Water at 25°C is trapped in a defunct irrigation ditch below ground. Every 100 m, there is a vent line with a 1.0 m inside diameter and it is 2.0 m deep below ground level, which is at 25°C. The outside air can be assumed to be dry. The vapor pressure of water is 23.76 mmHg at 25°C. Use the diffusivity from Table 18.2-1.
(a) Calculate the total evaporation loss in SI units.
(b) If the total water level is 0.25 m from the base underground or 1.75 m deep below ground level, how long will it take the vent line to completely dry?