To sample water near the bottom of a cooling tower basin, how should the bottle be positioned?

Sampling water near the bottom of a cooling tower basin requires careful consideration of the bottle's position to ensure accurate collection of water that may have settled or accumulated debris and contaminants. Positioning the sampling bottle downward, then rotating it upward, helps capture a representative sample from the bottom layer of water, where stagnant conditions often allow for the accumulation of microorganisms such as Legionella.

By initially directing the opening of the bottle downward, the sample can effectively gather water that is mixed with potential sediment. The subsequent upward rotation allows the bottle to fill while minimizing the disturbance of sediment, ensuring that the sample is not artificially altered by debris that might otherwise be stirred up. This method promotes the collection of a water sample that is both representative and meaningful for assessing potential Legionella presence.

In settings like cooling towers, where stratification can occur, this technique is vital; it ensures that the most relevant water, which may indicate contamination levels, is sampled correctly.