Indigenous opponents of Line 3 are raising money to fly a drone with thermal imaging equipment along the oil pipeline's Minnesota route to see for themselves whether there are more drilling fluid spills or groundwater problems.

Thermal imaging is a new direction for the Indigenous-led Line 3 opposition. It comes as state environmental regulators investigate whether construction crews damaged aquifers at two locations along the Line 3 route, in addition to the major aquifer breach in Clearwater County for which energy company Enbridge has been fined. The state's latest estimates are that the breach has spilled about 50 million gallons of groundwater, up from previous estimates of around 24 million gallons.

"I've ridden the whole line on horseback pretty much, but I never took that bird's eye view," said Winona LaDuke, co-founder of Honor the Earth. "I think it's going to show more damage than anybody knows. It's a crime that's underway."

The flyover project will cost an estimated $52,000. The group said it wants to get underway very soon.

Enbridge's controversial Line 3 replacement pipeline is complete now and transports Canadian tar sands crude oil across northern Minnesota to Superior, Wis. The company, which says it's doing what's required and cooperating with regulators, faces potential criminal charges for puncturing the Clearwater County aquifer.

State regulators ordered the company to pay $3.3 million for that accident, which the Canadian company didn't report to the state for months, and to close up the free-flowing artesian well it created.

The accident happened at a major pipeline junction called the Clearbrook Terminal near the town of Clearbrook, Minn. Enbridge has been moving in large equipment there to inject tons of grout into the ground to try to seal off the broken aquifer. The outflow endangers a nearby calcareous fen complex, a protected delicate wetland area fed by groundwater from the same aquifer.

The matter was sent to the Clearwater County Attorney for potential criminal charges. But shortly after Enbridge missed a 30-day deadline in October to fix the rupture, the county forwarded the investigatory reports to the state Attorney General for potential prosecution. Enbridge had to pay an additional $40,000 for wasting more groundwater.

The attorney general's office said it doesn't confirm or deny investigations.

Counties often forward complex cases that outstrip local resources, but the move also could indicate Enbridge faces more serious charges.

Attorney General Keith Ellison has indicated his willingness to take on oil companies. Last year he sued ExxonMobil, Koch Industries and the American Petroleum Institute, alleging they deliberately misled the public for decades about the effects of burning fossil fuels on climate change.

Meanwhile, both the Minnesota Department of Natural Resources (DNR) and the Minneapolis Pollution Control Agency (MPCA) say they are investigating other potential violations during Line 3 construction. They said that air imaging will be part of monitoring the wetland restoration work through 2026.

The MPCA is investigating the 28 drilling fluid spills it made public in August. Enforcement actions aren't expected until early 2022.

The DNR, which controls groundwater, is still investigating whether Enbridge crews punctured aquifers at two other unidentified sites.

Some Line 3 opponents say they suspect one is where the pipeline first crosses under the Mississippi River in Clearwater County, about 8 miles north of the river's official source in Lake Itasca. The well-known crossing was a major treaty rights flash point and home of a resistance encampment called Fire Light Camp. There were three documented drilling fluid spills, or frac-outs, there in July, according to the MPCA tally.

Both Enbridge and the DNR say there is no aquifer breach or uncontrolled flow of groundwater at that spot.

LaDuke and others involved with the flyover project are not convinced. They fear both the Mississippi River and protected groundwater resources have been gravely harmed.

Bemidji resident Ron Turney, a White Earth citizen who has documented Line 3 construction impacts with cameras and a drone, has published many images of the site on his Facebook page and the Indigenous Environmental Network website. He also aired them during a panel on Line 3 that was broadcast recently from the U.N. climate change summit in Glasgow, Scotland.

His pictures show muddied and rust-colored water welling up on either side of the river, some of it with an oily sheen, held back from the Mississippi by sandbags. LaDuke described them "scary as heck."

Turney said that before that spot the Mississippi is so clear you can see the bottom and the fish, then it gets so clouded you can't see either.

Enbridge said it has reviewed the spot multiple times since work ended and there have been no additional drilling fluid mishaps or aquifer breaches. The documented spills were cleaned up, said Enbridge spokeswoman Juli Kellner.

Kellner said Turney's images show "nothing more" than water collected on the stretch where the crews laid down a timber mat road to protect the wetlands surrounding the Mississippi from construction traffic.

"Water is all confined to the approved workspace and appropriate erosion controls are in place," Kellner said.

The DNR basically agreed. The standing water at the site is due to soil being compacted during construction in the wetlands, DNR spokeswoman Gail Nosek said. She said the sheen on the water in the photographs "is the result of naturally occurring bacteria that grow in iron-rich, oxygenated water."

LaDuke and Turney said they don't buy that. Turney said he thinks he has evidence of frac-outs that went unreported to the MPCA.

As for the flyover, the thermal imaging technique will be most effective when there's frost on the ground because warmer groundwater welling up will be easier to see, they said.

"We think some of the 28 blowouts might be a perpetual flow of water," said Jeff Broberg, an independent geologist assisting the group.

A Calgary-based company specializing in airborne remote sensing has estimated the project would cost about $52,000. The estimate was attached to a letter that Frank Bibeau, a lawyer for the White Earth Band of Ojibwe, sent to the Band last week.

It asks the Band for at least $10,000 for the project and says that Dawn Goodwin, co-founder of RISE Coalition, and LaDuke at Honor the Earth, each have pledged $10,000. Other environmental groups are being tapped.

The data they gather will be evidence in Bibeau's lawsuit against the DNR, he said. Bibeau filed the unusual "Rights of Nature" lawsuit in White Earth tribal court in August.

Wild rice, or manoomin, is the lead plaintiff asserting its own right to abundant clear water. Indian Country is exercising its environmental jurisdiction, Bibeau said: "The DNR and MPCA, they have let things go."