On June 14, APGA’s John Erickson was interviewed by Sarah Arnett, Senior Analyst Physical Infrastructure Team of the U.S. Government Accountability Office (GAO), about the actual and potential impacts of transmission pipeline disruptions on local distribution systems. A January incident in Rhode Island has raised concerns about service disruptions related to the interaction of interstate gas transmission and intrastate distribution pipeline systems. In that incident, Algonquin Pipeline experienced low pressure forcing the local distribution company, National Grid, to shut off gas to approximately 7,000 customers on an extremely cold January day. GAO received a request from Senators Reed and Whitehouse asking it to review the scope of disruptions of this type and the Pipeline and Hazardous Materials Safety Administration’s (PHMSA) oversight role. GAO seeks to get a sense of how common incidents of this type are, potential causes, and factors that may play a role.
John stated that there were several potential causes of pipeline supply disruptions, such as extreme demand during extreme cold, unplanned compressor or pipeline shutdowns and planned events such as running an internal inspection device as part of the pipeline’s integrity management program. Disruptions are particularly worrisome to the approximately 90 percent of public gas systems that only have one pipeline supplier and therefore cannot make up for reduced gas supply from one supplier by taking more gas from another pipeline. He did not, however, have any information on the frequency of incidents due to problems on interstate gas transmission lines that lead to problems on intrastate gas distribution lines or how long supply disruptions typic ally last.
GAO is just beginning its study and plans to speak with APGA again as the study progresses. Any members that have experienced supply disruptions during the past few years are encouraged to provide John with a brief summary of the disruption cause, number of customers affected and duration of the disruption.
For questions on this article, please contact John Erickson by phone at 703-407-0212 or by email at
jerickson@apga.org.