14 July 2013 – An independent report conducted by Hurst Metallurgical Research Laboratory Inc. faults manufacturing defects on the Pegasus Pipeline that ruptured and spewed 150,000 gallons of crude oil in Mayflower, Arkansas, Exxon Mobil Corp. reported Wednesday.
Cracks were found near a seam that opened on the ruptured pipeline, the report stated. The report was provided to ExxonMobil and the Pipeline and Hazardous Materials Safety Administration, which both declined to publicly release.
The defects identified in the report reflect the “root cause of the failure,” the company stated. Ongoing tests are being conducted to evaluate other factors in the spill that evacuated 20 families from their homes. ExxonMobil said the cleanup is continuing and the pipeline is shut-in.
“The cleanup is progressing well and restoration is complete in many affected areas,” ExxonMobil said on its website. “More than half of the evacuated homes have now completed the re-entry process, and the others are in various stages of completion.”
ExxonMobil also noted that corrosion wasn’t a contributing factor to the oil spill.
“Based on the metallurgical analysis, the independent laboratory concluded that the root cause of the failure can be attributed to original manufacturing defects — namely hook cracks near the seam,” ExxonMobil reported in a news release. “Additional contributing factors include atypical pipe properties, such as extremely low impact toughness and elongation properties across the … seam.”
“We are still conducting supplemental testing, which will help us understand all factors associated with the pipe failure and allow for the verification of the integrity of the Pegasus Pipeline. These tests will help us determine the mitigation steps we need to take to ensure a similar incident does not occur again,” ExxonMobil added.
Last month, Arkansas Attorney General Dustin McDaniel and U.S. Attorney Chris Thyer announced that they filed a joint lawsuit against the energy company. The filed complaint seeks civil penalties and injunctive relief and asks for damages related to the spill under the federal Clean Water Act and the Arkansas Water and Air Pollution Control Act.
One of the reasons a lawsuit was filed was due to ExxonMobil not fully responding to questions from state agencies, according to McDaniel. The attorney general hopes the discovery process would reveal how much oil spilled.
All visible, free-standing oil from the spill site has been recovered, according to ExxonMobil, but it will take months for the cleanup to be completed.
“We truly regret that the spill continues to impact the community and appreciate everyone’s continued patience,” ExxonMobil said. “We will remain here until the job is done and will work to restore your community as quickly and as safely as possible.”
*Robin Dupre, Rigzone