The impacts of Chiyadzwa - Marange Diamond mining activities on water quality.: a case of upper Save and Odzi catchment area in Manicaland Province Zimbabwe

Abstract

Chiyadzwa under Marange tribal trust land which is located between Save and Odzi South of Mutare city is rich in diamonds. There are 5 diamond mines which are currently operating in Chiyadzwa whose mining activities have brought a myriad of environmental problems . In light of the above the research sought to establish the types of contaminants and analyse the causes of water pollution on both upper Odzi and Save catchment areas. The research was carried out using both qualitative and quantitative methods. A case study method was used in carrying out this research. Both questionnaires and interviews were used to gather information on mine disposal methods, water quality problems and the mines environmental permits. Water samples were collected for chemical, BOD, COD, turbidity and conductivity analysis from October to December 2013 on 7 sampling points on each river. Point 7 on both rivers was the control. This was located 10km from the mines discharge points. Water samples were send monthly to GK laboratory in Harare for analysis. The study undertaken has shown a protracted increase in water quality problems in both Save and Odzi Rivers due to the mining operations. Heavy siltation was noticed on both Save and Odzi Rivers as well as the tributaries which feed the mighty rivers. The effect of contaminated effluent as a result of Ferrosilicon was evidence since there was heavy metal presence of (Iron, Nickel, Aluminium, and Manganese) as well as high conductivity, BOD and COD. All these parameters were found to be in the red and yellow categories on sampling points below the discharge points. In light of these water quality problems emanating from the mining operations, standard or appropriate slimes dams should be constructed by all the 5 operating mines in Chiyadzwa. Notably there is need to carryout comprehensive Environmental Impact Assessments and Social Impact Assessments on all the mining projects in Chiyadzwa to avert the water quality problems which are being envisaged.