‘World-first’ technique to clean up Welsh rivers
AN INGENIOUS technique used to remove pollution from natural water sources could clean up Wales’ polluting industrial past.
It is hoped the environmental impact of processes like mining can be reversed by a filtering technique successfully trialled in west Wales.
Natural Resources Wales claims the tech – described as a world-first – can remove up to 98% of metallic pollutants from water.
Wales has more than 1,300 abandoned metal mines, impacting more than 67 water bodies and in excess of 370 miles (600km) of river.
Evidence of Wales’ industrial history can be seen from slag heaps in the south to the striking remains of Parys Mountain on Anglesey.
In Ceredigion years of metal mining and resulting toxic by-products have had a severe effect on the water quality. Nestled deep within the Cambrian mountains is the Cwmystwyth site, one of many metal mines dotted across the area. Flowing from the mines, past the remains of the metal production plants, the highly acidic water runs orange, contaminated with heavy metals.
NRW has set out to combat this issue, using innovative technology that effectively filters metallic contaminants from the water.
Peter Stanley, from NRW, said: “Natural Resources Wales is responsible for tackling metal mine pollution and over the years we have earned the reputation for developing innovative and cost-effective solutions for dealing with the issue.”
The innovative treatment plant was tested on a stretch of the River Rheidol near Aberystwyth.
It is estimated that eight tonnes of metal, including zinc, chromium and cadmium, enter the Rheidol each year.
“Preliminary laboratory results were encouraging,” added Mr Stanley. “And the small footprint of the equipment makes it particularly suitable to rugged upland locations where traditional passive pond systems simply will not fit.”
NRW say trials of the technology in the field were “encouraging”.
The portable treatment plant is roughly the size of a car and is attached to a small generator.
A combination of electrolysis and ultrasound triggers a chemical reaction which removes heavy metals, adjusts acidity and pumps clean water back into the river.
The metallic leftovers can then be sold or disposed of safely.
Mr Stanley added: “The success of the Cwm Rheidol and Frongoch trials have the potential to offer NRW and others interested in metal mine water remediation and the clean-up of metal mine process waters, new tools for successfully treating harmful discharges. And it’s not just the environment which will benefit from this technology, the Welsh economy could also receive a boost as the companies involved in this work share the technology with overseas markets.”