What needs to be clarified
The task could establish which layers were actually sampled and whether they can be related to the relevant period. Imported soil provenance, work boundaries and undisturbed areas should be considered separately.
Materials to prepare
- A site plan showing sampling locations, depths, sample labels and section photographs.
- Delivery records and information on when, how much and where soil was placed.
- Sampling records, laboratory reports and available evidence of the site before the work.
What to compare
- The connection of each sample to its coordinates, depth, layer and test report.
- Consistency between section descriptions and records of delivery, removal and mixing.
- Comparable baseline information and explanations for differences between areas.
Possible outcome of the analysis
A possible result is a layer diagram and sample table specifying the circumstances each represents. It could identify missing information before conclusions about earlier conditions or the source of changes are drawn.
Limits of the conclusions
A sample represents the collected material within the examination performed. Earlier conditions may be impossible to reconstruct after mixing; finding a substance does not automatically identify its source or a responsible person.