Dick Zimmerlee spent decades as a rancher, farmer and agriculture consultant.
But each day he spends studying the soils and groundwater on his ranch near Prineville, trying to find out why black sludge started clogging pipes and settling in his toilet, his knowledge becomes more akin to an amateur geologist.
“We’ve become students of this whole thing,” he said. “Unwillingly, but we did.”
For Zimmerlee, dozens of his neighbors and a geology consultant, the case is clear: health-hazardous minerals are leaching in from a settling pond at a nearby gravel mine owned by Knife River Corp., they said. Two years after their water started to appear muddy, homeowners with private wells northwest of Prineville are growing with angst that state regulators still haven’t investigated the source of groundwater contamination they fear threatens plumbing, human health and livestock.
U.S. Sen. Jeff Merkley, who has pushed Oregon regulators to act swiftly in Crook County’s private well-water crisis, doubled down on his advocacy Sunday, when he visited two homes to see the contamination — black sludge that covered his hand as he plunged his arm into a toilet tank.
Though well owners are convinced the mine is to blame for contaminating wells, Knife River denies it. Community members said state agencies have offered drought and existing mineral conditions as explanations.
Merkley said it was “pretty outrageous” that a government investigation into groundwater hasn’t occurred.
“The state should be in the gravel mine right now testing the water,” he said.
He added, “This is the sort of thing that merits action within weeks. Not months, not years.”
Many well-water samples taken by residents and private geologists in the Prineville area over the past two years have shown concentrations of manganese at levels exceeding federal health advisory standards. Consuming too much of the naturally-occurring earth metal can affect the nervous system, causing problems with memory loss, attention and motor skills, according to the U.S. Environmental Protection Agency.
Merkley took the issue to the EPA after hearing reports of contaminated water during a visit to Prineville in April 2023, but found the federal agency doesn’t regulate manganese in drinking water. According to Merkley, federal regulators wouldn’t get involved unless the issue moved into public waterways.
Attention then turned to state agencies, in particular the Oregon Department of Environmental Quality and the Oregon Department of Geology and Mineral Industries, which regulates the nearby gravel mine owned by Knife River. In a March 20 letter, Merkley and Sen. Ron Wyden called on DEQ Director Leah Feldon, writing that the agency “has a crucial responsibility to exercise its oversight authority in order to protect Crook County residents who rely on this aquifer as the primary source of their drinking water.”
No consensus on contamination source
In an email to The Bulletin, agency spokesperson Antony Vorobyov said there is “no professional consensus” on the region’s groundwater chemistry conditions or what might be causing contamination.
According to Tony Spilde, a spokesperson for Knife River, independent testing dating to before the mine’s operation has shown digging for gravel has no impact on water quality. He said the company hopes to educate the public about geology of the Crooked River Caldera, which includes volcanic rock laced with minerals like manganese and aluminum, which has also been detected in well tests.
Locals contest the preexisting geology explanation, arguing wells in close proximity to the gravel mine show higher mineral levels than those farther away.
”We welcome participation from the DEQ in the ongoing groundwater testing in the Prineville area,” Spilde said.
On May 30, DEQ and the Oregon Health Authority hosted a public meeting on domestic well-water safety to gather information on well conditions and locations, including past test results.
That info will contribute to a groundwater sampling plan, Vorobyov said, for which the agency submitted a funding request through Congress. The plan will take about a year to complete, he said.
That’s a tedious timeline for well owners who say they contacted the state about the problem two years ago, and haven’t touched tap water in months for fear of health risks.
Health risks
Ashley McCormick, who’s front-yard view over the Crooked River valley includes Knife River’s gravel mine, blames the contaminated well water she used in her son’s bath for a recent allergic reaction that sent him to the hospital with hives. After moving into the rural Crook County home in 2017, the McCormicks’ water appeared clean until a few years ago, when the family installed a $10,000 water filtration system to direct sediment away from their pipes. Recent well samples produced manganese levels in excess of federal standards.
“This isn’t just harming our homes. This is harming my family,” she said.
It’s also harming cows, according to Brian Zednik, a rancher who recently cut his cattle operation out of fear he might be exposing beef consumers to health risks. The last straw was when a blood test from his keeled-over cow showed high levels of manganese. That was preceded by a string of calf mortality.
“Until we get this settled and test our water and we’re clean, we’re out of the cattle business,” he said.
Zimmerlee, a leader in the effort to test private wells, estimates about 50 wells are affected, the water source for about 150 people.
But even if the state’s sampling plan goes through, it won’t address what many people believe is causing the dark water.
The state’s mineral regulator, the geology and mineral industries department, is reviewing a permit application from Knife River to expand its operation onto a 78-acre piece of land leased by Zimmerlee. He opposed the expansion in a multiyear review process, when the Crook County Planning Commission denied the permit, a decision then overturned by the Crook County Court, the county’s governing body similar to a county commission.
“We believe strongly that if that’s allowed to move forward, the problem will just exacerbate,” he said.
Merkley said only the state agencies have the power to conduct testing on the Knife River property, and then use the results accordingly.
“If the state can say, ‘Yes, it’s clear that this (the mine) is the impact,’ then they have the regulatory authority, I think, to shut this down, would be my expectation,” he said.
Spanish 
English