Risk Modeling Report

In August 2018, PHMSA published its draft Pipeline Risk Modeling Report “Pipeline Risk Modeling—Overview of Methods and Tools for Improved Implementation”. The report was intended to gather the input of stakeholders, and the Risk Management Working Group (RMWG), and develop guidance for improving how operators use risk models in performing risk assessments for their integrity management programs – a weakness which was identified by the NTSB in their 2015 study “Integrity Management of Gas Transmission Pipelines in High Consequence Areas”.

PHMSA formed the RMWG in response to three NTSB recommendations:

    1. P-15-10: Upgrade guidance for transmission operators and inspectors on the evaluation of interactive threats
    2. P-15-12:  Evaluate the four risk approaches and determine if they produce a comparable safety benefit
    3. P-15-13: Update guidance for setting weighting factors, include factors for consequence of failure calculations, and appropriate risk metrics or methods for aggregating risk along a pipeline

The RMWG consisted of federal pipeline regulators, pipeline operators, industry organizations, national laboratory personnel and other stakeholders. The Associations and their representatives collectively represent over 50% of the RMWG. The RMWG’s mission statement was to (1) characterize state of the art pipeline risk modeling for gas transmission and hazardous liquid pipelines, (2) identify a range of state-of-the-art methods and tools capable of addressing the spectrum of pipeline risk management applications, and (3) provide recommendations to PHMSA regarding the use of risk modeling methods, tools and data requirements. The intent was for PHMSA to gather the input of various stakeholders and for PHMSA to author a report to make recommendations to operators on risk modeling.

In October 2018, AGA, APGA, API, AOPL and INGAA jointly filed comments supporting language within the report that articulates the need for flexibility and scalability in pipeline risk modeling. The joint industry comments also stating that the final report should provide a more balanced approach for evaluating risk modeling methods.