Reply To: Questions on Yoreh Deah, Choshen Mishpat

CKBSHL:

Generally if something other than water (and certain water based liquids) were to fall into a mikva, and changed its appearance, it invalidates the mikva. (YD 201:25) However, if the “mikva” were a spring, even if the appearance is changed by the liquid which fell in, it is still a valid “mikva”. (201:28) Oceans are considered a spring. (201:5)

One would therefore imagine that one may indeed tovel in the oil spill.

Unless one wished to argue that since the oil does not mix with the water, it is not part of the ocean?