When a coal mine closes, the pumps that were used to keep the water out of the mine while the mineral was extracted are switched off and removed.
Over time the water level recovers within the mine and picks up naturally occurring minerals from the rocks, such as iron.
If the mine water gets into underground aquifers and surrounding watercourses it could have a severe impact on water quality; affecting local drinking water supplies and aquatic life.
Mine water in this area of South Yorkshire has been steadily rising since the pumps that kept the mines dry were switched off during the late 1980s.
We develop strategies to manage rising mine waters and within this mining block, the solution is to pump and treat the water at Thorpe Hesley, near Rotherham.
Construction of the mine water treatment scheme at Thorpe Hesley began in November 2024 and it will use ‘pumped-passive’ technology.
Pumped-passive technology
Pumped-passive treatment requires no energy or chemical input through the treatment process and only requires energy to be consumed to pump the water out of the workings.
The mine water is brought to the top of a cascade structure and the water flows down these steps, which mixes in air, encouraging the dissolved iron in the water to become solid.
Through gravity the water then flows into lagoons where the iron has time to settle at the bottom so it can be removed. The remaining finer iron particles are filtered out when the water passes through a series of reed beds.
Once construction of the scheme is complete, we’ll plant new blocks of trees, bushes and introduce wild flowers to aid in blending the scheme into the surrounding landscape and to provide new habitats, improving the biodiversity of the local area.
We’ll also bring in bee and beetle boxes to further enhance biodiversity growth and access tracks around the reed beds will allow the public to enjoy the natural atmosphere of the scheme.
Enabling social value
When building our mine water treatment schemes we enable social value by considering impacts and opportunities when carrying out our work so that we can maximise the outcomes that can be achieved for local people.
This included focusing on initiatives like school presentations and volunteering opportunities, as well as delivering key stakeholder activities such as a community engagement event and development of a website so information is readily available to all.
The project has been a fantastic example of partnership working with our contractors to deliver a large infrastructure scheme effectively, with positive feedback being received from the local community on our level of engagement, our contractor’s responsive attitude and
how the scheme will benefit the environment.
Being nature positive by managing our land and making choices that support the natural world, and peoples’ relationship with it, demonstrates our commitment of delivering for the communities we serve.
Thorpe Hesley testimonials
How will we know we are succeeding?
| We will: |
|---|
| Take action to protect the drinking water supply of a further 2,400 people (650,000 in total) and improve the water quality of an additional 100km of rivers and streams (350km overall) |
| Continue to resolve 90% of subsidence hazards and claims within 12 months |
| Further develop our understanding of the scale and complexity of the risk from the recovering mine water from the English super mines. Undertake research and work with partners to determine appropriate solutions for saline mine water including new technology, water use and large infrastructure options |
| Use our information, services and expertise to support economic growth through Nationally Significant Infrastructure Projects and enable 800,000 hectares of regeneration and safe development, including 50,000 new homes in communities on the former coalfields |
| Improve our customer service response times, uphold our ServiceMark accreditation and refine systems and processes through feedback to improve our delivery |