Levels of heavy metals distribution near an urban wastewater in Southeastern Michigan.

The Detroit River watershed has been utilized for industrial and recreational activities. Over the past century, the river has undergone significant urban, industrial, and agricultural development. The Detroit River has a long history of environmental quality monitoring. However, due to changes in sampling methods and assessment techniques over the years, it is challenging to determine whether the river's condition has improved. The absence of baseline data to assess the levels of dissolved heavy metals near the Detroit wastewater treatment plant (WWTP) is evident in the literature. This study aimed to evaluate the concentrations of dissolved heavy metals (Cr, Fe, Cu, Zn, As, Cd, and Pb) near the upstream and downstream areas of the Detroit WWTP, allowing for an assessment of heavy metal mobility. The study found that all the sites had higher concentrations of heavy metals in the upstream sites (1, 3, and 4) compared to the downstream sites (5 and 6). However, the mean concentrations of all detected heavy metals at both sites were below the limits set by the US EPA. This information is crucial for identifying at-risk watersheds and can serve as a benchmark for future contaminant reduction strategies and remediation efforts.