The proper method of obtaining a sample of tap water for bacteriological analysis involves:

The proper method of obtaining a sample of tap water for bacteriological analysis emphasizes the importance of collecting a representative and uncontaminated sample. This is crucial for reliable test results.

In the correct method, the sample is collected from a tap that has been opened for 2-3 minutes. This ensures that any stagnation that may have occurred in the pipes is eliminated, allowing fresh water to flow and be sampled. Holding the sample bottle near the base minimizes the risk of contamination from the person's hands. If the sample bottle is held by the neck, there is a greater chance of contaminating the inside of the bottle, which can compromise the results of the bacteriological analysis.

Filling the bottle to within an inch of the top provides enough space for any possible expansion or turbulence that may occur after capping the bottle. This aspect helps maintain the sample integrity during transport to the laboratory.

Each of these considerations is crucial in a bacteriological sampling protocol to ensure the accuracy and reliability of the results obtained. Therefore, the method described is not only about the physical act of collecting water but also about preventing contamination and ensuring the sample is representative of the water system being tested.