the general public or property.

  b. A Grade 1 Leak requires an operator to take action immediately to
  eliminate the hazard and make repairs. The action may require one or
  more of the following:

  1. Implementing an emergency plan;

  2. Evacuating premises;

  3. Blocking off an area;

  4. Rerouting traffic;

  5. Eliminating sources of ignition;

  6. Venting the area by removing manhole covers, barholing, installing
  vent holes, or other means;

  7. Stopping the flow of gas by closing valves or other means; or

  8. Notifying emergency responders.

  3. Grade 2 Leaks

  a. A Grade 2 leak means a leak that is recognized as being
  non-hazardous at the time of detection but justifies scheduled repair
  or removal within six months or less of detection due to the
  probability of its future hazard.

  b. Grade 2 leaks vary greatly in degree of potential hazard. Operators
  must establish a repair priority for all Grade 2 leaks. In determining
  the repair priority, Operators must consider criteria such as the
  following:

  1. The amount and migration of gas;

  2. The proximity of gas to buildings and subsurface structures;

  3. The extent of pavement; and

  4. Soil type and conditions, such as frost cap, moisture, and natural
  venting.

  c. Operators must complete Priority 1 repairs within 30 days of
  detection of any leak:

  1. With a sustained reading of 40% LEL, or greater, under a sidewalk
  in a wall-to-wall paved area that does not qualify as a Grade 1 leak;

  2. With a sustained reading of 100% LEL, or greater, under a street in
  a wall-to-wall paved area that has significant gas migration and does
  not qualify as a Grade 1 Leak;

  3. With a sustained reading less than 70% LEL in small substructures
  (other than gas associated substructures) from which gas would likely
  migrate creating a probable future hazard;

  4. With a sustained reading between 20% LEL and 70% LEL in a confined
  space;

  5. With a reading on a pipeline operating at 30 percent SMYS, or
  greater, in a class 3 or 4 location, which does not qualify as a Grade
  1 leak;

  6. With a reading of 70% LEL, or greater, in gas associated
  substructures; and

  7. Which, in the judgment of operating personnel at the scene, is of
  sufficient magnitude to justify scheduled repair.

  d. Operators must re-evaluate all active Grade 2 leaks at a minimum of
  every 30 days until the leak is repaired and cleared.

  e. Operators must take action ahead of ground freezing or other
  adverse changes in venting conditions with respect to any leak which,
  under frozen or other adverse soil conditions, would likely allow gas
  to migrate to the outside wall of a building.

  4. Grade 3 Leaks

  a. A Grade 3 leak is a leak that is non-hazardous at the time of
  detection and can be reasonably expected to remain non-hazardous.

  b. Operators must survey and re-evaluate each Grade 3 leak at least
  once every 180 days from the date of discovery, until the leak is
  repaired. A leak requiring re-evaluation at periodic intervals
  includes any reading:

  1. Of less than 70% LEL in small, gas-associated substructures;

  2. Under a street in areas without wall-to-wall paving where it is
  unlikely the gas could migrate to the outside wall of a building; and

  3. Of less than 20% LEL in a confined space.

  c. Operators must repair each Grade 3 leak within 24 months of its
  detection unless the leak is located within an approved main
  replacement program area in which case the operator may extend the
  time for repair to the scheduled replacement.

  5. Bare Steel Service Line Leaks

  Operators finding a leak on a bare steel service line must replace the
  entire service line.

  6. Post-Repair Inspections

  a. In the case of leak repairs other than Grade 1, the need for a
  follow-up inspection must be determined by qualified personnel of the
  operator.

  b. Operators must conduct a follow-up inspection as follows:

  1. The adequacy of leak repairs must be checked before backfilling;

  2. The perimeter of the leak area must be checked with a combustible
  gas indicator (CGI) or equivalent gas detection equipment; and

  3. Where there is residual gas in the ground after the repair of a
  Grade 1 leak, the operator must 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.

  c. A leak is considered to be effectively repaired when an operator's
  operating personnel obtains a gas concentration reading of 0%.

  d. For a repaired leak with a gas concentration reading greater than
  0% at the time of repair, operators must conduct a post-repair leak
  inspection within 30 days after the repair to determine whether the
  leak has been effectively repaired. If the second post-repair
  inspection shows a gas concentration reading greater than 0%,
  operators must continue conducting post-repair leak inspections every
  30 days until there is a gas concentration reading of 0%. If on
  cathodically protected steel or plastic pipe, three post-repair
  inspections have been performed and the operator is unable to obtain a
  gas concentration reading of 0%, then the operator must initiate a new
  repair. For cast iron or unprotected steel pipe, which is included in
  an MPUC-approved pipe replacement program, and the operator is unable
  to obtain gas concentration readings of 0% after the third recheck,
  then these leaks must be regraded and moved to active status.
  Additional repairs will be required utilizing the requirements
  established for the new leak grading. If, after the third post-repair
  leak inspection, an operator regrades a leak and moves it to active
  status, the new leak classification will be based on the highest gas
  reading, or other conditions found during the third inspection, that
  results in the most conservative leak grade, prior to venting or other
  activity.

  e. Post-repair inspections are not required for leak repairs completed
  by the replacement or insertion of an entire length of pipe or service
  line, or for the repair of leakage caused by excavator or third-party
  damage, provided a complete re-evaluation of the leak area after
  completion of repairs verifies that no further indications of leakage
  exist.

  f. Remedial measures such as lubrication of valves or tightening of
  packing nuts on valves which seal leaks are considered to be routine
  maintenance work and do not require a post-repair inspection.

  7. Upgrading. When operators upgrade a leak to a higher grade, the
  time period for repair is the remaining time based on its original
  classification or the time allowed for repair under its new grade,
  whichever is less. This requirement does not apply to leaks that, at
  the time of discovery, the operator classified at a lower grade
  pending a further, more complete investigation of the leak hazard
  area.

  8. Downgrading. Operators must not downgrade a leak unless it is
  repaired.

  F. Leak Progression Maps. Operators must institute and maintain on a
  continuing basis a leak progression mapping system of their service
  areas in a format that conforms with the specifications of Chapter
  140. Map attributes to be included for each leak must be: pipe or
  appurtenance material; location of leak; cause of leak; and type of
  joint, if joint leak. Operators must enter into the system all leaks
  that have occurred since January 1, 2009. Operators should enter into
  the system leak history information prior to January 1, 2009 if the
  operator can verify the accuracy of the information.
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