Water Standards

8/3/2019 Water Standards

1/27

Water Quality Standards and Criteria

Environment & Health

Water


2/27

Water quality standards

1. Acceptability Aspects.

2. Microbiological Aspects3. Chemical Aspects.

4. Radiological Aspects.


3/27

Acceptability aspects

Physicalparameters-

Turbidity- > 5 NTU(before chlorination shouldbe < 1).

Colour : 15 true colourunits (TCU).

Tasteand Odour

Temperature


4/27



5/27


Inorganic constituents-

Chlorides-200-600mg/L

Sodium-200mg/L

Ammonia-0.2mg/LpH : 6.5 to 8.5.

Hardness -


6/27



7/27

Biological oxygen demand

Indicationoftheorganic qualityofwater.

Units-milligrams ofoxygen consumed/Lofsampleduring( 5

days/20C)

Values- rivers 1 mg/L.

Moderatelypolluted rivers -2 to 8 mg/L.

Untreated sewage -600 mg/L.

Measurement of BOD-

Dilutionmethod

Manometric method


8/27

Microbiological Aspects

Coliform organisms- Faecal -E ColiandnonfaecalgroupKlebsiellaaerogenes.

Faecal Streptococci : confirmatoryevidenceofrecentfaecalpollution.

Cl perfringes :indicates thefaecal contaminationat some

remotetime.

Virological aspects-WHO standards notmorethanone

plaqueforming unit (PFU)/L.

There shouldalsobe completeabsenceofenteropathogenic

viruses andfaecalbacteriophages.

Protozoa- No Entamoeba histolytica, Balantidium coli .


9/27

Coliform Clperfringes

Rotavirus

Faecal streptococciE histolytica


10/27

BACTERIOLOGICAL STANDARDS

Water entering in distribution system in piped -0-Coliform countinany

sampleof100 ml.

Water in the distribution system-1. E.Coli countin 100 mlofany sample shouldbe zero.

2. Coliformorganisms notmorethan 10 per100 ml shallbepresentinany

sample.

3. Coliformorganisms shouldnotbedetectablein 100 mlofanytwo

consecutive samples ormorethan 50 percentofthe samples collectedforthe

year.

In individual or small community supplies- E.Coli count shouldbe zeroin

any sampleof100 ml,Coliform < 3 per100 ml.


11/27

Chemical aspects- Inorganic

chemicals

Arsenic-0.01(mg/lit)-pesticides,minerals & ores,industry,

ground water.

Cadmium-0.003(mcg/lit)-Steel,plastic industry,mining.

Chromium-0.05(mg/lit)-earth crust

Fluoride-(1.5mg/L)-Earth crust-Dentalfluorosis>1.5mg/L.

Skeletalfluorosis-(3-6mg/L)

Lead-(0.01mg/L)pipes& fittings-


12/27


13/27

Chlorinated Pesticides

Aldrin/dieldrin 0.03 (mcg/L)

Chlordane 0.2 (mcg/L)

DDT 2 (mcg/L)Hexachlorobenzene 1 (mcg/L)

Lindane 2 (mcg/L)

Methoxychlor20 (mcg/L)

Pentachlorophenol 9 (mcg/L)


14/27

Radiological Aspects

Sources-Mines,nuclearfuel cycle

Somatic/Heredity effect -leukemiathyroid,breast,bladder, colon,liver,

lung,esophagus,ovarian,multiplemyeloma,and stomach cancers.

Fetus-abortion,teratogenicity (birth defects),mentalretardation, IUGR and

leukemiathatappearin childhood.

Permissible limits-

Gross alphaactivity-0.1Bq/LGross Betaacivity-1.0 Bq/L


15/27


16/27

Surveillance ofDrinking Water

Quality

The continuous andvigilantpublic

health assessmentandreview ofthesafetyandacceptabilityofdrinking-

watersupplies (WHO, 1976).


17/27

Functions of surveillance

Approvalofnew source.

Disinfectionofplantafterinterruptionofsupply.

Periodic maintenance.Regulations ofchemical usedinin waterT/T.

Laboratoryanalysis indicates hazardto health.

Anoutbreak ofwaterbornediseaseoccurs inthe

area.


18/27

Elements of surveillance

Sanitary survey - On-siteinspectionandevaluation

bya qualifiedpersonofallthe conditions,devices,

andpractices inthe watersupply system which poseadangertothe health and wellbeingofthe water

consumer.

Nobacteriologicalorchemicalexamination.


19/27

Sampling

Physical & Chemical examination - WinchesterQuart Bottles (2L).

Bacteriological examination- Groundglass stopperbottle( 200-250mL)

Tap water

Rivers/Lakes/reservoirs & well


20/27

Bacteriological Surveillance

Presumptive coliform count-

Multiple Tube Method : This testis basedonestimatingthemostProbable

Number(MPN) ofcoliformorganisms in 100mlofwater.

Byinoculatingmeasured quantities ofthe sample water(0.1, 1.0, 10, 50 ml)

intotubes ofMcConkeys Lactose Bile salt Broth with bromocresolpurpleas

anindicator(48hours).

Confirmation-Subcultureinbrilliantgreenbilebroth. At 37 & 44 c for6-24

hrs.

Membrane Filtration Technique- celluloseestermembrane.


21/27

Faecal Streptococci and Cl. perfringens Detection.

Colony Count : The colony countonnutrientagarat 37C and

22C.

Water atconsumer end

Plate count after2 days at 37C

late count after3 days at 22C

Disinfected 0 20

Not disinfected 10 100

Organic matter-Total Organic Carbon (TOC), Biochemical Oxygen Demand(BOD) orChemical Oxygen Demand (COD).


22/27

THANKS


23/27

Water filtration in large scale

Rapid Sand Filter

Coagulation- (Alum)

RapidmixingFlocculation

Sedimentation

Filtration


24/27

Coagulation

RapidMixing Flocculation


25/27

Flocculent(Al(OH)3 Sedimentation


26/27


27/27

Govt initiatives-

1954-National watersupply & Sanitationprogramme

1972-Accelerated RuralWaterSupply & Sanitation

Programmeidentifiedproblem Village.

1981-Internationaldrinking watersupply & Sanitation Decade

programme.

2002-Swajaldhara-Panchayatplan,implement,operate,

maintain & manage watersupply & sanitation.

Documents

Water Standards