A pump station arrangement and a method for turning off a pump configured for pumping liquid via a conduit. The pump, before being turned off, being driven at an operational frequency (FN) by a control unit. The method is characterized by the steps of, ramping down the frequency of the pump due to a turn off instruction, the terminal frequency of the ramping down being equal to the operational frequency (FN) of the pump minus at least 10 Hz and the ramping down time being at least a reflection time (TR) for the conduit in question, and the terminal frequency of the ramping down not being less than 10 Hz, and stopping the pump after the ramping down.