Community Health

Two types

Step 1: Recall the classification of wells from the chapter. Step 2: The chapter clearly states 'There are two types of wells'. Step 3: These two types are specifically identified as open wells and tube wells. Step 4: Open wells are exposed to the surface while tube wells are enclosed systems. Step 5: No other types of wells are mentioned in the chapter, confirming there are exactly two types.

A raised wall

Step 1: Identify the need for protection around open wells to prevent contamination. Step 2: Consider what structure would effectively prevent surface pollutants from entering the well. Step 3: A raised wall creates a barrier that prevents surface runoff and debris from flowing into the well. Step 4: A fence, roof, or garden would not provide the same level of protection against water contamination. Step 5: The chapter specifically recommends building a raised wall around open wells for contamination prevention.

Bathing cattle

Step 1: Review activities that maintain lake cleanliness versus those that pollute lakes. Step 2: Desilting, building embankments, and cleaning surroundings are all recommended practices for lake maintenance. Step 3: Bathing cattle in lakes introduces animal waste, bacteria, and other contaminants into the water. Step 4: The chapter specifically states 'Cattle should not be bathed in the lakes' as a cleanliness measure. Step 5: This activity directly pollutes the lake water, making it harmful for human use and ecosystem health.

It increases water retention capacity

Step 1: Understand what happens when lakes accumulate silt over time. Step 2: Silt accumulation reduces the depth and volume of the lake, decreasing its water holding capacity. Step 3: The chapter states 'A lake filled with silt reduces its capacity for retaining water'. Step 4: Desilting removes accumulated sediment, restoring the lake's original depth and volume. Step 5: This process increases the lake's capacity to retain water, which is essential for water storage and supply.