Assessing the Reduction in Spill Risk of the Keystone XL Special Conditions

Introduction

The Keystone XL is a proposed pipeline system intended to transport crude oil from existing facilities in Alberta, Canada to the United States Gulf Coast of Texas.  Its in-service date is projected for 2015, with an initial throughput estimated at 800,000 bpd.  The construction of the last pipeline segment is currently pending approval by the White House.  This segment is projected to extend for 1,115 miles from Hardisty, Alberta to an end-point near Steele City, Nebraska [1].  The Keystone pipeline operator has agreed to design, construct, operate, maintain, and monitor the project in accordance with the regulatory requirements of the US Code of Federal Regulations Title 49 Parts 194/195, as well as a set of 57 project-specific Special Conditions (SCs) [2].  Since the SCs will influence key design, construction, operational, and maintenance variables of the pipeline system, they will therefore affect the potential for loss of pipeline integrity in its entirety during the system lifetime.  An adequate characterization of the SCs from the perspective of pipeline integrity and risk would be advantageous from the system onset for identifying latent flaws in the system spill prevention plans.

The risk to pipeline integrity is a function of the severity of the potential consequences stemming from a release of pipeline contents and the likelihood of a leak occurring [3].  The frequency of events that pose integrity threats and their associated consequences must be considered when conducting a pipeline risk assessment.  This article focuses on the frequency component of risk; in particular, the assessment of the probability of the causes that could result in eventual loss of containment for the Keystone XL pipeline system.