The occurrence and persistence of surface water contaminants across different la ndscapes

Authors: NOTTINGHAM BYERS, EMILY - University Of Kentucky; MESSER, TIFFANY - University Of Kentucky; UNRINE, JASON - University Of Kentucky; BARTON, CHRISTOPHER - University Of Kentucky; AGOURIDIS, CARMEN - University Of Kentucky; Miller, Daniel

Submitted to: Science of the Total Environment
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/27/2024
Publication Date: 12/4/2024
Citation: Nottingham Byers, E.R., Messer, T.L., Unrine, J., Barton, C., Agouridis, C., Miller, D.N. 2024. The occurrence and persistence of surface water contaminants across different la ndscapes. Science of the Total Environment. 958. Article 177837.
DOI: https://doi.org/10.1016/j.scitotenv.2024.177837

Interpretive Summary: Contaminants of potential concern in natural waterways include both traditional pollutants (e.g., nitrogen, phosphorous, sulfate, trace elements) and emerging contaminants (e.g., pesticides, pharmaceuticals) and are heavily influenced by urban and rural land use practices. Nutrients, trace elements, pesticides, human pharmaceuticals, and personal care products appearing Kentucky streams were monitored monthly in order to identify primary contaminants during the growing season and understand how potential sources are associated with land cover and land use. Monthly composite samples and water grab samples were collected from March-October 2022 at four stream sites in watersheds where oil and gas, urban, mining, and agriculture use predominated. Contamination at sites varied by location, season, and flood conditions. Specifically, aluminum and iron exceeded chronic aquatic life water quality criteria in the agricultural watershed, while imidacloprid exceeded the chronic criteria limit for freshwater invertebrates in both the urban and agricultural watersheds. Sulfate concentrations also exceeded ambient water quality criteria in the mining watershed. This study provides important information for understanding how land use relates to surface water contaminants that may impact nontarget species, and necessary water treatment processes needed to ensure future safe water supply.

Technical Abstract: Contaminants of potential concern (CPCs) for water impairment, including both traditional pollutants (e.g., nitrogen, phosphorous, sulfate, trace elements) and emerging contaminants (e.g., pesticides, pharmaceuticals) are heavily influenced by urban and rural land use practices. The purpose of this was to characterize nutrients, trace elements, pesticides, human pharmaceuticals and personal care products appearing in streams in Kentucky, United States to determine monthly concentrations of contaminants and their relationship to watershed characteristics. Specific objectives were to (1) identify and quantify the type and concentration of contaminants in four streams during the growing season and (2) understand potential sources of contamination based on land cover and land use characteristics of the watershed. Monthly polar organic chemical integrative samples and water grab samples were collected from March-October 2022 at four stream sites in watersheds with distinct land uses (i.e, oil and gas, urban, mining, agriculture) and varied by location, season, and flood conditions. Specifically, aluminum (mean = 758 ug/L; max = 1,444 ug/L) and iron (mean = 1,134 ug/L; max = 1,817 ug/L) exceeded chronic aquatic life water quality criteria in the agricultural watershed, while imidacloprid exceeded the chronic criteria limit freshwater invertebrates in both the urban (mean = 5.96 ng/L; max = 17.78 ng/L) and agricultural (mean = 4.72 ng/L; max = 22.72 ng/L) watersheds. Sulfate concentrations (mean = 666 mg/L; max = 1250 mg/L) also exceeded ambient water quality criteria in the mining watershed. This study provides important steps for developing a comprehensive understanding of land use impacts on contaminant presence and concentration in surface waters, improved understanding of the implications to nontarget species, and necessary water treatment processes to ensure a safe water supply.