Water Criteria Std n Pollution 03

8/14/2019 Water Criteria Std n Pollution 03

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Water Quality Water Quality Criteria &Criteria &

StandardsStandards


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IntroductionIntroduction

Quest for pure waterQuest for pure waterFormulation of specificFormulation of specific

standardsstandardsTo judge the quality of To judge the quality of waterwater

To minimise healthTo minimise healthhazardshazards


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Guidelines for drinkingGuidelines for drinkingwater quality (WHO)water quality (WHO)

Relates to the followingRelates to the followingaspects:aspects:

AcceptabilityAcceptabilityMicrobiologicalMicrobiologicalChemicalChemicalRadiologicalRadiological


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AcceptabilityAcceptability

Physical parametersPhysical parameters

InorganicInorganicconstituentsconstituents


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Physical ParametersPhysical Parameters

CharacteristiCharacteristicscs

UpperUpperlevelslevels

Reason forReason forUpper levelsUpper levels

ColourColour 15 TCU15 TCU Coloured organicColoured organicmatter, metals,matter, metals,industrial wastesindustrial wastes

Taste & odourTaste & odour --TemperatureTemperature --TurbidityTurbidity 5 NTU5 NTU Inadequate treatment.Inadequate treatment.

Interferes withInterferes withdisinfectiondisinfection


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Inorganic constituentsInorganic constituentsConstituentsConstituents UpperUpper

levelslevelsSuggests /Suggests /ConsequencesConsequences

ChloridesChlorides 250mg/L250mg/L Water contaminationWater contamination

AmmoniaAmmonia 1.5mg/L1.5mg/L Possible bacterial,Possible bacterial,sewage, animal wastesewage, animal wastepollutionpollution

PP HH >8.5>8.5 Decreases the efficiencyDecreases the efficiencyof disinfectionof disinfection

Hydrogen sulphideHydrogen sulphide 0.05mg/L0.05mg/L Oxygen depletionOxygen depletion

IronIron 0.3mg/L0.3mg/L Stains laundry, plumbingStains laundry, plumbingfixturesfixtures

Total DissolvedTotal DissolvedSolids (TDS)Solids (TDS)

1000mg/1000mg/LL

unpalatableunpalatable


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Microbiological AspectsMicrobiological Aspects

Bacteriological indicatorsBacteriological indicatorsColiform organisms probableColiform organisms probablepresence of intestinal pathogens.presence of intestinal pathogens.

Faecal streptococci evidence of Faecal streptococci evidence of recent faecal pollution of water.recent faecal pollution of water.Cl. Perfringens their presence in theCl. Perfringens their presence in theabsence of coliforms suggests pastabsence of coliforms suggests past

contamination.contamination.


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Microbiological AspectsMicrobiological Aspects

Virological aspects Virological aspects 0.5mg/L of free residual0.5mg/L of free residual

chlorine & Ozone effectivechlorine & Ozone effectiveviral disinfectantsviral disinfectants

Biological aspects Biological aspects Protozoa, Helminths, FreeProtozoa, Helminths, Freeliving organismsliving organisms


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Chemical AspectsChemical Aspects

Cumulative toxic propertiesCumulative toxic propertiesInorganicInorganic

Potentially hazardous to human healthPotentially hazardous to human health

Those detected frequentlyThose detected frequentlyThose detected in relatively highThose detected in relatively highconcentrationsconcentrationsE.g. Lead, Arsenic, Mercury, Fluoride etcE.g. Lead, Arsenic, Mercury, Fluoride etc

OrganicOrganicPolynuclear aromatic hydrocarbonsPolynuclear aromatic hydrocarbonsPesticidesPesticides


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Chemical aspectsChemical aspectsHealth risk assessmentHealth risk assessmentTolerable daily intake (TDI)Tolerable daily intake (TDI)

No observed adverse effectNo observed adverse effectlevel (NOAEL)level (NOAEL)Lowest observed adverseLowest observed adverseeffect level (LOAEL)effect level (LOAEL)Uncertainty factorsUncertainty factors


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Radiological AspectsRadiological Aspects

Not only within safeNot only within safelimitslimits

As low as isAs low as isreasonably possiblereasonably possible


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Surveillance of DrinkingSurveillance of Drinkingwater qualitywater quality

Sanitary surveySanitary surveySamplingSampling

Bacteriological surveillanceBacteriological surveillanceBiological examinationBiological examination

Chemical surveillanceChemical surveillance


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Surveillance of DrinkingSurveillance of Drinkingwater qualitywater quality

Sanitary SurveySanitary SurveySamplingSampling

For physical& chemical examination Bottle capacity < 2 L.

Winchester quart bottles

For bacteriological examination Capacity 200-250ml Clean, sterile bottles

Collection of samples

Transport &


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Surveillance of DrinkingSurveillance of Drinkingwater quality ( contd)water quality ( contd)

Bacteriological SurveillanceBacteriological SurveillancePresumptive coliform testPresumptive coliform test

Colony countsColony countsDetection of faecal streptococci &Detection of faecal streptococci &Cl. perfringensCl. perfringens

Biological examinationBiological examinationChemical surveillanceChemical surveillance


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Presumptive coliformPresumptive coliformteststests

1.1. Multiple tube methodsMultiple tube methodsEstimating the most probable no. (MPN) of Estimating the most probable no. (MPN) of

colliform organisms in 100 ml of water colliform organisms in 100 ml of water

the test is carried out by inoculating measuredthe test is carried out by inoculating measuredquantities of the sample water (0.1,1.0,10, 50 ml)quantities of the sample water (0.1,1.0,10, 50 ml)into tubes of Mc Conkey's Lactose Bileinto tubes of Mc Conkey's Lactose Bilesalt broth with Bromocresol purple as indicator salt broth with Bromocresol purple as indicator


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the tubes are incubated for 48 hrsthe tubes are incubated for 48 hrsfrom the number of tubes showing acid andfrom the number of tubes showing acid andgas an estimate of MPN of coliformgas an estimate of MPN of coliformorganisms in 100 ml of the sample water organisms in 100 ml of the sample water can be obtained from the statistical tablescan be obtained from the statistical tablesthis result is known as presumptive coliformthis result is known as presumptive coliformcount (presumption - each tube showingcount (presumption - each tube showingfermentation- coliform organisms)fermentation- coliform organisms)

sometimes it may be due to other sometimes it may be due to other organisms or combination of organismsorganisms or combination of organisms


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Confirmatory testsConfirmatory tests

it is not required in case of unchlorinated water,it is not required in case of unchlorinated water,but required in chlorinated water but required in chlorinated water done by subculturing each presumptive positivedone by subculturing each presumptive positive

tube in 2 tubes of brilliant green bile broth, onetube in 2 tubes of brilliant green bile broth, oneof which is incubated at 37 deg C for upto 48 hrsof which is incubated at 37 deg C for upto 48 hrsfor confirmation of coliform organismsfor confirmation of coliform organismsother tube is incubated at44 Deg C andother tube is incubated at44 Deg C andinspected after 6 and 24 hrs to decide whether or inspected after 6 and 24 hrs to decide whether or not E. coli is presentnot E. coli is present


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E. coli is almost the only coliform organismE. coli is almost the only coliform organismwhich is capable of producing gas fromwhich is capable of producing gas fromlactose at 44 deg Clactose at 44 deg CFurther confirmation of the presence of Further confirmation of the presence of E. coli if desired can be obtained byE. coli if desired can be obtained bytesting for Indole production at 44 deg Ctesting for Indole production at 44 deg C


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2. Membrane Filtration2. Membrane Filtrationtechniquetechnique

in some countries used as a standardin some countries used as a standardprocedure to test for coliform organismsprocedure to test for coliform organismsA measured volume is filtered through aA measured volume is filtered through amembrane specially made of cellulosemembrane specially made of celluloseester ester


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All the bacteria present in water are retained onAll the bacteria present in water are retained onthe surface of the membrane and bythe surface of the membrane and byinoculating the membrane face upwards on ainoculating the membrane face upwards on a

suitable media and at appropriate temperature,suitable media and at appropriate temperature,it is possible to count the colonies and obtainit is possible to count the colonies and obtainthe results within 20 hrs as compared to72-96the results within 20 hrs as compared to72-96hrs required for the usual multiple tubehrs required for the usual multiple tubetechniquetechnique


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Colony countColony count

colony counts on nutrient Agar at 37 deg C andcolony counts on nutrient Agar at 37 deg C and22 deg C are frequently used in the22 deg C are frequently used in thebacteriological examination of water bacteriological examination of water

Colony counts provide an estimate of the generalColony counts provide an estimate of the generalbacterial purity of water bacterial purity of water A single count is of little value, but count from theA single count is of little value, but count from thesame source at frequent intervals is of same source at frequent intervals is of considerable value- a sudden increase will giveconsiderable value- a sudden increase will givean earliest indication of contaminationan earliest indication of contamination


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Recommended plateRecommended platecountscounts

Water at theWater at thepoint of point of consumptionconsumption

Plate countPlate countafter 2 days atafter 2 days at37 deg C37 deg C

Plate count after 3Plate count after 3days at 22 deg Cdays at 22 deg C

DisinfectedDisinfected 00 2020

notnot

disinfecteddisinfected

1010 100100


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Recent studies indicate that a bacterialRecent studies indicate that a bacterialplate count on yeast extract agar after plate count on yeast extract agar after incubation at 22 deg C for 7 days mightincubation at 22 deg C for 7 days mightserve as a general purpose indicator of serve as a general purpose indicator of microbial quality because in the absencemicrobial quality because in the absenceof chlorine residual the no. of bacteria canof chlorine residual the no. of bacteria can

grow enormously.grow enormously.


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Hardness of WaterHardness of Water

Soap destroying power of waterSoap destroying power of waterCaused by dissolved compounds of Caused by dissolved compounds of calcium and magnesiumcalcium and magnesiumExpressed in terms of mEq./L (< 1=Expressed in terms of mEq./L (< 1=soft & > 6= very hard water)soft & > 6= very hard water)Drinking water should be moderatelyDrinking water should be moderatelyhardhardDisadvantagesDisadvantages ::

Consumes more soap , Destroys fabricsConsumes more soap , Destroys fabrics

Unsuitable in certain industries, Scaling of Unsuitable in certain industries, Scaling of utensils / boilersutensils / boilersShortens life of pipes & fixturesShortens life of pipes & fixtures

Advantage - ? Protection from cardio-Advantage - ? Protection from cardio-vascular diseasesvascular diseases


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WATER POLLUTIONWATER POLLUTION


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Two major classificationsTwo major classifications

Point sourcePoint source Non point sourceNon point source


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Point SourcesPoint Sources

Single large sourceSingle large sourceCan localize it to one spotCan localize it to one spot-- Industrial PlantsIndustrial Plants

- Sewage pipes- Sewage pipes


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Point Source - ExamplePoint Source - Example

LUST - LeakyLUST - LeakyUnderground StorageUnderground StorageTanksTanks

22% of the 1.2 million22% of the 1.2 millionUST are LUSTyUST are LUSTy

Look at water pollutionLook at water pollutionfrom gasoline...from gasoline...


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PointPoint

sourcesourceexamplesexamples


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Non-point SourcesNon-point Sources

Diffuse source or many smaller pointDiffuse source or many smaller pointsourcessourcesAutomobilesAutomobiles

Fertilizer on fieldsFertilizer on fields


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Non pointNon pointsourcesource

examplesexamples


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Non-point sourceNon-point sourcepollutants - nutrientspollutants - nutrients

P i fP i f


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Prevention of waterPrevention of waterpollution???pollution???


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Thank youThank you

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Water Criteria Std n Pollution 03