A system for monitoring a level of product in a tank to detect one of a delivery and a drain operation is provided. The system comprises a monitor and a data center. The monitor is operably coupled to the tank and adapted to detect the level of product in the tank at a first rate and at a second rate. The data center is in communication with the monitor and adapted to receive a user inputtable threshold level of change. The monitor detects the level of product in the tank at the first rate until the threshold level of change is detected. Thereafter, the monitor detects the level of product in the tank at the second rate. The data center generates an alarm signal to indicate that one of the delivery and the drain has occurred.