CPUC General Order 112-F § 143 - DISTRIBUTION AND TRANSMISSION SYSTEMS

143.1Leakage Surveys and Procedures#

(a)A gas leak survey, using leak detecting equipment, must be conducted in business districts and in the vicinity of schools, hospitals and churches, including tests of the atmosphere in gas, electric, telephone, sewer and water system manholes, at cracks in pavement, and sidewalks, and at other locations providing an opportunity for finding gas leaks, at intervals not exceeding 15 months, but at least once each calendar year.#

(b)A gas leakage survey of transmission pipelines, using leak detecting equipment must be conducted at least twice each year and at intervals not exceeding 7 ½ months.#

143.2Leak classification and action criteria – Grade – Definition – Priority of leak repair -#

(a)A "Grade 1 leak" is a leak that represents an existing or probable hazard to persons or property and requiring prompt action, immediate repair, or continuous action until the conditions are no longer hazardous.#

(1)Prompt action in response to a Grade 1 leak may require one or more of the following:#

(i)Implementation of the gas pipeline company's emergency plan pursuant 49 CFR § 192.615;#

(ii)Evacuating the premises;#

(iii)Blocking off an area;#

(iv)Rerouting traffic;#

(v)Eliminating sources of ignition;#

(vi)Venting the area;#

(vii)Stopping the flow of gas by closing valves or other means; or#

(viii)Notifying police and fire departments.#

(2)Examples of Grade 1 leaks requiring prompt action include, but are not limited to:#

(i)Any leak, which in the judgment of the Operator personnel at the scene, is regarded as an immediate hazard;#

(ii)Escaping gas that has ignited unintentionally;#

(iii)Any indication of gas that has migrated into or under a building or tunnel;#

(iv)Any reading at the outside wall of a building or where the gas could potentially migrate to the outside wall of a building;#

(v)Any reading of eighty percent of the gas’ lower explosive limit (LEL) or greater in an enclosed space;#

(vi)Any reading of eighty percent of LEL or greater in small substructures not associated with gas facilities where the gas could potentially migrate to the outside wall of a building; or#

(vii)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 2 leak" is a leak that is recognized as being not hazardous at the time of detection but justifies scheduled repair based on the potential for creating a future hazard.#

(1)Except as required by Section 143.2(d), each Operator must repair or clear Grade 2 leaks within fifteen months from the date the leak is reported. If a Grade 2 leak occurs in a segment of pipeline that is under consideration for replacement, an additional six months may be added to the fifteen months maximum time for repair provided above. In determining the repair priority, each Operator must consider the following criteria:#

(i)Amount and migration of gas;#

(ii)Proximity of gas to buildings and subsurface structures;#

(iii)Extent of pavement; and#

(iv)Soil type and conditions, such as frost cap, moisture and natural venting.#

(2)Each Operator must reevaluate Grade 2 leaks at least once every six months until cleared. The frequency of reevaluation should be determined by the location and magnitude of the leakage condition.#

(3)Grade 2 leaks vary greatly in degree of potential hazard. Some Grade 2 leaks, when evaluated by the criteria, will require prompt scheduled repair within the next five working days. Other Grade 2 leaks may require repair within thirty days. The Operator must bring these situations to the attention of the individual responsible for scheduling leakage repair at the end of the working day. Many Grade 2 leaks, because of their location and magnitude, can be scheduled for repair on a normal routine basis with periodic reevaluation as necessary.#

(4)When evaluating Grade 2 leaks, each Operator must consider leaks requiring action ahead of ground freezing or other adverse changes in venting conditions, and any leak that could potentially migrate to the outside wall of a building, under frozen or other adverse soil conditions.#

(5)Examples of Grade 2 leaks requiring action within six months include, but are not limited to:#

(i)Any reading of forty percent LEL or greater under a sidewalk in a wall-to-wall paved area that does not qualify as a Grade 1 leak and where gas could potentially migrate to the outside wall of a building;#

(ii)Any reading of one hundred percent LEL or greater under a street in a wall-to-wall paved area that does not qualify as a Grade 1 leak and where gas could potentially migrate to the outside wall of a building;#

(iii)Any reading less than eighty percent LEL in small substructures not associated with gas facilities and where gas could potentially migrate creating a probable future hazard;#

(iv)Any reading between twenty percent LEL and eighty percent LEL in an enclosed space;#

(v)Any reading on a pipeline operating at thirty percent of the specified minimum yield strength or greater in Class 3 or 4 locations that does not qualify as a Grade 1 leak; or#

(vi)Any leak that in the judgment of the Operator personnel at the scene is of sufficient magnitude to justify scheduled repair.#

(c)A "Grade 3 leak" is a leak that is not hazardous at the time of detection and can reasonably be expected to remain not hazardous.#

(1)Each Operator must reevaluate Grade 3 leaks during the next scheduled survey, or within fifteen months of the reporting date, whichever occurs first. Thereafter, the leak must be reevaluated every calendar year, not to exceed 15 months until the leak is repaired, regraded or no longer results in a reading.#

(2)Examples of Grade 3 leaks requiring reevaluation at periodic intervals include, but are not limited to:#

(i)Any reading of less than eighty percent LEL in small gas associated substructures, such as small meter boxes or gas valve boxes; or#

(ii)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.#

(d)Any grade of leaks above Grade 3 can only be downgraded once to a Grade 3 leak without a physical repair. After a leak has been downgraded to Grade 3, the leak must be reevaluated every calendar year not to exceed 15 months. If the Grade 3 leak is upgraded at any time to a higher grade, the leak must be reevaluated and repaired per the Operator’s procedures for the higher grade to which the leak is upgraded and may not be downgraded again to Grade 3.#

(e)All underground leaks on transmission lines classified as Grade 2 or 3, or any subcategories of grades an Operator may establish between Grade 2 or 3, must be repaired by the Operator either upon discovery or within one year after discovery.#

143.3Valve Maintenance - Each valve, the use of which may be necessary for the safe operation of a distribution system, must be inspected, serviced, lubricated (where required) and partially operated at intervals not exceeding 15 months, but at least once each calendar year.#

143.4Operator Qualification - The equipment and facilities used by an Operator for training and qualification of employees must be identical, or very similar in operation to the equipment and facilities which the employee will use, or on which the employee will perform the covered task.#

143.5Encroachments – With the exception of gas pipeline facilities related to installations in gas meter rooms or other specially designed indoor locations where an outdoor meter installation is not possible or practical, a utility transporting LNG, natural gas or other gas shall not construct any part of a LNG, natural gas or other gas pipeline system under a building. In addition, the utility shall not allow a building or other encroachments to be constructed on to its pipeline right-of-way that would hinder maintenance activities on the pipeline or cause a lengthy delay in accessing its pipeline facilities during an emergency. If the utility finds a building or other encroachment built over a pipeline facility after the effective date of this section, then the utility may require the party causing the encroachment to remove the building or other encroachment from over the pipeline facility or to reimburse the utility for its costs associated with relocating the pipeline system.#

The utility shall determine, within 90 days after discovering the encroachment, whether the encroachment can be resolved within 180 days. If the utility determines that the encroachment cannot be resolved within 180 days, the utility shall, within 90 days of discovery of the encroachment, submit to the CPUC a written plan to resolve the encroachment within a period longer than 180 days. The CPUC may then extend the 180-day requirement in order to allow the party causing the encroachment and the utility to implement the written plan to resolve the encroachment. If the utility does not submit a written plan, and the encroachment is not resolved within 180 days of discovery, the utility shall isolate and discontinue service to the section of pipeline on which the encroachment exists. The utility must provide written notice of any imminent service discontinuance per this section to the Commission 30 days prior to discontinuing service.#

143.6Compatible Emergency Response Standard – In establishing emergency response procedures, all gas utilities shall use, at a minimum, the Incident Command Systems (ICS) as a framework for responding to and managing emergencies and disasters involving multiple jurisdictions or multiple agency responses. The ICS used by utilities must be compatible with the ICS used by the first responder community within the State of California, and as detailed in California Government Code Section 8607(a), All gas utilities must have the ICS in place to be activated when necessary to the types of emergency events listed and detailed within the written emergency plans gas utilities are required to maintain per 49 CFR Part 192, §192.615.#