FARMINGTON — Local residents, activists and industry officials found little common ground Tuesday in the protracted debate over San Juan Generating Station's future.

A meeting hosted by the New Mexico Environment Department to break an impasse between state and federal regulators yielded many of the same arguments that advocates on both sides have lobbed for months.

The U.S. Environmental Protection Agency has issued a mandate to San Juan Generating Station to install selective catalytic reduction technology — pollution control units that could cost $750 million or more.

Power plant operator Public Service Company of New Mexico backs a plan approved by the state Environment Department to install selective noncatalytic reduction technology, which would be cheaper but also less effective at removing pollutants linked to haze.

PNM says the state plan would cost only about $77 million.

The Clean Air Act requires power plants to use the "best available retrofit technology." State and federal regulators disagree about what that means. The outcome could lead to cleaner air and higher electricity bills in San Juan County.

"Ultimately, consumers will pay for whatever is decided here," said Ryan Flynn, general counsel for the New Mexico Environment Department.

More than 100 people attended the meeting.

The effort to gather comments is part of a 90-day stay issued by EPA Administrator Lisa Jackson. Gov. Susana Martinez had requested the stay in an April 26 letter to the EPA. The stay expires Oct. 15.

All sides are investigating whether a third alternative could meet the Clean Air Act's rules at lower cost to PNM and ratepayers.

"A viable alternative must comply with the requirements of the Clean Air Act," Flynn said. "Any alternative that does not comply with the Clean Air Act really is not viable and surely would be overturned."

The final plan would have to meet the approval of the EPA. An EPA official at the meeting deferred to state regulators.

"It's really the intent of the Act that states develop the plans, and that's what we're most comfortable with," said Carl Edlund, an air quality official with EPA Region 6, based in Dallas.

State Rep. Tom Taylor, R-Farmington, said requiring expensive pollution controls would yield "such a small amount of result for such a huge amount of money that it doesn't make sense."

Taylor, who serves as minority leader of the state House of Representatives, noted that the nearby Four Corners Power Plant plans to shut down its three oldest units, which would result in cleaner air.

Others argued that something must be done to clean up San Juan Generating Station, regardless of cost.

"From my classroom you can see two coal plants polluting the air on a daily basis," said Laura Comer, a teacher at Atsa Biyaazh Community School in Shiprock. She said the power plants affect children's health.

Abby Wear, executive director of the New Mexico chapter of Physicians for Social Responsibility, said coal particulates are linked to cardiac and respiratory disease.

"Coal is an assault on our health," Wear said.

A Navajo woman said haze from the power plant obscures the tribe's sacred sites. "We cannot eat the fish we catch because it contains too much mercury and other toxins," said Anna Rondo of Chi Chil Tah, south of Gallup.

The 1,800-megawatt coal-burning power plant in Waterflow, west of Farmington, is a major source of electricity in the Southwest. The plant and adjacent San Juan Mine also employ hundreds of workers.

But Rondo said it can't all be about jobs.

"What is a job if you die of lung disease at the age of 45?" she said.

Speakers who backed a gentler regulatory approach said environmental concerns must be considered along with other interests.

Farmington Mayor Tommy Roberts said any solution should consider environmental, physical and economic health.

"We have to achieve a balance," he said. The city of Farmington is one of San Juan Generating Station's nine owners through the Farmington Electric Utility System.

A local retiree, Bruce Higgins, pondered the cost of cleaning up the power plant.

"I wonder who's going to pay for all of this," he said.

While state and federal regulators are fighting over their competing pollution control plans, a lawsuit brought by several environmental groups is making its way through the courts. Oral arguments are set for late October at the U.S. 10th Circuit Court of Appeals in Wyoming.

PNM, which owns the largest stake in San Juan Generating Station and operates it, is proceeding as if the EPA's $750 million mandate will stand.

The Albuquerque-based utility company is evaluating competing bids to install selective catalytic reduction technology.

"We are proceeding to be assured that we could comply with that rule in 2016," PNM spokeswoman Valerie Smith said. "We don't want to put compliance at risk, but we also don't want to be needlessly spending money."

"We're hopeful that we'll be able to come up with a third alternative," she said.