Ingham County Circuit Judge Jamo granted the temporary shutdown, then on July 1 allowed the westernmost of the underwater pipelines to resume operation following inspections, keeping the eastern line shut down as its damage was further investigated and awaiting response from the federal Pipeline and Hazardous Materials Safety Administration, or PHMSA, which regulates interstate oil and gas pipelines. In a Sept. 4 letter to Enbridge, PHMSA officials gave approval for the eastern line to resume operations, and those flows resumed Sept. 10. "Our thorough investigation determined conclusively there was no internal or external metal loss, no dents, and no safety issues with either the east or west segments. The pipelines continue to be safe to operate," Enbridge spokesman Ryan Duffy said. Though what caused the anchor support damage was never conclusively determined, speculation has centered on Enbridge's own contracted vehicles used during inspections.