WATER QUALITY: WATER QUALITY: CONTAMINATION AND CONTAMINATION AND

PROTECTIONPROTECTION

1. Water Quality1. Water Quality

• Microbiological Quality:Microbiological Quality: Presence of organisms that cannot be seen by the Presence of organisms that cannot be seen by the

naked eye – faecal and total coliformsnaked eye – faecal and total coliforms

• Physical QualityPhysical Quality Affecting taste, odour and appearance. pH, Turbidity Affecting taste, odour and appearance. pH, Turbidity

etc.etc.

• Chemical QualityChemical Quality Nature and concentration of dissolved substances. Nature and concentration of dissolved substances.

E.g salts, organics, etc. Most of these are essential, E.g salts, organics, etc. Most of these are essential, but in high quantities may cause problems.but in high quantities may cause problems.

2. Common Water Quality 2. Common Water Quality Problems: Surface WaterProblems: Surface Water

• Faecal PollutionFaecal Pollution High faecal and total coliform counts –near dense High faecal and total coliform counts –near dense

human settlementshuman settlements

• Colour and StabilityColour and Stability Due to organic acidsDue to organic acids

• Salt Concentrations (TDS)Salt Concentrations (TDS) High sulphate and chloride concentrationsHigh sulphate and chloride concentrations. .

Corrosive and distinctly saltyCorrosive and distinctly salty

2. Common Water Quality 2. Common Water Quality Problems: Surface WaterProblems: Surface Water

• EutrophicationEutrophication

High nutrient concentration High nutrient concentration (nitrogen, phosphate) and high algal (nitrogen, phosphate) and high algal concentrations.concentrations.

3. Common Water Quality 3. Common Water Quality Problems: GroundwaterProblems: Groundwater

• SalinitySalinity Occurs where the predominant geological formations Occurs where the predominant geological formations

are sedimentary rocks of marine origin. Eg. The are sedimentary rocks of marine origin. Eg. The KarooKaroo

• FluorideFluoride Especially in the coal bearing regions (central and Especially in the coal bearing regions (central and

western parts of the country)western parts of the country)

• Sulphate and ChlorideSulphate and Chloride Especially water with high TDSEspecially water with high TDS

3. Common Water Quality 3. Common Water Quality Problems: GroundwaterProblems: Groundwater

• Calcium and MagnessiumCalcium and Magnessium Especially in dolomitic areasEspecially in dolomitic areas

• Iron and ManganeseIron and Manganese While they commonly occur in high While they commonly occur in high

concentrations in groundwater, treatment is easyconcentrations in groundwater, treatment is easy

4. Water Pollution4. Water Pollution

• Water Pollution occurs when water is rendered Water Pollution occurs when water is rendered less fit for use as a result of human activitiesless fit for use as a result of human activities

• Waste generated by human activity enters the Waste generated by human activity enters the water environment.water environment.

Human Activities Waste StreamsHuman Activities Waste Streams

-Intensive Irrigation/Agri. -Sewage Waste -Intensive Irrigation/Agri. -Sewage Waste (Domestic/Indust.)(Domestic/Indust.)

-Mining activities -Gray water-Mining activities -Gray water -Industrial activity -Stormwater-Industrial activity -Stormwater -Dense human settlements -Solid waste-Dense human settlements -Solid waste

5. Protection of Water5. Protection of Water

• Everyone needs to be involvedEveryone needs to be involved

• National Government must provide a framework (policy) National Government must provide a framework (policy) and legislation for protecting our water sourcesand legislation for protecting our water sources

• Provincial and local level management measures and Provincial and local level management measures and actions must be developed for giving effect to the national actions must be developed for giving effect to the national water quality management framework and legislationwater quality management framework and legislation

• Business OwnersBusiness Owners

• IndustryIndustry

• MinesMines

• FarmersFarmers

• Interest GroupsInterest Groups

• General PublicGeneral Public

6. Water Treatment: 6. Water Treatment: ChlorinationChlorination

• Water-borne diseases are spread by pathogens Water-borne diseases are spread by pathogens (disease-causing micro-organisms – such as (disease-causing micro-organisms – such as bacteria and viruses) in waterbacteria and viruses) in water

• Pathogenic micro-organisms enter water supplies Pathogenic micro-organisms enter water supplies as result of pollution by human and animal wastes.as result of pollution by human and animal wastes.

• A lot of bacteria and viruses will remain after the A lot of bacteria and viruses will remain after the First BarrierFirst Barrier and and Second BarrierSecond Barrier treatment treatment

• The final barrier is disinfection – destruction of the The final barrier is disinfection – destruction of the harmful micro-organism – though the use of a harmful micro-organism – though the use of a chemical agent.chemical agent.

7. Water Treatment: 7. Water Treatment: ChlorinationChlorination

• Types of possible disinfectantsTypes of possible disinfectants

Chlorine, Ozone, Chlorine Dioxide, Calcium Chlorine, Ozone, Chlorine Dioxide, Calcium hypochlorite (HTH), Sodium hypochlorite (bleach) hypochlorite (HTH), Sodium hypochlorite (bleach) and monochloramineand monochloramine

• Chlorine is by far the most effective, easy to Chlorine is by far the most effective, easy to control, cost effective and used in over 98% of control, cost effective and used in over 98% of water treatment works worldwide.water treatment works worldwide.

• Side effects and other issues such formation THM’s Side effects and other issues such formation THM’s have been highlighted – they are all minor and have been highlighted – they are all minor and negligible as compared to the benefits of negligible as compared to the benefits of chlorinating water. Eg. Cholera epidemic.chlorinating water. Eg. Cholera epidemic.

5. Water Treatment: 5. Water Treatment: FluoridationFluoridation• Water fluoridation involves addition of Water fluoridation involves addition of

predetermined amounts of a fluoride-containing predetermined amounts of a fluoride-containing chemical to the water during a water treatment chemical to the water during a water treatment process in order to increase the fluoride process in order to increase the fluoride concentration to a specific level.concentration to a specific level.

• The WRC is currently involved in research to The WRC is currently involved in research to parameters and control that determines safe and parameters and control that determines safe and effective fluoridation of watereffective fluoridation of water

• On the other side of the coin is defluoridation where On the other side of the coin is defluoridation where there is also ongoing research to reduce fluoride there is also ongoing research to reduce fluoride from waters with high fluoride concentration, from waters with high fluoride concentration, though the use of modified locally occurringthough the use of modified locally occurring

7. Relevant Research7. Relevant Research

• Five main fields of research addressed water Five main fields of research addressed water quality and related problemsquality and related problems

• Over 200 projects have been carried outOver 200 projects have been carried out• Over R150 million has been spentOver R150 million has been spent• Over 30 patents have been takenOver 30 patents have been taken• Over 200 reports, workshops, training session.Over 200 reports, workshops, training session.• At least 5 centres of expertiseAt least 5 centres of expertise • Over R40 million invested in on going projectsOver R40 million invested in on going projects• All major water treatment plants are using one All major water treatment plants are using one

or more processes or technology developed or more processes or technology developed through WRC fundingthrough WRC funding

RESEARCH OUTPUTSRESEARCH OUTPUTS

• Sewage sludge guidelines and addendum to promote Sewage sludge guidelines and addendum to promote safe use of sludge for crop productionsafe use of sludge for crop production

• Compilation of a guide to assess the magnitude of non-Compilation of a guide to assess the magnitude of non-point source pollutionpoint source pollution

• With DWAF – Development of methodology to implement With DWAF – Development of methodology to implement Waste Discharge Charges (Polluter pays principle)Waste Discharge Charges (Polluter pays principle)

• Models to simulate effect of acid mine water on the Models to simulate effect of acid mine water on the quality of Witbank Damquality of Witbank Dam

• Design of soil covers for coal discard dumps that exclude Design of soil covers for coal discard dumps that exclude oxygen formation of acid mine drainageoxygen formation of acid mine drainage

• Use saline mine water to irrigate crops and remove Use saline mine water to irrigate crops and remove gypsumgypsum

• Reduced cost to neutralize acid mine water using Reduced cost to neutralize acid mine water using cheaper agents.cheaper agents.

RESEARCH OUTPUTSRESEARCH OUTPUTS

• Aerobic Digestion (Low cost sanitation) – Aerobic Digestion (Low cost sanitation) – Almost all waste water treatment plants in Almost all waste water treatment plants in SA use this technologySA use this technology

• Biosure® Process – Treatment of high Biosure® Process – Treatment of high sulphate waters (acid mine water)sulphate waters (acid mine water)

• Environmental technology and Integrated Environmental technology and Integrated waste water beneficiation – treatment of waste water beneficiation – treatment of high volume saline watershigh volume saline waters

• Petro ProcessPetro Process• Membrane TechnologiesMembrane Technologies