Impact of small scale gold mining on some water quality parameters of river Ashire

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The study investigated the impact of Small Scale Mining on some water quality parameters in River Ashire in the Wassa Amenfi East District of Western Region by measuring the concentration of heavy metals (Mercury, Arsenic, Cadmium, Copper and Lead) and some physicochemical parameters using the Atomic Absorption Spectrophotometer and other standard methods. Water samples from River Ashire were collected monthly at seven (7) different locations along the river over a six month period from October 2010 to March 2011. Mean pH at the sampling points along the river ranged from 6.30-7.01, Electrical Conductivity ranged from 50-103.58 μS/cm, 0.026-0.113 ppm for Salinity and a range of 30.50-49.83mg/L for Total Dissolved Solids were all below the EPA guideline values, but mean Total Suspended Solids 166.83-127.78mg/L and 172-513NTU Turbidity values were above the EPA guideline values. The range of value for Dissolved Oxygen for downstream was 4.09-6.91mg/l; for which the upper limit of 6.91mg/l higher than the Ghana EPA Standard of 5.00mg/l. Lead values ranged from 0.035-0.064, Arsenic value ranged from 0.019-0.0372 mg/L and Mercury range of 0.009-0.085 mg/l values exceeded the EPA Standards. However, levels of Copper 0.001-0.004 mg/l and Cadmium 0.002-0.085 mg/l were lower than the Ghana EPA permissible levels of effluent discharged into natural water bodies. Considering the higher levels of Turbidity, Total Suspended Solids, Lead and Mercury in the River which all exceeded the EPA and WHO levels, Small Scale Mining activities along River has an impact on the river water quality. From the results obtained the levels of heavy metals and Physico-Chemical parameters can be injurious to human health and the environment since according to the World Health Organization, (WHO) (1996), about five million people die every year from drinking polluted water.
Thesis submited to the Department of Theoretical and Applied Biology in partial fulfilment for the award of MASTER OF SCIENCE (ENVIRONMENTAL SCIENCE) DEGREE, March 2013