vibudhā vismayaṁ yayuḥ
According to the commentary called Śrī-Bhāgavata-candra-candrikā, the water in which Satī used to bathe was Ganges water. In other words, the Ganges flowed through the Kailāsa-parvata. There is every possibility of accepting such a statement because Ganges water also flows from the hair of Lord Śiva. Since Ganges water rests on the head of Lord Śiva and then flows to the other parts of the universe, it is quite possible that the water in which Satī bathed, which was certainly very nicely scented, was Ganges water.