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The River Basin  
 Introduction
Geography
Climate and Weather
Hydrology
Water Quality
 Principles of Water Quality
 Water Temperature
 Dissolved Oxygen
 pH
 Total Dissolved Solids and Conductivity
 Suspended Sediment
 Salinity
Hardness
 Nutrients
 Metals
 Biological Water Quality Parameters
 Spiritual Meaning of Water
 Human Impacts to Water Quality
 Acidity, Heavy Metals and Radionuclides
 Groundwater Quality
 Water Quality Fitness for Use
Ecology and Biodiversity
 References


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Water Quality: Principles of Water Quality:

Water Hardness

   

Water hardness is defined as the concentration of ions of alkaline earth metals (mainly calcium and magnesium, sometimes also strontium and barium) in the water. There are, internationally, different methods to measure the hardness of water. Very common, but scientifically not totally correct, is the measurement in milligram of calcium per litre of 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.

Hardness in water is a common problem in the Orange-Senqu River basin, especially in supplies from groundwater sources. Water hardness can cause scaling in water pumps and damage valves, pipe fittings and other infrastructure, especially in rural systems that use very hard.

Hardness can damage valves and cause leaking on pipes and other infrastructure.
Source:DRFN 2004
( click to enlarge )

 

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