Pollution of Air and Water

Read the paragraph and answer the questions following it.
Water is essential for life. Without water there would be no life.
We usually take water as granted for its purity, but we must
ensure the quality of water. Pollution of water originates from
human activities. Through different paths, pollution reaches to
ground water. Easily identified source or place of pollution is
called as point source, e.g.– municipal and industrial discharge
pipes, where pollutants enter the water source. Non–point sources
of pollution are those where a source of pollution can not be
easily identified, e.g.– agricultural run off, acid rain etc.
(i) How do you classify the various sources of water pollution?
(ii) What are the point sources of water pollution?
(iii) Name any two non-point sources of water pollution?