Emerging Contaminants in Groundwater Resources: From Occurrence and Risk Assessment to Advanced Remediation

Abstract

Groundwater is a major source of drinking water, irrigation and industrial supply, yet its apparent protection from surface disturbances can be misleading. A diverse group of emerging contaminants (ECs)—including pharmaceuticals and personal-care products, endocrine-disrupting compounds, pesticides, per- and polyfluoroalkyl substances (PFAS), microplastics, antimicrobial-resistance determinants, industrial chemicals and engineered nanomaterials—can enter aquifers through wastewater infiltration, landfill leachate, agricultural recharge, industrial releases, septic systems and managed aquifer recharge. Their occurrence at trace concentrations does not necessarily imply negligible risk because persistence, mobility, mixture effects and chronic exposure can complicate risk assessment. Recent groundwater-focused reviews emphasize PFAS, microplastics, pharmaceuticals and microorganisms as major emerging pollutant classes, while newer work highlights the importance of hydrogeochemistry, source characterization and site-specific transport processes. This review analyzes the sources, occurrence, transport, transformation, exposure pathways and health implications of emerging contaminants in groundwater and critically evaluates remediation technologies. The review concludes that prevention, source control and risk-based monitoring should precede remediation; where remediation is necessary, treatment selection should be based on contaminant chemistry, aquifer properties, hydrogeological connectivity, exposure pathways and lifecycle impacts. Future systems should combine high-resolution monitoring, reactive transport modelling, artificial intelligence-assisted plume prediction and sustainable treatment trains.