How long must microbiological records be retained according to regulations?

The correct retention period for microbiological records is five years, in accordance with regulations for drinking water laboratories. This duration is set to ensure that sufficient historical data is available for reference, compliance verification, and to support any necessary investigations regarding water quality over time. Retaining records for five years allows for trend analysis and helps in addressing any issues that may arise related to water safety, thereby ensuring public health is prioritized. This retention period aligns with guidelines established by both federal and state regulatory bodies, underpinning the importance of documenting microbiological testing results and related information.