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ARS Home » Midwest Area » St. Paul, Minnesota » Soil and Water Management Research » Research » Publications at this Location » Publication #309374
Title: Sediment-water distribution of contaminants of emerging concern in a mixed use watershed

Author
item FAIRBAIRN, DAVID - University Of Minnesota
item KARPUZCU, EKREM - University Of Minnesota
item ARNOLD, WILLIAM - University Of Minnesota
item BARBER, BRIAN - University Of Minnesota
item KAUFENBERG, ELIZABETH - University Of Minnesota
item Koskinen, William
item NOVAK, PAIGE - University Of Minnesota
item Rice, Pamela
item SWACKHAMER, DEBORAH - University Of Minnesota

Submitted to: Science of the Total Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/13/2014
Publication Date: 11/7/2014
Publication URL: http://handle.nal.usda.gov/10113/60509
Citation: Fairbairn, D., Karpuzcu, E., Arnold, W., Barber, B., Kaufenberg, E., Koskinen, W.C., Novak, P., Rice, P.J., Swackhamer, D. 2014. Sediment-water distribution of contaminants of emerging concern in a mixed use watershed. Science of the Total Environment. 505:896-904.

Interpretive Summary: This study evaluated the occurrence and distribution of 15 contaminants of emerging concern (CEC), in stream water and sediments in the Zumbro River watershed in Minnesota and compared these with sub-watershed land uses. Sixty pairs of sediment and water samples were collected across all seasons from four stream sites over two years and analyzed for selected pesticides, veterinary and human medications, personal care products, and phytoestrogens. Spatial variations correlated with land use for many CECs in water and/or sediment. Spatial and temporal analyses indicate that pharmaceuticals and personal care products (urban/residential CECs) are significantly elevated in water and/or sediment at sites with greater population density (>100 people/km2) and percentage of developed land use (>8% of sub-watershed area) than those with less population density and land area under development. Significant spatial variations of agricultural pesticides in water and sediment were detectable, even though all sites had a high percentage of agricultural land use. Water concentrations exhibited seasonal variation while sediment concentrations did not. Agreement of measured and predicted distribution coefficients improved with increasing hydrophobicity and in-stream persistence of the contaminant. The more polar and degradable CECs showed greater variability in measured distributions across different sampling events. Our results confirm that CECs are present in urban and agricultural stream sediments. These results provide a greater understanding of occurrence of CECs that can serve as tools to differentiate agricultural sources from urban sources and help identify origins of pollution. This will aid in the design and implementation of future sampling protocols and help focus efforts and resources on mitigation and remediation strategies to reduce contaminants and sources of greatest risk; improving water quality.

Technical Abstract: This study evaluated the occurrence and distribution of 15 contaminants of emerging concern (CEC) in stream water and sediments in the Zumbro River watershed in Minnesota and compared these with sub-watershed land uses. Sixty pairs of sediment and water samples were collected across all seasons from four stream sites over two years and analyzed for selected pesticides, veterinary and human medications, personal care products, and phytoestrogens. Spatial and temporal analyses indicate that pharmaceuticals and personal care products (urban/residential CECs) are significantly elevated in water and/or sediment at sites with greater population density (>100 people/km2) and percentage of developed land use (>8% of sub-watershed area) than those with less population density and land area under development. Significant spatial variations of agricultural pesticides in water and sediment were detectable, even though all sites had a high percentage of agricultural land use. Seasonality in CEC concentration was observed in water but not in sediment, although sediment concentrations of three CECs did vary between years. Average measured non-equilibrium distribution coefficients exceeded equilibrium hydrophobic partitioning-based predictions for 5 of the 7 detected CECs by at least an order of magnitude. Agreement of measured and predicted distribution coefficients improved with increasing hydrophobicity and in-stream persistence. The more polar and degradable CECs showed greater variability in measured distributions across different sampling events. Our results confirm that CECs are present in urban and agricultural stream sediments, including those CECs that would typically be thought of as non-sorptive based on their log Kow values. These results and the observed patterns of sediment and water distribution can augment existing information to improve prediction of CEC fate and transport, leading to more accurate assessments of exposure and risk to surface water ecosystems.