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Water quality monitoring

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Water quality monitoring

  1. 1. Water Quality Monitoring and Standards, Sampling, Preservation, Transportation Techniques Arjesh Sharma Sr. Manager Pollution Control Research Institute BHEL, HARIDWAR – 249 403 arjesh@bhelhwr.co.in
  2. 2. Water  Water constitutes one of the important components in the life of man  Water has a direct bearing on health  In order to be used as healthful fluid for human consumption, water must be free from :  Organisms that are capable of causing disease  Minerals and organic substances that could produce adverse physiological effects
  3. 3. Water  Drinking water should be  Aesthetically acceptable  Free from apparent Turbidity, Colour, Odour & any objectionable taste  Drinking water also should have a reasonable temperature  Water meeting these conditions is termed as “Potable” - may be consumed in any desired amount without concern for adverse effect on health
  4. 4. Water Source Selection  The selection of a water supply source involves a review of the alternative sources available and their respective characteristics. Factors to consider when selecting a water supply source include :  Safe Yield  Water Quality  Collection Requirements (intake structures, wells etc.)  Treatment Requirements  Transmission and Distribution Requirements
  5. 5. Water Quality Monitoring and Surveillance  Department of Health  Department of Social Welfare  Jal Sansthan  Jal Nigam  Rural Development Department  Panchayats  The Swajal Project  Schools/Colleges/Medical/Technical Institutes  NGOs
  6. 6. Laboratory Infrastructure  Laboratory control in water quality management is indispensable  A Well Arranged and Adequately Equipped analytical laboratory with Competent Analysts is an important and integral part of any water quality monitoring and surveillance programme  Results of laboratory analysis are essential for evaluation of efficiency of water treatment system  The laboratory infrastructure depend on the level of analysis desired, location and other support available.
  7. 7. Types of Laboratory  Level – I (Village Level)  Bacteriological Identification, Field Test Kits  Level – II (District Level)  Chemical & Bacteriological Examination  Level – III (State Level)  Special analysis for metals, pesticides and organics  Analytical Quality Control  Data analysis and information transfer  Assist District Level laboratories  Policy formulation
  8. 8. Objectives of Water Quality Sampling  To obtain reliable and useful data  To assess the impact of human activities on Water quality and its suitability  To determine the quality of water in its natural state  To keep under observation the sources and pathways of pollutants/contamination
  9. 9. Factors Influencing Source Water Quality  Natural Factors  Climate  Watershed characteristics  Geology  Microbial growth  Fire
  10. 10. Factors Influencing Source Water Quality  Human Factors  Point :  Wastewater/Industrial discharge  Hazardous waste facilities  Mine drainage  Spills and releases  Nonpoint :  Agricultural runoff  Livestock  Urban runoff  Land development  Landfills  Erosion  Recreation activities
  11. 11. Location of Sampling  The sample taken be representative of the source  Sampling point should be uniformly distributed throughout the system  The sampling point should include the conditions at most unfavorable places in the system  There should be at least one sampling point directly after the clean water outlet from each plant  At least one sample be taken from farthest Stand Post
  12. 12. Types of Samples  Grab or Catch Samples  Composite Samples  Integrated Samples Generally for drinking water quality monitoring, Grab Samples are taken
  13. 13. Collection of Water Samples  Meaningful and reliable sampling assures correct laboratory results  Minimum time between the time of collection and conducting water analysis  For Chemical examination - Adequate care is required through proper preservation that would be parameter specific  For Biological examination - Extreme care be taken during sample collection & its preservation
  14. 14. Requirement for Biological Analysis  Frequency to ensure seasonal variations of water quality to be investigated  Samples to be collected, stored and dispatched in suitable sterilized bottles  The quantity of water collected be adequate enough for analysis
  15. 15. Requirement for Biological Analysis  Utmost care be taken during sampling to avoid contamination of sample being collected  In order to prevent significant alteration in the characteristics of sample prior to analysis, the sample be dispatched to the laboratory under iced condition as soon as possible  The details of the sample be clearly described and the sample bottles properly labeled to avoid any error
  16. 16. Sample Containers  Should be free from contamination  Should not change the water characteristics  Should not make any reaction with the water  Should contain adequate quantity for analysis
  17. 17. Sample Containers Chemical Analysis  Colourless/White plastic jerricans Bacteriological Analysis  Sterilized glass bottles with glass stopper  Sterilization in autoclave at 1 kg/cm2 for 15 minutes  Samples with residual chlorine be dechlorinated for Bacteriological analysis
  18. 18. Sampling Procedure  Sampling Bottle/Container be opened only when it is required for filling  The bottle should be held from the base while filling  Bottle should not be filled completely  Some space be left for air to facilitate shaking before analysis
  19. 19. Sampling Procedure  Sampling of Hand Pump Water  Water should be pumped for about 5 minutes before filling the sample bottle  Sampling of Water from a Tap  Water should be allowed to run for 3 – 4 minutes or more before filling the sample bottle  For estimation of Total Residual Chlorine, farthest stand post be considered for sampling  Data sheet be filled and accompanied with sample for analysis
  20. 20. Preservation and Storage of Samples  The sample should be examine preferably within one hour after collection  This period, in on case should exceed 24 hours  Efforts be made to keep the temperature of the sample as close as possible to that of source  Sample to be preserved in ice until analysis (if sample can not be analyzed within 24 hours)  For Bacteriological analysis, sample be analyzed within 72 hours
  21. 21. Sample Preservation  Temperature  Should be measured in - situ  Turbidity  Best to measured in the field  Sample can be stored in dark for 24 hours  Settling during storage & change in pH lead to precipitation, can affect the result during storage  pH  Should be measured in - situ  pH is temperature dependent
  22. 22. Sample Preservation  Hardness  Sample be filtered  If during storage, CaCO3 sediment appears, it must be dissolved with small HCl after decanting the clear liquid above the sediment  Nitrate & Nitrite  2 – 4 ml of chloroform be added to retard bacterial decomposition  Sample can be cooled and then stored at 3 – 4 ºC  Ammonia  Sample be deep frozen with 0.8 ml of H2SO4 per liter and then stored at 4 ºC  Prior to analysis, acid used be neutralised
  23. 23. Sample Preservation  Sodium & Potassium  Stored in plastic bottles  Calcium  Stored in plastic bottles  If any CaCO3 precipitate form during storage, it must be redissolved with HCl or HNO3 and then neutralised before analysis  Sulphate  Can be stored in the refrigeration for upto 7 days  Prolonged storage be avoided for polluted water  Magnesium, Chloride & Fluoride  No specific preservation required
  24. 24. Sample Preservation  Sulphide  Sample be fixed with cadmium acetate or Zinc acetate, after which it can be stored upto 3 days in the dark  Cyanide  Highly active and unstable  Preserved with sufficient NaOH to raise pH to 11 or more and then stored at about 4 ºC  Arsenic  Preserved by adding Conc. HCl (12 N) @ 1 ml/L of sample
  25. 25. Sample Preservation  Metals  Pretreated by acidification prior to transportation to suppress hydrolysis, sorption etc  A very high degree of cleanliness in sampling handling at all stages of collection and analysis is necessary to avoid contamination and incorrect results
  26. 26. Sample Container & Preservation Analysis Container Preservation General Glass, PE 4 ºC, dark BOD Glass, PE 4 ºC, dark COD, NH3, NO2, NO3 Glass, PE H2SO4, pH < 2 Coliform Glass Sterilized 4 ºC, dark Dissolved Oxygen BOD Bottle DO fixing chemicals Fluoride PE None Phosphate Glass None Pesticides Glass, Teflon 4 ºC, dark Toxic Metals Glass, PE HNO3, pH < 2
  27. 27. Frequency of Sampling  Frequency of sampling is generally determined by population served, size and type of system  Properly developed source require less sample frequency  In summer, there is a greater risk of contamination, due to low flow. After monsoon, there is likelihood of greater pollution due to surface run off.  Ideally sampling be carried out in streams during summers and again during the onset of monsoon.
  28. 28. Suggested Frequency of Sampling & Analysis Source and Mode of Supply Bacteriological Physical/Chemical Open Wells Every 7 days 4 times yearly Covered wells and shallow tube wells with hand pumps Every 15 days 4 times yearly Deep tube wells with hand pumps As per requirement 4 times yearly
  29. 29. Suggested Frequency of Sampling & Analysis Source and Mode of Supply Bacteriological Physical/Chemical Wells and Piped Supplies As per requirement  4 times yearly  Weekly for Residual Chlorine Spring and Piped Supplies As per requirement  4 times yearly  Weekly for Residual Chlorine Surface Water - Filtered and/or chlorinated and piped supplies Once in a month  4 times yearly  Daily for Residual Chlorine
  30. 30. Uniform Protocol on Water Quality Monitoring Order, 2005  Applicable to all orgnisations, agencies and any other body monitoring surface and ground water quality for observance on uniform protocol on water quality monitoring
  31. 31. Ground Water Monitoring  The frequency of sampling in respect of ground water shall be as follows :  All stations shall be classified as Baseline stations  20 – 25% of Baseline stations shall be classified as Trend stations where there is a perceived problem.  All agencies shall follow the sampling frequency and parameters for analysis of ground water as mentioned in the table :
  32. 32. Analysis of Ground Water samples  Type of Station : Baseline  Frequency : Twice a year (Pre & Post monsoon season)  Parameters :  General : Colour, Odour, Temp., pH, EC, TDS  Nutrients : Nitrate, Nitrite, Phosphate  Demand Parameter : COD  Major Ions : Sodium, Potassium, calcium, Magnesium, Carbonate, Bi-carbonate, Chloride, Sulphate, Sodium & SAR  Other Inorganics : Fluoride, Boron and other location specific parameters, if any
  33. 33. Analysis of Ground Water samples  Type of Station : Trend  Frequency : Twice a year (Pre & Post monsoon season)  Parameters :  April – May : Analyze parameters as listed for Baseline monitoring  Other times : Analyze 14 parameters as listed below :  General : Colour, Odour, Temp, EC, pH, TDS, % Na, SAR  Nutrient : Nitrite, Nitrate, Phosphate  Demand Parameters : COD  Major Ions : Chloride  Other inorganics : Fluoride, Boron  Microbiological : TC & FC
  34. 34. Analysis of Ground Water samples  Type of Station : Trend  Parameters :  Micro - pollutants (parameters may be selected based on local need) :  Pesticides : Alpha BHC, Beta BHC, Gamma BHC (Lindane), OP – DDT, PP – DDT, Alpha Endosulphan, Beta Endosulphan, Aldrin, Diedrin, 2, 4 – D, carbaryl (carbmte), malathion, Methyl parathion, Anilphos, Chloropyriphos  Toxic Metals : As, Cd, Hg, Zn, Cr, Pb, Ni, Fe  Pesticides and Toxic metals may be analysed once in a year in pre – monsoon on selected locations)  If COD value exceed 20 mg/L, the sample shall be analysed for BOD also.
  35. 35. IS : 10500 - 1991 Indian Standard Drinking Water - Specification
  36. 36. IS : 10500 : 1991  Bacteriological Examination :  Throughout any year, 95 % of samples should not contain any coliform organisms in 100 mL  No sample should contain E. Coli in 100 mL  No sample should contain more than 10 coliform organisms per 100 mL  Coliform organisms should not be detectable in 100 mL of any two consecutive samples  If any coliform organisms are found, immediate resampling be carried out. The repeated findings of 1 to 10 coliform organisms in 100 mL or the appearance of higher numbers in individual sample suggests that undesirable material is gaining access to the water and measures should be taken to discover and remove source of pollution.
  37. 37. Essential Characteristics Parameter Desirable Limit Permissible Limit Colour 5 25 Odour Unobjectionable - Taste Agreeable - Turbidity 5 10 pH 6.5 – 8.5 No relaxation Total Hardness 300 600 Iron 0.3 1.0 Chloride 250 1000 Residual Free Chlorine 0.2 - Fluoride 1.0 1.5
  38. 38. Desirable Characteristics Parameter Desirable Limit Permissible Limit Dissolved Solids 500 2000 Calcium 75 200 Magnesium 30 100 Copper 0.05 1.5 Manganese 0.1 0.3 Sulphate 200 400 Nitrate 45 No relaxation Phenolic Compounds 0.001 0.002 Mercury 0.001 No relaxation Cadmium 0.01 No relaxation Selenium 0.01 No relaxation
  39. 39. Desirable Characteristics Parameter Desirable Limit Permissible Limit Arsenic 0.01 No relaxation Cyanide 0.05 No relaxation Lead 0.05 No relaxation Zinc 5 15 Anionic Detergents 0.2 1.0 Chromium (as Cr+6) 0.05 No relaxation Mineral Oil 0.01 0.03 Pesticides Absent 0.001 Alkalinity 200 600 Aluminum 0.03 0.2 Boron 1 5
  40. 40. Thank You

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