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Water quality monitoring
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Water Quality Monitoring and Standards, Sampling,
Preservation, Transportation Techniques
Arjesh SharmaSr. Manager
Pollution Control Research InstituteBHEL, HARIDWAR – 249 403
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
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
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
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
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.
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
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
Factors Influencing Source Water Quality
Natural Factors
Climate
Watershed characteristics
Geology
Microbial growth
Fire
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
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
Types of Samples
Grab or Catch Samples
Composite Samples
Integrated Samples
Generally for drinking water quality monitoring,
Grab Samples are taken
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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.
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
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
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
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 :
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
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
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.
IS : 10500 - 1991
Indian StandardDrinking Water - Specification
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.
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
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
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
Thank You