The Texas Railroad Commission (TRRC) proposes new §§ 8.206, 8.207, and 8.208, relating to Risk-Based Leak Inspection Program, Leak Grading and Repair, and Mandatory Removal and Replacement Program, to enhance the Commission’s pipeline safety program. The proposed new rules would require Texas gas distribution companies to:
- Establish a risk-based schedule of increased leak inspections;
- Operators would create a risk model using five risk factors relating to the physical characteristics and environment of the pipeline segment. The factors include pipe location, nature of the pipe system, the history of corrosion, environmental considerations regarding gas migration, and other factors including weather, construction activity, and operator judgment.
- Based on a risk ranking from high to low, operators of gas distribution systems would schedule leak inspections for a given pipeline segment at a time interval that is appropriate to address the identified risk
- Standardize leak grading and repair times frames by adopting a slightly revised version of the Gas Piping Technology Committee (GPTC) standards in ANSI Z380.1.
- Grade 1 leaks would still be required to be repaired immediately.
- Grade 2 leaks would be re-evaluated monthly and repaired no later than six months from the date of detection.
- Grade 3 leaks would be re-evaluated once each calendar year, not to exceed 15 months and repaired no later than three years from detection.
- Remove and replace leaking compression couplings and compression couplings at presently known service riser installations if the couplings are not manufactured and installed with secondary restraint and if they are not resistant to pull-outs. The removal and replacement of such compression couplings must be completed within two years of the effective date of the rule. No later than May 31, 2008, and every six months thereafter, a progress report is required a detailing the number of service riser installations checked, the condition of the coupling, and the total number of compression couplings replaced.
TRRC proposes to incorporate risk-based leakage surveys to the natural gas distribution operators in Texas for two reasons: By adopting this model as the minimum standard, each operator can apply the risk factors to its pipeline system or segments within its system to determine if more frequent leak surveys are warranted for enhanced safety. The second reason is to reduce the number of leaks that may have been leaking over an extended period of time.
The leak survey model proposed in §8.206 will go hand-in-hand with the distribution integrity management rules being developed by the federal Office of Pipeline Safety. Leak survey, leak monitoring, and leak repair are very important factors in the integrity assessment and management of pipeline systems. The implementation of a risk model and consistent leak grading and repair procedures at the distribution system level will allow Texas operators to assess the overall integrity of their systems and manage them according to the federal requirements. Additionally, the proposed leak grading and repair model in §8.207 will provide a consistent application of what a “graded” leak is in Texas.
Comments on the proposed rulemaking are due by 5:00 p.m., Tuesday, February 5, 2008 and may be submitted to: Rules Coordinator, Office of General Counsel, Railroad Commission of Texas, P.O. Box 12967, Austin, Texas 78711-2967; online at www.rrc.state.tx.us/rules/commentform.html; or by electronic mail to email@example.com.
For more information or for a copy of the proposed new rulemaking, contact Jessica Roger.