Monitoring Water and Contaminant Fluxes in Aquifers, Streams, and Hyporheic Zones

Contaminant mass flux is the rate at which chemical mass passes through a unit cross-sectional area.  Point measurements of water and contaminant flux in aquifers and streams is spatially integrated to characterize the rate of contaminant mass discharged in streams and aquifers; whereas, the same measures in hyporheic zones can be used to quantify the rate of contaminant mass exchange at the stream/aquifer interface.  This type of information is critical to quantify off-site risks to down gradient surface and subsurface receptors and to prioritize remediation efforts that maximize risk reduction within available financial resources.  Quantifying contaminant mass flow also has important consequences with respect to evaluating the effectiveness of natural attenuation and active remediation.  This paper presents recent developments in four passive technologies for monitoring water and contaminant fluxes in aquifers, streams, and hyporheic zones and their applications in the field.