A power plant in Western Kentucky with a history of polluting groundwater is planning to phase out coal after four decades of operation.
It’s the seventh coal-fired power plant to close in the state since 2019.
The plant’s owner, Big Rivers Electric Corporation, says they have to stop burning coal at Robert D. Green generating station by June 1, 2022, in order to comply with environmental regulations, according to a Public Service Commission order from June.
In its place, the non-profit, member-owned cooperative plans to retrofit two generators to burn natural gas at a price tag of more than $45 million.
The conversion will improve air quality and limit the amount of coal ash added to the site’s ash ponds and landfill. But advocates and climate scientists aren’t yet ready to claim Green Station’s conversion to natural gas as a victory for health, the environment or climate.
“Even if we get gains from doing the transition today, 10 years from now, five years from now, 20 years from now … sometime, that’s probably going to be an asset that we regret,” said Jonathan Buonocore, research scientist at the Center for Climate Health and the Global Environment at Harvard’s T.H. Chan School of Public Health.
Green Station is one of three coal-fired power plants formerly located on the same site in Western Kentucky near the town of Sebree and is the last to announce plans to quit coal. The plants have left behind a literal mountain of ash: large enough to span 128 football fields and stand 50 stories high, not including the site’s two ash ponds.
Evidence of coal ash pollution around the site dates back nearly two decades. Since 2017 state inspectors have discovered unsafe levels of carcinogenic and neurotoxic heavy metals including arsenic, mercury and thallium seeping out of the banks of the nearby Green River. As recently as last year, plant owner Big Rivers Electric Corporation documented unsafe levels of ash pollution in groundwater nearby.
Despite the evidence of pollution entering groundwater and seeping out of riverbanks, Big Rivers says the impacts of the pollution are limited to its own property and won’t “migrate beyond the functional perimeter,” according to its corrective action report from Jan. 2021.
Big Rivers declined an interview request but a spokeswoman said in an email that converting Green Station to natural gas allows the utility to close the site’s ash ponds and comply with federal regulations from the Environmental Protection Agency.
“Closure activities on the Green ash pond will start next year after operations on coal cease,” wrote Jennifer Keach. “When all the ash ponds are closed, the landfill will no longer be receiving coal ash.”
Meeting Environmental Regulations
In early June, state utility regulators approved Big Rivers’ plan to convert the coal generators and permanently close the Green Station ash pond. The so-called “pond” is actually a 54-acre, 360-foot-deep slurry of coal ash and water that currently resides within five feet of an aquifer, known as the carbondale formation, records show.
That runs afoul of EPA’s coal ash regulations designed to prevent coal ash from polluting groundwater in order to preserve aquifers as natural resources for future generations, said Abel Russ, senior attorney with the Environmental Integrity Project.
“We all know that groundwater is a scarce resource. There isn’t a lot of clean groundwater left and there’s less and less all the time,” said Russ. “The coal ash rule was written for a specific policy goal and that was to protect groundwater as a source of drinking water.”
The Environmental Integrity Project has successfully pushed the EPA to more strictly regulate coal ash and is currently suing the federal government over Trump-era regulatory rollbacks, Russ said.
The Environmental Integrity Project has documented coal ash pollution affecting groundwater at 91% of 265 power plants across the country. Fifteen of those sites are in Kentucky including at Green Station.
From 2017 to 2019, inspectors visited Green Station and identified pollution leaching out of landfill and appearing at orange and green discolored seeps along the banks of the Green River, records show. Testing of the stained riverbanks revealed unsafe levels of the cancer-causing pollutant arsenic as well as mercury and lead (which are both neurotoxins), cadmium and thallium, according to state records.
And although Big Rivers found evidence of pollution on the riverbanks, the utility also claims it has not impacted the river’s water.
Big Rivers has since built trenches to reroute the pollution from entering the river or seeping out of its banks. The company then dilutes the pollution before it’s dumped back into the Green River at legally acceptable levels through a legally permitted outfall pipe.
The coal ash pollution however, continues to affect groundwater underneath the site. The station’s latest report documented unsafe levels of lithium as high as 10 to 44 times the federal standards designed to protect groundwater, as well as unsafe levels of arsenic, barium and mercury in the groundwater underneath the site.
As of Nov. 2020, Big Rivers had not taken any formal measures to address the groundwater impacts, according to the report.
“Big Rivers is following the required steps to address the matter,” Keach said in an email.
Much of the pollution at the site is typical of what’s happening at coal-fired power plants around the country, but Russ said the landfill has unusually high levels of lithium.
“Once that stuff, the lithium, the arsenic, the boron, is leached out of the ash and carried into the groundwater, it’s much, much, much harder to clean up and it’s much more expensive,” Russ said. “Instead of just digging up ash you are actually trying to treat the groundwater, or wait until it gets better which can take hundreds of hundreds of years.”
Climate Change and Natural Gas
Coal power continues to dominate Kentucky’s energy mix, but it’s waned over the last few years, from 73% of the state’s net electricity generation in 2019 to 69% of the generation in March 2021, according to the U.S. Energy Information Administration.
At least four coal-fired power plants, including Green Station, have been replaced with natural gas across the state in the last six years, including the high-profile retirement of the Paradise coal-fired power plant, made famous by John Prine. It was replaced with an 1,100 megawatt combined cycle gas turbine power plant in 2017.
The retirement of the coal stacks has immediate and lasting benefits for local and regional air pollution. Coal emissions contribute to acid rain and unhealthy ozone formation as well as respiratory illnesses. The fine particulate matter from the pollution is so small that it can even enter the bloodstream and cause myriad health problems, said Buonocore with the Harvard T.H. Chan School of Public Health.
Then there’s the carbon dioxide, the primary greenhouse gas produced by burning fossil fuels like coal.
Right now, the planet is on track to be 2.7 degrees Fahrenheit warmer than pre-industrial levels by about 2040. As little as 3.6 degrees of warming presents an urgent and potentially irreversible threat to humankind and the planet, according to the U.N.’s Intergovernmental Panel on Climate Change.
In order to prevent the worst impacts of climate change, scientists warn the entire planet needs to go on a serious carbon diet.
Natural gas is often touted as a transition fuel that will bridge the gap between the end of coal power and the rise of renewables like solar and wind with storage capacity, but Buonocore said the research coming out now indicates that gas is not necessarily better for the climate than coal.
That’s because of all the methane that leaks out in the process of converting it into energy. Methane is a far more potent greenhouse gas than carbon dioxide, though it lasts for a shorter amount of time in the atmosphere, he said.
“There’s a good argument, that, especially if you are concerned about meeting the Paris agreement by 2050, that smaller warming potential is way more relevant,” Buonocore said.
Big Rivers’ decision to convert Green Station from coal to gas could potentially impact the climate for decades to come. Big Rivers told utility regulators the “useful life” of the new plant could last through 2043.