Respuesta :
Water pollution is one, they were dumping sewage into the water, and the animals in said water would die.
Answer:
Bacterial and nutrient
Explanation:
Raw sewage contains large amounts of bacteria as well as nutrients like nitrogen and phosphorus. Drinking water that is contaminated by bacteria can cause outbreaks of typhoid fever, dysentery and a variety of other deadly diseases. The nutrients present in raw sewage can cause excess algal growth and oxygen depletion. Treatment of wastewater removes both dangerous bacteria and excessive nutrients.