water

Which of the following is an example

of ground water?

• Impounding reservoirs

• Rivers

• Tanks

• Shallow wells

Identify the protozoal water pollutant

• Typhoid

• Cholera

• Amoebiasis

• Hepatitis E

The thickness of the sand bed in slow

sand filter is:

• 0.25 m

• 0.5 m

• 0.75 m

• 1 m

Heart of slow sand filter

• Supernatant water

• Vital layer

• Umderdrainage system

• Filter control valves

The washing process of the rapid sand

filters is referred to as:

• Back washing

• Front washing

• Top washing

• Scrapping