AASHTO R 24-99 (2018) PDF Download

The AASHTO R 24-99 (2018) standard focuses on the objective and techniques of sampling and preservation of water samples. The objective of sampling is to collect a representative portion of water that accurately reflects its composition. The standard recognizes that complete preservation of water samples is not possible, as chemical and biological changes continue to occur after the sample is taken. However, preservation techniques can be employed to slow down these changes.

The standard emphasizes the importance of maintaining the relative portions or concentrations of all pertinent components in the water sample as in the original source. This ensures that the sample accurately represents the water being sampled. Additionally, the standard emphasizes the need to handle the sample properly to prevent significant changes in composition before laboratory tests are performed. The standard provides guidelines and recommended practices for the collection and preservation of water samples, taking into consideration the nature of the sample, whether it is domestic sewage, industrial waste, or natural waters.