Technical Report on Reclamation of Small Scale Surface Mined Lands in Ghana: A Landscape Perspective

Abstract

Small scale mining activities which involve surface mining is an acceptable means of mineral exploitation in Ghana but has serious environmental consequences. Although a number of laws and research papers have been written on restoration after a piece of land has been mined, not much detail is provided on the actual processes involved. This review paper attempts a look at the process of restoration with projections on cost of restoration. Although it is based on activities at a predominantly farming community like Akyem Hemang in the Fanteakwa district of the Eastern region of Ghana, the principles involved will be applicable to other mining communities in the tropics. The paper looks at aspects of surface mining popular in rural areas of Ghana and attempt to explain the process of restoration with suggestions on how to measure success and how to involve affected communities to safe guard and ensure the success of the programme. A licensed concession can be as small as 3acres or as large as 25acres and can be mined for 3-5 years after which the land should be reclaimed to a productive state. The reclamation process, after field establishment should last for at least 5years to determine success. Small scale mining is defined as the use of rudimentary implements as well as the more sophisticated mining operating at a relatively low level of production with limited capital investment. It is carried out in rural farming communities and is popular with itinerant poorly educated people and usually results in severe deterioration to the environment, especially, crop land; posing serious health risks to communities in which it is carried out. The deterioration results from the destruction of vegetal cover and excavation of the overburden to assess the mineral bearing soil. Where farm lands or forested lands have been affected, a combination of natural and artificial reclamation is recommended. The process of reclamation should be planned and begins when topsoil at the mined site is removed to store separately from the subsoil and over-burden at the pre-mining stage. Topsoil however cannot be stored for too long as the quality deteriorates with time. Depending on the depth of excavation, restoration should involve importation and replacement of subsoil to a depth of 600mm - 900mm spread in 150mm layers, and left to settle naturally for a period of 3 -6months. When the land is sufficiently settled, topsoil mixed with manure should be laid over the subsoil to a depth of 150mm minimum after settling. This is followed by sowing of nitrogen fixing leguminous green manure by broadcasting to provide the first blanket of vegetative cover to protect the soil from the direct effect of the elements. Although Crotalaria juncea (Sunnhemp) is highly recommended nitrogen fixing leguminous annual with high biomass production for highly degraded land, other area-specific nitrogen fixing plants can be recommended by the area agricultural extension officer. About 60days after sowing of the green manure cover crop, when it is in bloom, it is smothered and worked into the soil. Seedlings of both local and exotic tree plants can then be established on the land after pegging and holing to 563seedlings per acre. The reclaimed land should be maintained and managed by maintaining a balance between introduced exotic tree seedlings and native sprouted tree seedlings by weeding, staking, and occasional pruning for at least 5years before any assessment for the success of the reclamation can be done. The estimated cost for reclamation of 1acre of mined land excavated to a depth of 900mm is about US$ 52,419.33 (Gh¢101,000), inclusive of 2-3% for maintenance.