Drinking Water Resources

Literature Review

In many parts of the world, existing fresh water supplies have become overly exploited, and this is becoming a huge problem. There are many factors that account for these problems; the major ones being population growth, higher standards of living, and immense growth in the agricultural sector, industrialisation and climate change. In Europe, about 24% of water is used for agricultural purposes, with the industries consuming, averagely, 11% while 44% is used for cooling purposes during energy production and the remaining 21% is supplied for public use (European Environmental Agency, 2009).

Globally, the sectors that consume a lot of water are irrigation, urban and manufacturing industries. The agricultural sector is the major exploiter of water, particularly in countries which are already suffering from an increase in water shortages like Spain, Greece, UAE, and most North African countries. More

Classification of water according to concentrations of solids (National Research Council, USA, 2004).

Description Dissolved solids (mg/l)

Drinking water less than 1,000

Mildly brackish 1,000 to 5,000

Moderately brackish 5,000 to 15,000

Heavily brackish 15,000 to 35,000

Average seawater 35,000 According to UK water supply regulations (2000), there were no specifications when it comes to total dissolved solids for drinking water but instead the maximum value for its conductivity was established. Thus, a maximum of 2,500 micro Siemens at 200 C in drinking water. This value corresponds to about 1200mg/L of dissolved solids. WHO made a classification of water according to the amount of TDS as shown in the table below. The WHO recommends that drinking water should have at most 1000mg/L of TDS (WHO, 2006).

Table 2. The palatability of water according to its concentration of total dissolved solids (WHO, 2006).

Palatability Dissolved solids (mg/l)

Excellent less than 300

Good 300 to 600

Fair 600 to 900

Poor 900 to 1,200

Unacceptable more than