Elevated concentrations of heavy metals (HM) and other trace metals have been observed ubiquitously in urban streams, sourced from industrial waste or other anthropogenic activities. This thesis seeks to further our fundamental understanding of the geochemical controls on the transport of these constituents. Chapter 1 briefly introduces what is known about the sources and subsequent transport of trace metals, with an emphasis on the role of colloids. Chapter 2 presents a field study that characterizes the HM contamination found in the headwaters of the South River, an urban stream located in East Point, Georgia and immediately downstream of a hazardous waste site. Chapter 3 pivots to an investigation on determining the source and geochemistry of rare earth elements (REE) in the same study area. Both studies observe elevated trace metal concentrations nearest to the Tift Site, though chemical analyses reveal differing transport mechanisms and sources between REE and HM.