Application of the DRASTIC Model to Assess the Vulnerability of Groundwater Contamination Near Zaporizhzhia Nuclear Power Plant, Ukraine.

Russia's invasion of Ukraine continues to have a devastating effect on the well-being of Ukrainians and their environment. We evaluated a major environmental hazard caused by the war: the potential for groundwater contamination in proximity to the Zaporizhzhia Nuclear Power Plant (NPP). We quantified groundwater vulnerability with the DRASTIC index, which was originally developed by the United States Environmental Protection Agency and has been used at various locations worldwide to assess relative pollution potential. We found that there are two major gradients of groundwater vulnerability in the region: (1) broadly higher risk to the northeast of the NPP and lower risk to the southeast driven by a regional gradient in water availability and water table depth; and (2) higher risk in proximity to the channels and floodplains of the Dnipro River and tributaries, which host coarser-textured soils and sedimentary deposits. We also found that the DRASTIC vulnerability index can be used to identify and prioritize groundwater well-network monitoring. These and more detailed assessments will be necessary to prioritize monitoring and remediation strategies across Ukraine in the event of a nuclear accident, and more broadly demonstrate the utility of the DRASTIC approach for prognostic contamination risk assessment.