Non-toxic drilling mud: Cleanup complete near Solway, MN

July 21, 2021

On Tuesday, July 20, Enbridge reported that a small amount of drilling mud reached the surface during a horizontal directional drill (HDD) near Solway, Minnesota. Drilling mud is non-toxic and is primarily made up of naturally occurring bentonite clay and water.

Upon identifying the inadvertent return, the drilling operation was immediately shut down and crews followed the procedure for managing containment and cleanup of material as specified in Project permits. The Minnesota Pollution Control Agency and the Minnesota Department of Natural Resources were also notified.

The mud was contained on land. Cleanup of the of the affected area was completed under the supervision of trained environmental inspectors and third-party agency monitors. Current work on Enbridge's replacement of Line 3 includes HDDs at over a dozen sites. HDD is the preferred construction method for pipelines crossing bodies of water and involves drilling a tunnel under a designated area and then pulling a pipeline or other utility through. Learn more about the HDD process here.

Last week, the MN Department of Natural Resources suspended the use of some water sources due to low water flow in specific watersheds. We prepared for water restrictions to come into effect and have adjusted our workplans to protect and conserve water.

'The current drought conditions in Minnesota are concerning to everyone. Our project permits include conditions that protect the environment during construction and specifically wild rice waters,' said Barry Simonson Director of Mainline Construction for Line 3. 'We are focused on protecting and conserving water, and continue to work with agencies on next steps.'

Simonson added, 'It's worth noting that our pipelines have coexisted with some of the country's most productive wild rice waters for seven decades.'

The Line 3 Replacement Project is 70% complete in Minnesota and on track to be in service by Q4 of this year. The project is providing significant economic benefits for Minnesota counties, small businesses, Native American communities, and union members-including the creation of thousands of family-sustaining construction jobs, and millions of dollars in local spending and tax revenues. Enbridge has already spent over $250 million project dollars specifically with Tribal nations, citizens, communities, and contractors.