Protocol for Complying with the Consequence Analysis Requirement within DOT's Integrity Management Program for Hazardous Materials Pipelines

The following is a brief description of Quest's protocol for complying with the consequence analysis portion of DOT's Integrity Management Program (IMP) for Hazardous Materials Pipelines (49 CFR 195.452). The protocol is divided into three phases, although it will not be necessary to conduct all three phases for each pipeline. At the completion of each phase, the analysis can be stopped if the results of the analysis up to that point indicate that High Consequence Areas (HCAs) along the pipeline route cannot be affected by a release from the pipeline. This option is clearly illustrated by the use of STOP signs in the attached flow chart.

Phase 1 - Worst-Case Consequence Analysis Using Conservative Assumptions

Using our state-of-the-art consequence modeling software, CANARY by Quest^®, define the hazard footprints for worst-case releases (e.g., full-bore ruptures) along the pipeline route. The hazards of interest are:

For people

• Exposure to a toxic gas cloud
• Exposure to a flammable gas cloud
• Exposure to explosion overpressure
• Exposure to radiant heat from torch or pool fire

For waterways and the environmentally sensitive areas

• Ingress of hazardous pipeline fluids into commercial waterways
• Ingress of hazardous pipeline fluids into environmentally sensitive areas

Conservative assumptions are used in the analysis in order to define the maximum hazard footprint associated with each pipeline.

Determine if one or more of the hazard zones could reach an HCA along the pipeline route at a hazard level capable of severely impacting the public or the environment.

1. No - Document results for the pipeline. Analysis complete.
2. Yes - Proceed to Phase 2.

Phase 2 - Incorporation of Site-Specific Factors into Consequence Modeling

For those sections of a pipeline that affect one or more HCAs, determine if any site-specific factors can be incorporated into a refined consequence analysis. Examples of site-specific factors could include local terrain, local weather patterns, ....

Re-run the consequence analysis incorporating the site-specific factors. Using the same hazard impact criteria, determine whether the pipeline sections affect HCAs along the route.

1. No - Document results for the pipeline. Analysis complete.
2. Yes - Proceed to Phase 3.

Phase 3 - Review of Potential Mitigation Options

At this point in the analysis, one or more sections of the pipeline have been identified as being able to impact an HCA at a hazard level that could severely affect the public and/or the environment. A review of potential mitigation measures may be warranted, depending on the site-specific nature of each HCA impact.

Incorporate mitigation measures into the consequence analysis to determine the effect of active mitigation on the extent of potential hazard footprints. Using the same hazard impact criteria, determine whether the pipeline sections affect HCAs along the route.

1. No - Document results for the pipeline with active mitigation. Analysis complete.
2. Yes - Document results for the pipeline and potential impacts on HCA.

PDF version of Quest's Protocol for Complying with the Consequence Analysis Requirement within DOT's Integrity Management Program for Hazardous Materials Pipelines (includes flowchart).

For more information about our Pipeline Integrity Management Services, please contact us at info@questconsult.com.