Dr. Preeti Tiwari

1. ASSESSMENT AND SURVEILLANCE
OF WATER QUALITY
1
Dr. Preeti Tiwari.

2.  1976
 1032 monitoring stations
 Physical , chemical or biological character of water
by which user evaluates acceptability of water
 Drinking water – Pure, wholesome and potable
2

3. 3
 Quality
 Quantity

4. 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
4

5. Acceptability
Physical
parameters
Inorganic
constituents
5

6. 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
6

7. 7

8.  Turbidity refers to cloudiness of a solution
 It is imparted by solid particles obstructing
the transmittance of light through a water
sample
 Clay, organic matter, algae and other
microorganism

9.  Filtering a measured volume of sample through
a standard glass fiber filter.
 The filtrate (i.e., filtered liquid) is then added
to a preweighed ceramic dish that is placed in a
drying oven at a temperature of 103 C.
 After the sample dries, the temperature is
increased to 180 C to remove an occluded water
i.e., water molecules trapped in mineral matrix.
 http://www.waterresearch.net/index.php/w
ater-treatment/tools/total-dissolved-solids

10.  Drinking water should be free from colour .
 Organic matter, iron , manganese , industrial waste
etc.
 The guideline value - 15 true colour units (TCU).
10

11. 11

12.  Develop due to contamination by chemicals.
 Storage and distribution.
 Indicative of pollution or malfunction during
water treatment or distribution.
12

13. Low water temperature
 Decrease the efficiency of treatment process.
 More palatable
High water temperature
 Enhances the growth of microorganism, odour
.
 Corrosion problem may increase.
 No guideline value is recommended.
13

14.  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.
14

15.  Principle:
 The amount of chloride present in water can
be easily determined by titrating the given
samle with silver nitrate solution

16.  Burette with stand
 Pippettes
 Conical flask
 20 ml graduated cylinders
 Standard flask
 Beaker

17.  Silver Nitrate
 Phenophthalein indicator
 Sodium chloride
 Potassium chromate

18. Pipette out
20 ml of
sample
Add 2 drops of
potassium
chromate indicator
Fill the burette with
silver nitrate (stored
in brown bottle)
Titrate the
content against
silver nitrate
solution
Titratte till the
colour changes to
brick red

19.  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.
19

20.  Hardness in water is that characteristic,
which “prevents the lathering of soap”.
 This is due to presence in water of certain
salts of calcium, magnesium and other heavy
metals dissolved in it.

21.  Temporary or carbonate hardness:
 It is caused by the presence of dissolved
bicarbonates of calcium, magnesium and other
heavy metals and the carbonate of iron.
 Temporary hardness is mostly destroyed by mere
boiling of water.
 ( bicarbonates are decomposed)

22.  Permanent or non-carbonate hardness:
 It is due to the presence of chlorides and
sulphates of calcium, magnesium, iron, and
other heavy metals.
 Permanent hardness is not destroyed on
boiling

23.  Principle :
 The total hardness can be determined by
titrating the Ca2+ and Mg2+ present in a
sample with Na2EDTA solution.

24.  Burette with stand
 Pippettes
 Conical flask
 20 ml graduated cylinders
 Standard flask
 Beaker

26.  Ammonium chloride
 Ammonium Hydroxide
 EDTA
 Erichrome Black T
 Magnesium sulphate

27. Pipette out 200 ml
of the sample
Add 2ml of
ammonium
buffer
Add 2 drops of EBT indicatorFill the
burrette with
EDTA
Titrate the content
against EDTA
solution
Continue the
titration till the
colour change to
steel blue

28.  Pipette out 200 ml of the sample
 Add 2ml of ammonium buffer
 Add 2 drops of EBT indicator
 Fill the burrette with EDTA (Ethylenediamine
tetra-acetic acid )

29.  Titrate the content against EDTA solution
 Continue the titration till the colour change to steel
blue
 This is the end point of the titration.

30.  When colour changes from wine red to blue click
the "stop" button & note the volume of EDTA used.
 Then calculate the hardness of water sample in
ppm using the equation as follows.
Total hardness=
vol of EDTA(ml) X 0.1 X molarity of EDTA x 106
vol of sample (ml)

31.  The degree of hardness of drinking water has been
classified in terms of the equivalent
CaCO3 concentration as follows:
 Soft: 0-60mg/L
 Medium: 60-120mg/L
 Hard: 120-180mg/L
 Very Hard: >180mg/L
http://nitttrc.ac.in/Four%20quadrant/eel/Quadran
t%20 %201/exp5_pdf.pdf

32.  Ammonia originates from metabolic,
agricultural and industrial processes and from
disinfection with chloramine .
 Natural levels - below 0.2 mg/ litre
 Its presence indicates pollution by bacteria ,
sewage or animal waste.
32

33.  pH< 7 causes severe corrosion
 Acceptable range - 6.5 to 8.5.
 Measured with pH strip/pH meter
33

34.  Alkalinity is an aggregate property of the
water sample which measures the acid-
neutralizing capacity of a water sample.
 The alkalinity of surface water is due to the
carbonate, bicarbonate and hydroxide
content.

35.  Step 1
 Fill a clean glass with the water to be tested.
 Step 2
 Remove a test strip from the kit, being
careful not to get it wet before placing it in
the glass.

36.  Step 3
 Dip the pH test strip into the water for several
seconds.
 Step 4
 Remove the pH strip . Hold the test strip level and
wait for the color indicator on the end of the strip
to finish changing.

37.  Step 5
 Take a reading of the pH by comparing the color
indicator on the test strip to the chart that came
with the pH test kit. Different colors indicate
different levels of pH.
 Step 6
 Dispose of the used test strip. It cannot be used
again.

38.  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
38

39.  H S Test Medium is recommended for the
detection of Salmonella species and
Citrobacter species from water samples.

40.  Principle:
 Test medium contains ferric salts which are
reduced by certain species of enteric
organisms to H2S.

41.  Fill the bottle with water up to arrow level
(20 ml).
 Allow to dissolve the powder and if required
shake gently.
 Keep at o room temperature (preferably at
32-35 C) for 24-48 hours.

42.  After incubation if color turns black, water is
not fit for drinking.

43.  Principle:
 A commonly used method for the
determination of trace amounts of iron
involves the complexation of Fe2+ (ferrous)
with 1,10-phenanthroline to produce an
intensely red orange colored complex

44.  Iron present in the water predominantly exists as
Fe3+.
 It is necessary to first reduce Fe3+ to Fe2+.
 This is accomplished by the addition of the reducing
agent hydroxylamine.
 An excess of reducing agent is needed to maintain
iron in the +2 state (because dissolved oxygen will
reoxidize Fe2+ to Fe3+).

45.  Fe2+ is quantitatively complexed by 1,10-
phenanthroline in the pH range from 3 to 9.
 Sodium acetate is used as a buffer to maintain a
constant pH at 3.5.
 If the pH is too high, the Fe2+ will be oxidized to
Fe3+
 If the pH is too low, H+ will compete with Fe2+ for
the basic 1,10-phenanthroline (to form phenH+ ).

46.  Hydroxylamine solution
 Sodium acetate solution
 1,10-phenanthroline solution

47.  Use the 500 µL automatic pipettor to pipet 0,
0.5, 1.0, 1.5, 2.0, and 2.5 mL of the standard
iron solution.
 50 mL volumetric flasks - Pipet .
 1 mL of the hydroxylamine solution
 5 mL of the sodium acetate solution
 5 mL of the 1,10-phenanthroline solution
(http://web.pdx.edu/~atkinsdb/teach/427/Ex
pt-IronSpec.pdf )

48.  Principle:
 The amount of chloride present in water can
be easily determined by titrating the given
samle with silver nitrate solution

49.  Burette with stand
 Pippettes
 Conical flask
 20 ml graduated cylinders
 Standard flask
 Beaker

50.  Silver Nitrate
 Phenophthalein indicator
 Sodium chlorode
 Potassium chromate
 http://nitttrc.ac.in/four%20quadrant/eel/qu
adrant%20-%201/exp4_pdf.pdf

51. Pipette out
20 ml of
sample
Add 2 drops of
potassium
chromate
indicator
Fill the burette with
silver nitrate (stored
in brown bottle)
Titrate the
content against
silver nitrate
solution
Titratte till the
colour changes to
brick red

52.  Ion Selective Electrode
 Based upon measurements of the potential
that measures electromotive force of a
galvanic element.

53.  Fluoride selective electrode is very selective
to fluoride ions.
 PH value of the solution during the
measurement by the fluoride selective
electrode must be in the range 5.00-7.00.

54. 54
Flame photometer

55. Zinc
 Gives undesirable astringent taste
 Zinc content >4mg/litre gives opalescent look
and greasy film on boiling
Manganese
 Acceptable levels-<0.1mg/litre
 Excess Mg stains sanitary ware and laundry
55

56.  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.
56

57.  Bacteriological indicators
 Virological aspects
 Biological aspects
57

58. 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
58

59.  Free from virus
 Disinfect with 0.5 mg/ml of free chlorine
residual after contact period of at least 30
minutes at pH 8.
59

60.  Protozoa-
E.histolytica , Balantidium coli
 Helminths-
Infective form of round worm, hook worm
dracunculus medinensis , schistosomes
 Free living-
fungi ,algae interfere with water treatment
60

61.  Recognized as a suitable microbial indicator
of drinking-water quality.
 Easy to detect and enumerate in water.
 Traditionally, coliform bacteria - Escherichia,
Citrobacter, Enterobacter, and Klebsiella.

62.  Human and animal wastes are a primary source.
 Coliform bacteria may not cause disease, but can
be indicators of pathogenic organisms that cause
diseases
 Intestinal infections, dysentery, hepatitis, typhoid
fever, cholera and other illnesses

63.  Indicator both of treatment efficiency and of the
integrity of the distribution system
 Principal methods used in the isolation of indicator
organisms from water are
 The membrane-filtration (MF) method
 The multiple-tube (MT)

64.  10ml of the sample - sterile membrane filter
 All indicator organisms are retained
 Transferred to a suitable selective culture
medium in a Petri dish , appropriate
temperature and suitable time .

65.  To allow the replication of the indicator
organisms.
 Results are expressed in numbers of “colony
forming units” (CFU) per 100ml of original
sample.

66.  Inappropriate for waters – high turbidity
 Expensive.

67.  Remove the cap from the sample bottle.

68.  With the stopper in position, shake the bottle
vigorously to achieve a homogeneous
dispersion of bacteria.

69.  With a sterile 10-ml pipette, inoculate 10ml
of the sample into each of five tubes
containing 10ml of presumptive broth.
 Add 50ml of sample to a tube containing
50ml of presumptive broth.
 It is advisable to shake the tubes gently to
distribute the sample uniformly throughout
the medium.

70.  Incubate the tubes at 35°C or 37°C for 24
hours.

71.  At the end of the 24-hour incubation period,
examine each tube for the presence of gas.
 If present, gas can be seen in the Durham tube.
 If none is visible, gently shake the tube.
 if any effervescence - should be considered
positive

72.  Using a table like the one shown here, record
the number of positive tubes after 24 hours.

73.  Reincubate negative tubes for a further 24-hour
period.
 At the end of this period, check the tubes again for
gas production.
 Gas production at the end of either 24 or 48 hours’
incubation is presumed to be due to the presence
of coliforms in the sample

74. http://www.who.int/water_sanitation_health/dwq/2edvol3d.pdf

75.  Procedure :
 Collect 100 ml - sterile disposable bottle.
 Add entire quantity of powder medium (PA Broth)
 Incubate the bottles for 24 - 48 hours at 30 - 35 C.

76.  Observe the colour change of the medium from
reddish-purple to yellow
 Indicating the presence of coliform bacteria.

77. 77
 Inorganic constituents
 Organic constituents

78. 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
78

79. 79
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

80. 80
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

81. 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
81

82. SURVEILLANCE OF
DRINKING WATER
QUALITY
82

83. “ Continuous and vigilant public health
assessment
and overview of the safety and acceptability
of
drinking-water supplies”(WHO-1976)
83

84.  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 & international
targets
84

85. 85
1. Setting water quality monitoring objectives
2. Assessment of resources availability
3. Reconnaissance survey (preliminary survey)
4. Network design
5. Sampling
6. Laboratory work
7. Data management
8. Quality assurance

86. 1. Setting water quality Monitoring objectives
 Rational planning of pollution control strategies
 To identify nature and magnitude of pollution
control required
 Identification of state and trends in water quality
86

87.  Identification of the mass flow of
contaminants in surface water
 Formation of standards and permit
requirements
 Testing of compliance with standard and
classifications for waters
 Early warning and detection of pollution
87

88. 2.Assessment Resources Availability
 Sampling equipment (as per checklist)
 Transport for sampling
 Laboratory facilities
 Trained manpower adequate number and competence
 Equipment/instrument for desired parameters anlysis
 Chemical/glasswares and others gadgets for analysis of
desired parameters
 Funds
88

89. Itinerary (planned route) for
the trip (route, stations to be
covered, start and return time)
Personnel and sample
transport
arrangement
Area map Sampling site location map
Icebox filled with ice or icepacks
or ice
Labels for sample containers
BOD bottles Rope
Special sample containers:
bacteriological, heavy metals, etc.
Sample containers
Sample preservatives (e.g. acid
solutions)
Thermometer
89

90.  Survey -overview of the geographical location
of the water body to be monitored,
 Its accessibility
 All kind of human influences to decide
appropriate sampling
 Location and also appropriate number of
sampling locations
90

91.  Survey include acquisition of following information:
 Location map
 Background information on water body
 Human activities
 Identification of potential polluting sources
 Water abstraction – quantity and uses
 Water flow regulation
 Helps in proper designing the network/schedule for
sampling
91

92.  Optimum number of sampling location
 Sampling frequency and parameters
92

93. 93
Type of
Station
Frequency Parameter
Baseline Perennial rivers and Lakes :
Four times a year
(A) Pre-monsoon: Once a year
Analyse 25 parameters as listed below :
(a)General
(b) Nutrients
(c)Organic Matter : BOD, COD
(d)Major ions
(e)Other inorganics (f)Microbiological
Total and Faecal Coliforms
(B)Rest of the year (after the pre-
monsoon sampling) at
every three months’ interval:
Analyse 10 parameters: Colour, Odour,
Temp., pH, EC,
DO, NO2 + NO3, BOD, Total and Faecal
Coliforms.
Seasonal rivers :
3-4 times (at equal spacing)
during flow period.
Lake:
4 times a year

94. Type of
Station
Frequency Parameter
Trend Once every month starting April-May
(pre-monsoon), i.e. 12 times a year
(A)Pre-monsoon: Analyse 25
parameters as listed for
baseline monitoring
(B)Other months : Analyse 15
parameters as listed
below
(a)General (b)Nutrients
(c)Organic Matter
(d)Major ions
(e)Microbiological
(C)Micropollutant :Once in a
year in monsoon
season
(i)Pesticides
(ii)Toxic Metals-
94

95. Type of
Station
Frequency Parameters
Baseline Twice a year in Pre & Post
monsoon season. The
frequency
may be reviewed after 3
years of
monitoring
A)Pre & Post Monsoon
season: Analyse 20
parameters as
listed below :
(a)General
(b)Nutrients
(c) Organic Matter
(d)Major ions
(e)Other inorganics and
other location-specific
parameter,
if any
95

96. 96
Type of
Station
Frequency Parameters
Trend Four times every year (once
in pre monsoon,
April-May, and
thereafter at intervals of 3
months)
(A)April-May : Analyse 20 parameters as
listed for
Baseline monitoring.
(B)Other times: Analyse 14 parameters as
listed below
(a)General
(b)Nutrients
(c)Organic Matter : COD
(d)Major ions : Cl
(e)Other organics : F, B
(f)Microbiological
(C) Micropollutant :
(i)Pesticides
(ii) Toxic metals-

97.  Rinse sample container three times with the
sample before it is filled.
 Leave small air space in the bottle - allow mixing
of sample at the time of analysis.
 Label the sample
 The sample code and the sampling date should be
clearly marked on the sample container or the tag.
97

98.  Complete the sample identification form for each
sample.
 The sample identification form should be filled for
each sampling
 Sample identification forms should all be kept in a
master file at the laboratory where the sample is
analysed.
98

99.  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)
99

100.  Standard methods does not in itself ensure
that reliable and accurate results will be
obtained.
 Analytical quality control
 The generation of data for the purpose of
assessing and monitoring
 how good an analytical method is
 how well it is operating

101.  Analytical quality assurance – comprises
 All the steps taken by a laboratory to assure that
laboratory is producing valid results.
 Quality assurance analytical quality control also
includes many other aspects.
 Proving that the individuals who carried out an
analysis were competent to do so.

102.  Ensuring that the laboratory has established and
documented analytical methods
 Equipment calibration procedures/ Management
lines of responsibility
 Systems for data retrieval
 Sample handling procedures

104.  Supervision
 An effective network for on-site testing
cannot function without adequate
supervision.
 Cover all field activities, including
waterquality testing.
 This helps to maintain adequate standards
of analysis.

105.  Blank sample analysis.
 It is unlikely that staff will be willing to submit
reports from the field.
 Furthermore, it is often impractical to prepare,
distribute, and collect the results of known quality
control samples.
 which would anyway receive especially careful
treatment in the field.

106.  Therefore to encourage staff to process
sterile distilled water in place of the sample
from time to time.
 If contamination does occur - analysts should
then recognize the inadequacies in their own
technique and question their own work
accordingly.
 Similarly, samples known to be contaminated
may be processed to provide a crude positive
control.

107.  Equipment review
 Decentralized testing with field test kits and other
portable equipment normally results in a larger
quantity of equipment being in use.
 Regular review of the equipment
(e.g. temperature checking of incubators)
 To ensure standardization, this should be
undertaken by supervisory staff from a control
laboratory.

108.  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
108

109. 109