ENVIRONMENT REHABILITATION

ENVIRONMENT REHABILITATION

The objective of conducting environmental rehabilitation is to ensure that all environmental aspects required for eventual mine closure or to minimize ongoing environmental liabilities are adequately addressed before reclamation activities on mining sites are completed especially in sand mining areas around lake Victoria, stone query on foot hills of mountain Elgon, gold mines in Buhweju and Mubende and the like.

This article develops principles of environmental rehabilitation. Key issues include the following. Rehabilitation means restoring the previous condition. Whether or not to restore is not a technical but a value judgement. It is subject to adopting the sustainability ethic. If the ethic is followed under rule of law then rehabilitation must be done always to ‘the high standard’ which means handing down unimpaired environmental function and no extra land management. The elements of the former condition that it is intended to restore must be specified. Restoring these in any given case is the purpose of that rehabilitation project. The specified restoration elements must be easily measurable with a few simple powerful metrics. Some land damage is not fixable so restraint must be exercised in what construction, development and exploitation are permitted. If sustainability is adopted then cost benefit analysis is not a valid form of project appraisal because trading off present benefits against future losses relies on subjectively decided discount rates, and because natural capital is hard to price, indispensable, irreplaceable and non-substitutable. Elements often to be restored include agricultural land capability, landscape form and environmental function. Land capability is a widely used convention and, with landscape form, encapsulate many key land factors, and are easily measurable. Restoring soil and thereby environmental function provides the necessary base for an ecological pyramid.

An environmental impact assessment must be undertaken to ensure that all environmental impacts arising from the reclamation, processing, and redeposition activities are taken into consideration. Agreement will normally be required from the relevant authorities prior to the project proceeding to implementation, and in this respect, they will require guarantees that environmental impacts are kept at a minimum and that all closure obligations and liabilities are clearly understood and funded. The use of external independent consultants is advisable and ensures an unbiased input to the assessment process.

For completed reclamation sites, it is vitally important to understand what constitutes acceptable closure standards. These have tended to become more rigorous with the passage of time, and it is now generally accepted that minimum standards entail cleaning down to ground level, conducting soil amelioration and planting grass. When these activities have been completed, vegetation established, and run-off water meets acceptable standards, formal closure may be obtained.

Disposal and dumping of untreated material such as screen oversize and physical contaminants need to be fully addressed through on-site rehabilitation in conjunction with the relevant authorities.

The handling of radiation or contamination from other problematic species such as cadmium, copper or zinc needs to be identified at an early stage and an action plan to deal with this problem prepared for approval by the relevant authorities.

The cost, complexity, and impact on production of final environmental cleanup of remnant material on sites should not be underestimated. Deleterious elements such as arsenic from arsenopyrite mineralization and mercury from historic amalgamation operations require particular attention

Much land is subject to damage by construction, development and exploitation with consequent loss of environmental function and services. How might the loss be recovered?

Mugabe Robert

Lawyer & Environmentalist

@EnvironmentSwitch