Complaint Cell: 044- 4567 4567

Quality Assurance

PREAMBLE

The Quality of drinking water in Chennai is maintained and monitored by Chennai Metropolitan Water Supply and Sewerage Board through the Quality Assurance Wing. The Quality of water is monitored through sampling, testing and reporting through the team of trained personnel in the laboratory and field. This division is headed by Executive Engineer and consists of Engineers and Analysts.

The Engineers of this wing provides the necessary Engineering service for effective functioning of the wing and does investigation, preventive actions, sanitary survey and providing necessary assistance to the field staff in water quality surveillance.

The Analysts does the work of collecting water samples, analysis and report to the Engineers concerned in regard to the quality of water supplied to the public confirming to water quality standards.

MONITORING WATER QUALITY

The scientific personnel in the Analytical section have a periodical sampling programme as per the W.H.O. norms, for monitoring water quality at the sources, treatment plants, Water distribution stations and in the distribution net work.

Water samples are being collected, once in a month from the three lakes, which is major source of water supply to the Chennai City daily . The treated water from the water treatment plants are collected from the test tap and samples were examined for conformity to physical, chemical and Bacteriological standards, besides monitoring the treatment process at various units.

About 150 samples are collected from the City distribution system every day for physical, chemical and Bacteriological analysis, Out of this, 60 samples are tested for for Bacteriological analysis to ensure the water is safe for drinking.

Apart from the sampling carried out by Quality Assurance wing, 200 depot. Engineers monitor the minimum level of Residual chlorine available in the water distribution net work.

The water supplied to the public is assured as per norms laid down in BIS: 10500-2012,the Indian Standard. The Physical, Chemical and Bacteriological quality of water should not exceed the limits shown in the table below:

INDIAN STANDARD DRINKING WATER - SPECIFICATION (IS 10500 : 2012

Essential Characteristics

Sl.No. Substance or Characteristic Requirement (Acceptable Limit) Permissible Limit in
the absence of
Alternate source
1. Colour, (Hazen units, Max) 5 25
2. Odour Agreeable Agreeable
3. Taste Agreeable Agreeable
4. Turbidity (NTU, Max) 1 5
5. pH Value 6.5 to 8.5 No Relaxsation
6. Total Hardness (as CaCo3) mg/lit.,Max 300 600
7. Iron (as Fe) mg/lit,Max 1.0 No Relaxsation
8. Chlorides (as Cl) mg/lit,Max. 250 1000
9. Free Residual, chlorine,mg/lit,Min 0.2 1.0

Desirable Characteristics

10. Total Dissolved solids mg/lit,Max 500 2000
11. Calcium (as Ca) mg/lit,Max 75 200
12. Copper (as Cu)mg/lit,Max 0.05 1.5
13. Manganese (as Mn)mg/lit,Max 0.1 0.3
14. Sulphate (as SO4)mg/lit,Max 200 400
15. Nitrate (as NO3)mg/lit,Max 45 No relaxation
16. Fluoride (as F)mg/lit,Max 1.0 1.5
17. Phenolic Compounds (as C6 H5OH)mg/lit, Max. 0.001 0.002
18. Mercury (as Hg)mg/lit,Max 0.001 No relaxation
19. Cadmiun (as Cd)mg/lit,Max 0.003 No relaxation
20. Selenium (as Se)mg/lit,Max 0.01 No relaxation
21. Total Arsenic (as As)mg/lit,Max 0.01 No relaxation
22. Cyanide (as CN)mg/lit,Max 0.05 No relaxation
23. Lead (as Pb)mg/lit,Max 0.01 No relaxation
24. Zinc (as Zn)mg/lit,Max 5 15
25. Anionic detergents (as MBAS)mg/lit,Max 0.2 1.0
26. Total Chromium (as Cr6+)mg/lit,Max 0.02 No relaxation
27. Polynuclear aromatic hydro carbons (as PAH)g/lit,Max 0.0001 No relaxation
28. Mineral Oil mg/lit,Max 0.05 No relaxation
29. Pesticides - -
(i) DDT in Micro gm/l 1 No relaxation
(ii) Endosulfan Micro mg/lit Max 0.04 No relaxation
30. Alkalinity (as CaCO3) mg/lit.Max 200 600
31. Aluminium (as Al)mg/l,Max 0.03 0.2
32. Boron mg/lit,Max 0.5 1
33. Magnesium (as Mg). Mg/l.Max 30 100
34. Radioactive Materials
(i)Alpha emitters Bq/l,Max 0.1 No relaxation
(ii) Beta emitters Bq/l.Max 1.0

BACTERIOLOGICAL STANDARDS

I. Water entering the Distribution system Coliform count in any sample of 100 ml should be Zero. A sample of the water entering the distribution system that does not conform to this standard calls for an immediate investigation in to both the efficacy of the purification process and the method of sampling.

II. Water in the distribution system

  • E.coli count in 100ml of any sample should be zero.
  • Coliform organisms not more than 10 per 100 ml in any sample.
  • Coliform organisms should not be present in 100ml of any two consecutive samples or more than 5% of the samples collected for the year.

PRIVATE SAMPLES

Besides monitoring the Quality of water supplied by Metro Water, the C.M.W.S.S.B. facilitates the public to assess the water quality of their own sources(Well / Bore Well water) by testing for Physical and Chemical examination on nominal charges as follows:

1. Public (Individual houses-Drinking) Rs.75/- Per Sample
2. Private Institute(Drinking) Rs.200/- Per Sample
3. Private Institute(Construction) Rs.200/- Per Sample

The following parameters are tested for Physical and Chemical Examination for Drinking Purpose: Colour and Transparency, Odour, Turbidity (N.T.U.), Dissolved Solids mg/l, Calcium mg/l (as Ca), Magnesium mg/l (as Mg), Total Hardness mg/l (as CaCO3), Chlorides mg/l (as Cl), Ammoniacal Nitrogen mg/l ( as N), Albuminoid Nitrogen mg/l (as N), Nitrous Nitrogen mg/l (as N), Nitric Nitrogen mg/l ( as N), Oxygen absorbed mg/l, (Tidy's 4 hrs test), Hydrogen ion concentration (pH), Alkalinity to Phenolphthalein mg/l (as CaCO3 ), Alkalinity to Methyl orange mg/l (as CaCO3 ), Sulphates mg/l (as SO4 ), Phosphates mg/l (as PO 4), Iron mg/l (as Fe), Fluorides mg/l (as F) and Specific Conductance (micro siemens/cm) at 25 o C.

In case of water quality for Construction purpose the following parameters are tested for its suitability

Water used for mixing and curing shall be clean and free from injurious amounts of oils, acids, alkalis, salts, sugar, organic materials or other substances that may be deleterious to concrete or steel.

Permissible Limit for Solids for Construction purposes - IS 456 : 2000

Sl.No Description Permissible limit
1. Organic 200 mg/l
2. Inorganic 3000 mg/l
3. Sulphates (as So4) 400 mg/l
4. Chlorides (as Cl) 2000 mg/l
5. Suspended matter 2000 mg/l
6. pH 6.0
7. Iron Nil

1. To neutralise 200 ml of sample of water using Phenolphthalein as an indicator, it should not require more than 2.0 ml of 0.1 (N/10) Normal sodium hydroxide.

2. To neutralise 200 ml of sample of water using methyl orange as an indicator, it should not require more than 10 ml of 0.1 (N/10) Normal Hydro chloric acid.

3. Quantity of samples required for testing are as follows:

Drinking Purpose: 2 litres
Construction Purpose: 5 litres

The Containers used for collecting water samples should be free from any contamination. It is advised to use new plastic container of required capacity as mentioned above.

Procedure for remittance of Testing Charges:

On request, Junior Administrative officer, Q.A.Wing issues a challan for making payment at Canara Bank (Kellys Branch) located at Purasawalkam (Near Madharsha) and remitted challan is returned to Q.A.Wing for testing.

The Analytical Report shall be collected from the laboratory after15 days from the date of receipt of samples.


'
Daily Report of Residual Chlorine in City Water Supply
Residual Chlorine Report on 19.09.2017
R.C. in p.p.m. I II III IV V VI VII VIII IX X XI XII XIII XIV XV Total
More than 2.0 PPM - - 27 20 1 - 4 2 21 - 20 - - - - 95
1.0 to 2.0 PPM - - - - - - 5 9 - - - - - - - 14
0.6 to 0.9 PPM - - - - - - - - - - - - - - - 0
0.2 to 0.5 PPM - - - - - - - - - - - - - - - 0
Less than 0.2 PPM - - - - - - - - - - - - - - - 0
Total 0 0 27 20 1 0 9 11 21 0 20 0 0 0 0 109
Analytical Report

ANALYTICAL REPORT OF SEWAGE AT KODUNGAIYUR SEWAGE TREATMENT PLANT

S. No. Parameters   Raw Sewage Treated Sewage
1 Color   Greyish Sl.Yellowish
2 Odour   Objectionable Unobjectionable
3 Temperature oC 30 30
4 B.O.D (5 days at 20oC) mg/lit. 360 20
5 C.O.D mg/lit. 696 95
6 Total Suspended Solids mg/lit. 420 30
7 Total Solids mg/lit. 2170 1680
8 Total Dissolved Solids mg/lit. 1750 1650
9 Settelable Solids mg/lit. 25 2
10 pH   7.3 7.6

ANALYTICAL REPORT OF SEWAGE AT NESAPAKKAM SEWAGE TREATMENT PLANT

S. No. Parameters   Raw Sewage Treated Sewage
1 Color   Blackish Grey Colourless
2 Odour   Sulphide Odourless
3 Temperature oC 27 26
4 B.O.D (5 days at 20oC) mg/lit. 330 12
5 C.O.D mg/lit. 620 70
6 Total Suspended Solids mg/lit. 440 15
7 Total Solids mg/lit. 940 820
8 Total Dissolved Solids mg/lit. 1380 835
9 Settelable Solids mg/lit. 6 Nil
10 pH   7.3 7.8

ANALYTICAL REPORT OF SEWAGE AT KOYAMBEDU SEWAGE TREATMENT PLANT

S. No. Parameters   Raw Sewage Treated Sewage
1 Color   Blackish Colourless
2 Odour   Offensive Sl.Fishy
3 Temperature oC 29 28
4 B.O.D (5 days at 20oC) mg/lit. 350 21
5 C.O.D mg/lit. 910 79
6 Total Suspended Solids mg/lit. 563 29
7 Total Solids mg/lit. 1580 1510
8 Total Dissolved Solids mg/lit. 2143 1539
9 Settelable Solids mg/lit. 23 1
10 pH   7.3 7.8

STANDARD FOR TREATED SEWAGE EFFLUENT LET INTO INLAND WATER WAYS

1 B.O.D ( 5 days at 20o c) mg/l: 20
2 SUSPENDED SOLIDS mg/l: 30
Water Analytical Report
Sl. No. WATER QUALITY      
    RAW WATER KPS+300 MLD + Veeranam TEST TAP KPS+300 MLD + Veeranam CITY DISTRIBUTION
1 PERCENTAGE OF BACTERIOLOGICALLY GOOD SAMPLES 22 40 1276
2 NUMBER OF SAMPLES 0% 100% 98%
3 Colour Sl.Yellowish Colourless Colourless
4 Odour Sl.Earthy Chlorinous Chlorinous
5 Turbidity (NTU) 13 4 5
6 Total solids at 105 "C (mg/i) 303 295 305
7 Total Hardness (As CaCO3) 123 133 125
8 Calcium (As Ca) 24 22 23
9 Magenesium (As Mg) 14 18 18
9 Magenesium (As Mg) 14 18 18
10 Chlorides (AsCI) 64 71 78
11 Sulphates (As SO4) 33 32 39
12 Ammoniacal Nitrogen (As N) 0.07 0.04 0.03
13 Albuminoid Nitrogen (As N) 0.53 0.15 0.23
14 Nitrous Nitrogen (As N) Nil Nil Nil
15 Nitric Nitrogen (As N) 3.5 2.08 2.67
16 Oxygen absorbed (Tidy's test) 2.49 1.01 0.92
17 Alkalinity to Phenolphthaleint (As CaCO3) 108 Nil Nil
18 Alkalinity to Methyl Orange (As CaCO3) 0.01 107 101
19 Phosphates (As PO4) 0.15 0.01 0.01
20 Iron (As Fe) 8.1 0.06 0.12
21 Hydrogen Ion Concentration (pH) 8.1 7.9 7.6
22 Silicate (As SiO2) 10 10 10
23 Fluoride (As F) 0.1 0.1 0.1
24 Specific Conductance (Micromhos/cm) 472 450 475

LOCATION OF THE LABORATORY:

WATER ANALYSIS LABORATORY
C.M.W.S.S.Board, New Avadi Road, Kilpauk,
(Near Kilpauk Water Works) Chennai - 600 010.
Phone Number: 2644 9851