Between 80 and 100 gallons of drilling fluid spilled into a river during Line 3 pipeline construction in northern Minnesota last week.
Both the Minnesota Pollution Control Agency (MPCA) and pipeline operator Enbridge said the release happened accidentally on July 6, at a construction site along the Willow River, near Palisade, Minnesota.
Enbridge, in a media announcement, said crews were doing a horizontal directional drill procedure when "a small amount of drilling fluid reached the surface." The company said this "inadvertent return" prompted an immediate halt of construction activities as crews shifted to containment, management and clean-up efforts.
The company described "no impacts to any aquifers nor ... downstream impacts" as a result of the spill.
According to a statement from the MPCA, the drilling fluid, also referred to as mud, contained bentonite clay, water and a xanthan gum additive the agency described as a nontoxic, "sucrose-based emulsifier" that is often used as a food additive. Cori Rude-Young with the MPCA told Bring Me The News no short- or long-term environmental impacts are expected, since the substance is considered nontoxic.
The MPCA and Enbridge said clean-up of the site is completed, with Rude-Young adding it is working with Enbridge to determine when drilling can start again.
Protesters at the site noted this "frac out" — an industry term used to reference this type of drilling-related mishap — on July 6, and in the days that followed, shared video of work crews doing clean-up efforts. Here's one:
The group Honor the Earth, which is against the pipeline's construction, earlier that day highlighted protestors who tried to stop the ongoing work, and also mentioned the risk of a potential frac out. On Monday, the group wrote: "A week later, finally the [state] is investigating Enbridge Line 3 spill – gallons of a clay, water and xanthan gum were spilled into the Willow River."
Rude-Young said both Enbridge and independent environmental monitors on site alerted the MPCA the day of the incident. Enbridge did not publicly announce the spill in its newsroom or social media channels until July 13, when clean-up was complete.
The MPCA said it cannot release all information related to the incident until the active investigation is complete.