16 From Thin Section to Outcrop: Exploration of Undergraduate Research (Posters)

This session is designed to showcase undergraduate research across all disciplines. All submissions should be written by the student(s) and include a faculty co-author. Categories: Cross-Disciplinary, all topics welcome

Sunday, 22 March 2026
1:30 PM - 5:30 PM
CCC, Ballroom C

Grain Size Analysis and Spatial Distribution of Heavy Metals within the Bladen’s River Dam Impoundment (Seymour, Connecticut)

Paper number: 16-25
Program: Technical Sessions
Time: 1:30 PM – 1:30 PM

Authors

Abstract

Sediments play a critical role in the health and quality of aquatic ecosystems, acting as both a sink and a source of contaminants, particularly heavy metals. The accumulation of these pollutants behind dams, such as the Bladen’s River Dam in Seymour, Connecticut, can have long-lasting impacts on water quality and aquatic life. This study investigates the spatial distribution of heavy metals; arsenic (As), cadmium (Cd), copper (Cu), iron (Fe), lead (Pb), and zinc (Zn) in surface sediments from the Bladen’s River Dam impoundment. Sediments were evaluated based on grain size, loss on ignition (LOI), and both geochemical and ecotoxicological criteria. The results revealed significant variations in sediment characteristics, with finer grain sizes and higher organic content found in the impoundment areas. Notably, the SEY-4 sample from the impoundment exceeded the Probable Effects Concentration (PEC) for all measured metals, making it a potential hotspot for contamination. Although none of the sites exceeded the Threshold Effects Concentration (TEC) levels, suggesting limited immediate ecological risk, SEY-4’s elevated metal concentrations indicate a long-term risk to aquatic life. This study highlights the importance of understanding sediment composition and contaminant levels in assessing the risks associated with dam removal. The findings also contribute to the development of effective sediment management strategies to minimize the release of contaminants and mitigate ecological harm during dam removal processes. Given the relatively low degree of overall sediment contamination and the limited volume of material retained behind Bladen’s Dam, any mobilized metals are likely to undergo substantial dilution upon downstream transport. These findings suggest that, from a geochemical and eco-toxicological standpoint, the site presents a low risk of contaminant release, thereby supporting the environmental feasibility of dam removal with appropriate sediment management considerations.

Geological Society of America Abstracts with Programs. Vol. 58, No. 2

doi: 10.1130/abs/2026NE-411121

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