31-8 Hotspot Mapping and Risk Evaluation of Heavy Metals Source Identification in Missouri River floodplain and Surface Water Systems, Midwestern US

Session: Environmental Geochemistry and Health (Posters)

Presenting Author:

Authors:

Abstract:

This study addresses seasonal heavy metal dynamics and contamination sources in lakes and ponds across the Missouri River floodplain in the Midwestern United States, utilizing an integrated suite of statistical and geospatial approaches. Sampling campaigns conducted in Summer 2024, Fall 2025, and Spring 2026 provided water chemistry data covering twelve trace elements and key physicochemical characteristics (pH, temperature, electrical conductivity, and total dissolved solids). Results highlight persistent exceedances of benchmark concentrations for cobalt, manganese, aluminum, sulfur, lead, and cadmium, with mean Heavy Metal Pollution Index (HPI) values (181.26) signaling widespread water quality impairment. Pollution levels and source patterns were quantified using U.S. EPA exceedance ratios, contamination factors, and HPI calculations, while multivariate methods including Spearman correlation, principal component analysis, hierarchical and K-means clustering, PAM, Gaussian mixture modeling, and geospatial mapping revealed clear lithogenic and anthropogenic input gradients. The analysis consistently pinpointed Lake Manawa as the region's primary contamination hotspot and identified Steinhart Park pond as chemically unique and high-risk. By synthesizing pollution indices, regulatory exceedance, contamination frequency, and spatial clustering, the research introduces a novel environmental risk profiling strategy that streamlines hotspot detection and management prioritization. The framework delivers practical insights for adaptive water resource oversight and serves as a transferable model for freshwater systems confronting intensifying human and climatic pressures.

© Copyright 2026 The Geological Society of America (GSA), all rights reserved.