Drinking Water Quality: A Case Study

additional treatments to meet the standard quality for human consumption. For example, in 2000, the water quality of the river in terms of pH, aluminium, iron and manganese were reported to exceed the Malaysian standard for drinking water quality (Norris & Hawkins, 2000). These subsequently affected the normal operation of the water treatment plant and thus upset the normal supply of drinking water to the community.

Pollution of this river by heavy metals is a serious problem, because many such pollutants are both highly toxic and not biodegradable in the natural environment (Morillo et al., 2002). Heavy metal contamination in aquatic and soil environments threatens aquatic ecosystems, agriculture and human health (Overesch et al., 2007).

Another effect of the acid sulphate soil is the prevention of water logging and draining of industrial and agricultural runoff, which expose the pyrites to the atmospheric conditions for further oxidation (Rassam et al., 2002; Shamshuddin et al., 2004b). These dangerous compounds emanating from the oxidation of sulphate soil are easily moved into the rivers as rainfall runoff and thereby deteriorate the water quality. In addition, unless appropriate control measures are done to condition the soil, toxic substances penetrates to the surface and ground water through leaching and causes more severe damage to the eco-system (Lin et al., 1998). The major metals known to be associated with the acid sulphate soil are aluminium, iron and manganese and were all considered carcinogenic when their daily consumption are above the recommended levels. The high level of aluminium from the river is possible, since aluminium is naturally available on the earth crust and is easily released into the environment either through chemical speciation, hydrological flow paths, soil-water interactions, and the composition of the underlying geological materials (Gala-Gorchev, 1998). Although, the elemental iron is rarely found naturally, but it is the second most plentiful metal found on earth’s

However, other sources of pollution like discharge of partially treated effluents from domestic and industrial activities into the river could not be ruled out as possible contributions in the reduction of the river water quality. Because several industries such as fiberboard, electronics, food and textiles industries and agricultural-based industries are located within the vicinity of the rivers and they usually discharge their treated effluents into the river. The situation transformed the natural state of the river catchment area and thus gradually changes the ecological condition of the river. Typically, about 718 hectares of