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Innovative Tools to Identify and Quantify Groundwater Seepage to Surface Water
Oral Presentation
Prepared by J. Renda1, F. Selker2, B. Chadwick3, R. Schwarz4
1 - Anchor QEA LLC, 6650 SW Redwood Lane, Suite 333, Portland, OR, 97224, United States
2 - Selkermetrics, LLC, 4225 SW Agate Lane, Portland, OR, 97239, United States
3 - Coastal Monitoring Associates, 4741 Orchard Ave., San Diego, CA, 92107, United States
4 - Anchor QEA LLC, 6650 SW Redwood Ln, Suite 333, Portland, OR, 97224, United States
Contact Information: jrenda@anchorqea.com; 503-924-6171
ABSTRACT
Measurement of groundwater discharge, or seepage, to surface water is critical to the evaluation of many sites at which contaminated groundwater discharges to a surface water or where groundwater flows through contaminated sediment. Seepage rates are used as inputs to contaminant-transport modeling, to evaluate potential contaminant breakthrough in a sediment cap, and to calculate the service life for a reactive cap. Seepage meters have been used to accurately measure seepage rates at discrete points within a site, but the selection of measurement points is complicated by heterogeneity of sediment and underlying strata, which leads to preferential flow paths that may be missed when selecting locations for measurements. The application of distributed temperature sensing (DTS) to aid in the selection of locations for monitoring seepage rates and transition zone water quality is a recent development that greatly enhances the effectiveness of transition zone water sampling and seepage rate monitoring. The use of DTS to identify seepage locations, seepage meters to quantify seepage rates, and Trident probes to collect transition zone water samples for analysis is described in this paper with reference to specific applications. Limitations of these techniques are also identified.
Oral Presentation
Prepared by J. Renda1, F. Selker2, B. Chadwick3, R. Schwarz4
1 - Anchor QEA LLC, 6650 SW Redwood Lane, Suite 333, Portland, OR, 97224, United States
2 - Selkermetrics, LLC, 4225 SW Agate Lane, Portland, OR, 97239, United States
3 - Coastal Monitoring Associates, 4741 Orchard Ave., San Diego, CA, 92107, United States
4 - Anchor QEA LLC, 6650 SW Redwood Ln, Suite 333, Portland, OR, 97224, United States
Contact Information: jrenda@anchorqea.com; 503-924-6171
ABSTRACT
Measurement of groundwater discharge, or seepage, to surface water is critical to the evaluation of many sites at which contaminated groundwater discharges to a surface water or where groundwater flows through contaminated sediment. Seepage rates are used as inputs to contaminant-transport modeling, to evaluate potential contaminant breakthrough in a sediment cap, and to calculate the service life for a reactive cap. Seepage meters have been used to accurately measure seepage rates at discrete points within a site, but the selection of measurement points is complicated by heterogeneity of sediment and underlying strata, which leads to preferential flow paths that may be missed when selecting locations for measurements. The application of distributed temperature sensing (DTS) to aid in the selection of locations for monitoring seepage rates and transition zone water quality is a recent development that greatly enhances the effectiveness of transition zone water sampling and seepage rate monitoring. The use of DTS to identify seepage locations, seepage meters to quantify seepage rates, and Trident probes to collect transition zone water samples for analysis is described in this paper with reference to specific applications. Limitations of these techniques are also identified.