Question

explain why it is harmful to discharge untreated sewage into rivers lakes or ground​

Answer 1

Alternatively, leaking or flooding can cause completely untreated sewage to enter rivers and other water sources, causing them to become polluted. ... Contamination of water sources can cause diseases to spread, such as e-coli, diarrhea and hepatitis A. Even properly treated sewage can have its problemsHealth Effects

Health EffectsLife-threatening human pathogens carried by sewage include cholera, typhoid and dysentery. Other diseases resulting from sewage contamination of water include schistosomiasis, hepatitis A, intestinal nematode infections, and numerous others.Sewage is a liquid containing wastes which is disposed by households, industrial and agricultural activities in water. It is harmful to discharge untreated sewage into rivers or seas because it can pollute the whole sources of water. Sewage contains harmful substances and disease causing organisms.When sewage enters a lake or stream, microorganisms begin to decompose the organic materials. Oxygen is consumed as micro-organisms use it in their metabolism. Ecological Damage: Sewage-contaminated water causes eutrophication, which is the increase in concentration of chemical elements required for life.

Answer 2

Explanation:

Sewage contains various contaminants including disease causing bacteria and other microbes.. If this contaminated water is used for drinking then it can cause diseases such as cholera, typhoid etc.. which may even lead to death... That is why untreated sewage is harmful when discharged in rivers or lakes...