How long should chemical analysis records, such as THM/HAA results, be maintained?

Chemical analysis records, including results for substances such as trihalomethanes (THMs) and haloacetic acids (HAAs), should be maintained for a period of 10 years to comply with regulatory standards. This timeframe is consistent with guidelines set by the Environmental Protection Agency (EPA) and other regulatory bodies that govern water quality and safety.

Maintaining these records for 10 years ensures that laboratories and water providers can demonstrate compliance with drinking water regulations, track trends in water quality over time, and respond effectively to any investigations or public health concerns that may arise. It is essential for maintaining accountability and ensuring the reliability of water quality data.

The choice of a 10-year retention period balances practical considerations of recordkeeping with the need for sufficient historical data, allowing both operators and regulatory agencies to analyze and assess the long-term trends in water quality and treatment efficacy.