# Leak Grading and Repair

- **operation:** document
- **citation:** 16 TAC § 8.207
- **title:** Leak Grading and Repair
- **source type:** regulation
- **agency:** Railroad Commission of Texas
- **status:** current
- **official:** true
- **published on:** Not available
- **effective on:** 2008-09-01
- **summary:** (a) Purpose and qualifications. Operators shall have until March 1, 2009, to repair Grade 2 leaks identified prior to September 1, 2008, and shall have until September 1, 2011, to repair Grade 3 leaks identified prior to September 1, 2008. For all leaks reported on or after September 1, 2008, operat
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- **markdown:** https://regulus.evalyn.ai/document/tx-tac-16-8-207.md
- **app url:** https://regulus.evalyn.ai/document/tx-tac-16-8-207
- **source url:** https://texas-sos.appianportalsgov.com/rules-and-meetings?chapter=8&interface=VIEW_TAC&part=1&title=16
**body:**

(a) Purpose and qualifications. Operators shall have until
March 1, 2009, to repair Grade 2 leaks identified prior to
September 1, 2008, and shall have until September 1, 2011,
to repair Grade 3 leaks identified prior to September 1, 2008.
For all leaks reported on or after September 1, 2008,
operators shall comply with the requirements of this section.
(1) 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.
Each operator shall 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.
(2) Each operator shall ensure that leak grading is
made only by those individuals who possess training,
experience, and knowledge in the field of leak classification
and investigation, including extensive association with actual
leakage work. The judgment of these individuals, based upon
all pertinent information and a complete leakage
investigation at the scene, shall form the basis for the leak
grade determination. Each operator shall ensure that its leak
detection equipment is properly calibrated.
(b) Grade 1 leaks.

(1) A Grade 1 leak is an existing or probable hazard
to persons or property and requires the operator to take
action immediately to eliminate the hazard and make repairs.
A Grade 1 leak includes but is not limited to:
(A) any leak which, in the judgment of
operating personnel at the scene, is regarded as an immediate
hazard;
(B) escaping gas that has ignited;
(C) any indication of gas, which has migrated
into or under a building, or into a tunnel;
(D) any reading at the outside wall of a
building, or where gas would likely migrate to an outside
wall of a building;
(E) any reading of 80% lower explosive limit
(LEL) or greater in a confined space;
(F) any reading of 80% 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
(G) any leak that can be seen, heard, or felt, and
which is in a location that may endanger the general public
or property.
(2) A Grade 1 leak requires that the operator take
prompt action to eliminate the hazardous conditions. The
prompt action may require one or more of the following:
(A) implementing an emergency plan (49 CFR
§192.615);
(B) evacuating premises;
(C) blocking off an area;
(D) rerouting traffic;
(E) eliminating sources of ignition;
(F) venting the area by removing manhole
covers, barholing, installing vent holes, or other means;
(G) stopping the flow of gas by closing valves
or other means; or
(H) notifying emergency responders.
(c) Grade 2 leaks.
(1) A Grade 2 leak is non-hazardous at the time of
detection, but requires the operator to schedule repair based
on probable future hazard. A Grade 2 leak, because of its
location and magnitude, can be scheduled for repair on a
normal routine basis with periodic reinspection as necessary.
Each operator shall re-evaluate every Grade 2 leak at least
once every 30 days until repaired or cleared.
(2) Each operator shall repair within six months of
detection any leak:
(A) with a 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;
(B) with a 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;
(C) with a reading less than 80% LEL in small
substructures (other than gas associated substructures) from
which gas would likely migrate creating a probable future
hazard;
(D) with a reading between 20% LEL and 80%
LEL in a confined space;
(E) 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;
(F) with a reading of 80% LEL, or greater, in
gas associated substructures; and
(G) which, in the judgment of operating
personnel at the scene, is of sufficient magnitude to justify

scheduled repair.
(3) Grade 2 leaks vary greatly in degree of potential
hazard. Some Grade 2 leaks, when evaluated by the criteria
in this subsection, may require a scheduled repair within the
next five working days. Others will require repair within 30
days. In determining the repair priority, each operator shall
consider criteria such as the following:
(A) the amount and migration of gas;
(B) the proximity of gas to buildings and
subsurface structures;
(C) the extent of pavement; and
(D) soil type and conditions, such as frost cap,
moisture, and natural venting.
(4) Each operator shall 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.
(d) Grade 3 leaks.
(1) A Grade 3 leak is non-hazardous at the time of
detection and reasonably can be expected to remain non-
hazardous. Each operator shall repair a Grade 3 leak within
36 months of detection.
(2) Each operator shall re-evaluate each Grade 3
leak during the next scheduled survey, or within 15 months
of date reported, whichever occurs first, until the leak is
cleared, repaired, or re-graded. A leak requiring re-
evaluation at periodic intervals includes any reading:
(A) of less than 80% LEL in small, gas-
associated substructures;
(B) 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
(C) of less than 20% LEL in a confined space.
(e) Post-repair inspections.
(1) A leak is considered to be effectively repaired
when an operator obtains a gas concentration reading of 0%.
(2) For a repaired leak with a gas concentration
reading greater than 0% at the time of repair, an operator
shall 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%, the
operator shall continue conducting post-repair leak
inspections every 30 days until there is a gas concentration
reading of 0%. If after six inspections have been performed
the operator is unable to obtain a gas concentration reading
of 0%, then the operator shall create a new leak report with a
new leak grade determination.
(3) 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.
(4) 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.
(f) Upgrading. When an operator upgrades 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, an operator has classified at a lower grade

pending a further, more complete investigation of the leak
hazard area.
(g) Table. The following table provides a concise
reference for leak grading and leak repair deadlines.
Figure: 16 TAC §8.207(g) [See Figure at end of this
document.]

Figure: 16 TAC §8.207(g) DEFINITION GRADE 1 A leak that represents an existing or probable hazard to persons or property, and requires immediate repair. ACTION CRITERIA Requires immediate repair. Requires prompt action to eliminate the hazardous conditions. The prompt action in some instances may require one or more of the following: P Implementation an emergency plan (§192.615). P Evacuating premises. P Blocking off an area. P Rerouting traffic. P Eliminating sources of ignition. P Venting the area by removing manhole covers, barholing, installing vent holes, or other means. P Stopping the flow of gas by closing valves or other means. P Notifying emergency responders. 2 A leak that is recognized as being non-hazardous at the time of detection, but requires scheduled repair based on probable future hazard Leaks shall be repaired or cleared within six months from the date the leak was reported. In determining the repair priority, criteria such as the following should be considered: P Amount and migration of gas. P Proximity of gas to buildings and subsurface structures. P Extent of pavement. P Soil type, and soil conditions (such as frost cap, moisture and natural venting). Grade 2 leaks should be reevaluated at least once every 30 days until cleared. Grade 2 leaks vary greatly in degree of potential hazard. Some Grade 2 leaks, when evaluated by the above criteria, may require a scheduled repair within the next five working days. Others will require repair within 30 days. During the working day on which the leak is discovered, these situations should be brought to the attention of the individual responsible for scheduling leak repair. On the other hand, many Grade 2 leaks, because of their location and magnitude, can be scheduled for repair on a normal EXAMPLES P Any leak which, in the judgment of operating personnel at the scene, is regarded as an immediate hazard. P Escaping gas that has ignited. P Any indication of gas, which has migrated into or under a building, or into a tunnel. P Any reading at the outside wall of a building, or where gas would likely migrate to an outside wall of a building. P Any reading of 80% LEL, or greater, in a confined space. P Any reading of 80% LEL, or greater in small substructures (other than gas associated substructures) from which gas would likely migrate to the outside wall of a building. P Any leak that can be seen, heard, or felt, and which is in a location that may endanger the general public or property. Leaks Requiring Action Ahead of Ground Freezing or Other Adverse Changes in Venting Conditions. Any leak which, under frozen or other adverse soil conditions, would likely migrate to the outside wall of a building. Leaks Requiring Action Within Six Months P Any 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. P Any 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. P Any reading less than 80% LEL in small substructures (other than gas associated substructures) from which gas would likely migrate creating a probable future hazard. P Any reading between 20% LEL and 80% LEL in a confined space. P Any 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. P Any reading of 80% LEL, or greater, in gas associated substructures. P Any leak which, in the judgment of operating personnel at the scene, is of sufficient magnitude to justify scheduled GRADE DEFINITION 3 A leak that is non- hazardous at the time of detection and can be reasonably expected to remain non- hazardous. ACTION CRITERIA routine basis with periodic reinspection as necessary. These leaks should be reevaluated during the next scheduled survey, or within 15 months of date reported, whichever occurs first, until the leak is cleared, re-graded, or repaired within 36 months. EXAMPLES repair. Leaks Requiring Reevaluation at Periodic Intervals P Any reading of less than 80% LEL in small gas associated substructures P Any reading 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. P Any reading of less than 20% LEL in a confined space.
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