A contractor has started cleaning up an estimated 600 barrels of crude oil and 90,000 barrels of brine that slowly leaked from a faulty wellhead this winter northeast of Glasgow on the Fort Peck Reservation. The leaked mixture flowed downhill for about a third of a mile and into a stock pond.
There are no known effects to downstream water users from the spill, according to the Environmental Protection Agency’s website. Water and soil samples have been collected for analysis.
The well is owned by Anadarko Minerals Inc., an Oklahoma oil and gas exploration company, which has 30 other wells in the state. The EPA is overseeing the cleanup, which occurred in a remote area about eight miles west of the small community of Lustre. A landowner flying his plane over the well noticed the leak on April 27. EPA officials were notified April 30.
The well had been shut down and was last inspected in December. It’s believed that the wellhead froze and cracked in what was a brutally cold winter in the region.
“It’s the company’s responsibility to keep an eye on those wells,” said Todd Yeager, field manager for the Bureau of Land Management’s Miles City Office. The BLM has fiduciary responsibility for Indian trust assets and inspects the wells once a year.
It will also be Anadarko’s responsibility to pay for the cleanup costs, which had not yet been estimated.
The well site was on top of a hill that’s located south of the Lustre Grain Road and just west of Porcupine Creek, a tributary to the Missouri River. The oil-brine mixture flowed downhill blackening the surrounding vegetation before entering a stock pond, which had about 3 inches of oil atop the water. Fencing has been erected around the spill, and cattle were removed.
“This isn’t going to be a short-term project,” said Shane Findley, supervisory mineral resource specialist for the BLM in Miles City. “I’m guessing it will take more than a month and require long-term monitoring.”
According to the EPA’s website, an earthen berm was built around the wellhead and vacuum trucks have begun sucking oil from the stock pond.
A 2013 online pamphlet touts the Fort Peck Reservation to oil and gas companies. The handout notes: “Elimination of the dual production tax, a tax holiday, and joint venture opportunities make Fort Peck the place to be!”
Oil exploration is nothing new to the reservation, which is home to the Sioux and Assiniboine tribes. The pamphlet noted: “Oil was first discovered on the Fort Peck Indian Reservation in 1951 by Murphy Oil. That well opened the East Poplar Oil Field on the Poplar Dome. The unitized field has produced 50 million barrels of crude, ranking it in the top 10 largest producers in Montana.”
The western part of the reservation, where the spill occurred, was first developed in the 1980s. As of 2013 the pamphlet reported the Lustre Field had produced 7 million barrels of oil from approximately 50 wells.
According to MTN, Fort Peck tribal chairman Floyd Azure said the oil spill is “a further indication of the detrimental effects oil production can have on the environment and is yet another threat to the Tribe's water quality.” The Billings Gazette could not reach Azure for comment.
Members of the tribe have also protested the proposed Keystone XL Pipeline’s route across the reservation out of concern for possible threats to the tribal watershed.
Clean water is a precious commodity on the reservation. A 2014 study by the U.S. Geological Survey found that oil exploration in the 1950s contributed to groundwater contamination near Poplar spreading across 17.9 square miles.
Test wells showed that the aquifer was being contaminated by brine, which is almost 10 times saltier than the ocean. A 1997 USGS study had identified benzene, a common component of crude oil, in the groundwater. Long-term exposure to benzene can cause cancer and other health problems. A 1990 study identified high levels of nitrates in the water.
The brine plume had seeped southwest to Poplar, the Poplar River and the Missouri River, along the way contaminating 100 wells that serve about 3,000 people.
The groundwater contamination prompted the community of Poplar to seek a new source of water for its 2,900 residents, as well as the rest of the reservation. The portion of the Fort Peck-Dry Prairie Regional Water System that serves Poplar was finished in 2012.