CLINTON, Tenn. — State environmental authorities are testing unidentified substances that have been floating in the air in Clinton, Tennessee.

Tennessee Department of Environment and Conservation said it is investigating and has taken samples. Results are expected within two weeks.

Tennessee Valley Authority officials said the substances are not coming from the giant Bull Run Fossil plant but they, too, have sent samples of the substance to an independent lab for testing.

"Commissioner Tracy Wandell has contacted TVA regarding substances on vehicles in the vicinity of Bull Run Fossil Plant," TVA spokesperson Scott Brooks said in an email to 10News Tuesday. 

Brooks said Bull Run has state-of-the-art emissions controls, including equipment to limit particulate matter. He said plant personnel have checked the equipment and did not find anything to indicate the substance seen in pictures sent to them is coming from the plant.

"TVA has received similar reports in the past and the material was traced to the offsite burning of wood, which created ash," Brooks said.

Previously, they've known of flakes falling from the sky that turned out to be wood ash.

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