Contamination of water and its prevention

NOTE

1. CONTAMINATION OF WATER AND ITS PREVENTION SURYA ADHIKARI B V Sc & AH (PU) NPI, CHITWAN

2. INTRODUCTION Pollution signifies any degradation of natural ground water quality while contamination is reserved for pollution that constitutes a hazard to human health. Water Contamination is defined as the introduction of any undesirable physical, chemical or microbiological material into a water source.  There are two types of contamination sources: point sources and non-point sources. 

3. SOURSES OF WATER CONTAMINATION Water contaminant sources can be categorized into two super categories: 1. Point sources 2.Non point sources

4. POINT SOURCES Point source pollution refers to water contamination entering from a source that can be Identified and that belongs to the single sources . Discharge from a factory or sewage outfall, and include many of the common inorganic chemical water contaminants . Point source pollution or contamination can be broken down further into two common parts—factories and sewage treatment plants. (discharge pipe from factories, roadways or leaking underground storage tank)

5. NON-POINT SOURCES Non-point source pollution or contamination does not have a single source. It is often the cumulative effect of small pollutants gathered in a small area, usually runoff. It is very difficult to control because it comes from many different sources. Non-point sources that include agricultural runoff, urban storm water runoff and other area wide sources.

6. WATER CONTAMINANTS CATEGORIES AND EXAMPLES Categories Examples Physical sediment or organic material suspended in the water of lakes, rivers and streams from soil erosion Chemical Nitrogen Bleach Salts Pesticides Metals Toxins produced by bacteria, and human or animal drugs Biological Bacteria, Viruses ,Protozoan, Parasites, Fungi Radiological Cesium Plutonium Uranium

7. Agricultural and livestock sources Infiltration of fertilizers, pesticides, Wastes from slaughter houses , animal dung and urine. Chemical fertilizers and pesticides are mixed up with water, there will be harmful product for plants and animals. Similarly , when it rains, the chemicals mix up with rainfall and flow down into rivers and canals which pose serious damages for aquatic animals.

8. Sewage system and waste water Sewage water carries harmful bacteria, organic matter, inorganic salts, heavy metals, viruses, nitrogen and chemicals that can cause serious health diseases . It contains 99.9% of water and 0.1% of solid contains Lack of systems in un sewered areas, slum areas. Leakages and over flow from the sewerage pipelines. Overflow from deficient pumping sytems . Inadequate sewerage treatment facilities inclusive pipelines and pumping station for treated waste water.

9. Septic Systems Septic tanks, cesspools, and privies are most common types of ground water contaminants. Improperly sited, designed, constructed, or maintained septic systems can contaminate ground water with bacteria, viruses, nitrates, detergents, oils, and chemicals. Cesspools : large buried chamber with porous walls designed to receive and percolate raw sewage

10. Natural Sources Chemicals in drinking water Iron , manganese, arsenic, chlorides, fluorides, sulfates, or radionuclides, can become dissolved in ground water naturally from rocks or soils. Decaying organic matter, can move in ground water as particles. Ground water that contains unacceptable concentrations of these substances is not used for drinking water or other domestic water uses unless it is treated to remove these contaminants. Some substances may cause health threats if consumed in excessive quantities; others may produce an undesirable odor, taste, or color of water.

11. Industrial and trade wastes- Which contain toxic agents ranging from metal salts to complex synthetic organic chemicals. Non treated or poorly treated waste water from the textile  plants , tanneries, distilleries leachates from hazardous waste. eg fertilizer, petrochemical and caustic soda plants also contaminate the water   Inadequately treated industrial effluents. Leakage and spillages of chemicals. Irrigation water from distilleries and textile plants.

12. Municipal solid waste Leachates from inadequate collection facilities, uncontrolled  dumping sites and unprotected land fills. Uncontrolled dumping into surface waters and sewers . Energy plants- Leachates from coal, cinders and fly ash . Storm Water- Over flow from drainage with wash out of accumulated waste . Acidification : transportation of sulphur dioxide from power plants common in US and Europe

13. PREVENTION OF WATER CONTAMINATION Strict check should be maintained on the quality of drinking water Sanitation system must be improved . Public a wareness- Health education Cleaning chemicals that contain toxic substances should not be used extensively . Use proper procedures for handling chemicals (Paints, Pesticides, Insecticides, polishing materials, cleaning chemicals and detergents).

14. Ctnd…. The effluents from the industries should be neutralized and properly treated and suspended matter to removed by settlement or filtration. From the industrial effluents, specific poisons have to be removed by chemical methods before discharge into streams. Public sewers should be connected to biological treatment plants. Minimize the use of pesticides, herbicides, fertilizers. DO NOT dispose of these chemicals, motor oil, or other automotive fluids into the sanitary sewer or storm sewer systems. Both of them end at the river.

15. PARTICIPATION OF INDUSTRIES Minimize use of Toxic / Hazardous Raw Materials Maintain Integrity of the Storage Tanks, Pipelines, surface impoundments Adopt Good Engineering Practices for selecting proper material for tanks and pipes . Contaminants must be disposed, handled, and transported appropriately. Implement monitoring programs: Leak Detection and repair program, spill detection, spill control, emergency response plan etc. Manage Properly: Waste materials, their transport and disposal. Monitor Periodically: Groundwater quality

16. PARTICIPATION OF COMMUNITY Minimize use of house hold chemicals containing Hazardous substances. Avoid draining chemicals, motor oil, insecticides in community areas. Reduce pesticide application Immediately clean any spills and report any leakages to concerned department .

17. EFFECTS OF WATER CONTAMINATION Health Effects Health effects are the most common Problems associated with Groundwater contamination. Hepatitis , Dysentery, Poisoning, Bone tissue & tooth discoloration (Excessive consumption of fluoride), Cholera or giardiasis etc.

18. Environmental Effects The environment can be seriously damaged when groundwater is contaminated. Nutrient pollution Toxic water in ecosystems Soil Contamination

19. Economic Effects The economy and industries might be easily suffering and negatively affected when groundwater becomes contaminated . - Agricultural activities - Depreciating value of land - Industry instability

20. PURIFICATION OF WATER Impure water can be purified by the following methods. Natural methods e.g. Storage , Sunlight Artificial methods I. physical Distillation Boiling II . Chemicals Precipitation ( Addition of alum & chlorine treatment-100gm/5 gallons of water) Disinfection or sterilization (KMno4) III. Filtration Slow sand filtration Rapid Mechanical filtration

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