Yes, it was a mistake to call it god, but I think that can be excused. At least almost every religious Hindu still believes that bathing in Ganges can wash away

Yes, it was a mistake to call it god, but I think that can be excused. At least almost every religious Hindu still believes that bathing in Ganges can wash away his/her sins, so that part is correct. Bringing religious angle is important here to show that it should be even more important for us to keep it clean.