Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Coal ash ponds found to leak toxic materials

13.06.2016

Long-lasting contamination won't be cleaned up by ash removal alone

A Duke University study of coal ash ponds near 21 power plants in five Southeastern U.S. states has found evidence that nearby surface waters and groundwater are consistently and lastingly contaminated by the unlined ponds.


A study of power plants in five states has found that metals and other toxic materials are able to leach out of the unlined pits in which coal ash is currently stored. These materials have been found in surface waters and shallow groundwater, and may be able to work their way to the deeper groundwater resources used for drinking water wells.

Credit: Duke University

High levels of toxic heavy metals including arsenic and selenium were found in surface waters or groundwater at all of the sites tested. Concentrations of trace elements in 29 percent of the surface water samples exceeded EPA standards for drinking water and aquatic life.

"In all the investigated sites, we saw evidence of leaking," said Avner Vengosh, a professor of geochemistry and water quality in Duke University's Nicholas School of the Environment. "Some of the impacted water had high levels of contaminants."

The study, which appears June 10 in the journal Environmental Science & Technology, did not test drinking water wells, but that will be the next phase of the research, Vengosh said.

During the summer and fall of 2015, the team sampled 39 surface water and seep samples from coal ash ponds at seven sites. They also analyzed water chemistry data from 156 shallow groundwater monitoring wells near coal ash ponds at 14 North Carolina power plants that had been compiled by the state's Department of Environmental Quality.

Shallow wells -- typically 30- to 50-feet deep -- are not as deep as a drinking water well, which might be 100 to 300 feet. But there's a potential the shallower contamination could flow deeper and affect drinking wells, Vengosh said.

Not only was the evidence of contamination widespread, it also appears to be persistent in the environment. Some of the sites studied have been retired and no new coal ash is being deposited there, but nearby surface waters, and in one case groundwater, were still being contaminated.

"The degree to which leakage affects the concentration of toxins in nearby waters varies because of several factors, including the nature of the coal ash, processes in the pond and the flow through the local soil," said Jennie Harkness, a Ph.D. student at the Nicholas School and the lead author of this study.

While it is legally permitted for some coal ash ponds to release liquid effluents to nearby surface waters through regulated outfalls, the new data show that these ponds are also leaking in unpermitted ways. "Coal ash ponds pose risks to the environment and water resources," Vengosh said.

The highest concentrations of dissolved metals and metalloids (manganese, vanadium, selenium, arsenic and molybdenum) were found in shallow wells near a retired ash-disposal site in Tennessee. The contaminated groundwater there had concentrations exceeding drinking water and aquatic life standards for cadmium, iron, nickel, lead, selenium and zinc.

Vengosh said it is reasonable to conclude from these findings that physically removing the coal ash ponds would leave "a legacy of contamination. You would still have a major issue to address the subsurface groundwater contamination. After decades of leaking, the impact has already happened."

###

Funding for this study was provided by the Southern Environmental Law Center.

CITATION: "Evidence for Coal Ash Ponds Leaking in Southeastern United States," Jennifer Harkness, Barry Sulkin and Avner Vengosh. Environmental Science and Technology, online June 10, 2016. DOI: 10.1021/acs.est.6b01727

Media Contact

Karl Leif Bates
karl.bates@duke.edu
919-681-8054

 @DukeU

http://www.duke.edu 

Karl Leif Bates | EurekAlert!

More articles from Earth Sciences:

nachricht Tiny microenvironments in the ocean hold clues to global nitrogen cycle
23.04.2018 | University of Rochester

nachricht Clear as mud: Desiccation cracks help reveal the shape of water on Mars
20.04.2018 | Geological Society of America

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Molecules Brilliantly Illuminated

Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.

Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...

Im Focus: Spider silk key to new bone-fixing composite

University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.

Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.

Im Focus: Writing and deleting magnets with lasers

Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.

Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...

Im Focus: Gamma-ray flashes from plasma filaments

Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.

The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...

Im Focus: Basel researchers succeed in cultivating cartilage from stem cells

Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.

Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

IWOLIA: A conference bringing together German Industrie 4.0 and French Industrie du Futur

09.04.2018 | Event News

 
Latest News

Structured light and nanomaterials open new ways to tailor light at the nanoscale

23.04.2018 | Physics and Astronomy

On the shape of the 'petal' for the dissipation curve

23.04.2018 | Physics and Astronomy

Clean and Efficient – Fraunhofer ISE Presents Hydrogen Technologies at the HANNOVER MESSE 2018

23.04.2018 | Trade Fair News

VideoLinks
Science & Research
Overview of more VideoLinks >>>