Screening Level Assessment of Metal Concentrations

Authors: Ean M Garvin Cas F Bridge Meredith S Garvin

Publish Date: 2017/02/22

Volume: 72, Issue: 3, Pages: 349-363

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Abstract

Metal releases have been received by the Grand Lake watershed from the TriState Mining District TSMD since the mid 1800s To address data gaps in metal distributions in the Oklahoma portion of the watershed streambed sediment and floodplain soil was sampled on various streams The 63µm fraction was analyzed for Cd Pb and Zn concentrations by portable Xray fluorescence spectroscopy and inductively coupled plasmamass spectrometry Mean metal concentration results at reference transects indicated that background sediment/soil concentrations for Cd Pb and Zn within the watershed were 05 19 and 68 mg/kg respectively A significant difference in the distributions of metal concentrations was found between reference and impacted transects Cd Pb Zn p = 000 Cd n = 29 Pb Zn n = 283 These results demonstrated that concentrations of metals in streambed sediments and floodplain soils were significantly higher in areas downstream of major mining influences relative to upstream reference sites and the source of metal contamination within these media was the result of mining releases from the TSMD Toxicity risks to benthic macroinvertebrates were evaluated using a TSMDspecific sediment mixture model ∑PECQCdPbZn for metals MacDonald et al in Development and evaluation of sediment and porewater toxicity thresholds to support sediment quality assessments in the TriState Mining District TSMD Missouri Oklahoma and Kansas Draft Final Technical Report Volume I Text Prepared for the US Environmental Protection Agency and the US Fish and Wildlife Service Prepared by MacDonald Environmental Sciences Ltd US Geological Survey and CH2M Hill Nanaimo 2009 Toxicity risks to plant populations were also assessed by comparing soil metal concentrations to Ecological Soil Screening Levels EcoSSLs It was found that the survival and/or biomass of benthic invertebrates was highly impacted at Tar Creek highly to moderately impacted at Spring River and Elm Creek and unimpacted at Lost Creek and Grand Lake as a result of sediment metal concentrations It also was found that soil metal concentrations were likely sufficient to impact plant populations at all streams Within the Oklahoma portion of the watershed the majority of environmental studies remediation and restoration efforts by local state and federal agencies have been primarily focused within the Tar Creek Superfund Site TCSS boundary Importantly the findings of this study highlighted the downstream extent of metals contamination as well as the resulting potential toxicities to benthic invertebrates and plants that is present outside of the TCSS boundary Because the Oklahoma portion of the watershed comprises the jurisdictional lands of ten tribes these results emphasized the potential tribal loss of use of benthic invertebrates and plants due to their decline in population as a result of metal toxicity These overall findings provide an important basis for future data needs in assessing metal concentrations in aquatic and terrestrial biota that are consumed by tribal communities within the watershed to determine if certain organisms are unsafe to consume or warrant consumption advisories This will allow risk assessors and risk managers to better understand the potential loss of use of tribal biological resources as well as improving riskbased decision making to be protective of these resources and tribal human healthThe authors would like to thank the Cherokee Nation Eastern Shawnee Tribe of Oklahoma Miami Tribe of Oklahoma Ottawa Tribe of Oklahoma SenecaCayuga Tribe of Oklahoma and Wyandotte Nation for funding this study The authors also extend their sincere appreciation to Janice Wilson and Kathy Welch Wyandotte Nation Environmental Department for their sampling assistance Jason White Cherokee Nation Environmental Department for his aid in XRF metal analysis and Kit Garvin Tribal Environmental Management Services for driving the boat and sampling assistance

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