47-5 Mobility of Legacy Metals in Floodplain Soils: Incorporating Community-Based Science to Evaluate Intervention Strategies to Reduce Residential Exposure in the Tar Creek Watershed, OK

Session: Sharing Geology: Building the Geocommunity Through Creative Engagement (Posters)

Poster Booth No.: 54

Presenting Author:

Gabriela Montes

Authors:

Montes, Gabriela¹, Kim, Joanne², Ducos, Roxane³, Ries, Megan⁴, Crist, Ainsley⁵, Lively, Martin⁶, Jim, Rebecca⁷, Brabander, Daniel⁸

(1) Wellesley College Geosciences Department, Wellesley, , (2) Wellesley College Chemistry Department, Wellesley, , (3) Wellesley College Geosciences Department, Wellesley, , (4) Wellesley College Medieval & Renaissance Studies Department, Wellesley, , (5) Wellesley College Geosciences Department, Wellesley, , (6) Local Environmental Action Demanded Agency, Miami, , (7) Local Environmental Action Demanded Agency, Miami, , (8) Wellesley College Geosciences Department, Wellesley, ,

Abstract:

The floodplains along Tar Creek, City of Miami, OK have experienced decades of heavy metal (particularly Pb, Zn, Cd, and Mn) transport and deposition from the upstream Tar Creek Superfund site. Above ground mine waste piles (“chat”) and underground mine workings that form acid mine drainage (AMD) contribute to these metal loadings to Tar Creek and adjacent floodplains. Flooding events have enhanced dispersal of metals derived from both sources onto the floodplain, increasing residential exposure risks. 

In collaboration with the Local Environmental Action Demanded (LEAD) Agency, trace metal analyses of four floodplain transects were conducted using in situ FP-XRF and laboratory pED-XRF. From upstream to downstream, the transects examined include: an undeveloped wooded area, an unremediated area with passive use, an area with a flood control berm and passive use, and a remediated site for a planned park. Transects from Tar Creek across the remediated planned park area and the area with a flood control berm reveal that heavy metals are concentrated closest to the creek and in the lowest elevation areas prone to flooding. Pb concentrations obtained through FP-XRF in the low elevation areas of the planned park transect range from 105–602 µg/g and 111–353 µg/g in the transect with the flood control berm. Steep declines in Pb concentrations corresponding to an increase in elevation suggest topography serves as a barrier for metal remobilization and dispersal further into the floodplain. Following high elevation areas, Pb concentrations remain relatively low and constant with increasing distance from the creek: a factor of ten lower in the planned park area and a factor of seven lower following the flood control berm. Additionally, a 60cm-deep soil trench along the bank of the creek in the undeveloped wooded area was sampled. Geochemical analyses were conducted to evaluate the evolution of fluxes of creek transported metals, and their geochemical fingerprints, over time.

Spatial distributions of Pb, Zn, Cd, and Mn in floodplain soils suggest the City of Miami has succeeded in reducing flood-driven heavy metal mobility through soil remediation efforts and engineered floodplain features. Geochemical characterizations of these remediated and engineered floodplains provide a new baseline for understanding the ongoing fluxes of metal transport and will bolster future efforts to reduce residential exposure to legacy metals.

Geological Society of America Abstracts with Programs. Vol. 58, No. 2, 2026

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