Composite Sampling

Composite sampling involves combining the individual samples into one “composite” sample (for example, combining pond water samples taken over the course of two days into one large container). This method has several drawbacks:

• It loses information about individual samples making it difficult to detect unknown waste variations

For example, if the random samples were analyzed discretely, you might find a very high result and a very low result. The few extreme results may indicate the waste is not homogeneous and there are hot spots in the waste stream. You lose information.

• Analytical results are a pre-calculated “average”

For example, rather than analyzing 4 discrete samples they are combined into a homogeneous mixture. The resultant mixture ends up being an average of all the samples.

• Additional statistical analysis cannot be performed (such as data variations between samples)