|
WATER
QUALITY STANDARDS
The
basic purpose of making guidelines or standards is to provide safe
drinking water to all the citizens. The World Health Organization
(WHO) has provided guidelines for drinking water, which are advisory
in nature, and are based on scientific research and epidemiological
findings. The values of various water quality parameters recommended
by WHO are the general guidelines. That is why, different countries
have established their own water quality standards to meet their
national priorities taking in to account their economic, technical,
social, cultural, and political requirements. The PCRWR and Pakistan
Standard Institution (PSI) have already drafted drinking water quality
standards, however, the enforcement of these standards is still
pending. This matter needs to be addressed on top priority basis. The
WHO guidelines and standards proposed by national agencies like PCRWR,
Pakistan Standard Institution (PSI), International Bottled Water
Association (IBWA), Food Development Authority (FDA), Environmental
Protection Agency (EPA) and other countries are given in this chapter.
A.
Bacteriological Qualities
|
Source/Organisms |
Guideline Value |
-
All water intended for drinking
(E. Coli or thermo tolerant Coliform bacteria)
-
Treated water entering the distribution system (E. Coli or
thermo tolerant coliform and total coliform bacteria)
-
Treated water in the
distribution system (E. Coli or thermo tolerant coliform and
total coliform bacteria)
|
-
Must not be detectable in any
100 ml sample
-
Must
not be detectable in any 100 ml sample
-
Must not be detectable in any
100 ml sample
-
In the case of large supplies,
where sufficient samples are examined, must not be present in
95% of samples taken throughout any 12-month period.
|
B. Chemicals
of Health Significance
|
Inorganic |
mg/l |
Inorganic |
mg/l |
Inorganic |
mg/l |
|
Antimony
Arsenic
Barium
Boron
Cadmium
Chromium |
0.005
0.010
0.700
0.300
0.003
0.050 |
Copper
Cyanide
Fluoride
Lead
Manganese
Mercury |
2.000
0.070
1.500
0.010
0.500
0.001 |
Molybdenum
Nickel
Nitrate(NO3)
Nitrite(NO2)
Selenium |
0.070
0.020
50.00
03.00
0.010 |
C. Other
Parameters
|
Inorganic |
mg/l |
Inorganic |
mg/l |
Inorganic |
mg/l |
|
Colour
Taste, Odour.
Turbidity
Toluene
Xylenes
Ethyl-benzene
Styrene
Monochlorobenzene |
15 TCU
-
5 NTU
24-170
20-1800
2.4-200
4-2600
10-120 |
1,2 dichlorobenzene
1,4-dichlorobenzene
Dichlorobenzene
Synthetic detergents
Aluminum
Ammonia
Chloride
Copper |
1-10
0.3-30
5-50
-
0.2
1.5
250
1 |
Hardness,
pH, DO
Hydrogen sulfide
Iron
Manganese
Sodium
Sulfate
TDS
Zinc |
-
0.05
0.3
0.1
200
250
1000
3 |
D. Disinfectants and Disinfectant by-Products
|
Name |
Value |
Name |
Value |
|
Chlorine chlorophenol
2,4-dichlorophenol |
600-1000
0.3-40 |
2,4,6-trichlorophenol
2-chlorophenol |
2-300
0.1-10 |
|
3.2
Standards Drafted by PCRWR |
A. Bacteriological Standards (Urban
and Rural water supplies)
|
Categories |
Standards |
|
A. Piped Water Supplies
A-1 Treated water entering the
distribution system
·
Faecal Coliform
·
Coliform organisms
A-2 Un-treated water entering
the distribution system
·
Faecal Coliform
·
Coliform organisms
·
Coliform organisms
A-3 Water in the distribution
system
·
Faecal Coliform
·
Coliform organisms
·
Coliform organisms |
0/100 ml
0/100 ml
0/100 ml
0/100 ml
3/100 ml
0/100 ml
0/100 ml
3/100 ml |
|
B. Un-piped Water Supplies
·
Faecal Coliform
·
Coliform Organisms |
0/100 ml
10/100 ml |
B. Standards for Inorganic Health Related Constituents
|
Constituent |
Unit |
HDL* |
MPL** |
Toxic Effects |
|
Fluoride |
mg/l |
1.000 |
1.500 |
Dental fluorosis in children,
excessive concentrative may cause crippling skeletal fluorosis. |
|
Nitrate (NO3) |
mg/l |
45.000 |
45.000 |
Infantile methaemoglobinaemia. |
|
Lead |
mg/l |
0.050 |
0.050 |
Children particularly
susceptible to effects of lead on central nervous system |
|
Mercury |
mg/l |
0.001 |
0.001 |
Neurological effects |
*
Highest Desirable Level. ** Maximum
Permissible Level.
C. Other
Parameters
|
Constituent |
Unit |
HDL* |
MPL** |
Undesirable Effects |
|
Turbidity |
NTU |
2.5 |
5 |
Un-aesthetic, decrease in
efficiency of disinfections |
|
Colour |
PCU |
5 |
15 |
Un-aesthetic |
|
Taste & Odour |
- |
Unobjectionable |
Taste & Odour |
|
TDS |
mg/l |
500 |
1500 |
Fault or salty taste, corrosion
or instruction |
|
Iron |
mg/l |
0.1 |
1.0 |
Taste, discoloration |
|
Manganese |
mg/l |
0.05 |
0.5 |
Taste, discoloration |
|
Magnesium |
mg/l |
30 |
150 |
Stomach disturbances |
|
Copper |
mg/1 |
0.05 |
1.5 |
Taste, corrosion of pipes and
utensils taste |
|
Zinc |
mg/l |
5 |
15.0 |
Taste |
|
Sulfate |
mg/l |
200 |
400 |
Corrosion, Laxative effect |
|
Chloride |
mg/l |
200 |
600 |
Taste, Corrosion |
|
pH |
- |
7.0-8.5 |
6.5-9.2 |
Taste, Corrosion |
|
Hardness |
mg/l |
200 |
500 |
Corrosion or scale formation |
|
|
mg/l |
0.001 |
0.002 |
Taste |
*
Highest Desirable Level. ** Maximum
Permissible Level.
|
3.3
Pakistan Standard Institution |
Drinking Water Quality
Standards
A. Physical
Requirements
|
S. # |
Characteristics |
Unit |
MAC* |
MAC** |
|
1.
|
Turbidity |
NTU |
5 |
25 |
|
2.
|
Colour |
TCU |
5 |
50 |
|
3.
|
Taste & Odour |
- |
Unobjectionable |
|
4.
|
pH |
- |
7.0-8.5 |
³
6.5-
£
9.2 |
B. Chemical
Requirements
|
1.
|
Total Dissolved Solids |
mg/l |
1000 |
1500 |
|
2.
|
Chloride (Cl) |
mg/l |
200 |
600 |
|
3.
|
Sulfate (SO4) |
mg/l |
200 |
400 |
|
4.
|
Nitrate (NO3) |
mg/l |
- |
45 |
|
5.
|
Total Hardness (CaCO3) |
mg/l |
20 |
500 |
|
6.
|
Nitrite (NO2) |
mg/l |
Nil |
Nil |
|
7.
|
Magnesium (Mg) |
mg/l |
500 |
1000 |
|
8.
|
Total Ammonia |
mg/l |
0.1 |
0.5 |
|
9.
|
Hydrogen Sulfide |
mg/l |
Undetectable odour |
|
10.
|
Fluoride (F) |
mg/l |
- |
1.5 |
|
11.
|
Iron (Fe) |
mg/l |
0.3 |
1.0 |
|
12.
|
Zinc (Zn) |
mg/l |
5.0 |
15.0 |
|
13.
|
Manganese (Mn) |
mg/l |
0.1 |
0.5 |
|
14.
|
Copper (Cu) |
mg/l |
1.0 |
1.5 |
|
15.
|
Calcium (Ca) |
mg/l |
75 |
200 |
|
16.
|
Magnesium (Mg) |
mg/l |
50 |
150 |
|
17.
|
Phenolic Substances |
mg/l |
0.001 |
0.002 |
|
18.
|
Alkyl Benzyl Sulfates |
mg/l |
0.5 |
1.0 |
|
19.
|
Carbon Chloroform Extract |
mg/l |
0.2 |
0.5 |
C. Limits of
Toxic Substances
|
1.
|
Arsenic (As) |
mg/l |
0.01 |
- |
|
2.
|
Cadmium (Cd) |
mg/l |
0.01 |
- |
|
3.
|
Chromium (Cr) |
mg/l |
0.05 |
- |
|
4.
|
Cyanide (Cn) |
mg/l |
0.20 |
- |
|
5.
|
Lead (Pb) |
mg/l |
0.05 |
- |
|
6.
|
Selenium (Se) |
mg/l |
0.20 |
- |
|
7.
|
Radionaclider |
Uo/l |
1000 |
- |
D.
Biological Requirements (Chemical Indicators of Pollution)
|
1.
|
Chemical Oxygen Demand (COD) |
mg/l |
10 |
- |
|
2.
|
Biochemical Oxygen Demand (BOD) |
mg/l |
6 |
- |
|
3.
|
Ammonia (NH3) |
mg/l |
0.5 |
- |
|
4.
|
Grease |
mg/l |
1 |
- |
E.
Limits for Bacteriological Contaminants
|
Acceptable bacterial standards
for potable water supplies: |
|
i)
Standard plate count (SPC)/mls
ii)
Presumptive test for Coliform
iii)
Most probable number (MPN) |
No more than 100
Negative
< 101 subject to the frequency
of opportunity for water analysis. |
*
Maximum Acceptable Concentration. ** Maximum
Allowable Concentration.
|
3.4
International Bottled Water
Association (IBWA) Standards |
A. Chemical Quality
Characteristics
|
Unit
|
Standard
|
Characteristics
|
Unit
|
Standard
|
|
Arsenic (As) |
mg/l |
0.05 |
Mercury (Hg) |
mg/l |
0.001 |
|
Barium (Ba) |
mg/l |
1 |
Nitrate (NO3) |
mg/l |
10 |
|
Cadmium (Cd) |
mg/l |
0.005 |
Nitrite (NO2) |
mg/l |
1 |
|
Chromium (Cr) |
mg/l |
0.05 |
Selenium (Se) |
mg/l |
0.01 |
|
Chloride (Cl) |
mg/l |
250 |
Silver (Ag) |
mg/l |
0.025 |
|
Copper (Cu) |
mg/l |
1 |
Sulfate (SO4) |
mg/l |
250 |
|
Cyanide (Cn) |
mg/l |
0.1 |
Phenolic |
mg/l |
0.001 |
|
Fluoride (F) |
mg/l |
4 |
PCB |
mg/l |
0.0005 |
|
Iron (Fe) |
mg/l |
0.3 |
TDS |
mg/l |
500 |
|
Lead (Pb) |
mg/l |
0.005 |
Zinc (Zn) |
mg/l |
5 |
|
Manganese (Mn) |
mg/l |
0.05 |
Turbidity |
NTU |
0.5 |
B. Microbiological Quality
|
Escherichia Coli |
MPN/100 ml |
Nil |
Coliform |
MPN/100 ml |
Nil |
|
3.5
Food Development Authority (FDA) Water Standards
|
Characteristics
|
Unit
|
Standard
|
|
Characteristics
|
Unit
|
Standard
|
|
Arsenic (As) |
mg/l |
0.05 |
Nitrate (NO3) |
mg/l |
10 |
|
Barium (Ba) |
mg/l |
1 |
Selenium (Se) |
mg/l |
0.01 |
|
Cadmium (Cd) |
mg/l |
0.01 |
Silver (Ag) |
mg/l |
0.05 |
|
Chromium (Cr) |
mg/l |
0.05 |
Sulfate (SO4) |
mg/l |
250 |
|
Chloride (Cl) |
mg/l |
250 |
Phenolic |
mg/l |
0.001 |
|
Copper (Cu) |
mg/l |
1 |
Ra 226 activity (pCi/l) |
- |
5 |
|
Iron (Fe) |
mg/l |
0.3 |
Total Beta activity (pCi/l) |
- |
8 |
|
Lead (Pb) |
mg/l |
0.05 |
TDS |
mg/l |
500 |
|
Manganese (Mn) |
mg/l |
0.05 |
Zinc (Zn) |
mg/l |
5 |
|
Mercury (Hg) |
mg/l |
0.002 |
Coliform (MPN/100 ml) |
|
<2,20 |
|
3.6 National Environmental Quality Standards by EPA
(Liquid
Industrial Effluents) |
|
Sr.# |
Parameter |
Standards |
|
1. |
Temperature |
40
°C |
|
2. |
pH Value (acidicity/basicity) |
6-10 pH |
|
3. |
5-day Biochemical Oxygen Demand
(BOD) at 200C |
80 mg/l |
|
4.
|
Chemical Oxygen Demand (COD) |
150 mg/l |
|
5.
|
Total Suspended Solids |
150 mg/l |
|
6.
|
Total Dissolved Solids |
3500 mg/l |
|
7.
|
Grease and Oil |
10 mg/l |
|
8.
|
Phenolic Compounds (as phenol) |
0.1 mg/l |
|
9.
|
Chloride (as Cl) |
1000 mg/l |
|
10.
|
Fluoride (as F) |
20 mg/l |
|
11.
|
Cyanide (as Cn) |
2 mg/l |
|
12.
|
An-ionic detergents (as MBAS)
3 |
20 mg/l |
|
13.
|
Sulfate (SO4) |
600 mg/l |
|
14.
|
Sulfide (S) |
1.0 mg/l |
|
15.
|
Ammonia (NH3) |
40 mg/l |
|
16.
|
Pesticides, herbicides,
fungicides and insecticides |
6.15 mg/l |
|
17.
|
Cadmium |
0.1 mg/l |
|
18.
|
Chromium (trivalent and
hexavalent) |
1.0 mg/l |
|
19.
|
Copper |
1.0 mg/l |
|
20.
|
Lead |
0.5 mg/l |
|
21.
|
Mercury |
0.01 mg/l |
|
22.
|
Selenium |
0.5 mg/l |
|
23.
|
Nickel |
1.0 mg/l |
|
24.
|
Silver |
1.0 mg/l |
|
25.
|
Total Toxic Metals |
2.0 mg/l |
|
26.
|
Zinc |
5.0 mg/l |
|
27.
|
Arsenic |
1.0 mg/l |
|
28.
|
Barium |
1.5 mg/l |
|
29.
|
Iron |
2.0 mg/l |
|
30.
|
Manganese |
1.5 mg/l |
|
31.
|
Boron |
6.0 mg/l |
|
32.
|
Chlorine |
1.0 mg/l |
|
3.7
Indian Water Quality Standards |
A. Physical
and Chemical Standards
|
Sr.
#. |
Characteristics
(mg/l) |
Acceptable |
Marginal |
Sr.
#. |
Characteristics
(mg/l) |
Acceptable |
Marginal |
|
|
Turbidity (NTU) |
2.5 |
10 |
7 |
Fluoride |
1.0 |
1.5 |
|
2 |
Colour (TCU) |
5 |
25 |
8 |
Nitrate (N) |
45 |
45 |
|
3 |
Taste & Odour |
Unobjectionable |
9 |
|
75 |
200 |
|
4 |
pH |
7-8.5 |
6.5-9.2 |
10 |
Magnesium |
30 |
150 |
|
5 |
TDS |
500 |
1500 |
11 |
Iron |
0.1 |
1.0 |
|
6 |
Hardness |
200 |
600 |
12 |
Manganese |
0.05 |
0.5 |
|
13 |
Chloride |
200 |
1000 |
21 |
Copper |
0.05 |
1.5 |
|
14 |
Sulfate |
200 |
400 |
22 |
Zinc |
5.0 |
15 |
|
15 |
Phenolic Compounds
|
0.001 |
0.002 |
23 |
Lead |
0.1 |
0.1 |
|
16 |
Anionic Detergents
|
0.2 |
1.0 |
24 |
Selenium |
0.01 |
0.001 |
|
17 |
Arsenic |
0.05 |
0.05 |
25 |
Mercury |
0.001 |
0.2 |
|
18 |
Cadmium |
0.01 |
0.01 |
26 |
Polynuclear aromatic
hydrocarbons (mg/l) |
0.2 |
3 |
|
19 |
Chromium |
0.05 |
0.05 |
27 |
Gross Alpha Activity
|
3 (pCi/l) |
30 |
|
20 |
Cyanide |
0.05 |
0.05 |
28 |
|
|
- |
-
The
figures indicated under the column “Acceptable” are the limits
up to which the water is generally acceptable to the consumers.
-
Figures
in excess of those mentioned under “acceptable” render water not
acceptable, but still may be tolerated in absence of alternative and
better source but up to the limits indicated under column “Marginal”
above which the supply will have to be rejected.
B.
Bacteriological Standards
-
Water entering the
distribution system coliform count in any sample of 100 ml should be
zero.
-
Water in the
distribution system shall satisfy all the three criteria indicated
below:
-
E.Coli count in 100 ml
of any sample should be zero;
-
Coliform
organisms no more than 10 per 100 ml shall be present in any sample;
and
-
Coliform
organisms should not be detectable in 100 ml of any two consecutive
samples or more than 50% of the samples collected for the year.
-
Individual or small community supplies.
C. Virological Aspects
-
A level of 0.5 mg/l of
free chlorine residual for one hour is sufficient to inactivate virus,
even in water that was originally polluted. This free chlorine
residual is to be insisted in all disinfected supplies in areas
suspected of endemicity of infectious hepatitis to take care of the
safety of the supply from virus point of view, which incidentally
takes care of the safety from the bacteriological point of view as
well. For other areas 0.2 mg/l of free chlorine residual for half an
hour should be insisted.
-
The water quality standards developed and enforced by various
countries are given below:
|
3.8 Water
Quality Standards of Indonesia, Singapore, Malaysia, Thailand,
Philippines and Brunei. |
A. Chemical Quality
|
S. # |
Substances |
Unit
|
Indonesia |
Singapore |
Malaysia |
Thailand |
Philippines |
Brunei |
|
1 |
Arsenic (As) |
mg/l |
0.05 |
0.05 |
0.05 |
0.05 |
0.05 |
<0.003 |
|
2 |
Barium (Ba) |
mg/l |
- |
1 |
- |
1 |
- |
<0.02 |
|
3 |
Borate (BO3) |
mg/l |
- |
0.03 |
30 |
- |
- |
0.2 |
|
4 |
Cadmium (Cd) |
mg/l |
0.1 |
0.01 |
0.01 |
0.005 |
0.01 |
<0.002 |
|
5 |
Chromium (Cr) |
mg/l |
- |
0.05 |
0.05 |
0.05 |
0.05 |
<0.01 |
|
6 |
Chloride (Cl) |
mg/l |
250 |
0.05 |
- |
250 |
- |
- |
|
7 |
Chlorine (Cl2) |
mg/l |
- |
- |
1 |
1 |
- |
- |
|
8 |
Copper (Cu) |
mg/l |
0.5 |
- |
- |
0.1 |
1 |
<0.01 |
|
9 |
COD |
mg/l |
- |
- |
0.01 |
1 |
- |
- |
|
10 |
Cyanide (CN) |
mg/l |
0.05 |
0.01 |
2 |
- |
0.01 |
- |
|
11 |
Fluoride (F) |
mg/l |
1 |
2 |
- |
- |
2 |
0.09 |
|
12 |
Hardness (CaCO3) |
mg/l |
170 |
- |
- |
100 |
- |
- |
|
13 |
Iodine (I) |
mg/l |
- |
1 |
- |
0.3 |
- |
- |
|
14 |
Iron (Fe) |
mg/l |
0.1 |
- |
- |
0.05 |
1 |
- |
|
15 |
Lead (Pb) |
mg/l |
0.05 |
0.05 |
0.05 |
0.05 |
0.05 |
<0.01 |
|
16 |
Manganese (Mn) |
mg/l |
0.05 |
2 |
2 |
0.002 |
0.1 |
0.01 |
|
17 |
Mercury (Hg) |
mg/l |
0.001 |
1 |
0.001 |
- |
0.001 |
<0.005 |
|
18 |
Mineral Oil |
mg/l |
- |
ND |
ND |
- |
- |
- |
|
19 |
Nitrate (NO3) |
mg/l |
ND |
45 |
45 |
4 |
45 |
<0.01 |
|
20 |
Nitrite (NO2) |
mg/l |
ND |
0.005 |
0.005 |
- |
0.01 |
- |
|
21 |
Organic Matter |
mg/l |
1 |
0.003 |
3 |
- |
5 |
- |
|
22 |
Selenium (Se) |
mg/l |
- |
0.01 |
0.01 |
0.01 |
0.01 |
- |
|
23 |
| 
