One of Nigeria’s “ghost towns”, Sofon Birnin Gwari, North West Nigeria, a previously bubbling mining community recently witnesses the returns of miners as a result of a new discovery of gold deposits in the place.
Sofon Birnin Gwari was a town that once thrived on gold mining between 1914 and 1938 but was abandoned due to exodus of miners and prospectors to the Plateau tin fields in the early forties. Since minerals are exhaustible and irrenewable commodities, the life of a mine and, consequently, the mining activities in the community have had a limited time. This stoppage of mining activities imposed by depletion of the available reserves led to migration of people from the mining areas to other places.
Today, up to 12 per cent of soils under cultivation around the world contain metals that stunt plants growth and development and result in poor harvests. In the past, plant breeders dealt with these problems by crossing metal sensitive plants varieties with species that thrives in this type of poor soil. The physico-chemical properties of mine spoils have been completely altered and their ability to sustained plant growth have diminished due to low soil moisture, organic carbon and nutrients.
From creation, the earth was designed with the capacity to sustain man without losing its original qualities. The soil naturally replenishes itself when used “properly”. Man’s activities in his quest to conquer the earth have caused vital damages to this natural balance. There are frequent concerns about “worn-out soils” resulting from continuous exploration of mineral resources to enrich commercial entities and contribute to sustaining the ever increasing world population.
In Sofon Birnin Gwari, mining have left it once beautiful landscape scarred and deformed forever. Artisanal rat holes mines dot the whole community making it look like a bad case of chicken pox.
The landscape of mining district has been completely changed due to the activity of mining. Mining shaft has been dug almost everywhere. All kind of land use can be seen around the mining areas with mine shaft and mine spoils mixed with agricultural fields, pine grooves and human habitation.
Forest have slowly dwindled. Even agricultural land and fruit orchards have not been spared. One can catch a glimpse of lush green paddy fields or an orchard of citrus fruit with a gapping right holes right in their midst. Mining is usually carried out in the early months of the year up to around the month of May before the raining season set in. During the raining season, mine shaft and burrow are filled up with water. When work resumes after raining season, huge quantities of water are pumped out and discharged into nearby surface water bodies thus contributing to Acid Mine Discharge contaminating water bodies.
According to report, water that percolate into the soil during the raining season enters into the mines and come into contact with metals, oxidises them. This mine discharge has caused untold deterioration to the water quality to the many streams around the mining communities. The report indicates that PH values as low as 2.31 was recorded in one of the stream of the mining areas.
In 2005, an international research reported that a loss of 40 per cent of forest areas, while at the same time mining have increased at the rate of 1.2 sq kilometre per annum. Abandoned and exhausted mines are never backfilled and this has led to sub mergence and landslides in several areas. It is a common practice to never refilled abandoned mines as that would cost money. These have become a big danger to man and livestock, especially after they become overgrown with vegetations. The mine shaft are also never refilled after work is completed and this makes it very dangerous to walk around in mines areas.
Acid Mine Drainage
Acid Mining Drainage has been a source of concern in various parts of the worlds where mining has been carried out for several decades and centuries now. The full extent of environmental pollution caused by mine water discharge is difficult to assess accurately, however, in 1989 an estimate was made that about 19,300km of stream and rivers and about 72,000 ha of lakes and reserviour worldwide has been seriously damaged by mine effluents.
Metals are essential not only for the development of the society but also necessary in life functions. One of the pathway through which metal enter the environment is through mining activities. According to researchers, these activities may affect relatively small areas, but they may have great impact on the environment as a whole. Metal contamination of rivers or water can remained for years even after the source has been eliminated.
Some key mining activities are associated with Acid Mine Drainage which is caused by the hydrolysis and oxidation of metal sulphides found especially in coals, overburdens and in waste dumps.
The leaching of acid mine drainage leads to the surface water contamination by soluble heavy metals present in mineral deposits and other acid soluble weathered materials which adds to the deterioration of the water quality in mining areas. Heavy metals such as lead, zinc, copper arsenic selenium, mercury, and cadmium are released into surface water which become unsuitable for aquatic life, destroy mining equipment and render the water unsuitable fir drinking and recreation.
Though, hardly recourse to, because of the scale and clandestine nature of mining activities in Sabon Birnin Gwari, legislation already exists in the form of Minerals and Mining Decree of 1999. Therefore, a new Minerals and Mining law need to be put in place that will address, among others, the environmental conservation issues very seriously in Sabon Birnin Gwari and elsewhere.
Accordingly, the legislation provide that mining companies should submit environmental restoration plans together with their application for either prospecting or mining lease of an area. In addition, processing companies must install appropriate equipment, where necessary, for preventing or minimizing pollution. While large mining and processing companies are to prepare a prognosis of the possible environ-mental impact of their operations, as well as the technique for monitoring the impact for approval of the Mines Department before the commencement of mining activities.
For Sabon Birnin Gwari, environmental impact of the mining and processing activities extend for many kilometers from the operation site. For example, the dust pollutants spread up to a distance of more than 5 Km from the source. Therefore, before any remedy could be applied to the environmental problem, there is need to assess or measure the magnitude of the problem. According to expert, this can be done by direct measurements such as calculating the value of economic trees removed and changes in farm produce due to pollution; land, road and property reparation cost; water treatment cost; and the costs of treating diseases directly traceable to the environmental damage.
A major issue concerning the remedy or compensation for environmental damage resulting from mining and processing activities is that those who bear the costs of the environmental damage are the people who live in the environment and not the producing companies or miners.
Another well illustrated case is the Sagamu quarry field, South West Nigeria, where blasting of limestone in the quarry and dust pollution from the cement works are causing incalculable damage to life, crops and buildings. Although the cement producing firm, West African Portland Cement Company, which is the cause of the environmental problems appear relatively unharmed. However, the Sagamu citizens who do not share in the company’s profit bear the reparation or replacement costs resulting from the adverse environmental effects.
The problem requires the intervention of government through appropriate legislation that can compel the mining and processing companies to internalize the reparation or replacement costs, which are so far borne by the people who live in the environment. Safe disposal of unavoidable waste in stable and aesthetically acceptable structure must be enforced through legislation.