Groundwater contamination is often the result of spills and leaks associated with more than one source. Once the contamination is discovered, the contaminants are usually so mixed that it is difficult to distinguish which contaminants were released first and who is responsible for the cleanup. Such uncertainty often leads to disputes among potential principally responsible parties and millions of tax dollars are spent in settling them. As a first step towards reducing the uncertainty and initiating faster settlement of disputes in order to save tax dollars, the authors investigated the development of a practical tool that can characterize source releases. An inverse optimization approach was used to analytically track source releases in the saturated zone. In this approach, a groundwater transport model was combined with a numerical integration scheme and an optimization routine to back calculate contaminant source parameters. The resulting computer model was able to track the history of contaminant releases, by predicting the time and intensity of release. In this analysis, the location of the source was assumed to be known. To validate the model, simulations were performed using data from a field tracer test and the results confirmed that the model was capable of accurate prediction of the time and strength of contaminant release. This paper describes the research approach employed in developing the model and validation process performed to demonstrate the applicability of the model.
|Journal||Geotechnical Special Publication|
|Issue number||58 II|
|State||Published - 1996|