SRK Cardiff and Cardiff School of Engineering are collaborating to characterise the impacts associated with mine waste at historical sites in central Wales, stretching back over 800 years. Our study will systematically collect representative mine waste samples from historic mine dumps. Working with industrial archaeologists, the dumps will be dated. Samples will be subjected to a range of diagnostic leaching and characterisation tests and compared to fresh, unweathered wall rock from underground. The results will be compared with reported levels of environmental impact at the site to determine the most effective test procedures.
Typically, efforts to deal with pollution from abandoned metal mines have been made by local, national and regional agencies. Most projects involve major upheaval to the site during civil engineering works that are designed to control leaching and dust generation from spoil heaps, often because of concerns over human health.
In some instances, such as at Bwlch and Cwmsymlog lead mines in mid-Wales, pollution impacts on the water have not been improved, spoil was disturbed and contamination released. There is also a common problem of unlicensed removal of spoils for use as aggregates. It is clear that any earth works on these sites can cause or aggravate impacts and concomitantly impact their archaeological and historical value.
The issue to be considered is which scientific methods should be used to quantify the impact potential of mine spoils so that the effect of disturbances can be predicted and mitigated. This is not a straightforward question; a plethora of experimental procedures are available. Applying the wrong type of test can, and often does, lead to a gross misinterpretation of the impact potential.
