b'APPENDIX APPENDIXLeak DetectionAtmos Energy surveys the approximately 75,000 miles of our distribution and transmission pipelines at rates and frequencies that meet and often exceed state and federal guidelines. Monitoring frequency of pipelines is determined by federal and state pipeline safety codes, accepted industry standards, and internal Atmos Energy practices and procedures. The technology used to complete a pipeline leak survey may vary, depending on the conditions at the time of survey. It is our practice to use the instrument that is best suited for the existing conditions to complete pipeline surveys. Here is a brief summary of the frequency of leak surveys of our transmission and distribution systems:Transmission Pipelines Distribution Pipelines In many of our more densely populated areas, Distribution mains located outside of business districts transmission pipelines are visually surveyed twice perare surveyed at least as often as prescribed by federal month and incorporate the use of aircraft, whereand state regulations (with the maximum being five appropriate, to look for oxygen-starved vegetation,years) using the various technologies discussed on the right-of-way encroachment, erosion, landslides, andprevious left-hand page of this appendix under possible security threats. Investing in Technology to Improve Safety. Our Mississippi and West Texas divisions use aircraft For distribution pipelines located within business to leak survey annually. Our Atmos PipelineTexasdistricts, a survey is required and completed atand Mid-Tex divisions use aircraft to leak survey twiceleast annually.per year. Our Texas jurisdictions, Mid-Tex and West Texas,Technicians leak survey all pipeline road crossingscontain over 95 percent of our unprotected steel quarterly using the appropriate leak survey equipment. distribution pipe inventory and Mid-Tex contains 100 percent of our remaining cast iron pipe inventory. InAtmos Energy also completes annual visualthese jurisdictions, we leak survey at intervals that are vegetation/leak surveys on all transmission pipelinesmore frequent than the federal requirements. ForGrading a Leak Grade 1using highly trained technicians performing patrols. coated steel pipe, we survey at least once every three1 Leaks which represent an immediate hazard to persons and/or property. These leaks are addressed and repaired immediately.years, bare steel we survey at least once every twoLeaks identified on the Atmos years, and cast iron at least once every 12 months.Energy transmission andGrade 2We are committed to replacing all remaining cast irondistribution systems are2 Leaks recognized as being non-hazardous at the time of detection but main by 2021. investigated and graded inhaving the potential to become a future hazard. In general, these leaks accordance with our procedures,must be scheduled for repair or eliminated within one year. Our Kansas,In Texas, distribution main segments that are identifiedwhich meet or exceed theMid-Tex, and West Texas distribution systems collectively make up60 percent of our total distribution system. Grade 2 leaks on these systems as high relative risk are scheduled for replacement orrequirements of state or federalare repaired within six months.they are leak surveyed within 12 months. regulation. As required by regulation, these proceduresGrade 3 In Kansas, coated steel pipe and plastic pipe arecategorize leaks in three grades: 3 Leaks that are non-hazardous at the time of detection and can be expected surveyed at least once every three years, and bareto remain non-hazardous. Grade 3 leaks on our Kansas, Mid-Tex, and West steel is surveyed at least annually. Texas distributions systems are repaired within three years and some within two and a half years. In jurisdictions that do not prescribe a repair intervalFor our other jurisdictions, we leak survey at least for Grade 3 leaks, we target these to be repaired within 36 months.as often as state regulations prescribe. However, we evaluate performing leak surveys in accordanceAt Atmos Energy compressor stations subject to New Source Performance Standard Subpart OOOOa, leak surveys are conducted quarterly using a FLIR camera. Any detected leaks are with the more stringent regulations of other states intagged. Leaks are repaired within 30 days of detection or as soon as repair parts can be obtained. Any component found to be leaking is checked using a soap and water test within our footprint. 30 days after it has been repaired. Annual reports summarizing the results of all leak surveys are submitted to state regulatory authorities.ATMOS ENERGY CORPORATION ATMOS ENERGY CORPORATION'