Carrshield Tailings Dam

Work to prevent erosion of spoil into the River West Allen from Carrshield Tailings Dam was completed in 2019. This involved re-profiling and capping the mine tailings and installing perimeter drains to stop rainfall washing metals out of the wastes.  

A thin layer of mine tailings was placed on top of the cap and planted with local seeds, including protected calaminarian plants found in the area, to increase the biodiversity and maintain the industrial nature of the site. 

Damaged sections of the walls were rebuilt using concrete blocks and then faced with local stone to blend in with the existing walls. 

The Carrshield Tailings Dam stores over 1000 tonnes of lead, cadmium and zinc in the mine wastes behind a dry-stone wall constructed in the 19th Century. Up to 3 tonnes of zinc, cadmium and lead was being eroded each year from these wastes, contributing to pollution of 40km in the adjacent River West Allen, and into the Tyne estuary. 

The site is designated as a Scheduled Monument, is situated in the North Pennines National Landscape area and contains protected calaminarian grassland habitat. In addition to preventing metal pollution in the River West Allen, the work has also meant the Scheduled Monument is no longer on Historic England’s ‘at risk’ register. 

Carrshield Tailings Dam after being hydroseeded.

Find out more about the work here: £2 million scheme at Carrshield to prevent major river pollution in the north of England