Which of the following is NOT a situation that requires testing well water?

Testing well water is crucial in various situations to ensure its safety and quality. The correct choice identifies a scenario that is not immediately necessary for testing.

When a well is first drilled, initial testing is indeed important, but it typically falls within an initial evaluation phase rather than ongoing monitoring. The reason for this is that, although it is critical to establish safety prior to using the well, it does not directly trigger a later need for testing as frequently as the other situations mentioned. The other circumstances—after servicing the well, whenever there is a noticeable change in taste, and when flood risk increases—constitute situations where contaminants might enter the water supply or indicate changes in its quality, thus necessitating prompt testing to safeguard against potential hazards.

In summary, while well water should be tested after drilling for many reasons, including establishing baseline measurements, the consistent need for testing emphasized in the other situations reflects ongoing concerns for water quality, making the initial drilling a less pressing scenario for repetitive testing.