When should microbiological samples be collected for reasons other than monitoring compliance?

Microbiological samples should be collected from new water lines and lines that have been repaired to ensure the integrity and safety of the water supply. This type of sampling is crucial because new installations or repairs can introduce contaminants that may not be present in established, well-maintained systems. By conducting microbiological testing at these times, water systems can identify any potential health risks and take remedial actions before the water is consumed by the public.

Sampling before a holiday or only during emergencies does not address the proactive measures needed for newly installed or repaired lines, as those times are not systematic or comprehensive. Regular sampling schedules are important for compliance monitoring but do not specifically focus on the transitional phases of water lines where risks may be elevated. Therefore, the emphasis on new and repaired lines is particularly significant in maintaining water safety and public health.