TRACKING TRANSPORT OF ‘CHEMICAL COCKTAILS’ OF TRACE METALS USING SENSORS IN URBAN STREAMS

Abstract

Understanding transport mechanisms and temporal patterns in metals concentrations and fluxes in urban streams are important for developing best management practices and restoration strategies to improve water quality. In some cases, in situ sensors can be used to estimate unknown concentrations and fluxes of trace metals or to interpolate between sampling events. Continuous sensor data from the United States Geological Survey were analyzed to determine statistically significant relationships between lead, copper, zinc, cadmium and mercury with turbidity, specific conductance, dissolved oxygen, and discharge for the Hickey Run, Watts Branch, and Rock Creek watersheds in the Washington, D.C. region. At Rock Creek, there were significant negative linear relationships between Hg and Pb and specific conductance (p<0.05). Watershed monitoring approaches using continuous sensor data have the potential to characterize the frequency, magnitude, and composition of pulses in concentrations and loads of trace metals, which could improve management and restoration of urban streams.