Topeka ? Opposition to a proposed power plant in western Kansas picked up steam Wednesday as the state extended the deadline until Dec. 15 for public comment, and environmentalists scheduled a rally to protest the coal-fired facility.

A coalition of groups, including the Sierra Club, True Blue Women and University of Kansas Environs, plan to rally Saturday at the Capitol to ask Gov. Kathleen Sebelius to issue a moratorium on new coal-fired plants.

“We ask the governor to stop new coal plant construction and take steps to move Kansas forward without endangering the health of Kansans and further increasing global warming,” said Jennifer Byer of True Blue Women.

Environmentalists say the proposal by Sunflower Electric Power Corp. to build three 700-megawatt plants in Holcomb will emit harmful pollutants, suck valuable water from the underground aquifer and stall development of renewable sources, such as wind energy.

Sunflower officials have defended their proposal, saying it will pump jobs and development into the western Kansas economy and produce needed electricity more cleanly and efficiently than older plants.

Sebelius has declined to declare a moratorium on coal plants, saying she would only consider one if the Kansas Department of Health and Environment and the Kansas Energy Council recommended one as part of a comprehensive energy plan.

As rally plans got under way, state officials extended the deadline for the public to comment on the Sunflower proposal.

“Because of the significant interest in this issue, we feel it is important to extend the deadline to Dec. 15 to ensure that everyone interested will have an opportunity to make their thoughts known,” said Roderick Bremby, Kansas Department of Health and Environment secretary.

The period to comment was previously set to expire today.

Now comments can be sent to KDHE postmarked no later than Dec. 15.

All comments should be submitted in writing to Rick Bolfing, KDHE Bureau of Air and Radiation, 1000 S.W. Jackson, Suite 310, Topeka, KS 66612-1366.

Steve Miller, a spokesman for Sunflower, said the company had no problem with the longer comment period.

“We understand that the agency has a large amount of information that they have to deal with,” Miller said.

Earlier this month, a public hearing in Lawrence on the plant proposal drew so many people that the meeting had to be extended for a second night.

Later, the Lawrence City Commission submitted a letter to KDHE opposing the issuance of permits for the proposed project.