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1. QUALITY

3.  Guideline of drinking water quality
 WHO published- vol 1 1993
vol 2 1996
 Acceptability aspects
 Microbiological aspects
 Chemical aspects
 Radiological aspects

4.  Physical parameters
 Turbidity- <5 NTU
 Colour - upto 15 TCU
 Taste & odour
 Temperature

5.  Chlorides- std 200mg/l
max 600mg/l
 Hardness- calcium- 100-300 mg/l
 Ammonia- NH3 & NH4+
upto 1.5mg/l
 pH - 6.5-8.5
<7 -corrosion & incrustation
>8- compromise efficiency of disinfection
 H2S - 0.05-0.1mg/l
 Fe - 0.3mg/l
 Na - 200mg/l

6.  Total dissolved salts
TDS level <600mg/l [good]
< 1000mg/l [acceptable]
 Sulphate <250mg/l CaSO4 – 270mg/l
MgSO4 – 90mg/l
 Zn 3mg/l
 Mn 0.1mg/l
 Dissolved O2 indirect effects
 Cu 1mg/l
 Al 0.2mg/l

7.  Bacteriological indicators
 Coliforms- faecal groups -E coli
Non faecal –klebsiella aerogens
 Faecal streptococci - recent faecal pollution
 Clostridium perfringes - remote infection
 Virological aspects
 Cl2 - 0.5mg/l , 30min ,pH - 8
 O3 - 0.2-0.4mg/l , 4min
 Biological aspects
 Protozoa- E.histolytica ,giardia ,balantidium coli
 Helminths –
 Free living organisms – algae , fungi

8. inorganic constituents
organic constituents
inorganic constituents
arsenic – 0.01mg/l
dissolution of mineral ores ,industrial effluents
cadmium – 0.003mg/l
accumulate in kidney, long T1/2- 10-35y
chromium -0.05mg/l
cyanide – 0.07mg/l
processed cassava ,thyroid and CNS effects
fluoride – 1.5mg/l
dental & skeletal flurosis
production of Al ,manufacture of phosphate fertilizers (4%)

9. Lead Pb – 0.01mg/l , plumbing systems
placental transfer -12th week and continues
interfere with Ca2+ metabolism, renal tumors
subencephalopathic neurological &behavioural effects
Hg - 0.001mg/l ,target organ- kidney, methylHg- CNS effects
nitrate & nitrite – nitrate- 50mg/l
nitrite – 3mg/l
concent of nitrate + concent of nitrite = < 1
G.value of nitrate G.value of nitrite
selenium Se- 0.01mg/l

10. ORGANIC CONSTITUENTS UPPER LIMIT OF CONCENT
( microgm/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

11.  TDI- tolerable daily intake
 NOAEL- no- observed –adverse- effect level
 LOAEL- lowest- observed- adverse -effect level
 UF - uncertainty factor
 TDI = NOAEL/LOAEL
UF
 GV =TDI x BW x P
C
P=Fract of TDI allocated to drinking water
C=daily drinking water consumption
BW= body wt

12.  Somatic
 Hereditary
 Stochastic ef fect - carcinogenesis
 Non-stochastic ef fect - severity
 Aim- prevent NSE &reduce probability of SE
 DW- safe limits + reasonably low
 Becquerel- 1 disintegration/sec
 GV- gross alpha activity 0.1Bq/L
gross beta activity 1Bq/L

13.  Activities in surveillance
function
 approval of new sources
 watershed protection
 approval-construction & operating procedures of WW

disinfection of plant & distribution
system
 periodic flushing programmes & cleaning
 of water storage facilities
 certification of operators
 regulation of chemical substances
 Cross-connection control ,back flow
control ,leaK detection control
 Sanitary surveys
 Monitoring programmes

14.  Development of codes of practice for well construction ,pump
installation and plumbing
 Inspection quality control in bottled water
Elements of surveillance
programme
 SANITARY SURVEY
 SAMPLING
 BACTERIOLOGICAL SURVEILLANCE
presumptive coliform test- MULTIPLE TUBE METHOD
MEMBRANE FILTER TECHNIQUE
Confirmatory tests
 DETECTION OF FAECAL STREP & Cl.PERFRINGES
 COLONY COUNT
 BIOLOGICAL EXAMINATION
 CHEMICAL SURVEILLANCE

15. THANK U