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Haggs mine water treatment scheme

Information and updates on the Nent Haggs mine water treatment scheme in Cumbria, England.

The River Nent is the second most metal polluted river in England. This pollution, by cadmium, lead and zinc, comes from several different sources and the effects on water quality and aquatic life can be seen for 60km along the River South Tyne and in the Tyne Estuary.

One of the most significant sources of pollution is the Haggs adit, an abandoned mine water drainage tunnel.

To improve the environment for people and wildlife, the Coal Authority and Environment Agency are developing a treatment scheme to remove the metals from the Haggs adit mine water before they get into the river.

Following discussions with the public and other stakeholders, we submitted a planning application to build the treatment scheme on land between Blagill and Nentsberry in Cumbria.

Planning permission was granted by Cumbria County Council in June 2019. You can look through the planning application on the Cumbria County Council website, using the reference: 3/18/9001.

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The mine water will be captured at the adit portal in Nentsberry and taken to the treatment site in an underground pipeline.

The metals will be removed using 3 treatment ponds, then the water will pass through a new wetland before being put back into the River Nent.

We have appointed a contractor to build the scheme, I&H Brown Ltd.

We have also completed all of the land agreements we need to build and operate the scheme.

2023 construction and operation schedule

Our contractor, I&H Brown, expects construction of the mine water treatment scheme to be completed in autumn 2023, so that we can start cleaning up the 60km of river polluted by the Nent Haggs mine water.

The treatment ponds, pumping station, mine water distribution pipes, odour control tanks and building, and reed beds have now been constructed. The reeds, which had been grown off site, were planted in May 2023.

Work during 2023 includes:

  • installing the electrical and mechanical equipment for the odour control systems
  • constructing the inlet and flow monitoring chambers
  • completing the site access tracks, permanent walls and fences, and planting the final vegetation cover at the site
  • installing temporary cabins for the extra staff who will be monitoring the scheme during the initial operating period of up to 2 years
  • if planning permission is granted, we will extend the odour control building to provide a small office, welfare space and a toilet
  • subject to the planning authority approving our Commissioning Strategy – which will set out how we will start treating mine water at the scheme, including how we will monitor for odours – we intend to start operating the scheme in autumn 2023
  • reinstate the site cabins and compound area across the road from the treatment ponds

Biodiversity improvements at site 38

Work was completed in 2022 to enhance the biodiversity of the Horse and Wagon field that contains the pumping station.

The nature reserve has been designed to enhance the environmental value of the land and the River Nent that flows through it.

It is hoped that the site will become a valued community asset that locals can enjoy and could be used for communities and school groups to visit to learn about environmental land and river management, as well as the economic and environmental impact of historic metal mining activities in the region.

The site 38 work was co-funded by the Water and Abandoned Metal Mines (WAMM) programme and Northumbrian Water.

This is one of several projects Northumbrian Water is supporting across the South Tyne catchment, aiming to improve river water quality and habitats, support biodiversity, and address the impacts of climate change.

Completed works

Since we started construction in July 2020, the following work has been completed:

At the pumping station (site 38)

  • construction of pumping station, including installation of mechanical and electrical equipment
  • improvements to surface water drainage along the A689 from Haggs adit to site 38
  • improved surface water drainage across site 38

At the treatment ponds (site 4)

  • completion of the 3 mine water treatment ponds and 2 reed beds
  • land drainage to manage surface water on site
  • final outfall to the river from the treatment system
  • improvements to the Isaac’s Tea Trail footpath alongside the River Nent adjacent to the site

Mine water pipeline installed

  • from the Haggs adit to site 38, mostly in the A689 carriageway
  • between site 38 and the junction between the A689 and the B6294, including by directional drilling under the river just downstream of Nenthall Bridge
  • from Nenthall to site 4 along the A689 and B6294 carriageway
  • repairs to the A689 and B6294 road surfaces were carried out during summer 2022

View Nent Haggs mine water treatment scheme maps

View past updates relating to the Nent Haggs mine water treatment scheme

Read more about the work of the Water and Abandoned Metal Mines programme

Maps

Maps and drawings relating to the Nent Haggs mine water treatment scheme.

Published 25 February 2016
Last updated 5 June 2023 + show all updates
  1. Updates to the timeline of construction work.

  2. The 2022 work schedule has been updated

  3. Work schedule for March to November 2022 added

  4. Work schedule for July to September 2021 added

  5. Updated work schedule with information for April and May 2021

  6. Added schedule of works, with more detailed plans for the initial 12 weeks between July and October 2020

  7. Building contractor details added to the page.

  8. Updated to include information about anticipated construction date and to remove out of date information

  9. Link for the interactive map of proposals for cleaning up mine water discharges into the River Nent added

  10. Removed information about out of date proposals

  11. First published.