Abstract: In one aspect the invention provides an apparatus for treating contaminated fluid. The apparatus comprises a base member, a peripheral containment wall connected to the base member defining a containment volume, a dividing member for dividing the containment volume into an evaporation region for receiving contaminated fluid and a boiler region for heating contaminated fluid. The evaporation region is substantially open to atmosphere and the boiler region is substantially closed and comprises an inlet to introduce contaminated fluid into the boiler region and an outlet to allow evaporated water to exit the boiler region. Heating means are provided to heat any contents in the boiler region while fluid transfer means transfer contaminated fluid from the evaporation region to the boiler region. Preferably, the boiler region is at least partially within the evaporation region. System and method aspects are also provided.