On Dec. 22, 2008, a coal fly ash spill occurred at the Tennessee Valley Authority's (TVA's) Kingston Fossil Plant, allowing a large amount of fly ash to escape into the adjacent waters of the Emory River. A dike failure released approximately 5.4 × 10⁶ yd³ of coal ash that covered approximately 300 acres and affected about 40 area homes. In addition, a section of the Emory River channel was blocked by released ash. In response to the impoundment failure event, TVA initiated comprehensive measures to assess and delineate the extent of the fly ash release to the Emory, Clinch, and Tennessee River Systems. One measure was to develop and implement a quality assurance (QA) program to ensure the generation of high-quality, defensible data for use in decision making and regulatory compliance. In order to rapidly delineate the distribution of released coal fly ash within these river systems, the QA team evaluated various coal ash delineation and assessment methodologies, developed standard operating procedures for implementation, and audited sampling methods in order to ensure compliance with procedures and document the advantages and disadvantages of each technology employed. The quantitative and qualitative coal ash delineation methodologies employed include sub-bottom profiling and bathymetric mapping, visual and manual sediment inspection, sediment sampling for laboratory analysis, x-ray fluorescence analysis, and polarized light microscopy analysis. A review of the impact the QA program has had on the determination of the most effective coal ash delineation technologies is presented.