About 5,000 barrels of oil spilled from a 22-foot rupture on the Pegasus pipeline in late March. The pipeline, installed in the 1940s, was carrying diluted tar sands oil from Canada.
Exxon said it has removed most of the residual oil and is focusing on cleanup operations in a marshland near the spill. The company said it's moving from emergency to long-term remediation and restoration operations.
"This transition follows ongoing air quality monitoring conducted by the U.S. Environmental Protection Agency, which continues to show levels that are either non-detect or below action levels established by the Arkansas Department of Health," the company said.
Exxon removed the damaged pipeline section for third-party investigation and installed new pipe. The cause of the accident is under investigation and Exxon gave no indication as to when Pegasus would restart.
Exxon apologized to residents affected by the spill in a newsletter delivered by mail last week.
"Again, we are very sorry for the disruption that we have caused," the newsletter states.