Enbridge has successfully retrieved a 45-foot steel rod that had been used in the recent geotechnical work for the Great Lakes Tunnel Project. The rod had been at the bottom of the Straits of Mackinac since September, when a borehole collapsed during geotechnical work in advance of tunnel construction. The retrieval operation was completed just after Christmas and State officials have been notified.
After continuing to evaluate available options to retrieve the 3-inch diameter rod, Enbridge deployed a specialized underwater remote operated vehicle (ROV) from a work barge to retrieve the rod from the lakebed at a depth of 225 feet. The project team worked over the past two weeks to prepare the ROV for retrieval operations. State officials with EGLE were consulted before the ROV was deployed. In November, Enbridge notified EGLE of the issue with the rod on the lakebed. Favorable weather conditions at the Straits in recent weeks prevented the water from icing over, providing Enbridge a window of opportunity to complete this work. The rod had moved from its original position near the pipeline and was found resting on the west leg of the pipeline. According to Enbridge spokesmen, Ryan Duffy, the rod never posed any safety or environmental risk to Line 5, the water, nor ship traffic in the Straits.