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Water - The lifeblood of our ecosystems

  • Drilling is taking place in an area of abandoned mines which are already contaminating Porthleven Stream with arsenic, cadmium & mercury.

  • Improperly decommissioned boreholes from the exploratory drilling may leave conduits for contaminated water.

WATER overflowing mineshaft.jpg

Image: Continuously overflowing mineshaft at the head of Porthleven Stream in the Flow Valley

One of the unacceptable consequences of metalliferous mining is contamination of groundwater and surface water. Water is the lifeblood of our ecosystems. Metals mix with it in the depths of a mine. They find their way to the surface in abnormally high concentrations and mix with organic materials and settle in the sediments of streams and rivers.

Porthleven Stream is already the second most polluted waterway in Cornwall. (The Carnon River is the most polluted in the UK.)

Micro-organisms at the base of the food chain cannot survive in this polluted environment. Organisms higher up the chain become starved and die out. Insects, invertebrates, fish, amphibians, birds and small mammals lose their food source and either die or move elsewhere. Biodiversity is eroded and will not recover until the water is de-contaminated.

Our Government’s own Climate Projections, 2018, showed that hotter drier summers, milder wetter winters, rising sea levels and more extreme weather were arriving. Droughts increase the severity of pollution because there is less dilution by cleaner water, and more erosion of mine wastes occurs after intense rainfall. Ancient shafts collapse, particularly when in-filled or capped a long time ago, releasing once-dormant pollution.  

Mining companies spend a lot of money on this problem, while they are mining. The pollution problem arises after the mining operation is abandoned, filtration systems are shut down and the mine floods. Up until 1999, mine operators could abandon a mine without notifying anyone!


Many people remember the Wheal Jane Pollution disaster that resulted in a massive and unsightly permanent treatment works that still fall short of filtering out all levels of contamination.

WATER wheal jane pollution treatment.jpg

Image: Pollution treatment at Wheal Jane

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