1. Compounds Affecting the potability of water
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|
Substance
|
Maximum allowable limit
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- Total dissolved solids
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1500 mg/l
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- Iron
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50 mg/l
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- Manganese(assuming that the ammonia content is less than 0.5 mg/l)
|
5 mg/l
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- Copper
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1.5 mg/l
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- Zine
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1.5 mg/l
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- Magnesium plus sodium sulfate
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1000 mg/l
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- Alkyl benzyl sulfonates (ABS : surfactants)
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0.5 mg/l
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2. Components hazardous to health
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|
Substance
|
Maximum allowable limit
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- Nitrate as NO3
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454 mg/l
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- Fluoride
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1.5 mg/l
|
3. Toxic substances
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|
Substance
|
Maximum allowable limit
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- Phenolic substances
|
0.002 mg/l
|
- Arsenic
|
0.05 mg/l
|
- Cadmium
|
0.01 mg/l
|
- Chromium
|
0.05 mg/l
|
- Cyanide
|
0.2 mg/l
|
- Lead
|
0.05 mg/l
|
- Selenium
|
0.01 mg/l
|
- Radionuclides(gross beta activity)
|
1000 mg/l
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4. Chemical indicators of pollution
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|
Indicator
|
Maximum limit of pollution
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- Chemical oxygen demand (COD)
|
10 mg/l
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- Biochemical oxygen demand (BOD)
|
6 mg/l
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- Total nitrogen exclusive of NO3
|
1 mg/l
|
- NH3
|
0.5 mg/l
|
- Carbon chloroform (CCE : organic pollutants)
|
0.5 mg/l
|
- Grease
|
1 mg/l
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5. Bacteriological Standards
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|
Classification
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MPN/100 ml coliform bacteria
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- Bacterial quality applicable to disinfection treatment only
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0-50
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- Bacterial quality requiring conventional methods of treatment(coagulation,Filtretion, disinfection)
|
50-5000
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- Heavy pollution requiring extensive types of treatment
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5000-50000
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- Very heavy pollution, unacceptable unless special treatment designed for such water are used ; source to be used only when unavoidable
|
greater than 50000
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