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Home The River Basin People and the River Governance Resource Management
The Limpopo River Basin
Climate and Weather
Water Quality
 Principles of Water Quality
 Human Impacts to Water Quality
 Agricultural Impacts
 Industry and Mining
 Heavy Metals
 Persistent Organic Pollutants
 Water Temperature
 Case Study: Upper Olifants River
 Water Quality Fitness for Use
Ecology and Biodiversity
Sub-basin Summaries



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Water Quality: Hardness  

Hardness is measured as mg/L of CaCO3; although the hardness may not be in fact due to the CaCO3. This measure is equivalent to alkalinity and is caused by the presence of multivalent ions such as calcium, magnesium, iron or manganese, released from minerals dissolved in water. Water that is considered hard (150-300) generally has lower toxicity than water that is soft (0-75) and breaks down soap more easily. The downside is that hard water can cause problems in the water treatment process and industrial use. Although hardness is not attributed to human activities, it can have a significant impact on infrastructure and water quality and is therefore mentioned here.

Within the Limpopo River basin, hardness in water could cause a problem especially in supplies from groundwater sources. Hardness causes scaling in water pumps, and damages valves, pipe fittings and other infrastructure especially in rural systems that draw groundwater with high concentrations of the hardness-related ions. 

Hardness can damage pipes and fittings.
Source: DRFN 2009.
( click to enlarge )



Explore the sub-basins of the Limpopo River

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Examine how the hydrologic cycle moves water through and around the earth

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