Heavy Metal Contamination in the Pilcomayo River Basin
Spatiotemporal dynamics, sediment-water partitioning, and geochemically targeted remediation strategies.
The Pilcomayo descends from the Bolivian Andes through Argentina and into Paraguay across an 850 km transboundary corridor, gathering sediment, silver, and a long historical load of cadmium, lead, and zinc from upstream mining. The investigation asks how those metals partition between dissolved phase, suspended sediment, and the river bed across space and time — and what that partitioning behavior implies for site-specific remediation.
The analysis draws on 1,436 samples across 46 monitoring stations spanning eight years (2016–2024), contributed by the Comisión Trinacional para el Desarrollo de la Cuenca del Río Pilcomayo. Spatiotemporal partitioning is modelled in Spyder 6 Python 3 using a coupled hydrological–geochemical framework, with field campaigns paired against discharge regimes for the wet, dry, and shoulder seasons.
Findings track which reaches and which seasons drive the highest dissolved-metal load, and use that mapping to evaluate where geochemically targeted remediation interventions — wetland buffer reactivation, sediment capping, and source-side controls — are likely to deliver the largest reduction in downstream exposure for the indigenous communities and agricultural regions that depend on the river. Findings have additionally been presented to Diputada María Ángela Ruíz Farfán during her visit to UCSB.