This paper describes a comprehensive program designed to collect field data to inform integrity and risk assessments on critical distribution assets operated by Enbridge Gas Ontario (EG Ontario) in Canada. EG Ontario’s distribution network supplies natural gas to approximately 3.9 million customers. It comprises over 150,000 km (over 90,000 miles) of steel and plastic mains and services, typically incompatible with free-swimming in-line inspection (ILI) tools.

The authors begin by highlighting EG Ontario’s Distribution Integrity Management Program (DIMP) elements in the context of the more extensive corporate Integrated Management System (IMS) structure. They then illustrate select data collection activities aimed to refine and quantify distribution integrity decision-making, including focused crawler ILIs, depth of cover surveys, and non-destructive examinations (NDE). Finally, they describe how such field evidence has been employed to form the basis of a newly established targeted integrity management program that emphasizes higher-stress steel distribution assets prioritized using a customized risk model.

Keywords: Distribution Integrity, Integrated Management System, Difficult-to-Inspect Pipelines, Distribution Assets, Risk Management Framework, Field Inspections, Risk-informed Decision-making, Risk Prioritization, Asset Management.