Water Data Services - Composite Sampling

Over recent years Water Data Services have worked closely with Government water resource agencies to develop and refine the Composite Volume Proportional method of water quality sampling.

This method requires that an accurate predetermined calibration of the river flow versus height relationship is available. This relationship together with other relevant information is used to program a data logger. The logger extracts water samples at predetermined volume increments and stores them in a large plastic container during the sampling period. A composite sample is collected from the tub at each sample visit and a reliable estimate of load concentration for the sampling period is determined.

The advantages of the Composite Volume Proportional method are:

• Reliable pollutant load estimates which are far more representative than grab sampling programs or stage activated composite sampling techniques.
• Cheaper ongoing costs than a detailed grab sampling program.