drinkingwaterquality-120925031300-phpapp02 Copy.pptx

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

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

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

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

5. Bacteriological indicators Coliforms- faecal groups -E coli Non faecal Faecal streptococci Clostridium perfringes –klebsiella aerogens - recent faecal pollution - 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

6. 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%)

7. Lead Pb – 0.01mg/l , plumbing systems placental transfer - 12 th 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

8. 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

9. 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

10. ➢ ➢ Somatic Hereditary Stochastic effect - carcinogenesis ➢ ➢ ➢ ➢ ➢ Non- stochastic effect - 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

11. 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

12. ❖ 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

13. THANK U