Closure and Rehabilitation Planning

Umwelt has been actively involved in closure and rehabilitation planning for a large number of mining operations. This involvement has included the preparation of conceptual mine closure plans for pre-feasibility through to the operational phases of an operation and the development and implementation of detailed closure plans following the cessation of operations.

Two notable projects recently led by Umwelt included the development and implementation of mine closure plans right through to completion of closure activities for Xstrata Coal Australia’s New Wallsend No.2 Colliery and Great Greta Colliery. These projects are recognised by industry peers as benchmarks for other closure projects. New Wallsend No.2 Colliery was awarded the inaugural NSW Minerals Council Environmental Excellence Award in 2006 and Great Greta Colliery was announced as a finalist in the Hunter Coal Industry Environmental Management Awards in 2001.

Based on the extensive involvement in closure and rehabilitation planning, Umwelt has prepared both mine closure and rehabilitation monitoring standards for one of our key corporate clients to be applied across their world-wide operations.

Service and Capabilities

We have particular skills in:

  • the preparation of conceptual and detailed mine closure plans, which include cost estimates for closure activities;
  • the development of mine closure and rehabilitation standards;
  • development of mine closure objectives and criteria;
  • future land use planning;
  • final landform design including water management design;
  • development of post-closure groundwater management strategies;
  • providing rehabilitation advice and assessment;
  • design and implementation of rehabilitation monitoring and assessment programs;
  • operational support and environmental management supervision of multi-disciplinary closure and rehabilitation activities including contamination remediation, creek line re establishment, revegetation, sediment and erosion control, acid mine drainage treatment, hazardous substances management, bulk earthworks and subsidence remediation;
  • facilitating community involvement programs as part of mine closure including community meetings and preparing community information brochures;
  • understanding relevant policy and regulatory frameworks relating to mine closure, including development of good working relationships with government authorities;
  • rehabilitation security calculations and negotiation with government authorities;
  • preparing both internal and statutory environmental reporting documentation including the close-out reports for sign-off by government authorities on successful closure; and
  • development of post-closure rehabilitation care and maintenance programs.

Umwelt Case Studies for Mine Closure

New Wallsend No.2 Colliery

New Wallsend No.2 Colliery is owned by Xstrata Coal and is situated on the western urban fringe of Newcastle NSW. In 2002, Umwelt was engaged by Xstrata to prepare the Mining Operations Plan for the closure of the mine as well as provide environmental operational support throughout the project. The scope of the closure project involved the remediation of land affected by 150 years of coal mining to a stable condition that will now support a range of land uses. A number of technical challenges that were faced as part of the closure project, which required the development of innovative techniques, include the following:

  • the removal and treatment of contaminated material to eliminate potential exposure and consequent harm to human health and the environment;
  • the re-sealing of previously filled adits to be consistent with the latest industry standards;
  • stabilisation of a landslip associated with the former trial box-cut; and
  • the re-establishment of Maryland Creek and its associated riparian ecosystem.

In 2006, the New Wallsend No.2 Colliery closure project was awarded the inaugural NSW Minerals Council Environmental Excellence Award. In May 2007, due to the success of rehabilitation, Xstrata Coal was given approval by the government agencies to commence with the relinquishment of the mining leases for the site. This significant milestone was achieved only two years from the completion of decommissioning activities.

Wallsend Colliery BeforeWallsend No. 2 Colliery Before

Wallsend Colliery AfterWallsend No. 2 Colliery After

Great Greta Colliery

Great Greta Colliery is owned by Xstrata Coal and is situated near Singleton in NSW. In 1999, Umwelt was engaged to prepare the Mining Operations Plan for the closure of the mine as well as provide environmental operational support throughout the project. The major challenge of the closure project was the management of the potential for fill and spill of acid water from the underground workings post-mining.

Following eight years of monitoring, Umwelt has developed a ground water model to provide greater certainty on the likely rise and fall of ground water levels under various rainfall scenarios. Based on this model, a sustainable ground water management strategy has been established, which includes measures to prevent overflow from the former mine workings. This strategy has been accepted by the relevant government authorities and local community, all of whom have been actively engaged in its development. The site is currently going through the process of being signed-off by the government authorities.

In 2001, the Great Greta Colliery closure project was announced as a finalist in the Hunter Coal Industry Environmental Management Awards.

Greta Colliery BeforeGreat Greta Colliery Before

Greta Colliery AfterGreat Greta Colliery After

Environmental Excellence Award

Xstrata Coal's New Wallsend No.2 Colliery decommissioning project, led by Umwelt, was awarded the inaugural NSW Minerals Council Environmental Excellence Award in 2006. Read more ›

Great Greta Colliery

Xstrata Coal's Great Greta Colliery decommissioning project, led by Umwelt, is in the process of being signed-off by the government agencies following the success of decommissioning. Read more ›