Modification of GLEAMS for modeling movement of organic contaminants from land-applied biosolids.

Municipal biosolids are commonly applied to agricultural lands as fertilizer, but this also poses potential risks to groundwater and surface water quality from constituents that may be mobilized during storm events. In the present study, an existing model, Groundwater Loading Effects of Agricultural Management Systems (GLEAMS), is modified to predict the fate and transport of organic contaminants from land-applied biosolids, primarily via addition of a labile biosolids organic carbon phase distinct from soil organic carbon. While capable of simulating contaminant transport in runoff and via percolation, only the runoff portion of the model was able to be calibrated using existing experimental data, and showed good agreement with field runoff data for acetaminophen, ibuprofen, triclosan, triclocarban, and estrone, but substantially under-predicted concentrations for carbamazepine, androstenedione, and progesterone.