Nearly 4 years after about 850,000 gallons of crude oil leaked from a rupture in a 30-inch Enbridge-operated pipeline and befouled 35 miles of wetlands near the Kalamazoo River in Marshall, Michigan, the federal government continues to issue guidance intended to convey lessons learned to operators of natural gas and hazardous liquid pipelines.  In the latest action, the Pipeline and Hazardous Materials Safety Administration (PHMSA) has released an advisory bulletin primarily based on the investigations of the spill and reports by the National Transportation Safety Board (NTSB).

The Enbridge spill was a vivid case of nondetection.  The rupture, which was probably caused by corrosion cracking, was not discovered for over 17 hours.  During that time, Enbridge twice pumped additional oil comprising 81 percent of the total release into the line.  Local residents were evacuated and 320 people reported symptoms consistent with crude oil exposure.  Cleanup and remediation continues, and costs have exceeded $1 billion.

Organizational failure

According to the NTSB, the rupture and prolonged release were caused by “pervasive organizational failures” at Enbridge, which included deficient integrity management (IM) procedures, which allowed well- documented crack defects in corroded areas to propagate until the pipeline failed; inadequate training of control center personnel, which resulted in Enbridge’s failure to recognize the rupture through two restarts of the pipeline; and insufficient public awareness and education, which allowed the release to continue for nearly 14 hours after the first notification of an odor to local emergency response agencies.

In its safety advisory, the PHMSA says that the ability to analyze and integrate threat- and integrity-related data from many sources is essential for operators to continually improve and sustain safety performance and proactive IM programs. “A lack of data integration was a significant contributor to the incident at Marshall, MI,” says the PHMSA. 

The PHMSA urges pipeline operators to evaluate their safety programs and implement changes to eliminate deficiencies similar to those the NTSB found when it investigated the Enbridge spill. 

Recommendations

The PHMSA recommendations in the advisory include the following:

• IM.  PHMSA’s IM regulations require operators of gas transmission and hazardous liquid pipelines to institute a continual process for the evaluation of pipeline integrity.  Operator IM programs should reflect that each pipeline is unique and has its own specific risk profile that is dependent on the pipeline’s attributes, geographical location, design, operating environment, and the commodity it transports, among other factors.  It is vital for operators to compile and integrate this information into the IM programs to effectively identify and evaluate risk.  If this information is unknown, unknowable, or uncertain, operators need to take a more conservative approach to operations.
• Control center operations.  Operators should regularly train their control room teams and consider establishing a program to train control center staff as teams in the recognition of and response to emergency and unexpected conditions that include supervisory control and data acquisition indications and leak detection software.  Operators should also perform periodic evaluations of their leak detection capabilities to ensure that adequate leak detection coverage is maintained during transient operations, including pipeline shutdown, pipeline start-up, and column separation.
• Public awareness programs.  The PHMSA advises operators to analyze and evaluate the effectiveness of their public awareness programs and whether local emergency response agencies are prepared to identify and respond to early indications of a rupture.  Strong public awareness and education programs can help shorten incident response times and improve overall response.  Further, operators are encouraged to review their procedures for communicating during emergency situations to ensure compliance with existing PHMSA advisory bulletins (Emergency Preparedness Communications, November 3, 2010, FR, and Communication During Emergency Situations, October 11, 2012, FR).

“Operators should proactively implement improvements to their pipeline safety programs based on [NTSB past and future] observations and recommendations so that the entire industry can benefit from the mistakes of one operator,” concludes the PHMSA.

The advisory bulletin was published in the May 6, 2014, FR.

NTSB’s final report on the incident