What is non-point source pollution and why is this kind of pollution hard to monitor and control?

When the source of pollution is widely distributive in nature, it is called as the Non-point source pollution, for example, acid rain.

Explanation:

the source of pollution when is not concentrated over a particular area or any particular defined pinpoint is termed to be as the Non - point source pollution.

this type of pollution is very hard to be monitored or controlled due to its nature of widely distributive nature of the origin. It has several pathways for the effect to undertake and thus the control over the effect is not easily accessible.

For example, during rain, the tree fall off can enter water stream from any source, either be it open lake or ponds or even street fall offs.

chemical properties of thing