The proposed development site is located on the side of the valley adjacent to a shaft and engine house for a former copper mine that worked between 1817 and 1874 producing almost 25,000 tons of copper ore. This site has also been used as a telephone exchange and radio hut during the war as well as a private workshop and printers.
It was an interesting challenge to attempt to offer pragmatic cost effective options for safe development for residential use. With risk of contamination and possibility of ground instability the structural integrity of the mine shaft, the surrounding wall and the nearby chimney all to be considered it certainly makes for an interesting project.
On a housing project located on an old industrial site the levels of arsenic in the soil were such as to give cause for concern.
Rather than remove the material from site, we undertook bio-accessibility testing in order to estimate the fraction of the contaminant soluble in the gastrointestinal tract, and therefore available for absorption into the blood stream. Using these test results we were able to demonstrate that there was no significant risk to human health posed by the soil which could therefore be left in place.
Removal of the soil with elevated arsenic to the required depth of approximately 500mm across the site would have cost an estimated £20,000. This compared with a site visit to collect some near surface samples, testing and report at a cost of around a tenth of this figure.