As we’ve previously written, of the more than 200 waterways that Line 3 will have to cross through northern Minnesota, Enbridge will be tunneling underneath 21 of them using a process called Horizontal Directional Drilling (HDD).
As there has already been one documented frac-out at the Willow River HDD crossing (July 6), it is critical that we keep our eyes on these locations. Below, we have compiled some resources–including a new training video–to prepare volunteers for monitoring HDD locations.
Enbridge Line 3 construction is damaging wetlands. The proposed route is crossing 78 miles of wetlands, or one fifth of its entire route. Workers often install temporary plank roads in and around wetlands to support heavy equipment.
Line 3 is crossing different types of wetlands: emergent, unconsolidated bottom, scrub-shrub, and forested wetland, Enbridge says. One challenge in trenching a pipeline through a wetland is that pipelines can float. Workers have to put weights on them to get them to sink and stay down.
When you are monitoring Line 3 construction, you might see some large black bags near construction sites. These are bags filled with local aggregate to sink the pipeline in place. The industry term is “buoyancy control.”
In water saturated wetlands, one crossing method is called the “push-pull.” Workers excavate a trench working from the plank road, float the assembled pipeline, put weights on it, then push and pull it to get it to sink.
Horizontal Directional Drilling also is used to cross wetlands. Click here for Enbridge’s summary of wetland crossing methods.
Line 3’s approved routecrosses approximately 41 miles of public/municipal land in Cass, Crow Wing, and Aitkin counties, according to the state’s Environmental Impact Statement (EIS). Most of this land is state forest land administered by Minnesota Department of Natural Resources (DNR). More than 10 percent of Line 3’s route crosses public lands.
In January, Enbridge realized that it had vastly underestimated the amount of water needed for temporary trench dewatering during construction.
Dewatering is necessary when constructing a pipeline through wet areas. Excess water must be drawn out from the trench to protect workers and stabilize the soil. The water is later discharged back into the ecosystem. The appropriation of groundwater for dewatering requires a DNR (Minnesota Department of Natural Resources) permit.
Monitors have recently observed what looks like recent construction activity within the western area of Savanna State Forest, east of the AK-12 marker on our online map. Photos indicate digging and/or removal of topsoil, as well as staged pipes. Numerous signs indicate wetlands are present in and around this construction zone.
Enbridge Line 3 would travel 337 miles across northern Minnesota, crossing 200+ waterbodies along the way. In most cases, Enbridge plans to trench through them. At 21 different crossings, Enbridge is going to tunnel underneath the waterbody, using a process called Horizontal Direction Drilling (HDD).
Enbridge will use HDD to tunnel under the Mississippi River at two separate locations.
Watch the Line monitors have seen the preparation work at several sites. Here’s what we’ll be looking for when the company is getting ready to drill.
Watch the Line MN is a citizen-led effort to lawfully monitor construction of the Enbridge Line 3 tar sands pipeline through northern Minnesota. We oppose this pipeline as a threat to the water and land, a violation of Anishinaabeg treaty rights, and a dangerous escalation of climate change. Our volunteer monitors have been traveling along the Line 3 route since construction began in December 2020, documenting the environmental damage. We have published all of our observations for public use.
With this blog, we intend to engage our volunteer monitors, alert the broader coalition opposed to Line 3, and inform the public about matters relating to Line 3 construction. We will provide updates on construction, interpretations of our observations, educational resources, and more.