Interstate Power and Light (IPL) will be forced to spend $620 million to retire 10 coal-fired units and retire, refuel, or install pollution controls at several others in Iowa under a settlement reached with the federal government.
The Alliant Energy subsidiary has long anticipated the settlement announced on July 15 by the Environmental Protection Agency (EPA) and the U.S. Department of Justice. It said in a July 15 statement that it has been executing a plan for several years “to create cleaner and more efficient ways to generate energy for [its] customers.”
IPL’s seven coal-fired plants in Iowa have a total capacity of 1.9 GW. They include the 212-MW Burlington plant Unit 1; the three-unit Dubuque Plant (38-MW Unit 1, 29-MW Unit 5, and 15-MW Unit 6); the 275-MW Lansing Plant’s Unit 4; the 219-MW ML Kapp Plant’s Unit 2; the 726-MW Ottumwa Plant’s Unit 1; the four-unit Prairie Creek plant; and the two-unit Sutherland Plant (38-MW Unit 1 and 82-MW Unit 3).
The settlement will require the retirement of the Lansing Units 1, 2, and 3; M.L. Kapp Unit 1; and Sutherland Unit 2 upon entry of the consent decree.
At Lansing Unit 4, it requires continuous operation of selective catalytic reduction (SCR). Ottumwa Unit 1 must run a low-NOx combustion system until SCR or an alternative is installed in 2019. Both units will need to install and run dry flue gas desulfurization units.
It also requires closure of Units 1, 2, 3, 4, and 5 at the Sixth Street Generating Plant—but Alliant Energy has already shuttered that plant and plans to complete its demolition this year.
The settlement says that IPL should have retired or refueled M.L. Kapp Unit 2 by June 2015, Prairie Creek Unit 4 by December 2020, and Prairie Creek Boiler 1, 2, and Unit 3 by December 2025. IPL must also retire or repower Dubuque Units 1, 5, 6, and Sutherland Units 1 and 3 by June 2019.
IPL will also spend $6 million on environmental mitigation projects—including developing a “major” solar photovoltaic project and anaerobic digestion installation project—and pay a civil penalty of $1.1 million.
The case stems from an agency determination that IPL commenced construction of one or more major modifications at the Lansing and Ottumwa plants in violation of the Clean Air Act’s Prevention of Significant Deterioration (PSD) clause. “Such modifications resulted in significant net emissions increases, as defined by the relevant PSD regulations, of oxides of nitrogen (NOx) and/or sulfur dioxide (SO2),” it said.
According to the EPA, IPL approached the agency in late 2011 to “explore a voluntary system-wide PSD settlement at its Iowa units.” The State of Iowa, Linn County, Iowa, and the Sierra Club are co-plaintiffs to the settlement.
—Sonal Patel, associate editor (@POWERmagazine, @sonalcpatel)