Prelims 993

Which of the following are non-point sources of pollution in rivers?
1. Surface drains carrying municipal sewage
2. Run-off from agricultural fields
3. Dhobi Ghats
4. Effluents from industries
Select the correct answer using the code given below.
1 and 4 only
2 and 3 only
1, 2 and 3
3 and 4 only
Explanation :
Point sources: These are organized sources of pollution where the pollution load can be measured, e.g. surface drains carrying municipal sewage or industrial effluents, sewage pumping stations and sewerage systems, trade effluents from industries, etc. Pollution loads due to untreated sewage is one of the main reasons threatening the ecological health of rivers. Most of the urban lakes in the country are also facing similar challenges.
Non-point sources: These are non-measurable sources of pollution such as run-off from agricultural fields carrying chemicals and fertilizers, run-off from solid waste dumps and areas used for open defecation, dumping of un-burnt/half-burnt dead bodies and animal carcasses, dhobi Ghats, cattle wallowing, etc.
Out of the total measurable pollution in the rivers from various point sources, around 75% is contributed by municipal sewage from towns located along the banks of rivers and remaining 25% by industrial effluents.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s