Citation:

Shelton, S., S. Kaushal, P. Mayer, AND T. Newcomer-Johnson. Chemical Cocktails from Coast to Coast: Investigating Urban Convergence of Water Quality. Gordon Research Seminar - Catchment Science: Interactions of Hydrology, Biology and Geochemistry (GRS) - Catchment Science in the Anthropocene, Andover, NH, June 17 - 18, 2023.

Impact/Purpose:

This is an invited presentation to the Gordon Conferences series.  We present the nascent work of Sydney Shelton, a new ORISE fellow working at sites spread across the US in effort to identify patterns of convergence of water quality and chemistry in urban ecosystems.  We focus on understanding the patterns of water quality and the formation of chemical cocktails as water moves along flowpaths through select cities in the Washington DC area, Cincinnati, OH, Denver, CO, and Portland, OR.  We hypothesis that chemical cocktails form as flow paths intersect with multiple sources of contaminants (heavy metals) and ions (e.g. road salts) and that conservation areas, riparian buffers, and green spaces represent zones of contaminant attenuation and reduction. 

Description:

In urban systems, a wide variety of processes (including increasing impervious surface cover, road salt application, sewage leaks, and weathering of the built environment) contribute to novel chemical cocktails made up of metals, salts, nutrients, and organic matter. Due to heterogeneous land use and a myriad of pollution sources, water quality is highly variable throughout urban areas. National sensor data sets reveal that many U.S. streams in a wide variety of metropolitan areas have urban water quality impacts; however, these datasets lack concurrent measurements of contaminants over local spatial scales. To investigate whether urban streams in different U.S. cities undergo urban convergence and demonstrate similar water quality characteristics, we are conducting synoptic style sampling campaigns for nine rivers in five major metropolitan areas. 10-24 samples are taken along the flowpath of each stream as they flow through progressively more urbanized areas. Preliminary results demonstrate that each stream portrays unique chemical cocktails, including variations in ion concentrations, organic matter quality, and conductivity downstream. Trends in these parameters tend to shift around land use transition zones. For example, base cation concentrations increased within cities and decreased through conservation and restoration efforts. These results suggest that urbanization impacts chemical cocktails, but ultimately each stream demonstrates different changes in water quality along its flowpath.

Record Details: