Abstract: A specialized TDR probe for simultaneous measurement of water level and bulk electrical conductivity is developed,calibrated and field-tested.The probe can be used to continuously monitor water level and give the alarm.The obtained waveform is automatically analyzed by computers with the water level being a simple function of the wave velocity and travel time.The electrical conductivity of the sample is measured by the calibration procedure in the lab.The application of this TDR method is demonstrated in a field test on a municipal waste landfill.Water level measurements obtained with this TDR technique show close agreement with those obtained using the visual procedures.Moreover,it is also shown that the probe can be used in highly caustic and high temperature environment.