"Building a massive, new polluting coal facility will have serious long-term consequences for Kansas, and the public's voice should be heard on such an important matter," said Stephanie Cole, spokeswoman for Kansas Sierra Club.
Health Department spokeswoman Maggie Thompson said the agency received and was reviewing the letter.
"We're still reviewing it and consideration will be given to their request. That's where we are right now," Thompson said. "It's a pretty extensive letter."
In April, Gov. Mark Parkinson and Sunflower officials reached a settlement over plans to build a new plant, reducing the company's request from two plants to one 895 megawatt plant. The settlement also contains other renewable energy provisions.
The two-plant plan would have cost about $3.5 billion, though a revised estimate for the single plant hasn't been released.
Bremby, the health department secretary, denied Sunflower's initial application for two plants in 2007 over concerns about carbon dioxide emissions. He said then that the state couldn't ignore the dangers of global warming, which many scientists link to greenhouse gases such as carbon dioxide.
A new application submitted by Sunflower on Friday contains revisions to reflect that it wants to build one generator, not two, but leaves some data "to be determined," including levels of emissions of pollutants.
The environmentalists' letter argues that the health department should be required to hold a public hearing before the new application and permit are approved.
Sunflower and its supporters in the Legislature tried unsuccessfully during the 2008 and 2009 sessions to push through legislation to overturn Bremby's decision. Each time the measures were vetoed by then-Gov. Kathleen Sebelius. But within days of her resignation in April, to become U.S. secretary of health and human services, Parkinson announced he and Sunflower had reached an agreement to build one new plant.
Legislators quickly approved a bill codifying the agreement, along with measures to increase wind energy and promote conservation.
"The initial agreement was made privately between Gov. Parkinson and Sunflower. We just want to have an opportunity to participate," said Cole, of the Kansas Sierra Club.
Sunflower will be allowed to build a plant with enough capacity to meet the peak electric demands of about 448,000 households. The utility agreed to take steps to offset the plant's potential carbon dioxide emissions, estimated at almost 6.7 million tons a year.
The agreement between Parkinson and the utility also calls for new transmission lines in western Kansas, which would then be used to carry power from wind farms.
Sunflower expects the power plant to take about 18 months to construct and creating about 1,500 jobs.