Tees Swale
Metal mines pollution
Around 200km of rivers in Teesdale and Swaledale are polluted by metals and waste minerals released from long-abandoned metal mines.
Project Overview
Britain’s abandoned metal mines have left a lasting legacy of river pollution. Water draining from historic mines carries toxic metals that contaminate rivers and threaten aquatic life across the UK.
The Tees-Swale Diffuse Metals Project is tackling this environmental challenge head-on. Funded by the Department for Environment, Food and Rural Affairs (Defra) and the National Lottery Heritage Fund, the project is part of Tees-Swale: Naturally Connected, led by the North Pennines AONB Partnership in collaboration with the Yorkshire Dales National Park Authority.
The first phase of work in Upper Teesdale has already reduced the impact of mine pollution in local rivers. Planning is now underway for the next stage in Swaledale, where further restoration efforts will improve water quality, protect biodiversity, and safeguard river ecosystems for future generations.
Little Eggleshope
The creation of more than three hectares of vegetation plots above Middleton-in-Teesdale will limit heavy metals being washed out of abandoned mine sites next to Great Eggleshope Beck, Little Eggleshope Beck and Marl Beck; all tributaries of the River Tees.
By encouraging new plants to grow, less rain water will wash over or filter into the mine waste, reducing erosion and the amount of heavy metals washed into the becks.
Great Eggleshope
Mine wastes cover six hectares of the former Wiregill lead mine in Teesdale. Metals are being washed out of these wastes and polluting approximately 8km of rivers. Research trials by the WAMM Programme near Alston show that one way to address this problem is to encourage plants to grow as this decreases infiltration of rain.
An innovative hydroseeding technique, developed with Terraffix Soil Solutions has been utilised to establish vegetation on the sites. This specialised, efficient technique uses seed and various mulch materials that are mixed with water and spread by hose to create erosion resistant layers in which plants can grow.
Marl Beck
Large areas of mine wastes at the former Lodge Sike mine in Teesdale pollute more than 4km of Marl Beck and other rivers. Metals are being washed out of the fine-grained processing wastes left by the miners in the 19th century and harming river wildlife.
We have reinstated former drainage channels to divert clean surface water away from the metal-contaminated wastes. We also spread 1500m3 of clean subsoil from Raby Castle over the highly metal-contaminated mine wastes, helping to encourage vegetation growth, increase biodiversity and reduce the risk of metals being washed into the rivers.
This project generated key learns and ways of working now adopted by the Ashfoldside Beck diffuse metal pollution project.
The diffuse metals project is led by the Yorkshire Dales Rivers Trust working with the Tees Rivers Trust as part of the Water and Abandoned Metal Mines (WAMM) programme. We are working with the North Pennines AONB Partnership and local landowners and farmers including the Eggleston Estate (Neamour Holdings) and Raby Estate. The WAMM programme is a partnership between the Environment Agency, the Coal Authority and Defra and aims to deliver the Government’s statutory target to halve the length of rivers polluted by harmful metals from abandoned metal mines by 2038.
