An arrangement for filling a tank (1) in a tanker, preferably a slurry tanker, with liquid such as water containing varying amounts of contaminants. The arrangement includes:- a feed line 52) with a filling pump (3) for pumping the liquid to the tank (1)- a discharge line (49) with an emptying pump (2) for pumping the liquid out of the tank (1)- a return line (50) to the tank (1) associated with the emptying pump (2)- an ejector (6) provided in the return line (50)- a suction line (51) connected with the suction side of the ejector (6) for aspirating the liquid through the filling pump (13) and- valves (3,9,29) for shutting off/opening connections between the ejector, the pumps and the tankthe suction line (51) being identical to the feed line (52) such that the filling pump (13) only pumps liquid to the tank (1) via the ejector (6).
