The Department of Defense PFAS Discharge Prevention Act requires the Secretary of Defense to request modifications to stormwater permits at all military facilities within one year of the law's enactment. These permit modifications would mandate quarterly monitoring of PFAS (per- and polyfluoroalkyl substances, commonly found in firefighting foam and other products) in stormwater discharges and require the Department of Defense to implement best management practices or control technologies to reduce these harmful chemical releases. The bill affects all Department of Defense facilities that currently operate under federal stormwater discharge permits. At least one percent of annual funding allocated for PFAS remediation efforts must be spent specifically on testing for these substances in stormwater runoff at military installations. This legislation aims to address the significant contamination problem caused by PFAS, which has been found in groundwater and drinking water supplies near military bases nationwide.