What is the temperature range of the public water supply over six months of the year?

The temperature range of the public water supply over six months of the year is most accurately represented by 68 to 78 degrees Fahrenheit. This range aligns with typical seasonal variations in many geographic areas, where the temperature of water can fluctuate due to both environmental factors and the operational characteristics of public water systems.

Maintaining water temperatures within this range is critical for preventing conditions that could promote the growth of Legionella bacteria, as these organisms thrive in warmer water. The temperatures specified in the other choices either exceed or fall short of typical public supply ranges, which could result in increased risks for Legionella proliferation. Hence, the selected range effectively reflects the standards and recommendations outlined for water supply management to mitigate health risks.