Climate change means more flooding: what will become of the contaminated water beneath Missouri’s coal ash ponds?
Our warming planet is the catalyst behind heavier rains that threaten to bring about a hidden danger — rising water tables seeping into unlined coal ash pits, mixing with and contaminating groundwater used not only for agriculture, but as drinking water.
In Missouri, out of the 16 coal-fired power plants and 41 coal ash ponds, almost every major coal-fired power plant is located alongside a river. These plants are located in close proximity to rivers because they use the water for cooling processes.
Everyday, for instance, over a billion gallons of water is pumped from the Missouri River. It is used to generate steam that turns the coal plant turbines and generates electricity. After it is used, the water is pushed back out into the river.
“It’s a very old technology of cooling a power plant that as a result, everything they do is right near the water,” Patricia Schuba, President of the Labadie Environmental Organization said. “The coal ash ponds, which have operated for decades and in some places as many as six decades, were all built along the rivers and they’re in the water table.”
The coal ash ponds are dug deep into the ground near rivers, exposing the groundwater to harmful toxins. A study from the Environmental Integrity Project shows 91% of coal plants have unsafe levels of one or more coal ash toxins in groundwater on or around the property.
Climate change could make contamination from ash ponds worse throughout the Missouri flood plains.
With heavy rainfall events increasing due to climate change, flooding in the Midwest has become even more prolific. Missouri is home to three major rivers: the Missouri, Mississippi and the Meramec. The rivers converge on the borders of the state, which means that anything throughout the floodplains is susceptible to high and intense flood waters.
When the electric companies built their coal-fired power plants near bodies of water in the early to mid-20th century, climate change and flooding was not a concern.
Contaminated groundwater is unsafe because water is fluid, affecting the people near it, as well as downstream. Contaminated groundwater eventually migrates to local rivers, streams and lakes where it threatens human health.
What is coal ash?
Coal ash is leftover residue from when coal is burned to generate power. One of the largest types of industrial waste in the United States, an estimated 110 million tons generated annually, is coal ash.
This residue contains contaminants like mercury, lead, chromium, boron and arsenic. These contaminants are toxic to human health, causing illnesses that range from asthma to cancer and sometimes death.
Made up of a combination of by-products from the coal burning process, the ash is mixed with water and put in pits next to the coal plants on the power plant property.
These pits are now what is referred to as “ash ponds.”
In 2015, the Environmental Protection Agency (EPA) established the first ever federal coal ash regulations to manage coal ash disposal. As part of these regulations, the EPA set standards for new coal ash landfills and also existing coal ash landfills as well as coal ash disposal ponds.
The standards included requirements regarding structural integrity, groundwater monitoring, operation and closure of the ponds.
Prior to 2015, the coal ash ponds were unregulated and because there were no regulations when the ash ponds were built, many were unlined, meaning that there is no barrier or a thin layer of soil between the ash and the water table below, allowing cross-contamination to occur.
The regulations put in place began the process of permanently closing the basins where coal ash is stored, in ways that put safety first, protected the environment and minimized impacts to communities around the toxic ponds while managing costs for customers.
Following the Obama administration, in which the regulations were instituted , the Trump administration rolled back almost all of the set regulations, which are now being reinstated by the Biden administration.
There are a few ways in which coal plants can close their ponds. They can close the ponds in place by leaving the coal ash where it is and “capping” the pond with a cover or they can remove that ash by excavating it and moving it to a properly lined landfill for permanent disposal.
Capping looks a lot like how an old landfill would be covered. An impermeable cap is installed along with soil and clay, grass or turf to make the ground look like it did before the ash pond was there. Capping does not remove the ash from the floodplain, and leaves the possibility of toxins leaking into the groundwater.
“They, [Ameren and other utilities] do what we call a cap and run,” Andy Knott, said. “It’s like, we’re gonna leave it here and we’re not going to take responsibility for it anymore.”
The problem could be in your backyard
In Missouri, there are 25 ponds that are unlined and will be closed in place, or are undecided on whether they will be clean closed or closed in place, allowing their contents to continue to seep into the groundwater.
For example, the Labadie Power Plant and the Rush Island Power Plant run by Ameren, an electric utility company that runs several coal fired plants throughout Missouri, are located only a few miles away from the major Missouri and Mississippi rivers.
“The ash ponds like Labadie and Rush Island are dug extremely deep in the floodplain,” Peter Goode, an environmental engineer and law lecturer at Washington University’s Interdisciplinary Environmental Clinic, said. “The ash ponds in Labadie are almost 100-feet deep and the ash pond at Rush Island is 90-feet deep.”
Schuba, president of the Labadie Environmental Organization, a volunteer-led nonprofit advocating for the removal and clean closure of the coal ponds ash in Labadie knows firsthand the effects of coal ash contamination.
“In the case of Labadie, we have sunflowers being grown down there right next to these leaking ash ponds and we’ve done it for decades,” Schuba said. “We feed that to animals. We produce high fructose corn syrup out of it and we feed it to humans.”
If toxins aren’t ingested that way, Schuba added that a lot of the “fresh” drinking water available in the state comes from these rivers.
“Most Missourians drink from those rivers, from wells, so were exposed in one way or another,” Schuba said.
Initially, Ameren claimed that there was no contamination of groundwater on their property. But when building another landfill, they sunk monitoring wells into the ground to test for toxins and the results came back positive, which required them to apply for permits from the Missouri Department of Natural Resources.
“We have even more data today, at times six to seven times the drinking water standards for arsenic on that site,” Schuba said.
According to Ash Tracker, a public outreach data source by EarthJustice, a nonprofit environmental law organization, 12 of the coal plants in Missouri have publicly recorded unsafe levels of toxins in the water.
Toxic groundwater doesn’t sit still
Groundwater contamination can happen in two ways: by the mix of water and toxins leaching through the bottom of the pond or the water table rising high enough to reach the bottom of the pond, thereby mixing with the toxic contents of the pond.
The potential for groundwater contamination is especially great in the flood plains where the water table can be so high that it percolates to the surface of the ground, even during moderate floods.
“The areas that we’re talking about have a very high groundwater table and it comes up close to the surface and above the surface when the river comes up,” Goode said.
When the water table is high enough, it makes contact with the ash, contaminating the water.
Even if ash ponds are ‘capped’ and left in place, the contaminants are still sitting in unlined pits. For ash ponds in or out of the floodplain this is an issue, but the proximity of these ponds to large bodies of water makes it more likely for contaminants to reach the groundwater, which puts fresh water sources at risk.
There are plants that are not in the floodplain that are excavating the ash instead of leaving it where it is. Ameren, which has 15 ash ponds along the Missouri, Meramac and Mississippi rivers, has decided to cap their ponds in place instead of excavating them.
Ameren made this decision even though their Meramec Energy Center’s nine ash ponds sit at the confluence of the Meramec and Mississippi rivers, which are in constant contact with this region’s groundwater.
“Other utilities are doing the right thing even when they’re not in the floodplain,” Andy Knott, a senior representative for the Beyond Coal Campaign for the Sierra Club, said. “It’s really these larger utilities that are being irresponsible.”
He uses the Columbia City Power Plant and the Springfield Utilities Power Plants as examples for clean closure. Clean closure is when the ash is taken out of the wet environment and moved to a dry landfill with an impermeable liner that prevents leaching of contaminants into the groundwater.
According to Craig Giesmann, senior manager of environmental services at Ameren Missouri,
“Ameren has performed extensive studies in surface water bodies near its energy centers and has determined that there are no effects from its ash basins.”
They also say that contaminants are limited to the powerplant property.
“At the Labadie power plants, they’ve done some additional groundwater monitoring out near the property line of the plant that shows that there is contamination at least reaching the property line,” Goode said.
Because the EPA regulations set up in 2015 are self implementing, there is virtually no oversight from outside entities, like the state or the federal government monitoring coal plants compliance with coal ash regulations.
Typically, the coal plants hire another company to do ground water testing for them. For example, Ameren employs Golder Associates, an engineering company who focuses on things like natural resources management, ground engineering and environmental management.
“There is influence when you are buying the person to do your work,” Schuba said. “As a citizen, I would hope that the testing is overseen by the local regulator or the EPA, or that there are ways to ensure that there’s no undue influence by the person who’s paying the bill, namely the utility.”
After years of citizen lawsuits, Schuba has little faith in the way the coal ash regulations and the way they were set up.
“Self-implementation is a big problem,” Schuba said. To make sure companies follow regulations, individuals, nonprofit organizations or the state government has to sue them.
“There’s virtually no oversight by the state’s [Missouri] DNR,” Schuba said.
Climate change exacerbating the issue
As temperatures increase, the warmer atmosphere holds more water resulting in intense rainfalls and flooding. The ash ponds that are still open and working or ‘capped’ near high-risk flood areas will be at a higher risk of groundwater contamination.
Floods saturate the ground, essentially raising the water table to a high level, when it would normally be either just below the surface or a few feet below the surface of a floodplain.
“Contaminants that are already in the groundwater once the floodwaters start to recede flow off of the property and into the surrounding water bodies,” Goode said.
The groundwater table isn’t static; it moves up and down with the level of the river. If the river comes up, it forces the groundwater to rise as well.
“Rainfall that flows down from the surface through the ground can cause leaching of contaminants from that ground because that rain water comes in contact with the ash,” Goode said. “Which then flows downward into the groundwater.”
Schuba says she is concerned about the rising groundwater levels coupled with the frequency of extreme weather events that are becoming major threats to the coal ash sites.
“[Toxic] material could end up outside of the community downstream, polluting a whole region,” Schuba said
According to the EPA, nearly 90 million people in the United States rely on groundwater for their drinking supplies. Groundwater is also widely used in agriculture for irrigation.
Groundwater contamination from coal ash is a long term issue, and the regulations surrounding them only reach the bare minimum.
“The end goal is for the ash to be removed from the floodplain where it’s endangering everything, and put in a lined landfill out of the floodplain,” Schuba said. “So our goal is that eventually, hopefully, in my niece and nephews lifetime, that is just floodplain again.”
Colleen Wouters earned her bachelor’s degree in science, health and environmental journalism at the Missouri Journalism School in May 2021.