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Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
Assessment and surveillance of drinking water quality
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Assessment and surveillance of drinking water quality

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  • 1. Guide : Dr.Ansuman Panigrahi Associate Professor Dept . Of Community Medicine,KIMS Presented By: Dr . Shalini Ray 1
  • 2.  Quality  Quantity 2
  • 3. The WHO published guideline for drinking water quality.  Its implementation ensures safety of drinking water supplies.  Guidelines for drinking water quality recommended by WHO (2011) relate to : I. Acceptability aspects II. Microbiological aspects III. Chemical aspects IV. Radiological aspects 3
  • 4. Acceptability Physical parameters Inorganic constituents 4
  • 5. Turbidity  Drinking water should be free from turbidity.  Interferes with disinfection and microbiological determination.  Acceptable level - turbidity of less than 4 NTU  Measured with Turbidity meter 5
  • 6. 6
  • 7.  Drinking water should be free from colour .  Organic matter, iron , manganese , industrial waste etc.  The guideline value - 15 true colour units (TCU). 7
  • 8.  Develop due to contamination by chemicals.  Storage and distribution.  Indicative of pollution or malfunction during water treatment or distribution. 8
  • 9. Low water temperature  Decrease the efficiency of treatment process. High water temperature  Enhances the taste, odour .  Corrosion problem may increase.  No guideline value is recommended. 9
  • 10.  All water including rain water contain chlorides.  Standard level for chloride - 200 mg/ litre .  Maximum permissible level - 600 mg/ litre  Measured by spectrophotometer or titration method.  Spectrophotometer 10
  • 11.  Taste threshold for calcium ion - 100-300 mg/ litre .  Excessive soap consumption and scum formation.  Forms deposits of calcium carbonate scale on heating.  Soft water : low buffer capacity ,corrosive for water pipes.  Measured by titration method. 11
  • 12. 12
  • 13.  Ammonia originates from metabolic, agricultural and industrial processes and from disinfection with chloramine .  Natural levels - below 0.2 mg/ litre  Anaerobic ground water contains 3mg/ litre  Its presence indicates pollution by bacteria , sewage or animal waste. 13
  • 14.  pH< 7 causes severe corrosion  Acceptable range - 6.5 to 8.5.  Measured with pH meter 14
  • 15.  Acceptable limits- 0.05-0.1 mg/l  Gives rotten egg odour (stagnant water) Iron  On exposure to atmosphere ferrous iron oxidises to ferric ion  Gives reddish brown colour to water  Deposit slimy coating on pipes Sodium  Measured with Flame photometer.  Average taste threshold for sodium - 200 mg/ l 15
  • 16. Flame photometer 16
  • 17. Important effect on taste of water  Acceptability levels of TDS -<1000mg/litre  Excessive levels cause scaling of boilers , pipes Zinc  Gives undesirable astringent taste  Zinc content >5mg/litre gives opalescent look and greasy film on boiling Manganese  Acceptable levels-<0.1mg/litre  Excess Mg stains sanitary ware and laundry 17
  • 18.  Increases corrosion of steel fittings  Concentration >1mg/litre cause staining of laundry and sanitary ware Aluminium  Concentration >0.2mg/l leads to deposition Aluminium hydroxide floc. 18
  • 19.  Bacteriological indicators  Virological aspects  Biological aspects 19
  • 20. Coliform organisms-  Present in human intestine  Presence indicates faecal contamination Faecal streptococci- Occur in faeces  Confirmatory evidence of recent faecal contamination Cl.perfringens –  Resist chlorination  Presence suggest faecal contamination 20
  • 21. Coliforms - Faecal groups -E coli Non Faecal – Klebsiella aerogens Why coliforms?  Coliforms are abundant in intestine(200-400billion/day)  Easily detected by culture  Survive longer than other pathogens  Greater resistance to forces of natural purification 21
  • 22. ORGANISMS GUIDELINE VALUE All water intended for drinking Must not be detectable in any 100ml sample Treated water entering distribution system (E.coli ,total coliform count) Must not be detectable in any 100ml sample Treated water entering distribution system (E.coli ,total coliform count) Must not be detectable in any 100ml sample In c/o large supplies, must not be present in 95% of samples taken throughout any 12month period 22
  • 23.  Free from virus  Disinfect with 0.5 mg/ml of free chlorine residual after contact period of at least 30 minutes at pH 8.(Hep A)  Others need 0.2 mg/ml  Criteria  Ozone :0.2-0.4 mg/ml for 4 minutes 23
  • 24.  Protozoa- E.histolytica , Balantidium coli  Helminths- Infective form of round worm, hook worm dracunculus medinensis , schistosomes  Free living- fungi ,algae interfere with water treatment 24
  • 25. Guinea worm disease 25
  • 26.  Inorganic constituents  Organic constituents 26
  • 27. Inorganic constituents Guideline value Arsenic 0.01mg/l Cadmium 0.3ug/l Chromium 0.05 mg/l Cyanide 0.07 mg/l , acute toxicity Fluoride 1.5mg/l Lead 0.01mg/l Mercury 0.006 mg/l Nitrate 50mg/l Nitrite 3mg/l Selenium 0.01mg/l 27
  • 28. Nitrate & nitrite – nitrate - 50 mg/l nitrite – 3 mg/l Conc: of nitrate + Conc:of nitrite = < 1 G.value of nitrate G.value of nitrite 28
  • 29. 29
  • 30. ORGANIC CONSTITUENTS UPPER LIMIT OF CONC(mcg/l) CHLORINATED ALKANES CCl4 2 dichloromethane 20 CHLORINATED ETHENES Vinyl chloride 55 1.1-dichloroethene 30 1.2-dichloroethene 50 AROMATIC HYDROCARBONS benzene 10 toluene 700 xylene 500 Ethyl benzene 300 styrene 20 30
  • 31.  PAH and turbidity  Restriction on coal tar based lining in storage tanks  Source of contamination should be identified 31
  • 32. Radioactivity should be as low as possible Guideline values- Gross alpha activity-0.5 Bq /L Gross beta activity- 1.0 Bq /L 1Bq= 1 disintegration per second 32
  • 33. SURVEILLANCE OF DRINKING WATER QUALITY 33
  • 34. “ Continuous and vigilant public health assessment and overview of the safety and acceptability of drinking-water supplies”(WHO-1976) 34
  • 35.  Quality  Quantity  Accessibility  Affordability  Continuity of drinking-water supplies 35
  • 36. •At home •Source •Safe source •Ways to prevent 36
  • 37.  Identify & evaluate factors associated with drinking water which could pose a health risk  To take both preventive & remedial action  For development of rational strategies for improvement of quality of water supply services  To meet agreed national standards & institutional targets 37
  • 38. Audit approach Information regarding system performance Review records to ensure data is reliable. Direct Assessment 38
  • 39.  Approval of new sources(Including private owned)  Watershed protection  Approval-construction & operating procedures of water works  disinfection of the plant & distribution system  periodic flushing programmes & cleaning of water storage facilities  certification of operators  regulation of chemical substances  Cross-connection control ,back flow prevention ,leak detection control 39
  • 40.  Sanitary surveys  Monitoring programmes  Development of codes of practice for well construction ,pump installation and plumbing  Inspection quality control in bottled water 40
  • 41.  Sanitary Survey  Sampling  Bacteriological Surveillance 1)Presumptive Coliform Test - Multiple Tube Method Membrane Filtration Technique 2)Detection Of Faecal Strep & Cl.Perfringes 3)Colony Count  Biological Examination  Chemical Surveillance 41
  • 42.  A sanitary survey defined as “an on-site inspection and evaluation by a qualified person of all the conditions, devices, and practices in the water supply system which pose a danger to the health and well being of the water consumer ” 42
  • 43.  A new source is being contemplated  Laboratory analysis indicates hazard to health  An outbreak occurs  To interpret bacteriological, chemical and physical analyses of samples  When any change takes place that can affect the water system, e.g. industries coming up in watershed and  On a regular basis 43
  • 44.  Ensure no external contamination  Asepsis Glass bottles with securely fitting stoppers or caps with non toxic liners.  Sample for general analysis= 2 litres(non-acidified)  Bacteriological analysis=250 ml (sterilized bottle)  Metals analysis=1000 ml (acidified sample) 44
  • 45.  Sampling done by sampling assistant 45
  • 46.  Water from a tap in a distribution system  Water from watercourse (river, lake,well etc) 46
  • 47. 47
  • 48. 48
  • 49. 49
  • 50.  Date  Time of collection  Despatch  Source  Rainfall  Findings 50
  • 51. 51
  • 52.  Take the positive tube from the presumptive test  Incubate one plate at 37°C for 24 hours and another at 44.5°C for 24 hours.  Look for typical colonies in the media ; blue black with green metallic sheen colonies are of E. coli 52
  • 53.  Lactose Tegritol agar  Membrane lauryl sulfate lactose 53
  • 54.  Nutrient agar at 37 deg C and 22 deg C  An estimate of the general bacterial purity of water.  Same source at frequent intervals may be of considerable value.  A sudden increase in the colony count may give the earliest indication of contamination. 54
  • 55.  The recommended plate counts are Water at the point of consumption Plate count after 2 days at 37 deg C Plate count after 3 days at 22 deg ( i ) Disinfected 0 20 (ii) Not - disinfected 10 100 55
  • 56.  The National Rural Drinking Water Quality Monitoring & Surveillance Programme was launched in February 2006 (2005-06)  Institutionalization of community participation and involvement of PRIs for water quality monitoring & surveillance of all drinking water sources  Jal surakshak 56
  • 57.  Park K. Textbook of preventive and social medicine. 22nd ed. Jabalpur (India): Bhanot publishers; 2009. p. 667-78.  WHO - Guidelines for Drinking-water quality: surviellance & control of community supplies. Vol.3, Recommendations. – 3rd ed.  Uniform Drinking Water Quality Monitoring Protocol: Govt Of India, Ministry of Drinking Water and Sanitation ; Feb 2013  http://www.mdws.gov.in/wqms 57
  • 58. 58

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