The Effects and Impacts of Quarrying on Forest Land: the Case of Gami Quarries, Mwache Forest, Kwale County, Kenya

摘要

This paper highlights the effects and impacts of quarrying on Forest Land, with Mwache Forest, located in the Kwale County, whose land use is defined as conservation –as the study case. Despite the defined land-use, Gami Quarries Ltd had been given the rights of exploiting the rock out-crop in the forest to make ballast –a raw material needed in the construction industry. Ballast processing operations were initiated through blasting the rock structure using explosives inserted onto holes drilled on the rock, disseminating it into boulders that were sized into smaller rocks that were transported for processing into ballast. The explosions resulted into the generation of wave energy that weakened the rock formation and, damaged the existing neighbouring infrastructure; it produced dust and higher levels of noise. Transport of the rock material for processing into ballast, resulted in the emission of fugitive dust due to tracking on the unpaved road. This was in addition to the emission of the oxides of nitrogen and sulphur, carbon monoxide, suspended particle matter (SPM) and, volatile organic compounds (VOCs) from the poorly maintained diesel engine powered tracks. The significance of air pollution from the ballast-making operational processes was low, bearing the wind regime, which scattered and diluted the pollutants. Run-off from the quarry spoils however introduced undesirable elements in water; while lack of sanitation on-site was recipe for transmission of water borne disease. Quarrying for ballast exposed the groundwater aquifer, making it vulnerable to contamination; it at the same time led to the potential of altering the existing drainage characteristics, interfering with stream flow and aquifer recharge. Quarrying created Bad Lands, exposed the bed rock to erosion and reduced the moisture content usually experienced in forested land with impact on local ecology, arising from the destruction of the habitat. The effects of enhanced noise from the blasting operations was traced into hearing loss among the workers; the noise also disturbed wildlife and grazing animals. Fire-outbreaks were also potential due to the explosives use, it could also result from the domestic activities of the workers. Fire outbreak on dry forest could lead to severe and significant effects, including the loss of life. On occupational health and safety matters, the workers have had to do with the consequences of potential exposure to dust, potential injuries from flying blasted rock debri, from the impacts of water borne and, water related diseases and, high levels of noise. To minimize the identified effects and impacts, operating rules had been given. These offered adequate protection. However, it was recognized that the rules and procedures ought to be engraved into an Environmental Management and Monitoring Plan in order to promote sustainability of the actions. This had not been done. Key words : quarrying, dust, noise, pollution, habitat destruction, water borne and water related diseases, cancer, operating rules and procedures