The Albuquerque Journal reports that a stay granted by federal regulators so parties could evaluate alternatives for the San Juan Generating Station expired with no agreement on an alternative.
The extra time given to explore different technologies to the one proposed by the U.S. Environmental Protection allowed discussion of alternatives, but the "compliance date remained in effect so we have continued to move ahead with preparations to implement the federal plan that remains in place," said Pat Collawn, PNM Resources' president, chair and chief executive.
PNM will make a filing with the Public Regulation Commission this month seeking approval to move ahead with EPA-mandated selective catalytic reduction equipment.
The federal plan calls for selective catalytic reduction on each of San Juan's four coal-fired units.
PNM, which owns 46 percent of the plant, says the total cost will be between $824 million and $910 million. Even though PNM and the state have challenged the plan in federal court, the company recently hired a company to design and install the equipment to stay on the compliance schedule.
The state's far-less-expensive alternative, selective non-catalytic reduction was rejected by the EPA. Near the end of an original EPA stay, the state proposed a compromise to close two units by 2017, install selective non-catalytic reduction technology on the other two and build a natural gas-powered plant to meet peak demand.
New Mexico Environment Department spokesman Jim Winchester said the agency is disappointed the EPA hasn't agreed to the proposal and stay the compliance deadline.
The 1,800-megawatt plant is New Mexico's single largest source of electricity, and also provides power to customers in California, Arizona and Utah.