Gold Mining Zone
The Gold Mining zone extends over most of Chunya DC and covers the north and central Chunya plain and Msangani plateau. The predominant features are the popular Gold mining areas and miombo woodlands. The topography of the area is predominantly flat and undulating with scattered small hills and rock outcrops. The altitude ranges between 1,000 to 1,800 m above sea level, with mean annual rainfall ranging between 600 to 1,000 mm and rainy season occurring during December to March. The predominant soil types include deep reddish brown loamy sands of poor fertility and dark grey clays in valleys. Common vegetation types include wooded grasslands of Acacia Commiphora bushlands and Brachystegia Julbernadia woodland. Common crop types grown include maize, groundnuts, finger millet, sorghum, banana, cocoa, oil palm, cashew nuts, and paddy. This zone is also attractive for livestock keeping, bee keeping, and hunting. The zone is predominantly rural and is characterized by poor socioeconomic infrastructure. Agriculture is the most important socioeconomic activity employing about 65% of the population in the zone. Most of the agriculture in the zone is rainfed with very little, if any, traditional irrigation taking place in a few isolated farms.
Domestic water supply for Chunya town and the rural areas is an important water use in the zone. Chunya town is supplied by the urban water supply and sanitation authority while rural areas depend on local water supply schemes managed by Community Owned Water Supply Organizations for their domestic water needs. Water resources play a crucial role in supporting Gold mining activities in the zone in two main ways: as a source of water supplies and as recipient of wastewater effluent from processing. The total amount of water used in the Gold mining activities is very small compared to other uses like domestic water use.
However, Gold mining activities pose a considerably bigger risk to water pollution and environmental. Two major types of Gold mining and processing methods are practiced in the zone: (a) Mining from alluvium ores mainly carried out by small-scale artisanal miners using manual methods and unsophisticated tools; and (b) Open pit mining often practiced by small-scale and large commercial miners. Small scale miners use manual tools while commercial miners have heavy machinery and mechanized operations. The two methods have different characteristics and pose different threats to the environment. The main threat comes from unregulated use of chemicals (mercury and cyanide), especially in artisanal gold mines, and poor handling and disposal of mine effluent. Unregulated mercury use in gold mining is of particular concern because of its potential health and general environmental hazards.