Compilation of Rules and Regulations of the State of Georgia
Department 515 - RULES OF GEORGIA PUBLIC SERVICE COMMISSION
Chapter 515-9 - SAFE INSTALLATION AND OPERATION OF NATURAL GAS TRANSMISSION AND DISTRIBUTION SYSTEMS
Subject 515-9-1 - SAFE INSTALLATION AND OPERATION OF NATURAL GAS TRANSMISSION AND DISTRIBUTION SYSTEMS
Rule 515-9-1-.05 - Leak Standards

GRADE

DEFINITION

ACTION CRITERIA

EXAMPLES

1

A leak that represents an existing or probable hazard to persons or property, and requires immediate repair or continuous action until the conditions are no longer hazardous.

Requires prompt action

* to protect life and property, and continuous action until the conditions are no longer hazardous.

* The prompt action in some instances may require one or more of the following:

a. Implementation of company emergency plan (192.615)

b. Evacuating premises.

c. Blocking off an area.

d. Rerouting traffic.

e. Eliminating sources of ignition.

f. Venting the area.

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

h. Notifying police and fire departments.

1. Any leak which, in the judgement 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 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 80% LEL, or greater, in a confined space.

6. 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.

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

GRADE

DEFINITION

ACTION CRITERIA

EXAMPLES

2

Leak that is recognized as being non-hazardous at the time of detection, but justifies scheduled repair based on probable future hazard.

Leaks should be repaired or cleared within one calendar year, but no later than 15 months from the date the leak was reported. In determining the repair priority, criteria such as the following should be considered.

a. Amount of migration of gas.

b. Proximity of gas to buildings and subsurface structures.

c. Extent of pavement.

d. Soil types, and soil conditions (such as frost cap, moisture and natural venting).

Grade 2 leaks should be reevaluated at least once every six months until cleared. The frequency of reevaluation should be determined by the location and magnitude of the leakage contition.

Grade 2 leaks may vary greatly in degree of potential hazard. Some Grade 2 leaks, when evaluated by the above criteria, may justify scheduled repair within the next 5 working days. Others will justify 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 routine basis with periodic reinspection as necessary.

A. 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.

B. Leaks Requiring Action Within Six Months.

1. 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.

2. 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.

3. 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.

4. Any reading between 20% LEL and 80% LEL in a confined space.

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

6. Any reading of 80% LEL, or greater, in gas associated substructures.

7. Any leak which, in the judgement of operating personnel at the scene, is of sufficient magnitude to justify scheduled repair.

GRADE

DEFINITION

ACTION CRITERIA

EXAMPLES

3

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

These leaks should be reevaluated during the next scheduled survey, or within 15 months of the date reported, whichever occurs first, until the leak is regraded or no longer results in a reading.

A. Leaks Requiring Reevaluation at Periodic Intervals

1. Any reading of less than 80% LEL in small gas associated substructures.

2. Any reading under a street in areas without wall-to-wall paving where it is unlikley the gas could migrate to the outside wall of a building.

3. Any reading of less than 20% LEL in a confined space.