Published: Dec 13, 2011 10:10 PM EST

CHATTANOOGA, Tenn. (AP) - An environmental group Tuesday added 20 sites to its list of almost 140 nationally where it contends coal ash appears to have contaminated groundwater or soil at unsafe levels.
    
An Environmental Integrity Project report adds 19 sites - seven in Illinois, three in South Carolina, two each in Iowa and Texas and one each in Tennessee, Kentucky, Georgia, Florida and Nevada - where it says coal combustion waste appears to have caused contamination at levels above primary Safe Drinking Water Act maximum limits for pollutants like arsenic. The Indiana site involves contaminated soil at a site used for rail bed construction.
    
The Washington, D.C.-based group's report adds the locations to 67 "potential damage" pollution cases that the Environmental Protection Agency already documented and another 70 coal ash sites that the project previously identified.
    
Coal ash, a byproduct of generating electricity, contains arsenic, selenium, lead, cadmium and mercury. The pollution report coincides as the EPA is struggling to decide whether to regulate the ash as a hazardous material. Some Republicans in Congress are trying to block the stricter regulation at the behest of industries that make drywall and other products from coal ash.
    
EPA did not immediately respond to messages seeking comment about the group's coal ash pollution report.
    
EPA proposed the stricter regulation after a December 2008 breach of an earthen dam at the Tennessee Valley Authority's Kingston Plant west of Knoxville spilled 5.4 million cubic yards of coal ash into the Emory River and across 300 acres in the Swan Pond community, destroying or damaging about two dozen homes.
    
No one was hurt in the spill, which the EPA has described as "one of the worst environmental disasters of its kind."
    
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Online:
    
Environmental Integrity Project report: http://www.environmentalintegrity.org/documents/121311EIPThirdDamageReport.pdf

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