Helicopter airlift protects rare habitat during essential pollution prevention work

When urgent work was needed to stop fast moving water eroding polluted mining waste on a riverbank at a site home to rare plants, Natural Resources Wales (NRW) and the Mining Remediation Authority chose the lowest impact solution: using a helicopter.

Nant y Mwyn Lead Mine near Rhandirmwyn, Carmarthenshire is undergoing remediation works as part of The Wales Metal Mines Programme, a Welsh Government funded scheme to tackle pollution from Wales’ most harmful abandoned metal mines, improve water quality, restore ecosystems, and protect the communities and industries that rely on healthy rivers.

As part of the remediation efforts, tonnes of material were needed on site to stabilise mining waste heaps on the riverbank with an estimated 300m3 of material at immediate risk of being washed into the river.

But given Nant y Mwyn’s protected status for its rare Calaminarian Grassland, minimising ground disturbance was a major consideration for the project team.

To solve the problem, a helicopter was commissioned to drop the 109 bags of materials needed along the riverbank. Its work was completed in a single day, with the remaining work completed by hand to protect the fragile habitat.

Severe spoil erosion along the Nant y Bai adds several tonnes of metals each year to the Afon Tywi, contributing a significant part of the pollution arising from the Nant y Mwyn Mine which results in elevated cadmium and zinc levels for up to 25 kilometres downstream.

The work, carried out ahead of the lambing and bird-nesting seasons, is expected to reduce metal-rich sediment entering the stream, improve water quality and safeguard heritage features and nearby habitats.

Dave Johnston, Wales Metal Mines Programme Manager at Natural Resources Wales, said: “These works are a vital step at one of our most challenging sites, reducing the risk of several hundred cubic metres of metal-rich mining waste being carried into the Afon Tywi and the wider environment.

“Wales has a long legacy of metal mining, and pollution from abandoned mines contributes to reduced river health in many areas. Through the Wales Metal Mines Programme, we’re targeting the most harmful sites to deliver cleaner rivers for wildlife and for the communities and businesses that rely on them.”

Marika Gates, Project Manager at the Mining Remediation Authority, said: “Abandoned metal mines are a significant part of Wales’ industrial story, and Nant y Mwyn is central to the history of Rhandirmwyn.

“Our aim is to protect the environment while recognising and respecting this unique ecology and heritage. This project shows what is possible when innovation, environmental care and strong community collaboration come together.”