Land cover, stream discharge, and wastewater effluent impacts on baseflow sediment and nutrient concentrations in SW Ohio streams

• Published in: River research and applications 2024-05, Vol.40 (4), p.497-507
• Main Authors: Spahr, Rachel E., Lazar, Jeffrey A., Grudzinski, Bartosz P., Fisher, Thomas J.
• Format: Article
• Language: English
• Subjects: Agricultural land; Base flow; Bioavailability; Discharge; Effluent treatment; Effluents; Environmental impact; Freshwater; Freshwater environments; Inland water environment; Land cover; Land management; Land use; Nitrates; Nutrient concentrations; Nutrients; Phosphates; Rivers; Sediment; Sediment concentration; Sediments; Stream discharge; Streams; Suspended sediments; Trends; Urban agriculture; Urban watersheds; Wastewater treatment; Wastewater treatment plants; Water quality
• ISSN: 1535-1459; 1535-1467
• DOI: 10.1002/rra.4248

Elevated nutrient and suspended sediment concentrations often result in negative environmental impacts within freshwater environments. Studies that directly compare suspended sediment and bioavailable nutrients between predominantly agricultural and predominantly urban watersheds during baseflow conditions are largely lacking. The purpose of this study was to determine the impacts of land cover, stream discharge, and wastewater treatment plant (WWTP) discharge on nutrient and sediment concentrations, across a large land cover gradient in Southwest Ohio streams. Weekly baseflow samples were collected from eight streams over 1 year from November, 2016 through November, 2017. Total suspended sediment, nitrate, and phosphate concentrations were measured. Results indicate that agricultural land cover and WWTPs increase nitrate and phosphate concentrations in the study area. Total suspended sediment and nitrate concentrations increased with discharge, and discharge was a relatively weak predictor of phosphate concentrations. Seasonal water quality trends varied by parameter and land use also had unique impacts on seasonal water quality trends. Results suggest that to improve water quality in the study area, efforts should focus on improving WWTP effluent treatment and agricultural land management.