An environmental group is launching a new legal attack on a proposed coal-fired power plant in southwest Kansas.

The Sierra Club said Monday it has asked the U.S. District Court for the District of Columbia to require a study of the environmental effects of a new coal-plant and possible alternatives.

Hays-based Sunflower Electric Power Corp. wants to build the plant and brokered a deal in May with Kansas Gov. Mark Parkinson to clear state regulatory hurdles.

The Sierra Club is represented by attorneys for Earthjustice, another national group. They want the Rural Utilities Service, part of the U.S. Department of Agriculture, to do the study.