Presence of Emerging Contaminants Upstream and Downstream of an Urban Wastewater Treatment Plant

Several issues about the quality of urban surface waters, such as the Detroit River, are becoming a concern due to the increasing detection of emerging contaminants. Although the emerging contaminants are present in low concentrations—ranging from nanograms per liter (ng/L) to micrograms per liter (µg/L)—these raise serious concerns about long-term effects on human health and aquatic ecosystems, particularly when left unregulated. Municipal wastewater effluent has been reported as one of the major pathways for these emerging contaminants. Most treatment plants are not equipped to effectively remove many emerging contaminants, allowing them to enter surface waters. To assess the presence of these emerging contaminants, water samples were collected during the summer from sites near the upstream and downstream of the Detroit wastewater treatment plant. Among the sixteen emerging contaminants analyzed were pharmaceuticals, personal care products, and pesticides. Ten of these, such as sucralose, caffeine, acetaminophen, and bisphenol A, were detected at both locations, with concentrations ranging from 42 to 4100 ug/L. Elevated contaminant levels found downstream can come from various sources, such as agricultural runoff, leachate from landfills, overland flow, and Combined Sewer Overflows (CSOs). Furthermore, local pharmaceutical usage patterns and the effectiveness of our treatment facilities play significant roles in the contaminant concentrations we see. Tracking emerging contaminants both upstream and downstream of treatment plants is crucial for pinpointing vulnerable watersheds. This vital information enables us to establish a solid baseline and craft effective strategies to lower contaminant levels.