ICMM - International Council on Mining & Metals

CASE STUDY

Exploration in a biodiversity hotspot

Background

New mineral deposits are needed to replace the resources depleted by mining. Exploration is a process whereby a continual stream of projects, varying in maturity, are examined, advanced and either developed or passed up. Exploration is sustained by establishing a pipeline of projects ranging from area selection in the earliest stage to more advanced deposit delineation.

The Four Stages of Exploration

Area Selection: large tracts (typically at least 100,000 hectares) are reviewed through desktop studies and airborne surveys, with limited reconnaissance visits that include geological traversing and collecting of some surface geochemical samples; impact zero to low.

Target Generation: a reduced area (~10,000 hectares) is explored (usually within a year) by airborne surveys, geological mapping, ground geophysics and surface geochemical sampling; typically fewer than 10 in field team; impact low

Target Testing: a reduced area (~1,000 hectares) is evaluated over several field seasons by more intense ground testing, with some drilling; up to 25 people in exploration camp; due to ground disturbance from road clearing and some noise and dust from drilling, impact moderate.

Deposit Delineation: a very small area (less than 100 hectares) is explored over several years; more than 50 people on site; activities include close-spaced drilling, road and vegetation clearing and bulk sampling of mineralised material; impact moderate to high.

In September 2000, Anglo American plc announced that it would develop the Skorpion zinc mine and refinery near Rosh Pinah, in southern Namibia. The deposit is approximately 85 kilometres north-east of Oranjemund and 25 kilometres north of Rosh Pinah. Construction of the open-pit mine and plant commenced in 2000 and first production occurred in April 2003. At full capacity, the mine will produce 150,000 tonnes of zinc metal a year. Ongoing exploration for zinc is being conducted in the surrounding area mainly by means of drilling on a broad grid basis and by sampling rock chips and cores.

Stakeholder Concerns

Southern Namibia is recognised as one of the world’s top 25 biodiversity hotspots. It is the only arid hotspot environment, and over 10 per cent of the plant species there are found only in the Sperrgebiet area. Of particular importance are the indigenous succulents Mesembryanthemaceae, known as ‘mesembs’.

The main concern of the Namibian Ministry of Environment and Tourism (MET) is that the Sperrgebiet habitat is extremely sensitive and cannot rehabilitate itself and that exploration may cause irreparable damage. They wanted the impacts of exploration to be minimised and the land restored to a near-original state for future uses, such as ecotourism.

In addition, MET had concerns over unrestricted exploration for all commodities in the region, conflict between government pro-development and conservation lobbies, poor track discipline and drilling techniques, the collecting of plants and wood and the poaching or disturbance of animals. Delays in rehabilitation and the turnover of exploration staff could also mean the loss of environmental knowledge.

Agreeing on an Environmental Management Plan

The Skorpion Mine Environmental Management Plan (EMP) addressed exploration issues, and a specific Exploration EMP was developed. In addition, and in conjunction with other stakeholders, a Rosh Pinah Environmental Forum was formed in late 2000 to develop site-specific plans for exploration areas. Stakeholders in this process included Anglo American exploration staff, a consultant retained as external auditor, the Chief Warden of Sperrgebiet, staff from the Namibian Ministry of Mines and Energy and a botanist from the National Botanical Research Institute in Windhoek.

The exploration methodology required wide-spaced, rotary air blast drilling, which had potential impacts on the environment. A field visit was arranged for the external environmental consultant and the Chief Warden so they could discuss the drill programme and suggest ways to minimise any possible impacts. In addition, rehabilitation options for unavoidable damage were suggested.

This process led to an agreement to, among other actions, restrict drill site access to single tracks on grid lines; use wide, low-pressure tyres and lightweight drill rigs; ban camping within the Sperrgebiet; rehabilitate all drillsites and access tracks; and monitor the drillers’ environmental conduct daily.

A more specific management plan set prevention and protection as the first objective. It highlighted pollution control (dust suppression), reporting and biannual audit commitments and layout design of new tracks to avoid track and drill damage. In addition, field crews were trained to recognise endangered plant species.

The second management objective was rehabilitation of unavoidable environmental damage. A team of four was dedicated to full-time rehabilitation of drill sites and access tracks. They levelled and raked all disturbed ground (harrow in places) and collected and disposed of drill materials (chips, muds, pegs, pipes). They also replanted and watered species from surrounding areas.

As part of the follow-up, site visits were conducted with all stakeholders, ‘before-and-after’ photographs were taken and biannual audits were conducted with full reporting. Spot checks were held, and formal sign-off was given to previously affected areas.

Lessons Learned

Large tracts of ground have been returned to their original state at minimal cost, including over 90 kilometres of tracks created by other parties before the current exploration phase. The exploration objectives were achieved within budget, and the rehabilitation provided additional local employment opportunities. The level of environmental awareness and regard for the importance of biodiversity by all exploration staff increased considerably, and an excellent relationship of trust developed between Anglo American and MET staff.

Through dialogue and an openness to admit failings, very high standards were set and achieved. It is clear that environmental protection and remediation solutions do not have to be high-tech. A continuing relationship with consultants after the EMP was drafted provided continuity and added credibility to the efforts to retain biodiversity.