All About Coal Ash on the Catawba River and Its Lakes

Marshall Steam Station coal ash discharge into Lake Norman

Coal ash continues to be a major issue for the Catawba River, as well as the Carolinas and rest of the United States and the world. Perhaps nowhere is that is true, though, than the Catawba River, whose lakes have two of Duke’s largest sites – more than 50 millions tons in all – piled high on the shoreline of what also serve as drinking water reservoirs and major economic hubs.

We hope this information will prove helpful so that you can be better informed and join us in taking real action to get real cleanups.

No Ash Left Behind.

What is the coal ash problem?

For decades, Duke Energy has burned coal to generate electricity. These power plants are located on major waterways because they need a source of cooling water. After coal was burned, Duke would mix the ash with water and pipe it to a pond. These ponds were formed by piling up dirt to form a dam at the mouth of a cove. No liners were put down, and Duke dumped the mix of coal ash and water into the pond, where the bulk of the ash would settle out. Over the years, the dams were built higher and higher to hold back more and more ash. These ponds are more like mounds propped up high – as much as 130 feet in North Carolina – on the banks of drinking water sources. At the bottom of the pond, even were the ash to be capped in place (as Duke says it wants to do), the coal ash would remain significantly below the groundwater table.

What’s the problem with coal ash? The burning of coal concentrated metals and other elements – things that did not go up into the air – in the ash. These are contaminants like arsenic, boron, cobalt, manganese, thallium and even radioactivity (from radium 226 and 228). These contaminants do not stay with the particulate ash that settles out. The contaminants dissolve into the water, which then migrates through the bottom of the pond through groundwater (remember: unlined ponds) and through the top of the pond through the permitted discharge.

In recent years, we have learned just how extensive coal ash’s groundwater and surface water contamination has been. And we continue to learn more as Duke performs monitoring it has long resisted. The data reveal seemingly countless violations of water quality standards and the Clean Water Act.


Riverbend coal ash cleanup on Mountain Island Lake
Riverbend coal ash cleanup on Mountain Island Lake

Where is the data? And what are the standards?

Data, engineering reports, studies – it’s available but scattered lots of places. In the past, Duke has had to do very little monitoring. Now, Duke has to do a lot more, though it is still not enough and is often inconsistent depending on the differing requirements among different agencies and regulations.

Remember that federal rules are the minimum.




Catawba Riverkeeper comparison of data for hexavalent chromium in natural waters at drinking water intakes versus water around Duke Energy coal ash sites:

Hexavalent chromium in drinking water at intakes
Factors Above Legally Required Screening Level for Hexavalent Chromium in Drinking Water Wells

Does coal ash impact me? How?

Remember that you first need to know where your water comes from. Is it surface water? Groundwater? Is it a private system or a public municipal utility?

In March 2018, Duke Energy released new groundwater monitoring data from around the perimeter of its coal ash site. That data indicated high levels of radioactivity (from radium 226 and 228) and thallium, in addition to other metals and elements that have been acknowledged in previous samplings. Duke has also had to test drinking water wells within one-half mile of coal ash sites and has found high levels of contaminants associated with coal ash (e.g., hexavalent chromium, vanadium).

Coal ash contamination of groundwater is most likely to stay on the same side of the river as the coal ash itself. Lakes and river channels are hydrologic “low pressure” areas that groundwater migrates toward and emerges into. Thus, for example with Marshall on Lake Norman, it is very unlikely that coal ash contamination would pass through groundwater, under Lake Norman and contaminate wells in Mooresville. However, residents in Sherrills Ford and Terrell area have merited concerns. Exactly how far the contamination goes is difficult to say, but the state has only required Duke Energy to look out one-half mile. Thus far, approximately three dozen wells around

One other potential source of well contamination to keep in mind is prior activity on a site. Was it a farm? Could there have been pesticides or other chemicals used?

But also, coal ash was once used as structural fill (and was unlined) to even out land. While use of coal ash in place of dirt should have been recorded in deeds starting in the 1990s, it often did not happen.

Other discharges from Marshall’s coal ash ponds have caused issues, most notably the discharge of bromides. In recent years, this practice caused high levels of trihalomethanes to form in treated drinking water throughout the region, even exceeding the safe level prescribed in the Safe Drinking Water Act. Catawba Riverkeeper Foundation initiated legal action to stop Duke from receiving approval to continue this practice.

The most concerning scenario for drinking water is similar to what happened in Dan River in 2014 and Kingston, Tennessee, in 2008. A spill of coal ash into the Catawba River would release into surface water the very material that is the source of all the different contaminants currently contaminating groundwater.


What is Catawba Riverkeeper doing?

Sampling coal ash discharge

For the Catawba Riverkeeper Foundation, coal ash is life. We are the only group working full-time to protect the water of the Catawba River and its lakes. We have been on the ground, on the water, in the office and in the air to sample, monitor and research so that we can take direct action – legal action, represented by the Southern Environmental Law Center – to secure real cleanups of coal ash. We started our lawsuits in 2012 and have had success getting the Wateree and Riverbend (Mountain Island Lake) sites cleaned up. We remain in court to secure cleanups at Marshall (Lake Norman) and Allen (Lake Wylie).

While we have lots of great volunteer programs (e.g., cleanups, youth paddles), the work we do takes five full-time staff. We and our attorneys are experts on this subject. Support from our members make it possible to devote not just effort but full-time jobs on this issue.

We have been particularly active around Marshall and Allen, challenging Duke’s refusal to release coal ash failure inundation modeling maps, Duke’s grossly inadequate NPDES discharge permits and more of Duke’s dangerous pattern of failing to learn from its past mistakes. We continue to find structural concerns and major oversights with Duke’s operation of its coal ash. We have even found pipes and documents Duke lost for decades, possibly preventing a major disaster on an unprecedented scale.

Any assessment of risk looks at past behavior, and both the past and present behavior indicate that it is too risky to trust Duke to change its future behavior.


What can I do?

First, as noted above, our members make our work possible. We are a tax-deductible 501(c)(3) nonprofit charity. Please consider making a tax-deductible donation today to support our work. Without your support, we won’t exist. Please make a brief visit to right now!

One of the most important things you can do is contact your STATE representative and senator – the folks who represent you in Raleigh. This level of government is where much of the coal ash regulations have been set. They answer to you, their constituents. Write them. Call them. Visit them. Catch them at a local town hall forum. The most important thing is that you engage them and let them know that you don’t want the coal ash near you left behind. Coal ash on Lake Norman and Lake Wylie merits cleanup just like the other sites do, and as long as we are importing coal ash from India, it makes no sense not to at least use coal ash in concrete.

Who represents you? It’s actually in a state of flux as districts have been drawn, redrawn and redrawn again. For the most part, districts will remain the same around Lake Norman. You can visit for more information or if you live somewhere not around Marshall, for which we have provided contact information here:

  • If you live in southeast Catawba County (Sherrills Ford, Terrell), you have now and still will after redistricting:
    • NC House of Representatives District 89: Mitch Setzer, 919-733-4948,
    • NC Senate District 42: Andy Wells, 919-733-5876,
  • If you live in Mooresville:
    • NC House of Representatives District 95: John Fraley, 919-733-5741,
    • NC Senate District 34 (as of 2018 election): Dan Barrett*, 919-715-0690,
      • *Likely will be Republican primary winner Vickie Sawyer after this year

If you would like testing of your groundwater well, contact PRISM Laboratories (704-529-6364). Pace Analytical has not been able to accept additional samples. Statesville Analytical (704-872-4697) is another option that has recently been accepting samples. We do not endorse any specific lab. It is important that you use state-certified labs for testing. If getting your water tested because of coal ash concerns, we can certainly note which parameters you want covered as they have been noted to be of concern or even in exceedance of regulations with coal ash: As, B, Ba, Pb, Sb, Be, Cd, Cr, Fe, Ni, Co, Mo, Se, Tl, Mn, V, Hg, Sr, hexavalent chromium, radioactivity (from radium 226/228), and sulfate.

Many people have noted illnesses in the area. You can also request a Public Health Assessment by contacting your elected officials, the NC Dep. of Health and Human Services, and the Centers for Disease Control. In the meantime, installing reverse osmosis and carbon filtration can help remove contaminants; there is not a specific brand or model we endorse.


Further Questions?

Please contact us if you have further questions and concerns. We hope this information will answer questions and provide information for as many folks as possible. If you do have additional questions, you can contact us at Please keep in mind that we do this work as a full-time job while maintaining full-time litigation to clean up coal ash, so we can be delayed in responses. We hope you will join us and make a donation to support our work!

Recent Posts of Catawba Riverkeeper’s Coal Ash Work

April Packed With Coal Ash News, Significant Decisions

Groundwater Monitoring at Marshall (Lake Norman) & Other Duke Energy Coal Plants​ Reveals Widespread Radioactivity

Draft Consent Order, Marshall Discharge Permit Comments Submitted by Catawba Riverkeeper