Code for Contaminant Mass Discharge Quantification and Uncertainty Estimation in Groundwater

<p dir="ltr">This software analyses the spatial variability of multilevel concentration data from a transect located downstream of a contaminated site.</p><p dir="ltr">This is version 1.0 of the software. </p><p dir="ltr">It uses a geostatistical framework to estimate the contaminant mass discharge (CMD) and its uncertainty. The method is published and described in detail in Bøllingtoft et al. (2025) and is a continuation of the work originally published by Troldborg et al. (2012).</p><p dir="ltr">The method combines:</p><ul><li>An analytical trend model (Domenico & Palciauskas, 1982) to estimate the mean concentration field and generate concentration residuals which are then transformed used Box-Cox transformation</li><li>Bayesian model parameter calibration using Markov-Chain-Monte-Carlo (MCMC) is used to determine the best fit of variogram, transformation and analytical trend model parameters</li><li>These residuals are then used for spatial simulation via kriging and conditional simulation</li></ul><p dir="ltr">The code is modular and designed for practitioners working with subsurface contaminant data.</p><p dir="ltr"><b>Publications</b></p><p dir="ltr">Bøllingtoft, A., Bjerg, P. L., Rønde, V., Tuxen, N., Nowak, W., & Troldborg, M., 2025. Quantification of contaminant mass discharge and uncertainties: Method and challenges in application at contaminated sites. <i>Journal of Contaminant Hydrology</i>, 268, 104453. <a href="https://doi.org/10.1016/j.jconhyd.2024.104453" target="_blank">https://doi.org/10.1016/j.jconhyd.2024.104453</a></p><p dir="ltr">Domenico, P.A., Palciauskas, V.V., 1982. Alternative boundaries in solid waste management. <i>Ground Water,</i> 20 (3), 303–311.<a href="https://doi.org/10.1111/j.1745-6584.1982.tb01351.x" rel="noreferrer" target="_blank">https://doi.org/10.1111/j.1745-6584.1982.tb01351.x</a></p><p dir="ltr">Troldborg, M., Nowak, W., Lange, I. V., Pompeia Ramos dos Santos, M. C., Binning, P. J., & Bjerg, P. L., 2012. Application of Bayesian geostatistics for evaluation of mass discharge uncertainty at contaminated sites. <i>Water Resources Research</i>, 48(9), W09535. <a href="https://doi.org/10.1029/2011WR011785" target="_blank">https://doi.org/10.1029/2011WR011785</a></p>