Cwmnewydion metal mine project
Overview
The Cwmnewydion project is focused on Graig Goch mine and Frongoch Adit, which are situated within the Cwmnewydion valley, located approximately 1.5 km southwest of Trisant village and 3.75 km northwest of Pont-rhyd-y-groes in Ceredigion.
The Nant Cwmnewydion watercourse flows along the valley floor immediately adjacent to the northern boundary of Graig Goch mine.
Upstream to the east of Graig Goch mine is Frongoch Adit and Wemyss mine.
Frongoch mine is further to the north east and is in a different surface water catchment (Nant Cell), although the groundwater within the mine system discharges from Frongoch adit. A number of phases of remediation work have already been undertaken at Frongoch mine, which have addressed multiple surface water issues with designs currently being advanced at Wemyss mine.
The Graig Goch mine produced lead and zinc ore from 1840 to 1889 and worked the same mineral vein as nearby Wemyss and Frongoch mines to the east, although the mine workings are not connected sub-surface.
The Frongoch Adit is driven in a roughly north-easterly direction for approximately 1.5km and drains both Wemyss mine within the same catchment, and Frongoch mine.
The Nant Cwmnewydion is heavily contaminated with zinc, lead and cadmium with the largest source being the Frongoch Adit. The stream is a significant source of metals to the Nant Magwr and Afon Ystwyth, causing failures in standards for zinc, lead and cadmium.
Possible Migitation Options
- Mine water treatment
- Surface water management e.g. Mine site drainage
- Sediment control
- Mine waste reprofiling
- Mine waste capping
- Watercourse management e.g. separation
Project Progress
Over the past few years we have been gathering information to better understand the pollution risk from Wemyss Mine, Graig Goch Mine and Frongoch Adit to identify a list of potential mitigation solutions. Graig Goch Mine and Frongoch Adit are being progressed together under one project called Cwmnewydion, while Wemyss Mine is being progressed as a separate project within the overall Programme. The two project teams are working closely to seek efficiencies and maximise benefits. We have commissioned a Scoping Report that includes both Graig Goch Mine and Frongoch Adit and conducted archaeological and ecological assessments, in order to identify the problems that are causing pollution of the watercourse/ water quality issue and which need addressing.
We have installed a flow monitoring structure at Frongoch Adit to record flow and continue to monitor the water quality monthly in locations along the Nant Cwmnewydion.
Next Steps
At Graig Goch Mine and Frongoch Adit the next step is to undertake a Feasibility Study to assess the technical, environmental and economic suitability of the various possible mitigation options.
We are exploring possible intervention options to mitigate pollution to the surrounding waterways, with the aim of improving water quality.
Each site is unique and presents its own challenges and opportunities. It is likely that a combination of the high-level potential mitigation options will be needed to successfully improve water quality in the Nant Cwmnewydion, Nant Magwr and Afon Ystwyth.
We welcome your input as we continue to develop our options, as well as wider environmental, social and economic opportunities available.
This will lead to a short list of feasible options from which a preferred remediation strategy for the site will be selected. It is likely that this will be a phased strategy, targeting specific pollution sources over a number of years, allowing design, construction and then assessment of each intervention.
We would like the local community and other stakeholders to play a key part in this process.
We will be holding public consultation events later in the project, and issuing newsletters to communicate progress on the project.
Current Timeline
To date: Assessment Baseline surveys and water quality monitoring to inform a Scoping Study and long list of remediation options.
Summer 2024: Defining the problem Feasibility Study to assess long list options and identify a suitable short list.
Spring 2025: Short List Options Stakeholder consultation event to seek feedback on the short list of options.
Summer 2025: Preferred Remediation Strategy Development of the preferred Remediation Strategy for the site with ranked intervention options for further consultation.
2026 Onwards: Preferred Option Design and construction of the highest ranked intervention option, followed by assessment of its impact on water quality.
Newsletter
2023
Further Information
Should you wish to request a specific information, please contact the team via cwmnewydion@metalmineswales.co.uk.
Website links
Related document downloads
Keeping in touch and how to get involved
We want to hear from you as we progress the Cwmnewydion Mine Project and explore the wider environmental and social opportunities that can be developed as part of the preferred strategy for this site.
If you’d like to share your views, be added to an email mailing list, or have any questions please get in touch on the details below:
cwmnewydion@metalmineswales.co.uk
Areas
- All Areas
Audiences
- Metal mines
Interests
- Metal mines
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