APPLICATION OF REMOTE SENSING TECHNOLOGY TO STUDY COAL ASH SPILL IN RIVER WATER

On December 22, 2008, Tennessee Valley Authority, Kingston Fossil Plant produced the largest coal ash spill in U.S. history causing 5.4 million cubic yards of coal ash to be deposited into the Emory and Clinch river systems. This research project was designed to study and assess the initial and remaining amounts of coal ash pollutants in the Clinch and Emory rivers from the day of the spill event (December 22, 2008) to 25 days after the event (January 16,2009). A time series of NASA’s Landsat 5 (TM) images was collected from before (November 20, 2008), during (December 22, 2008), and after (January 16, 2009) the spill event to study the fate and transport of the spilled coal ash deposits.

The density slicing image processing technique in association with a spatial model was used to extract the water pixels from the near infra-red (NIR) bands in all three images. The reflectance values of the water pixels obtained from the image acquired during the spill event was subtracted from the reflectance values of the water pixels obtained from the image acquired before the spill event to detect the areas affected by the spilled coal ash deposits initially. The reflectance values of the water pixels obtained from the imagery acquired after the spill event was subtracted from the reflectance values of the water pixels obtained from the imagery acquired before the spill event to determine how far the spilled coal ash deposits traveled after 25 days of the spill event.

The obtained preliminary results indicate that remote sensing technology and digital image processing techniques can be used to detect and map the distribution of spilled coal ash deposits into the Emory and Clinch river systems. Future research should include a larger area of interest to enable further tracking of the pollutants downstream and estimating the maximum extent of the spill event.