114-3 Geochemical Evolution of Floodplain Soils Downstream of the Tar Creek Superfund Site: A Participatory Action Research Approach Evaluating Engineered Remediation Strategies

Session: Environmental Geochemistry and Health (Part I)

Presenting Author:

Ainsley Crist

Authors:

Crist, Ainsley Faith¹, Jim, Rebecca², Lively, Martin³, Hayhow, Claire⁴, Dricker, Alice⁵, Cessna, Iris⁶, Lynch, Eliza⁷, Ries, Megan⁸, Calderon, Anna⁹, Schofield, Suzanna¹⁰, Brabander, Daniel Joseph¹¹

(1) Geosciences, Wellesley College, Wellesley, MA, USA, (2) Local Environmental Action Demanded Agency, Miami, Oklahoma, USA, (3) Local Environmental Action Demanded Agency, Miami, Oklahoma, USA, (4) Earth, Atmospheric & Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA, (5) Geosciences, Wellesley College, Cambridge, Massachusetts, USA, (6) Geosciences, Wellesley College, Wellesley, MA, USA, (7) Environmental Studies, Wellesley College, Wellesley, MA, USA, (8) Medieval and Renaissance Studies, Wellesley College, Wellesley, Massachusetts, USA, (9) Geosciences, Wellesley College, , (10) School of Geography and the Environment, Oxford University, United Kingdom, (11) Geosciences, Wellesley College, Wellesley, MA, USA,

Abstract:

Intensive lead (Pb) and zinc (Zn) mining during the 1900s at the Tar CreekSuperfund Site (Ottawa County, OK) has left the community with 67 million tons of mine waste (“chat”) and acid mine drainage (AMD) from mines. Flooding disperses heavy metals from chat and AMD onto residential floodplains. Research has focused on Pb, Zn, and cadmium (Cd), but manganese (Mn) remains understudied despite downstream floodplain soils reporting concentrations 10x the Ottawa County background level. Several studies have found that elevated Mn is correlated with lower neurodevelopmental scores at Tar Creek. Thus, investigation of spatial and temporal trends of Pb, Zn Cd, and Mn throughout the watershed is necessary to characterize exposure risk over time. 

Using a Participatory Action Research approach with LEAD Agency, riverbank sediment cores and a soil trench were analyzed using benchtop X-Ray Fluorescence. Trace elemental fingerprinting using Mn/Uranium and 1/Uranium demonstrated that AMD and chat pile runoff both contribute Pb to the floodplain. Fingerprinting also suggested that there is a third, recent source contributing to an increase in Mn temporally constrained to the top 10 cm of the cores and trench. 

To investigate this finding, we compared archival (2007) and contemporary (2023-2025) elemental analysis of three floodplain soil transects. Principal component analysis (PCA) of these datasets expressed that archival floodplain samples were more associated with Pb, Zn, Cd, Fe, Ge, Ti, and Fe, whereas contemporary floodplain soils were more associated with Mn, Mg, Al, and Si. Additionally, the 2007 dataset contained samples collected before and after a 100-year flood event, providing an opportunity to investigate the geochemical impact of flooding. While the PCA suggested that the flood event did not change the overall geochemical composition of the soils, differences in the concentrations of Pb, Zn, Cd, and Mn as a function of distance from Tar Creek suggests flood-driven geomobility. 

The City of Miami has responded to flood-driven heavy metal deposition with engineered features on the floodplain to protect some low-lying areas. Differences between the archival and contemporary spatial distributions of Pb, Zn, Cd, and Mn suggest that these engineered features have reduced heavy metal deposition. However, in unprotected flood–prone locations, metal concentrations remain comparable to 2007 levels, indicating the need for further mitigation efforts.

 

 

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