TOPEKA ? Kansas’ top environmental regulator gave the go-ahead Friday for the construction of a $2.8 billion coal-fired power plant, only days before the federal government was expected to announce new rules for utilities designed to curb greenhouse gas emissions.

Robert Moser, secretary of the Kansas Department of Health and Environment, approved changes in a 2010 pollution-control permit for Sunflower Electric Power Corp., for a proposed 895-megawatt power plant outside Holcomb, in southwest Kansas. The changes impose stricter controls on nitrogen dioxide, sulfur dioxide and other pollutants and were mandated by a state Supreme Court ruling last year.

Environmentalists have long fought Sunflower’s plans to build a coal-fired plant next to an existing coal-fired plant, and the Sierra Club filed a lawsuit challenging the 2010 permit. The Supreme Court agreed that the state didn’t use strict enough standards in some areas but refused to void the entire permit.

Kansas hasn’t regulated emissions of carbon dioxide, the heat-trapping greenhouse gas linked to climate change, and the amended permit wouldn’t limit them from Sunflower’s new plant. Several representatives of national environmental groups said Friday that Moser and his department should have tackled greenhouse gas emissions because allowing Sunflower to build the plant will make it far more difficult to reduce them in Kansas.

“I think they’re just hoping that if they close their eyes and cover their ears, all this will just go away,” said Amanda Goodin, an attorney for Earthjustice, which represented the Sierra Club in the lawsuit over the 2010 permit.

Moser said his department had anticipated that Sunflower’s project would meet the tougher standards required by the Supreme Court but spent months reviewing the proposed amendment to make sure. Among other things, the court is requiring Sunflower to meet hourly limits on nitrogen dioxide and sulfur dioxide, instead of standards that average emissions every three hours.

“KDHE has done its due diligence to ensure this plant will deliver clean power to Kansans within current emissions limits,” Republican Gov. Sam Brownback said in a statement.

Brownback and many legislators back Sunflower’s project because they believe it will create jobs and boost the economy in southwest Kansas. The Sierra Club and other environmentalists have accused Brownback’s administration of rushing its consideration of the permit changes.

Sunflower, a nonprofit based in Hays, supplies wholesale power for about 400,000 homes in southwest Kansas through six electric cooperatives. The new plant would generate enough electricity to supply 537,000 homes, according to one state estimate, but Sunflower would reserve 78 percent of that for Tri-State Generation and Transmission Association Inc., a wholesaler supplying 44 cooperatives in its home state of Colorado and Nebraska, New Mexico and Wyoming.

Sunflower has sought to add coal-fired generating capacity since 2001, but only a deal between the company and then-Democratic Gov. Mark Parkinson in 2009 cleared the way for a state air-quality permit. As part of the deal, the GOP-controlled Legislature approved renewable energy standards for utilities that it had resisted.

Goodin and Sierra Club representatives said they’ll review the permit amendment closely to determine whether they’ll pursue further litigation.

KDHE officials acknowledged that Sunflower’s amended permit doesn’t anticipate the rules on greenhouse gas emissions expected from the U.S. Environmental Protection Agency next week. Administration officials have said the rules will give states reduction goals and allow flexibility for how states choose to meet them.

However, a new Kansas law taking effect in July allows Moser and future KDHE secretaries to set separate rules for carbon dioxide emissions for coal and natural gas-fired power plants that include “flexible” standards for older facilities to avoid “unreasonable costs” or requiring utilities to switch fuel sources. The legislation passed both houses with large, bipartisan majorities, and Brownback had a ceremonial signing ceremony at the Holcomb plant site last month.

Brownback said in an interview this week, “Our effort now is to say, ‘We want to do this at our level.'”