Coal Ash Fact Sheet

Why Coal Ash is Bad


Coal Ash Contains Toxic Substances

Introduction: Coal itself contains in trace quantities heavy metals and other elements like Lead, Arsenic, Mercury, Selenium, Boron and Thallium. When coal gets burned, these elements don’t, and so their presence in the ash is increased.  The dangers come when these materials are released into our environment, either by leaching into our groundwater, and/or runoff, or being disposed of in our streams via effluent pipes or dust.  Just drinking the water is dangerous, but also dangerous is ingesting vegetables or crops grown with the water, or eating fish or other wildlife that have been drinking or living in contaminated water. 

Coal Ash Diagram

Diagram by Alan Morin for Clean Air Task Force

Glossary/Good to Know

CCW: Coal combustion waste. Also known as CCP (coal combustion product) or more generally as coal ash.

Dike: A dike is essentially a dam, but rather than preventing water flow, it holds one body of water or material back from another- Side note:  All dikes along the Catawba are made of earth and ash.

Effluent: In this case effluent is the liquid waste that comes directly out of the ash pond into a stream or river. It’s water that may or may not have been treated, but is filtered.

Liquefaction: When a solid material acts as a liquid. So: If there is water in a loose soil that is shaken dramatically, or gets really wet it can begin to flow like a liquid. See below  what happened at Lake Merced in 1957 when soil was disturbed by an earthquake and slid into the lake.Coal Ash Picture: Lake

Slope Movement: Slope movement is the movement of a solid slope over time- the most dramatic example of this would be a landslide, but more often than not, it’s the gradual slumping of a slope.

Surface Impoundments vs. Landfills: Surface Impoundments are coal ash dumps on the surface of the land- usually these are “ponded” or are a mix of water and CCW to prevent the ash from blowing away. Landfills are similar to trash landfills. The three sites along the Catawba are all active surface impoundments that also have landfills associated with them. The surface impoundments may also be referred to as ash basin

Wet vs. Dry Storage: Very self-explanatory. Dry storage is without added water, or at least without a lot of water. Dry storage is viewed as safer, as there is less runoff/ less contaminated water.


Cancer/Human Consequences- Arsenic, if ingested via drinking water has a potential risk of over 60,000 times the acceptable average.  Arsenic is a carcinogen.  Selenium can poison and deform fish that are exposed, and eating contaminated fish or drinking contaminated water can cause severe heath risks in humans including severe bronchitis, loss of feeling in limbs, and skin reactions. This has been an issue in North Carolina since the 1970’s and 80’s when this subject was first researched.  Cadmium and Nickel can both cause cancer.  Lead and Mercury are non-carcinogens that can severely impair the nervous system. Children are especially vulnerable to even low exposures of lead and mercury because they’re in a very vulnerable stage of development. Lead and Thallium can cause birth defects if pregnant women are exposed. 

Accumulation in local wildlife- because of how the food chain works, small amounts of dangerous elements absorbed into plants, or small invertebrates becomes more and more concentrated as the food chain progresses.  Anyone who eats local food from contaminated sites is at a far greater risk of ingesting hazardous substances.

Coal Ash Can Contain Radioactive Material: Depending on the type of ash burned at the site there can be varying amounts and types of radioactive materials within the CCW which can have severe effects. Thorium-228 has been found to cause cancer due to radiation.

Catastrophic Failure= Catastrophe: When the dams failed in Tennessee last December three homes were destroyed and 23 were damaged. The fact that the sludge that swamped the river contained dangerous material is of huge concern, but even without that the sheer force of the flood can be dangerous to housing on the lake. It will also reduce property values on the lake and prevent recreation until it can be cleaned up. Clean up is still continuing in Tennessee, and likely will not be done for a while. (The realtors will not be happy, as you can see below!) 

Coal Ash Picture: House
Local Issues Along the Catawba

There are CCW disposal locations at each of the four power plants along the Catawba-Wateree River: Wateree, Riverbend, Allen and Marshall.  In fact, almost 10% (4 out of 45) of the high coal ash ponds in the United States are located on the Catawba River.  Wateree is being cleaned up pursuant to the settlement between the Catawba Riverkeeper Foundation and SCE&G.  Riverbend presents a hazard because of it’s proximity to the water supply for a highly populated area, Marshall is hazardous because of the content of elements in the effluent, and Allen is a hazard as the stability of it’s dikes are in question.

Riverbend Steam Station

Disturbing fact: Riverbend Steam Station was built in 1929- The plant that was associated with the ash pond that failed in Tennessee last December was built almost 30 years after that in 1955.

Riverbend Ash Ponds by J Wes BobittPrimary Concern: Riverbend is of great concern to the river, as it is situated on the banks of Mountain Island Lake, which supplies water to Charlotte, Gastonia and numerous other towns. Nearly 750,000 people get their water from Mountain Island Lake. The site of the Riverbend Steam Station covers 143 acres and can hold 3,200,000 cubic yards of ash and coal waste. There is no liner to protect the underlying soil, and no leachate collection system to treat any liquid that might leak out. 

Riverbend Steam Station Ash Pond

Arsenic is the element of greatest concern here, with small amounts of it flowing into Mountain Island Lake with the effluent stream.

Secondary Concerns: Data regarding contamination levels of groundwater, surface water, soil, and fish populations is needed at this site if there is to be any analysis on the impact of the unlined CCW impoundment on surrounding communities.

Marshall Steam Station

Marshall Steam Station is located on Lake Norman upstream of Mountain Island Lake. Any breach in the dikes or release of coal ash into Lake Norman could affect the water supply of Charlotte as mentioned above, in addition to the water supply of communities which get their water directly from Lake Norman, including: Davidson, Mooresville, Cornelius, Huntersville, and others. 

Marshall Steam Station and Ash Ponds - Lake NormanPrimary Concerns: High selenium content in effluent from Ash Basin- a memo from 2007 shows that Duke is working on a wastewater treatment facility specifically for selenium. Selenium is particularly dangerous to fish, and can greatly reduce the ability of fish to reproduce, and can cause severe birth defects in their young.

Also, they are proposing to/already have converted part of (101 acres) the active ash basin into a lined landfill. This sounds good but they are essentially constructing this atop the ash already there and an asbestos landfill that is there as well.

Secondary Concerns: Data regarding contamination levels of groundwater, surface water, soil, and fish populations is needed at this site if there is to be any analysis on the impact of the unlined CCW impoundment on surrounding communities.

Allen Steam Station

Allen is not only one of the 45 sites listed as high hazard by the EPA, but is also listed by the EPA as a Potential Damage Case. It is located on Lake Wylie, the source of drinking water for Rock Hill, SC and surrounding communities.

Allen Steam Station - aerial photo

Primary Concern: Dam Stability-In the 2009 report there were several areas that stuck out as being of concern. There are two dikes at Allen, North and East.  At the north dike there was a leak in the ash sluice line (now repaired) this leak had resulted in localized erosion. There was also seepage, standing water, cracking in the embankment crest, and slope movements, all along the north dike embankment.

There was also slope movement and standing water along the east dike, and seepage at the toe of the east dike. Both dikes had sparse vegetation, which makes them a lot more vulnerable to erosion.

The slope movements and cracking in the embankment are worrying for obvious reasons, though Duke considers fixing them to be just a part of routine maintenance.  Seepage and standing water are bad because they indicate not only where water is getting through, and therefore places where toxic materials can get through, but water reduces the strength of materials to hold together. This places the dikes at Allen at a fairly high risk of liquefaction should an earthquake occur.  The foundations at Allen have been formed from ash and alluvial sands (very fine sediments). Duke Energy has had it recommended to them that they perform some seismic analysis, but the latest report indicates that they have not done so, but expect it to be done in 2010.

A breach in the dikes would have a devastating impact on Lake Wylie, and developments directly across the lake from the ash pond are in danger of being “impacted by a flood wave”. 

Overfilling- though warned in 2004 report about the dangers of overfilling the basin (greatly increases the north dike’s potential to collapse) the 2009 report indicates that “ash level elevation above design normal pool operating elevation”. As a result there is even less area for any stormwater storage, potentially leading to direct runoffs.

Secondary Concerns: Monitoring suggests high levels of chloride and arsenic going into ash pond, but there is no analysis of these elements in the effluent stream into the lake. There is also no analysis of these elements before March 2009. 

Data regarding contamination levels of groundwater, surface water, soil, and fish populations is needed at this site if there is to be any analysis on the impact of the unlined CCW impoundment on surrounding communities. Allen is of particular concern because there are houses located within 500 feet of the ash pond.  According to the data gathered so far, none of these have been tested for contaminated water.  No groundwater monitoring has occurred since 1985, when a single study was done that documented exceedances of manganese and iron.

Others Working on Issue

All of these are already involved in either cases or public awareness campaigns, and would more than likely be very willing to help.

Southern Environmental Law Center- Has NC at “top of list” Chandra Taylor on Case

Ashholes.Org- Focuses primarily on the movement of CCW from TN to AL. They seem to have a good group and at the very least, a good videographer.

The Sierra Club- More focused on getting word out to members, but still a good resource of environmentally conscious people.

Earth Justice- A legal group that brings environmental lawsuits.

Clean Air Coalition: More focused on the removal of harmful toxins from the air, but also concerned with where they go afterwards.

Energy Justice Network: Their focus is more on the many issues surrounding energy use and production, but they do have some information on CCW. It’s focus on coal concerns the burning of waste coal more than the disposal of coal waste, surprisingly two very different things. They run ‘No New Coal Plants” and have speakers for a charge.

For more information about coal ash:

  • Click here for overview of coal ash issues
  • Click here for video overview of coal ash issues
  • Click here for coal ash disasters
  • Click here for information about coal ash recycling
  • Click here for more video reports about coal ash issues
  • Click here for library of coal ash documents


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