TransCanada Corp. inspecting Keystone pipeline

? Nearly four dozen “anomalies” have been found along a major pipeline that moves Canadian oil through several U.S. states, prompting a new round of tests to determine what is causing the potential problems and whether any of the irregularities violate federal guidelines.

Terry Cunha, spokesman for TransCanada Corp., which built the 1,087-mile Keystone pipeline, said the 47 anomalies were detected on segments of the pipeline in Missouri, Kansas, Nebraska and South Dakota. They may be the result of areas of pipe expanding as oil passes through, according to federal regulators.

Although there have been no major leaks and some of the irregularities “could be very minor,” Cunha said the new tests will diagnose whether any parts of the pipe have widened beyond the standard federal limit. The original tests were conducted in November during an inline inspection.

Paul Blackburn, a lawyer for Plains Justice, a South Dakota-based environmental law nonprofit that has been critical of the multiphase Keystone pipeline, said too much expansion in a pipeline could mean a greater risk of the line breaking. The standard federal limit for expansion in pipe on such a pipeline is 1.5 percent.

“If they expand more than 1.5 percent, whether it ruptures or not is hard to say,” Blackburn said. “They have to be nearly perfect, and if it’s not, then the risk may not be today or tomorrow, but it may be 10, 15, 20 years down the road.”

Cunha said the earlier inspection was done to comply with guidelines issued in October 2009 by the U.S. Pipeline and Hazardous Materials Safety Administration, the federal agency that oversees the nation’s pipeline network. Damon Hill, a spokesman for the agency, said in an e-mail Wednesday that the pipeline was being examined to ensure it hasn’t expanded beyond the limits mandated in those guidelines.

Hill declined to say how much the pipe may have expanded because the evaluation is ongoing.

The anomalies were found at nine sites in Missouri, 12 in Kansas, 14 in Nebraska and 12 in South Dakota, Cunha said. The company has since been testing 10 of those sites, but has not completed evaluating the results. Cunha said the 10 sites selected for retesting — six in South Dakota, three in Nebraska, and one in Missouri — showed possible expansion from 1 percent to 1.5 percent.

The new testing was likely to be finished later this month, and the evaluation of those tests could take several more weeks, Cunha said Wednesday.

“All new pipelines when they start, you’re going to see some expansion,” he said. “We want to continue to ensure the public in general that this is a safe pipeline.”

Cunha said the remaining 37 sites with anomalies would be retested if the results from the 10 test sites showed more testing was needed. He said PHMSA has conducted 55 audits of the pipeline and has found the pipeline “in compliance and safe.”