Testing the Validity of the Sediment Fingerprinting Technique.

Excessive sediment is widely considered a pollutant in surface waters. The aim of this study is to test the validity of the sediment fingerprinting as a reliable discriminator between various sediment sources in a watershed. The study area is the Oostanaula watershed in East Tennessee, which consists of rural and urban land uses, and is representative of the Cumberland Ridge and Valley ecoregion. Seventy samples representing potential sediment sources were collected throughout the watershed. Twelve samples representing random known mixtures of source material were created to verify the use of sediment fingerprinting for source discrimination. Major and trace elements in each sample were extracted through total dissolution and through nitric acid extraction, and the extractions were analyzed using ICP-OES. Extractions were then analyzed using a discriminate function analysis. Elements with discriminatory power were used to run a divisive hierarchical cluster analysis and a canonical discriminate analysis. Samples extracted through total dissolution did not cluster by source groups. Samples extracted through nitric acid did cluster by source groups. A model will be developed from these source groups to verify the sediment fingerprinting technique. With an effective model for sediment fingerprinting, regulators will be able to distinguish between non-point sources and promote management strategies to efficiently mitigate soil erosion.