Coal-based energy plants remain air/water threat
Michigan, like all other states, continues to face the environmental impact from coal burning energy plants, both in terms of air pollution and potential threats to water quality from coal waste produced in the process.
Inhibited by high costs and environmental challenges, energy providers in Michigan and other areas say coal-fired power plants are already on their way out, with a mix of natural gas and renewable energy sources set to take the place of coal. But with more than a decade until the transition will be final, state lawmakers and federal regulators continue to look for ways to relax the rules on the use of coal-fired power plants, particularly those pertaining to coal ash, the toxic remnants left over from the burning of coal.
"References to 'clean coal' have to do with carbon emissions and lower carbon emissions," said Charlotte Jameson, energy policy and legislative affairs director for the Michigan Environmental Council (MEC), who recently wrote a report for the MEC titled, "Impacts of Burning Coal on Michigan's Water Quality." "A lot of the discussion is because of the climate impacts. We have the technology and scrubbers that can limit air emissions, but at the end of the day, if you're burning coal, you're going to have carbon impacts and carbon emissions. And that doesn't get into the other sorts of toxins we talk about in this report. Burning coal also leaves a high amount of waste with mercury, arsenic and lead.
"As we have put more emphasis on air pollution controls, we have reduced the amount of toxins in the air, but they don't go away. Even more is retained in waste and ash, and we are seeing the toxicity of ash increased as we decrease emissions. It's an interesting interplay."
The MEC's report follows a report by researchers at Duke University that reviewed 30 years of research, which found people living near coal-fired power plants have higher death rates and at earlier ages, along with increased risks of respiratory disease, lung cancer and cardiovascular disease. The health risks are associated both with air emissions and heavy metals and other waste found in coal ash.
To remove coal ash and other contaminants from scrubbers, boilers and other areas, plant operators use water as a rinse. That water, combined with the ash, creates ash sludge filled with various chemicals, such as arsenic, mercury, lead and cadmium. Utility operators have traditionally dumped the ash sludge into giant waste ponds – typically unlined pits that are open to the elements.
Leftover ash from burning coal contains mercury, lead, arsenic and other toxic heavy metals. For decades, utilities have dumped wet coal ash sludge into unlined ponds. The ponds, or what are often referred to as impoundments, average more than 50 acres in size and nearly 20-feet deep. About 37 such ponds exist in Michigan, including one located in a 100-year flood plain. With most ponds being unlined and located near a waterbody that can be utilized by the power plant, the ponds pose a serious threat to groundwater and many drinking water sources for years after the power plants are closed.
A key issue is that as the sludge leaks into the soil at the sites, it has a high potential to contaminate ground and surface water, typically located near the sites. Once in the groundwater, the contaminants may migrate and pollute drinking water sources.
Further, some utilities have discharged waste directly into nearby rivers, lakes and streams. According to the Environmental Protection Agency (EPA), toxic discharges from coal plants into lakes and rivers occur in close proximity to nearly 100 public drinking water intakes and more than 1,500 public wells across the nation. Across the country, about 2.7 million Americans live within three miles of a coal plant that discharges pollutants into a public waterway.
Coal ash disasters in Tennessee and North Carolina gained national attention after toxic coal ash ponds were flooded and led to ash spilling into local rivers, staining the landscape with toxic ash containing carcinogens, neurotoxins, arsenic, boron, cadmium, hexavalent chromium, lead, lithium, mercury and other toxins.
In 2008, an ash dike ruptured at an 84-acre containment area at the Tennessee Valley Authority's Kingston Fossil Plant in Roane County, Tennessee, releasing about 1.1 billion gallons of coal ash slurry into the nearby Emory and Clinch rivers, tributaries to the Tennessee River. Surveys after the release revealed the spill covered the surrounding land with up to six feet of sludge. In September of 2018, a Duke Energy plant in Wilmington, North Carolina, was inundated by Hurricane Florence flood waters from the Cape Fear River. The water overtook an earthen damn and Sutton Lake, pouring over a retaining wall between the lake and an unlined coal ash dump, sending the ash into a nearby river that supplies drinking water to much of the southeastern part of the state.
In 2016, Michigan's 13 largest coal plants generated about 1,440 thousand tons of coal ash waste, with DTE Energy's Monroe coal plant accounting for over half, according to the MEC.
Nationally, there are at least 14 coal plants with on-site coal ash ponds located within FEMA 100-year flood plane zones, including one in St. Clair County, Michigan. The China Township Belle River Power Plant in St. Clair County produced about 181,000 tons of coal ash each year.
According to Environment America, nine of the 14 plants were found to be in "poor" condition with seven considered "satisfactory" and 12 ponds representing a "significant" hazard. The St. Clair County facility was considered "satisfactory" by the EPA.
"We don't necessarily have a natural disaster risk, but we do get flooding," said Nate Murphy, with Environment Michigan. "We are the Great Lakes State, so the ponds may lead into rivers and eventually the Great Lakes."
While no coal-fired power plants exist in Oakland County, five major plants reside in southeast Michigan, including the River Rouge Power Plant, the Trenton Channel Power Plant and the Monroe Power Plant, all along the shores of the Detroit River.
Andrew Sarpolis, with Sierra Club of Michigan, said other utilities have shifted direction, dropping coal plants as they become less economical. Still, he said, coal-fired power plants are a major contributor of pollution that can have impacts on wildlife.
"With coal ash, there are severe impacts on water quality in Michigan," he said. "It's a large source of pollution and things can bioaccumulate in our food chain."
Overall, there were 88 coal-fired power plants at 32 locations in Michigan in 2016 that generated about 12,891 megawatts, or about the nation's 10th largest state in terms of coal generation. By 2017, Consumer's Energy had retired seven smaller coal plants, reducing its net generation provided by coal-fired power plants to 37 percent. Meanwhile, about 65 percent of DTE's generation comes from coal. Plans are underway to take coal-fired power plants offline. However, power companies will still need to address the legacy costs of the plants, specifically, coal ash impoundments.
"The more we can speed up the transition away from coal, the better," MEC's Jameson said. "The secondary issue is to tackle the impoundments leading to contamination above drinking water standards."
About 77 percent of the impoundments in which the MEC was able to obtain monitoring data showed contamination, she said.
"Under the federal regulations, they would have to be closed or cleaned and then retrofitted with linters. If we stick to the federal rule, we see that happening. But, if we move to the state bill, we don't see that happening, and they would stay open longer and be able to contaminate groundwater moving forward," Jameson said.
Matt Paul, vice president of fossil generation for DTE Energy, said the move away from coal-fired plants is based on both economic and environmental concerns. "On the environment, we have committed to reducing carbon emissions by 80 percent by 2050, and those cuts are in excess of those that would have been required under the proposed clean power plan.
"The average age of a coal plant is about 60 years old. The cost to maintain those old units, as well as the cost of some of the timing of other environmental regulations, just makes those units more and more expensive, and they don't make sense economically."
Paul said the closure of DTE's Harbor Beach and Marysville plants were completed in 2013, with the River Rouge Unit number 2 plant closing in 2016. Other plants scheduled for closure include the remaining unit at River Rouge (2020-2023); St. Clair (2020-2023); Trenton Channel (2020-2023); Belle River (2030) and Monroe (2040).
The future closures represent more than 6,600 MegaWatts (MW) of capacity, with the Monroe plant making up nearly half. The company produces about 2,800 MW from natural gas. DTE also will be constructing a 1,150 MW natural gas power plant expected to be online in 2022. In terms of wind and solar, DTE currently has about 1,000 MW in generation capacity.
Consumers Energy in July 2018 released official renewable energy goals, saying it would file its plan with the state about how the utility will go coal-free and be 43-percent renewable energy fueled by 2040. The plan calls for closing its Karn 1 and two units near Bay City in 2023, with two of three of its Campbell units scheduled for retirement in 2031, and the third Campbell unit closed in 2040 to be fitted with a state of the art air quality control system during its remaining operation.
With DTE's Monroe Power plant supplying a massive portion of energy to DTE's power grid, the plant remains a crucial part of supplying affordable and reliable energy, the company said.
"Our planning is based on what we can do while keeping energy affordable and reliable for our customers, and how it aligns with recommendations from the scientific community," said DTE spokeswoman Renee McClelland. "We may adjust our timeline based on technological advances."
In terms of legacy cleanup, Paul said there haven't been any issues at any of DTE's clay-lined ash storage areas, but that cleanup would need to be done after closures were made.
"There will be cleanup work that we have to do," he said. "I may have to get the environmental team to point to specifics, but we would cap existing impoundments, or we would remove the material and take it to a certified landfill. We are working through those assessments now, and figuring out what the right thing to do is."
Meanwhile Paul said groundwater monitoring that is taking place hasn't shown any issues, and that he's "confident we are in good shape."
Lisa Evans, an attorney with Earthjustice specializing in hazardous waste law and an expert on coal ash, said claims there are no issues with groundwater at any DTE sites may be misleading. She pointed to a recent groundwater assessment at the company's River Rouge plant on DTE's own webpage.
"There's going to be some revelations that will be available to the public in Michigan in the nature of coal ash. There's a requirement that by November 17 all of the energy utility websites must have data posted that is accessible, so the public has an idea of groundwater contamination," Evans said. "They must post information whether landfills or coal ash ponds comply with local restrictions... It should be easy to see if they are in compliance, and if they aren't, they are required to close."
According to documents on DTE's website, the company established an assessment monitoring program at the River Rouge plant's bottom ash basin, which must be established if a pollutant is detected over background levels. A related letter indicates arsenic concentrations were detected above Michigan's drinking water and groundwater, and was being proactively managed. That management involves operating a groundwater extraction system to control the uncertainty around the potential migration path.
"I would be surprised if they found no problems," Evans said. "What we are finding across the board, nationwide, is that 95 percent (of the basins) are leaking into underlying groundwater at levels above the groundwater... at the River Rouge plant, they have established a monitoring program, which means they found a significant increase of levels over background levels."
As of press time, 22 of the 29 coal ash units in Michigan had released preliminary groundwater monitoring results for the first time. Of the 22 units, 17 (or 77 percent) showed levels of toxic chemicals in the groundwater which were above state and/or federal drinking water standards, according to the MEC.
Among the highest levels were Consumers Energy's Karn bottom ash pond, with one monitoring well reading arsenic levels at 52 times the federal drinking water standard. A comparison between background wells and down gradient wells at Consumers' bottom ash pond units 1 and 2 revealed increases above background concentrations of boron, calcium, chloride, pH, sulfate and total dissolved solids in down-gradient wells, with three out of five down-gradient wells exceeding the EPA's maximum contaminant level for drinking water for arsenic by up to 4.5 times.
Additional assessments by the MEC found:
• Monitoring at DTE's Belle River diversion basin registered lead well above the state's drinking water cleanup criteria, with one monitoring well having lead levels close to six times higher than the state's protective standard.
• DTE's River Rouge bottom ash basin also had increased levels of boron, fluoride, lead, thallium, radium 226-228 and radium 226 in the groundwater above federal and/or state drinking water standards.
• Monitoring and analysis at Holland Board of Public Works that started in 2011 at three bottom ash ponds at the James De Young coal plant identified that "certain metals" were present in the groundwater above the EPA's Safe Drinking Water Act's maximum contaminant level, and concluded that the groundwater quality may have been affected by the historical use of coal ash detention. Monitoring data from 2017 revealed excessive amounts of boron, chloride, pH, sulfate, total dissolved solids, cobalt, lead, fluoride, lithium and thallium.
The information required to be released doesn't include inactive ponds at power plants which aren't producing energy.
In 2016, the majority of coal ash generated by Michigan utilities was disposed of in landfills or sold for reuse, according to the MEC. More than 1.1 million cubic yards of coal ash was disposed at landfills in 2016, with another 47,000 cubic yards generated outside of Michigan imported into the state.
Storing coal ash sludge in ponds, however, isn't the only way disposal method for coal ash.. A portion of coal ash is sold as "beneficial use" and reused in construction fill, concrete wallboard, cement and other products. Some coal ash has also been disposed of in landfills, including municipal solid waste landfills and landfills owned by utility companies.
John Ward, with the American Coal Ash Association, said beneficial uses of coal ash include use by 48 different states, including Michigan, in road construction, as well as many other items. Further, he said new technology is being used to dry out coal ash ponds and use the waste for safe products.
"The two biggest uses out there are for fly ash, and that's getting used in concrete and synthetic gypsum in wallboard," he said. "Fly ash and concrete are the most valuable applications, and are the most economically viable as well."
Fly ash is ash recaptured in coal smokestacks as opposed to bottom ash, which is usually mixed into concrete at about 40 to 70 percent, depending on its use. Bottom ash, which comes in heavier chunks, is used as a replacement for aggregate, while boiler slag is used in blasting grit and mineral filler for asphalt and flue glass is used in wallboard. All of the different ashes are considered coal ash.
Ward said these beneficial uses are safe for the environment.
"When you compare materials, the EPA actually came up with a risk evaluation methodology, and it compares the impacts to whatever you're replacing it with. This is actually slightly more pure," he said. "When you put it in concrete, it gets locked up. It's not the ash itself that's dangerous – it's the metal in trace quantities. The problem is when you pile up millions of tons by a riverbank."
While coal ash is one way that coal-fired power plants impact health and environment, emissions from coal-fired power plants have long been a source of contamination. Fine particles of smoke, dust, dirt, soot and other items produced during the combustion process enter the air and eventually fall to earth, contaminating soil or water many miles away from where they were produced.
Pollution from particulate matter is monitored throughout the year by the Michigan Department of Environmental Quality (DEQ), which determines if facilities may be failing to meet air quality standards mandated by the federal Clean Air Act.
Jim Haywood, a meteorologist with the DEQ said particulate matter is worst in winter months. However, pollution related to coal power plants is often higher in the summer.
"Usually, that's sulfur dioxide in summer months as people ramp up their air conditioners. In the cooler weather, there's more of a byproduct of other combustion, like people having their heat cranked up with natural gas. Those are more nitrogen-based pollutants in the winter from fossil fuel, and more sulfur in the summer from coal," Haywood said. "Sulfur dioxide in that southeast area of Michigan