Winchester-based East Kentucky, one of the largest generation and transmission co-ops in the U.S., blamed the federal Environmental Protection Agency’s new Mercury and Air Toxics Standards (MATS) rule for its decision to shutter the plant indefinitely. The MATS rule goes into effect in April 2015 and installing advanced pollution controls to comply with the rule would require “cost-prohibitive measures,” according to the co-op.

“Dale station’s generating units are quite small compared to today’s standard coal-fueled power plants,” said Don Mosier, East Kentucky’s chief operating officer. “EKPC’s goal is to provide reliable, affordable power to our 16 owner-member cooperatives, and it is very difficult to justify the costs necessary to keep such small units operating.”

The co-op is closing Dale Units 1 and 2 this spring and will begin to explore marketing the assets of those units. Starting in April 2015, Units 3 and 4 will be conditioned for indefinite storage. All four units were built between 1954 and 1960.

Mosier said Units 3 and 4, rated at 75 MW apiece, “will be carefully maintained in place but in inactive status. Should market, regulatory, or other conditions change at some point in the future to allow Dale Units 3 and 4 to operate economically again, the units will be available for retrofit or conversion, subject to regulatory or other approvals.”

Dale currently accounts for about 6% of East Kentucky’s total generating capacity. The co-op also owns and operates the 341-MW Cooper coal-burning power plant in Pulaski County, Kentucky, and the 1,279-MW Spurlock coal-fired power plant in Mason County. Both plants are equipped with modern pollution controls that should allow for their continued operation for many years.

East Kentucky is spending about $15 million to construct ductwork to route flue gas from 116-MW Cooper Unit 1 through a dry-circulating scrubber already installed on Cooper Unit 2, rated at 225 MW. The project should enable Unit 1 to comply with new environmental rules and avoid retirement. Unit 1 also should be able to continue burning Central Appalachian coal instead of switching to high-sulfur Illinois Basin coal.

Excepting Dale, East Kentucky’s other coal plants will comply with the MATS rule, the co-op said. In the past decade, East Kentucky built the 278-MW Gilbert and Spurlock 4 units at the Spurlock plant. Gilbert and Spurlock 4 are two of the cleanest coal-burning units in the nation. Two older Spurlock coal units also have been retrofitted with scrubbers and other emission-control equipment in recent years.