Distribution Systems: Leakage Surveys and Procedures

§ 192.723 Distribution Systems: Leakage Surveys and Procedures#

(a)Each operator of a distribution system shall conduct periodic leakage surveys in accordance with this section. These surveys must be performed by, or under the direct supervision of, personnel trained and qualified in both the use of appropriate equipment and the classification of leaks. In addition, maps that approximate the location of the mains and transmission lines being surveyed must be available.#

(b)The type and scope of the leakage control program must be determined by the nature of the operations and the local conditions, but it must meet the following minimum requirements.#

(1)A leakage survey with leak detector equipment shall be conducted in business districts including test of the atmosphere in electric, gas, sewer, telephone, and water system manholes, at cracks in pavement and sidewalks and at other locations providing an opportunity for finding gas leaks. This survey shall be performed with a flame ionization unit or a gas detector at intervals not exceeding 15 months, but at least once each calendar year.#

(2)A leakage survey with leak detector equipment must be conducted outside business districts as frequently as necessary, but at intervals not exceeding 5 calendar years not exceeding 63 months. However, for cathodically unprotected distribution lines subject to §192.465(e) on which electrical surveys for corrosion are impractical, a leakage survey must be conducted at least once every 3 calendar years at intervals not exceeding 39 months.#

(i)A leakage survey of all underground natural gas distribution systems outside of a business district, that are owned/operated or the responsibility of a public or municipal utility shall be performed as frequently as necessary but at intervals not exceeding five#

(5)calendar years.#

(ii)A leakage survey of all underground natural gas distribution systems, not owned nor the responsibility of a public or municipal utility and used to transport gas from a master meter or utility company gas main to multiple buildings, shall be performed as frequently as necessary but at intervals not exceeding five#

(5)years. Owners/operators of these systems shall be responsible to ensure these surveys are accomplished.#

(c)The type and scope of the surveys required in subdivisions (b)(2)(i) and#

(ii)of this section, must ensure detection, location, evaluation and classification of any gas leakage. The following methods may be employed depending on the design and size of the system or facility:#

(1)Flame Ionization Detector.#

(2)Combustible Gas Indicator (includes bar holing).#

(3)Pressure Drop or No Flow. Only to be used to establish the presence or absence of leakage on a distribution system. Where leakage is indicated, further evaluation by another detection method must be accomplished to locate, evaluate and classify leaks. When this method is used to verify no leakage exists a test record certified by a qualified person, organization or agency must be retained with records of survey. NOTE: Test duration must be of sufficient length to detect leakage, and the following should be considered: Volume under test and the time for the test medium to become temperature stabilized.#

(d)All leaks detected shall be classified to assure a standardized priority of repair is established. There is no precise means presently developed to accurately classify leaks, however, there are four general categories that must be considered when judging the severity of gas leaks:#

(1)Proportion. The quantity of gas escaping based on gas indicator readings, pressure of line or container from which gas is escaping and concentration of odor.#

(2)Location. The centralized location of escaping gas; under buildings and paved surfaces, near occupied buildings, near source of ignition or in open areas where the concentration of gas is improbable.#

(3)Dispersion. The areas to which escaping gas may spread. Based on depth of line, type of soil, pressure, surface cover, moisture, frozen soil and other soil conditions.#

(4)Evaluation. All factors must be evaluated, applying experience and good judgment in arriving at the proper classification.#

(e)To standardize leak classification, using the above factors, all leaks shall be classified in the following categories:#

(1)Class 1. Leaks that represent an existing or probable hazard to persons or property and requires immediate repair or continuous action until the hazardous condition no longer exists.#

(2)Class 2. Leaks that are considered non-hazardous at the time of detection, but could become hazardous if repair is not accomplished in a reasonable length of time. Repair as soon as possible, but within a period not to exceed five months.#

(3)Class 3. Leaks that are non-hazardous at the time of detection and can be expected to remain non-hazardous. These leaks should be re-evaluated during the next scheduled survey. Repair as time and expenditures permit.#

(f)#

(1)In addition to leak surveys, any leak or gas odor reported from the public, fire, police or other authorities or notification of damage to facilities by outside sources shall require prompt investigation. Thorough investigations shall be performed on all suspected leaks to determine the degree of existing hazard to person or property. This includes entering structures in a reported or suspected leakage area and checking for presence of gas.#

(2)Leaks reported on customer's piping shall be investigated by trained and qualified employees who must judge the degree of hazard and establish the required repair priority. If a hazardous leak exists on customer's piping, the service shall be immediately terminated upstream of the leak. If the leak is not presently hazardous but may become hazardous, the customer shall be given a reasonable time to repair the leak.#

(g)A leak repair record shall be made for every leak detected or identified. Leaks discovered on customer's piping, downstream of the meter, shall be documented on operator's service orders and retained until the customer's piping has been repaired to the satisfaction of the operator. Corrosion leaks shall be documented on permanent records and shall be retained for as long as the segment of pipeline on which the leak was located is in service. As a minimum, leak records other than corrosion shall be maintained on the two most current leak surveys. Each leak record shall contain, as a minimum, the following:#

(1)Date leak discovered.#

(2)Location.#

(3)Classification.#

(4)Cause of leak.#

(5)Unique identifier for person making the repair or responsible for maintaining the records of work accomplished.#

(h)Leaks may be reclassified by responsible and suitable experienced persons whose name shall appear on the documents.#