Wheal Maid Tailings Dam
The valley below Wheal Maid was used as in the 1970s and 1980s a tailings dam (waste dump) for the Mount Wellington tin mine. The mining company who owned the Wheal Maid site sold it to Gwennap Parish Council for £1 in 2002.
The mine waste used to create the dams, and the tailings (grit and sludge) within the lagoons all contain residual minerals. Of these, the grey sand in the lagoons with yellow mineral crystals has the greatest potential to release minerals into the water. As a result, the lagoon water contains high levels of arsenic with the water in the lower lagoon containing the highest levels.
Note that walking past the lagoon doesn't pose a serious health risk because these materials are not volatile and do not evaporate into the air - they stay in the lagoon. The main risk to the environment is from water escaping from the lagoon.
On walks
- Wheal Maid and Poldice Valley (3.4 mile walk)
Also mentioned in walks
- Twelveheads and Chacewater (6 mile walk)