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24 www.coalage.com July 2016 coal ash Intelligent Approach to Ash by donna schmidt, field editor With the technology to monitor any coal mine operation, prep plant, stockpile and overall property virtually every second of each day year-round, it seems strange to consider that some coal ash impound- ments still rely on more time-consuming manual methods for keeping an eye on things from both a safety and environ- mental perspective. The Tennessee Valley Authority (TVA) is working to help change that through both intelligent compaction technology and state-of-the-art monitor- ing methods. Both efforts have been under way for some time, particularly since the high-pro- file December 2008 ash spill at TVA's Kings- ton plant in Tennessee that left dozens of homes damaged and three destroyed. While considered one of the largest spills in history with 5.4 million cubic yards of coal ash lost from a dike failure, there were thankfully no serious injuries or deaths. With the topic of coal ash storage always at the forefront for power facilities, TVA's environmental scientist and civil engineers, Jason Hill, Nicole Walker and Nicholas Mc- Clung recently told Coal Age that making strides in this area was of paramount im- portance — leading them to implement a more efficient and safer storage technique known as intelligent compaction. Getting to that point meant a lot of testing, placing instruments and gathering as much infor- mation as possible on the characteristics of that ash. The primarily question, the group said, was how to manage TVA's ash for long periods of time, as well as how to more effi- ciently compact material and understand its characteristics and movements over months and years. "That event [Kingston] set in motion a chain of events that made TVA [a] leader in coal ash safety to ensure that we'd never have that kind of event again," according to McClung, a profes- sional engineer and TVA's manager for risk and quality assurance. Working with operations and instru- mentation personnel teams across the TVA, one core mission was automating the instrumentation for information collec- tion and, once it was there, to make it re- al-time. The concept has grown exponen- An example of a topographic map created by the intelligent compaction technology. Tennessee Valley Authority tackling safer, more efficient coal ash storage and monitoring About TVA The Tennessee Valley Authority, or TVA, is the largest public power utility in America. Its facilities are in seven states, serving nine million customers. With a total work- force of 10,000, it has 72 total power com- plexes and 22 coal ash impoundments. As of 2015, TVA confirmed it has recy- cled 25% of its ash produced by its fossil plants for products like roofing, cement, concrete and wallboard. The Kingston Fossil Plant's dry ash impoundment.