Non-toxic drilling mud: Part of the HDD process

August 10, 2021

There has been a great deal of misinformation about inadvertent returns and the HDD process. Horizontal Directional Drilling (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. It actually protects waterbodies from disturbance. Inadvertent returns are not unusual or unexpected. Learn more about the HDD process here.

Drilling fluid, also known as drilling mud, is non-toxic and primarily made up of naturally occurring bentonite clay and water and is approved for use by the Minnesota Department of Natural Resources and Minnesota Pollution Control Agency. Upon identifying an inadvertent return, drilling operations are immediately shut down and crews follow the procedure for managing containment and cleanup of material as specified in Project permits.

In the majority of instances, drilling mud was contained entirely on land and cleaned up. In the case of the Willow River there were no impacts to any aquifers nor were there downstream impacts because environmental control measures were installed at the location.

In each instance the Minnesota Pollution Control Agency and the Minnesota Department of Natural Resources were also notified and cleanup was completed under the supervision of trained environmental inspectors and third-party agency monitors.

The current drought conditions in Minnesota are concerning to everyone. In response, the Minnesota Department of Natural Resources has suspended the use of some water sources due to low flow in specific watersheds. We are focused on protecting, conserving and reusing water on the Line 3 project. More than 50% of pipeline sections being tested on Line 3 by reusing water. We continue to work with agencies on next steps during these drought conditions.

Enbridge has demonstrated ongoing respect for Tribal sovereignty. The Minnesota Court of Appeals recently concluded 'the commission reasonably selected a route for the replacement pipeline based upon respect for tribal sovereignty, while minimizing environmental impacts.' As the result of negotiations with Tribal leadership Line 3 was routed outside of the Leech Lake Band of Ojibwe Reservation and through the Reservation of the Fond du Lac Band of Lake Superior Chippewa. Both Leech Lake and Fond du Lac have written in support of project permits. White Earth Nation was also included and invited to be part of the process, and because of their concerns Line 3 was routed outside of the Upper and Lower Rice Lake and its watershed.

Line 3 construction permits include conditions that specifically protect wild rice waters. As a matter of fact Enbridge pipelines have coexisted with Minnesota's most sacred and productive wild rice stands for over seven decades.

The project is already over 80% complete in Minnesota and is expected to be finished in Q4 of this year. The project is providing significant economic benefits for Minnesota counties, small businesses, Native American communities, and union members-including creating thousands of family-sustaining construction jobs, and millions of dollars in local spending and tax revenues. Enbridge has already spent well over $250 million project dollars specifically with tribal nations, citizens, communities, and contractors.