Caledonia — Dozens of private wells near the Oak Creek coal-fired power plant have elevated levels of a metal called molybdenum, and We Energies is providing some homeowners in the area with bottled water for drinking and cooking.

An investigation by the state Department of Natural Resources has not determined the source of the metal, which is considered a health risk when consumed at high levels.

The We Energies plant in Oak Creek is a potential source of molybdenum, but environmental regulators are also investigating a longtime landfill in Caledonia, west of the tainted wells, that is now a Superfund site.

The Milwaukee utility said its environmental consultant has concluded that its power plant is not the source of the contamination, but environmental groups dispute that. The DNR has not pinpointed a source.

Caught in the mess are homeowners, some of whom have lived in the area for decades. Unable to drink their water, and concerned about the impact of the problem on their property values, they wait for an answer.

"I just wish I could sell my house and get out of here," said Josey Dorval, who has been living on her nearly 3-acre property since 1989. "It's too big for me, and it's too much for me since my husband died. Now who's going to buy it with bad water?"

Frank Williams agreed. The retiree is one of dozens of homeowners who have been supplied with bottled water by We Energies for the past year after groundwater tests of well water found the elevated levels of molybdenum.

"We can't say we want to sell our home, but if you've got bad well water and that's the only drinking water you've got, who's going to buy it?" he said.

At issue is a metal that's found in the Earth's crust and is used in industrial processes. It's also found in coal ash - and three coal ash landfills on the Oak Creek power plant property are near the tainted wells.

According to the state Department of Health Services, elevated molybdenum exposures have been linked to higher rates of gout. "If your water tests higher than the enforcement standard, WDHS recommends that you find an alternate source of safe water to drink," a department advisory says.

Molybdenum, which can be found in green leafy vegetables, "is an important dietary nutrient in very small quantities," according to the department.

A health standard for molybdenum was set in 2007, and testing of local wells found the elevated levels last year, We Energies spokesman Barry McNulty said. For homeowners found to have levels above the health standard of 40 micrograms per liter, the utility began providing bottled water in August 2009.

Dorval is drinking bottled water, but it isn't supplied by We Energies because her home wasn't included in an agreement the utility signed with the town. Some other homeowners are in the same situation.

"We don't get bottled water," said Barb Hugier of Caledonia. "I think in a way that admits that you're guilty, it's your fault, if they keep supplying everybody with water."

A consultant hired by the utility determined that groundwater flows toward, rather than away from, the power plant, McNulty said. That would lead to the conclusion that there must be another source of the molybdenum.

"It flows toward the plant and the plant property, not toward the residences," he said.

But a report by the Environmental Integrity Project and Sierra Club released last month says the presence of fractured bedrock in the area means that water can drain in different directions, despite the general flow of the groundwater toward the northeast.

Asked about the discrepancy between the reports by We Energies' consultant and the environmental group report, Ann Coakley, bureau director of waste and materials management for the DNR, said the source remains under investigation.

"Groundwater flow through sand is much easier to understand and see than it is through bedrock, so fractures can come into play," she said.

Sorting through piles of papers on her dining room table, Barb Hugier, one of several residents along Foley Road whose wells have high levels of molybdenum, said she is spending several hours a day making phone calls and trying to learn more about the issue.

She has more questions than answers.

Could the Superfund site, which locals call "the toxic ponds," be to blame? Or could it be We Energies? Pointing to a map of the area, she notes her home sits on a line between the two.

"I'm trying to find some rhyme, some reason, some pattern," she said. "I'm not going to point a finger," she said of We Energies, "but it's an answer."

"We're not finding a consistent pattern," said Rhonda Volz, manager of DNR's drinking water and groundwater program.

Some homes with deep wells have high levels, while others do not. Some homes with more shallow wells have high levels and others do not. "That's why we have not been able to attribute it to a specific source or determine if it's naturally occurring," Volz said.

Residents were told by DNR representatives that it could be years before its investigation is complete and a source is found. The next step is expanding the testing up to two miles west of the power plant - farther west than the area already found to have tainted wells.

Heading farther west will help assess whether the Hunts Disposal Landfill, a federal Superfund site, could be a source of the molybdenum, Coakley said.

But Coakley took issue with several aspects of the environmental groups' report, which she said didn't emphasize the role Wisconsin DNR has played in avoiding putting fly ash and bottom ash from coal-fired power plants into landfills.

The environmental groups are raising concern about coal ash in advance of public hearings being sponsored by the U.S. Environmental Protection Agency on a rule that could regulate coal ash as hazardous waste.

The environmental groups are pushing EPA to adopt an aggressive rule instead of one that is being favored by utilities that are recycling the fly ash into road materials.

The more aggressive rule, said Jennifer Feyerherm of the Sierra Club, is more important given the damage caused by coal ash in incidents around the country.

"Leaving things the way they are means a patchwork of regulations that leave us all at risk," she said.

But Coakley said regulating coal ash as hazardous waste will create new challenges, such as the need to build a hazardous waste landfill in the state. Wisconsin has no such landfills today.

"It's been problematic for utilities to even site regular coal ash landfills, but to have a hazardous waste coal ash landfill would be pretty controversial for surrounding communities," Coakley said.

Just down the street from the entrance to the power plant lives George Bink, 80. His brother lives next door and his son lives in the house next to that, and testing showed all three homes have elevated levels.

"The three of us here, we don't have a well we can drink out of," said Bink.

Bink believes the problem is linked to the coal ash but just wants it resolved so he or his relatives can sell his home at some point.

"I'm sure you understand that the power company's not going to admit to anything. They're going to fight it to the very end," he said.