In order to find the correct answer we must take into consideration two aspects of the case, first is the presence of heavy metals and the other is the waste ponds of water. In the first case the heavy metal cannot be easily disposed by the human body that's why they are so dangerous for health, and in the second one, the waste of materials in ponds, if this is not properly sealed (which doesn't say in the question) there would be infiltration to the underground water which it is highly probable that also nourishes the wellspring of the river thus causing contamination of the same.
So taking into account this, options two and three are the correct answer.
