Analysis of the Effects of Septic Leach Field Failure on Groundwater Contamination

On-site septic treatment systems can be considered as one of the largest potential sources of groundwater pollution and contamination in the world, due to their widespread proliferation and variety of contaminants in wastewater. This project aimed to investigate the hypothetical scenario of a septic leach field failure on groundwater contamination through the formation of a septic system plume. The , and the expected values for the septic system plume were calculated. A MODFLOW groundwater model of the septic system was developed, and the solute transport simulator, MT3D-USGS was used to solve the model. Comparing the model results to the calculated values revealed a large discrepancy in the septic system plume dimensions, which was attributed to model geometry constraints and the addition of dispersion effects to the model. Potential future investigations for this project involve developing a more geometrically representative model and experimenting with dispersion effects on septic system plume formation.