Contaminant mass discharge to streams: Comparing direct groundwater velocity measurements and multi-level groundwater sampling with an in-stream approach

- PVPs can measure seepage velocity and flow angle near streams with a high precision.
- PVP data are useful for contaminant mass discharge (CMD) quantification to streams.
- CMD estimation using PVP data yields results comparable to Darcy-based methods.
- The in-stream CMD can help account for the total contaminant mass at the streambank.