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Calverton Colliery Remediation completed 40 weeks early

Client: Coal Authority

Value: £3.2m


  • Capping 3 lagoons covering 128 hectares
  • Excavate and landscape 1.35m3 of shales
  • Apply 400,000m3 of soil and soil creation material
  • Project completed 40 weeks ahead of schedule


The Calverton Colliery restoration works project involved the capping of three extensive coal slurry lagoons. These lagoons and the adjoining spoil heaps extended over 128 hectares in total and required the excavation and re-profiling of 1.35 million m3 of shale.

The coal slurry lagoons had been left over from the operation of the colliery and contained a substantial amount of wet, coal by-product that included coal dust and other chemicals that were considered unsafe contaminants. For this reason, the filling operation had to be undertaken strictly in accordance with the remediation strategy.


Once the initial excavation and placing of shale had been undertaken, Walters followed on by placing 400,000m3 of soil and other soil-making material onto the site.

This scheme included cultivation, grass, heathland and tree planting with five years of aftercare.

At the peak of the project there were an estimated 40 machines used on site and maximum outputs of 100,000m3 per week were achieved. This was a major factor in enabling the overall works to be completed 40 weeks ahead of the two year programme.

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