The operation I work for sumps the tanks on the preflight if the airplane flew on the previous shift. So it is preflighted by a new crew twice a day. If it sits for more than a few days we usually sump again. We have mechanics on site or a phone call away so the leaking sump isn't an issue for long.

FWIW the instructor teaching the class in my initial B200 training actually said that sumping was a maintenence function only, citing that turbine engines are not susceptible to water like recips. Yeah right