Oily mixture means a mixture, in any form, with any oil content. Oily mixture includes, but is not limited to -
(1) Slops from bilges;
(2) Slops from oil cargoes (such as cargo tank washings, oily waste, and oily refuse);
(3) Oil residue (sludge); and
(4) Oily ballast water from cargo or fuel oil tanks.