Land Use Practices and their Resulting Impacts on Surface Water Quality

Contaminants of emerging concern (CECs) are becoming a major source of water impairment throughout the world. Land use practices within urban and rural areas have shown to be sources of CECs. Contaminants enter the environment through direct application or waste disposal with runoff and soil leaching depositing CECs into streams and lakes. Therefore, this study sought to characterize the nutrients, heavy metals, pesticides, human pharmaceuticals, and personal care products appearing in streams across varying Kentucky landscapes. Field sampling included using both Polar Organic Chemical Integrative Samplers and water grab samples from March-October 2022 at four stream sites in an oil and gas, urban, mining, and agricultural regions of the Commonwealth. Preliminary results exhibited occurrence of contaminants varied by location, season, and flood conditions. The urban site resulted in the highest concentrations of chloride, nitrate-N, caffeine, and cotinine (by-product of Nicotine), particularly in the spring months. The watershed with the most active mines showed the highest concentrations of strontium along with significantly larger concentrations of sulfate that were above the ecotoxicology limits (200 mg/L) and EPA secondary drinking water standards (250 mg/L). The watershed associated with the most oil and gas wells showed the highest concentrations of barium. This site also showed higher concentrations of human pharmaceuticals (e.g., Carbamazepine, Codeine, Diltiazem, Diphenhydramine, Fluoxetine), likely a result of an older wastewater infrastructure and straight-pipes that discharged untreated water into the sampled stream. Finally, the agricultural site showed the highest concentrations of aluminum, iron, and lead and had higher sediment loads during flood events in the spring months, which likely resulted in the concentrations of these three metals being above the chronic criteria for aquatic organisms. Additionally, the agricultural site had the highest concentrations of both lincomycin and sulfonamide, common antibiotics used to treat livestock. This study is the necessary first step in reaching the UN’s Sustainable Development Goals by developing a comprehensive understanding of land use impacts on contaminant presence and concentration in surface waters. Further, findings from this project will be incorporated into the design and placement of best management practices to limit the impact of CECs.