NE Iowa coal-fired power plant nears end of long run

NE Iowa coal-fired power plant nears end of long run
NE Iowa coal-fired power plant nears end of long run(MGN)
Published: Dec. 3, 2022 at 11:26 AM CST
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LANSING, Iowa (AP) — Alliant Energy’s Lansing Generating Station — a coal-fired power plant — has operated for nearly 75 years along the Mississippi River in Northeast Iowa.

After this year, it will no longer produce electricity. Its closure will take hundreds of megawatts of energy generation out of Iowa and its neighbors on the power grid.

It marks the latest casualty in the series of coal-fired power plant retirements sweeping the country in the past decade. The gaps present opportunities for cleaner and often cheaper energy sources: renewable generation, like wind and solar power.

In October 2020, Alliant announced its Iowa Clean Energy Blueprint: the company’s road map for retiring its coal fleet, increasing its use of renewable resources and reducing its emissions in the state. Alliant made the decision to retire its Lansing Generating Station while creating that plan, spokesperson Morgan Hawk told the Cedar Rapids Gazette.

“Retiring the facility would help to control long-term costs for customers,” he said, referencing how renewable resources have grown to be more cost-effective than traditional fuels like coal. “And, obviously, retiring the facility contributes to a healthy environment.”

The facility’s closure will leave Iowa with seven utility-owned coal-fired power plants, with at least one — Alliant’s Prairie Creek Generating Station in Linn County — scheduled to stop using coal by 2025. Meanwhile, Alliant’s blueprint has mapped hundreds of new megawatts of renewable energy generation in Iowa for the coming years. MidAmerican Energy has, too, although some environmental groups, tech companies, manufacturers and a state attorney said they are skeptical of the plans without seeing more data.

In its lifetime, the Lansing Generating Station has helped provide electricity to customers across the central United States thanks to its role within the region’s power grid. The facility’s retirement prompts a look at its history and the environmental impacts that come with operating and closing coal-fired power plants — some of which could persist without proper cleanup efforts, which Alliant has said it is abiding by.

The Lansing Generating Station started providing coal-fired energy in 1948 with one 15-megawatt generating unit. A similarly sized unit was added a year later, followed by a 38-megawatt unit in 1957.

Twenty years later, a fourth and final unit joined the site — one capable of producing 275 megawatts of energy, blowing away the capacities of its on-site predecessors.

Each of the generating units has retired one by one since the turn of the century. Unit 4 has operated on its own since 2013. At the end of this year, its reign will end with the power plant’s retirement.

The close of this chapter brings Alliant one step closer to achieving its energy goals, which include eliminating all coal from its energy portfolio by 2040.

The Lansing facility’s coal consumption varies, Hawk said, typically burning between 400,000 to 800,000 tons of coal per year — all of which is delivered by barge on the Mississippi River.

Alliant aims to reach net-zero carbon dioxide emissions from its energy generation by 2050.

Throughout its life span, the Lansing facility’s carbon dioxide emissions have fluctuated depending on how frequently the plant is called into action. In recent years, that hasn’t occurred as often, thanks to more renewable energy and cheaper natural gas, said Jeff Hanson, Alliant’s director of environmental services and corporate sustainability.

“The coal plants really have been dispatched less, especially in Iowa, over the last few years,” he said. “That’s where the sector is heading.”

When power plants generate electricity by burning coal, the process produces a waste called coal ash that contains harmful contaminants. Facilities historically have disposed of the waste by mixing it with water and storing it in coal ash ponds.

The Lansing Generating Station currently features one coal ash pond that has been in use since 1974. It can hold about 587,000 cubic yards of waste — enough to fill roughly 200 Olympic-size swimming pools. On average, 1.7 million gallons of coal ash are discharged into the pond per day. Some of the waste is regularly dredged, drained and taken to a dry landfill on-site.

Coal ash is regulated under the U.S. Environmental Protection Agency’s 2015 Coal Ash Rule. Under this ruling, unlined coal ash ponds — like the one at the Lansing facility — were required to stop receiving waste and begin closure by April 2021. Alliant requested an extension until the end of this year.

To close the pond, crews will excavate and consolidate some of the waste to reduce the amount of area that must be maintained over time. Then, a cap made of clay and vegetation will cover the remaining waste and help prevent contamination of groundwater.

The coal ash left in the closed pond will be within 5 feet of groundwater — a characteristic that nonprofits Environmental Integrity Project and Earthjustice deemed concerning and illegal in a recent nationwide report, especially for unlined ponds more susceptible to contaminating surrounding groundwater.

“The ash pond is probably sitting in groundwater, which is a problem and not a situation where they should be closing in place,” said Abel Russ, an Environmental Integrity Project senior attorney and Center for Applied Environmental Science director.

However, Alliant representatives said they believe the report mischaracterizes both the Coal Ash Rule and the industry’s implementation of it. The rule specifies that new coal ash ponds cannot be constructed within 5 feet of groundwater, but that doesn’t apply to closing older ponds, said Jeff Maxted, who leads an Alliant team completing environmental compliance for the company’s power plants.

The pond’s closure should be completed by October 2023. The Lansing Generating Station marks Alliant’s last Iowa generating station to send material to coal ash ponds.

“Once it’s closed … we’re not done,” Maxted said. The Coal Ash Rule requires companies to monitor groundwater for at least 30 years. “We’ll be continuing to make sure that that facility is well taken care of well into the future.”

As required under the EPA’s Coal Ash Rule, Alliant uses wells placed before and after its Lansing coal ash pond to monitor groundwater as it passes through the area. The company is required to publicly post the results and any potential contamination.

Alliant’s 2021 groundwater monitoring report detailed elevated concentrations of 16 substances in the monitored groundwater after the pond compared with the groundwater monitored before the pond. These included boron, chloride and barium. Detected levels of three parameters — arsenic, molybdenum and thallium — exceeded groundwater protection standards.

These elevated levels prompted Alliant to further assess the groundwater monitoring to ascertain the sources of the contamination. In the near future, the company will be publishing a report with a broader investigation, Maxted said.

For now, he said that Alliant installed additional wells closer to the pond to further investigate the elevated concentrations of arsenic. Those wells didn’t show similar exceedances — so the company has come to the conclusion that the pond isn’t responsible for the contamination.

He also said the elevated levels of molybdenum may be due to natural background concentrations in the area.

“I think the jury’s still out in terms of us continuing to run down questions we have with groundwater in the area,” he said. “We’re very happy to see that there are no drinking water sources that are affected.”

Elevated boron levels, often accompanied by increased molybdenum, are the “fingerprints of coal ash,” Russ said. That’s why he suspects it’s unlikely the pollutants didn’t originate from the Lansing site. He also noted that Alliant hasn’t solidified a cleanup plan for the associated contamination yet, which the Coal Ash Rule required “as soon as is feasible.”

Maxted said the reason a cleanup plan hasn’t been chosen yet is because the utility is taking time to fully understand the underground groundwater system. More details about the selection will be shared in Alliant’s forthcoming report.

“We know a lot more now than we used to,” Maxted said. “It’s a sign that the (EPA’s) rule is working, but it does take time.”

Russ did commend Alliant for acknowledging the potential pollutants — which is more than about half of the country’s power plants do, in his experience. And, although the company hasn’t picked a cleanup plan yet, the delay is in line with more than three-quarters of plants in the nation.

“They’re not unusual in the fact that they haven’t selected a remedy, even though we think it’s not totally consistent with the Coal Ash Rule,” Russ said. “They’re on the better side of the divide, if you were to put the power plants in America into two categories.”

From coal to cleaner energy

As the power grid has matured through the decades, so have the sources energizing it. Transmission lines now span miles, spreading generation infrastructure further apart, and fuels are evolving.

For Alliant, that progress means swapping coal for cleaner and cheaper renewable energy. Its Iowa Clean Energy Blueprint aims for 400 megawatts of solar power and 75 megawatts of battery storage as coal-fired power plants are phased out. The renewable additions will boost the company’s existing 1,300 megawatts of wind power in the state.

“We’re moving away from having these large centralized power plants to having more smaller, decentralized power plants,” said Alliant strategic project manager Justin Foss. “You’ve got a stronger, more resilient power system — a better system overall.”

Transitioning to renewable resources will avoid the investments required to keep Alliant’s coal fleet operational — providing lower-cost energy to customers.

However, it’s unclear if those decreased expenses will translate to lower rates for customers. Alliant touted in its blueprint that the investments will help Iowa customers avoid more than $300 million in costs over the next 35 years. But energy bills are made up of several components, including usage costs, transmission service charges and energy costs according to current fuel prices, Hawk said.

“Solar and clean energy resources are only part of the total cost of delivering energy,” he said. “While clean energy resources will cost less in the long run, other costs will continue to fluctuate.”

Even with more solar and wind power appearing on the landscape — which depend on weather conditions — Alliant staffers said Iowa’s energy won’t be compromised.

Just as coal-fired power plants can operate 24/7, facilities powered by natural gas can as well. This reliable and arguably cleaner non-renewable — along with more battery storage — can help supplement solar and wind.

“It’s all about having a diverse generating portfolio,” Hanson said.

Alliant’s Lansing Generating Station will be demolished after it retires this year. As of yet, there’s no word about what may take its place. The existing infrastructure could be used for a future energy project, although nothing has been finalized or announced.

For now, the utility still is analyzing its options, Foss said.

“At the end of the day, we still have to have the same amount of electrons going on the grid as our customers are pulling off of it,” he said. “What’s the most cost-effective way to do that? That’s what we’re constantly trying to evaluate.”