Physico - Chemical Analytical Results of Surface Water Samples of Amarsagar, South Tripura

Pollution Status Assessment of Amarsagar , South Tripura

1.0 Introduction :

Lakes are considered to be one of the most productive and biologically rich inland surface water ecosystem. They are either natural or man-made. Several important urban conglomerations have various natural and man- made lakes, reservoirs, which objectively fulfill various demands of mankind. The growing urbanization, scarcity of potable water and ever increasing anthropogenic influences have been constantly exerting pressure on surface water bodies.

The availability and quality of fresh water resources have always remained an important consideration in taking decision about any development project, and planners usually confine themselves to the problems of meeting requirement of water and its disposal after use. Until recently the water bodies were thought to be the cheapest convenient refuse disposal systems. This tendency has resulted in indiscriminate and excessive loading of waste matter into the aquatic system beyond their capacity of self purification. In recent times, the faulty development policies and mismanagement of watershed areas have resulted into unprecedented nutrient enrichment of water bodies causing ‘cultural eutrophication’ which is manifested in raised tropic status, increased rate of sedimentation, loss of water storage capacity, lowered retention period and deteriorated water quality.

2.0 Background :

Nature has been bountiful and the environs of Udaipur are generously provided with many lakes and streams. Udaipur is hence known as “City of Lakes” as well. Amar Sagar is one of the largest lakes at Udaipur, South Tripura. The lake was dug during the reigns of Maharaja Amar Manikya. It took three years (1578-1581 A.D.) to excavate ‘Amar Sagar”. The lake is 3684 ft. in length and 906 ft. in breadth.

Dense human settlements are present in the catchment area of the lake. Receiving waste water through five drains located on the western side, the lake is contaminated with domestic sewage. One piggery is also present on the western side of the lake. Previously this lake was the source of drinking water. Even now the urban population depends heavily on this lake for their daily needs which include bathing, washing, fishery etc.

Tripura State Pollution Control Board 1 3.0 Objectives :

The lakes and ponds are important surface water resources which facilitate harvesting and storage of rain water from their catchment areas and replenishment of the ground water. Due to increasing urbanization along the catchment area within past few years, the quality of the water of these lakes is deteriorating fast creating social, economical and technological problems. The present study has been undertaken with a view to assessing the pollution load of Amar Sagar of Udaipur, South Tripura.

4.0 Methodology :

In order to assess the water quality of Amar Sagar, a scientific team of Tripura State Pollution Control Board went to Udaipur and collected water samples from sixteen points covering the whole area of Amar Sagar during January, 2004, and analysed the different parameters that determine water quality in the Laboratory of the Board. The Physico-Chemical quality of surface water was analysed using the standard methods given in APHA (American Public Health Association).

5.0 Observations :

Visual : Waste water from houses situated on the west bank of Amar Sagar are discharged into Amar Sagar. In addition solid wastes are also dumped on the banks. A piggery is also located here. (Fig-4)

Temperature : Water temperature showed variation at different sites. Minimum temperature recorded was 20oC whereas maximum temperature was 22oC.

pH : The pH value of water samples of the Amar Sagar were within the standard limits. Observed pH values ranged from 7.23 to 7.83 at different sites. (Tables 1,2, 3 & 4)

Tripura State Pollution Control Board 2 Conductivity :There was wide variation of conductivity at different sites of Amar Sagar. The maximum Conductivity value was recorded as 169  mho/cm & the minimum value was found to be 43  mho/cm.(Tables 1,2, 3 & 4)

Turbidity : Turbidity showed a wide amplitude of variation at all the study points. The minimum value observed was 5 NTU and maximum was 29 NTU as shown in table 1, 2, 3 & 4.

Colour : The colours of water samples of Amar Sagar were within the standard limits. The observed values ranged from 1.2 1/m to 4.0 1/m at different sites.

Total Suspended Solid : The value of Total Suspended Solid ranged from 24 mg/l to 72 mg/l at different sites. (Tables 1,2, 3 & 4)

Total Dissolved Solid : The total dissolved solid also showed wide variations at different sites of the lake. The maximum & minimum values of total dissolved solid were found to be 184 mg/l & 80 mg/l.

Alkalinity : The values of alkalinity indicate that there is fluctuations among all the sixteen sites, ranging from 35.35 mg/l to 69.11 mg/l. (Tables 1,2, 3 & 4)

Dissolved Oxygen : From tables 1,2,3 & 4, a significant observation comes out in respect of Dissolved Oxygen (DO) of the water samples of Amar Sagar. It was found that the DO values of seven sites were below the standard limit (BIS: 6 mg/l) & the rests were above the standard limit.

Bio-chemical Oxygen Demand : From the tables 1,2,3&4 it may be seen that the Bio-chemical Oxygen Demand (BOD) values of all the sample sites of Amar Sagar were much higher than the standard limit ( BIS: 3 mg/l) and range from 3.57 mg/l to 35.0 mg/l. The variation of BOD value of all the sites are graphically represented in fig-2 at page-10 .

Chemical Oxygen Demand : There was variation of Chemical Oxygen Demand (COD) value among the water samples of all the sites of Amar Sagar. The maximum COD value was recorded as 28 mg/l & the minimum value was found 8 mg/l.

Nitrates : The observed values of Nitrate of the water samples of all the sites of Amar Sagar ranged from 0.07 mg/l to 0.75 mg/l. The Nitrate

Tripura State Pollution Control Board 3 content of the water samples of all the sites were much lower than the standard limit. The standard limit of Nitrate prescribed by BIS is 20 mg/l.

Nitrites : The observed value of Nitrites of the water samples of all the sites of Amar Sagar ranged from 0.00 mg/l to 0.72 mg/l.

Ammonical Nitrogen : Significant high values of ammonical nitrogen were recorded at all the sites from where water samples were drawn except the water samples of two sites. The observed values of Ammonical Nitrogen of the water samples of all the sites of Amar Sagar ranged from 0.8 mg/l to 6.4 mg/l whereas the standard limit is 1.2 mg/l.

Sulphate : The observed sulphate content of the water samples of all the sites ranged from 8.17 mg/l to 12.48 mg/l. The sulphate content of the water samples of all the sites were lower than the standard limit. The standard limit of sulphate prescribed by BIS is 400 mg/l.

Total Hardness : From the tables 1,2,3&4, it may be seen that the Total Hardness of the water samples of Amar Sagar were within the standard limit (300 mg/l). The maximum value of Hardness was found 39.22 mg/l and minimum value was found 9.8 mg/l.

Calcium : From the tables 1,2, 3 & 4, it may be seen that the value of Calcium of the water samples of Amar sagar were within the standard limit (BIS: 75 mg/l). The maximum value of Calcium was found to be 15.72 mg/l and minimum value 1.96 mg/l.

Chlorides : The Chloride contents of the water samples of all the sites were lower than the standard limit. The standard limit of Chloride prescribed by BIS is 250 mg/l.

Arsenic : Arsenic was absent in the water samples of all the sites of Amar Sagar.

. If DO is above standard value (6 mg/l) the water quality is good.

. If BOD is more than 3 mg/l the water quality is bad.

. If COD is high then the water quality is bad.

Tripura State Pollution Control Board 4 . If Ammonical Nitrogen is more than 1.2 mg/l the water quality is also bad.

Physico - Chemical Results of Surface Water Samples of Amar Sagar, Udaipur, South Tripura

Date of Collection : 09.01.2004 Table : 1 Sl. Parameters S1 S2 S3 S4 Standard No (BIS) 1 Temperatures (0C) 20 22 20 21 - 2 Total Suspended Solid 34 43 72 62 - (mg/l) 3 Total Dissolved Solid (mg/l) 136 112 80 97 500 4 Volatile Solid (mg/l) 62 49 12 40 - 5 Fixed Dissolved Solid 74 63 68 57 - (mg/l) 6 pH 7.23 7.28 7.39 7.31 6.5-8.5

7 Colour (1/m) 4.0 3.4 1.2 2.5 10 8 Turbidity (NTU) 19 15 5 12 -

9 Conductivity 169 96 59 43 - ( mho/cm) 10 Total Alkalinity(mg/l) 69.11 56.1 38.88 36.2 -

11 Phenolphthalein Alkalinity Nil Nil Nil Nil - (mg/l) 12 DO (mg/l) 6.24 5.23 5.95 5.84 6 13 BOD (mg/l) 19.05 22.1 15.0 13.0 3

14 COD (mg/l) 24 16 8 10 - 15 Sulphate (mg/l) 10.29 8.85 8.17 9.35 400

16 Hardness (mg/l) 39.22 24.51 9.8 29.41 300 17 Calcium (mg/l) 15.72 5.89 1.96 11.79 80.10

18 Magnesium (mg/l) Nil 4.5 1.2 Nil 24.28 19 Nitrate (mg/l) 0.75 0.31 0.07 0.15 20

20 Nitrite (mg/l) 0.20 0.41 0.02 0.03 -

21 Ammonia (NH3 -N) (mg/l) 3.6 2.9 4.2 2.1 1.2

22 Phosphate (mg/l) 0.009 0.018 Nil 0.007 -

23 Arsenic (mg/l) Nil Nil Nil Nil 0.05

24 Chloride (mg/l) 26.52 18.45 7.23 10.25 250

Tripura State Pollution Control Board 5 Locations :

S1 : North Side of Amar Sagar, Udaipur, South Tripura. S2 : North Side of Amar Sagar, Udaipur, South Tripura. S3 : West Side of Amar Sagar, Udaipur, South Tripura. S4 : West Side of Amar Sagar, Udaipur, South Tripura.

Date of Collection : 09.01.2004 Table : 2 Sl. Parameters S5 S6 S7 S8 Standard No (BIS) 1. Temperatures (0C) 21 21 20 21 - 2. Total Suspended Solid 52 33 60 56 - (mg/l) 3 Total Dissolved Solid (mg/l) 156 162 176 154 500 4. Volatile Solid (mg/l) 88 92 112 76 -

5. Fixed Dissolved Solid (mg/l) 68 70 64 78 - 6. pH 7.24 7.35 7.24 7.42 6.5-8.5

7. Colour (1/m) 3.3 4.0 3.4 2.6 10

8. Turbidity (NTU) 24 29 27 14 -

9. Conductivity 150 148 151 154 - ( mho/cm) 10. Total Alkalinity (mg/l) 51.84 35.35 51.84 44.48 -

11. Phenolphthalein Alkalinity Nil Nil Nil Nil - (mg/l) 12. DO (mg/l) 5.22 5.63 5.27 6.13 6 13. BOD (mg/l) 12.5 23.5 35.0 17.35 3

14. COD (mg/l) 15 12 13 8 -

15. Sulphate (mg/l) 11.25 11.25 9.71 12.48 400

16. Hardness (mg/l) 34.32 37.25 19.61 14.71 300

17. Calcium (mg/l) 11.79 7.68 5.89 3.93 80.10 18. Magnesium (mg/l) 1.2 4.2 1.2 1.2 24.28

19. Nitrate (mg/l) 0.29 0.55 0.12 0.38 20

20. Nitrite (mg/l) 0.03 0.35 0.03 0.18 -

21. Ammonia (NH3 -N) (mg/l) 1.3 6.2 4.8 3.9 1.2 22. Phosphate (mg/l) 0.029 0.022 0.026 0.018 -

23. Arsenic (mg/l) Nil Nil Nil Nil 0.05 24. Chloride (mg/l) 31.34 25.15 26.52 12.32 250

S5 : West Side of Amar Sagar, Udaipur, South Tripura. S6 : West Side of Amar Sagar, Udaipur, South Tripura. S7 : West Side of Amar Sagar, Udaipur, South Tripura. S8 : West Side of Amar Sagar, Udaipur, South Tripura.

Date of Collection : 09.01.2004 Table : 3 Sl. Parameters S9 S10 S11 S12 Standard No (BIS) 1. Temperatures (0C) 20 22 21 21 - 2. Total Suspended Solid 60 48 24 65 - (mg/l) 3 Total Dissolved Solid (mg/l) 168 142 168 171 500 4. Volatile Solid (mg/l) 76 58 92 75 - 5. Fixed Dissolved Solid 92 84 76 96 - (mg/l) 6. pH 7.42 7.51 7.66 7.24 6.5-8.5 7. Colour (1/m) 3.7 3.2 2.8 3.9 10 8. Turbidity (NTU) 29 23 22 26 -

9. Conductivity 158 162 148 144 - ( mho/cm) 10. Total Alkalinity (mg/l) 49.68 56.32 49.68 52.31 - 11. Phenolphthalein Alkalinity Nil Nil Nil Nil - (mg/l) 12. DO (mg/l) 6.24 6.56 7.02 5.85 6 13. BOD (mg/l) 5.0 4.12 6.34 5.95 3 14. COD (mg/l) 21 28 11 14 -

15. Sulphate (mg/l) 10.1 12.2 10.48 11.5 400 16. Hardness (mg/l) 19.61 24.51 19.61 29.41 300

17. Calcium (mg/l) 7.86 3.93 7.86 7.86 80.10

18. Magnesium (mg/l) Nil 3.5 Nil 2.4 24.28

19. Nitrate (mg/l) 0.11 0.25 0.21 0.62 20 20. Nitrite (mg/l) 0.06 0.11 Nil 0.1 -

21. Ammonia (NH3 -N) (mg/l) 6.2 5.1 1.4 2.6 1.2 22. Phosphate (mg/l) 0.03 0.025 0.034 0.015 -

23. Arsenic (mg/l) Nil Nil Nil Nil 0.05

24. Chloride (mg/l) 33.75 25.12 21.69 31.75 250

S9 : South Side of Amar Sagar, Udaipur, South Tripura. S10 : South Side of Amar Sagar, Udaipur, South Tripura. S11 : East Side of Amar Sagar, Udaipur, South Tripura. S12 : East Side of Amar Sagar, Udaipur, South Tripura.

Date of Collection : 09.01.2004 Table : 4 Sl. Parameters S13 S14 S15 S16 Standard No (BIS) 1. Temperatures (0C) 20 20 21 20 -

2. Total Suspended Solid (mg/l) 28 39 64 70 - 3 Total Dissolved Solid (mg/l) 128 158 184 174 500 4. Volatile Solid (mg/l) 64 86 116 98 -

5. Fixed Dissolved Solid (mg/l) 64 72 68 76 - 6. pH 7.73 7.6 7.83 7.51 6.5-8.5 7. Colour (1/m) 2.7 1.9 3.9 2.3 10

8. Turbidity (NTU) 23 20 25 17 -

9. Conductivity 150 163 148 147 - ( mho/cm) 10. Total Alkalinity (mg/l) 51.84 52.38 47.52 57.25 - 11. Phenolphthalein Alkalinity Nil Nil Nil Nil (mg/l) 12. DO (mg/l) 8.29 7.15 6.59 6.86 6

13. BOD (mg/l) 4.49 5.84 3.57 4.35 3

14. COD (mg/l) 20 24 21 19 -

15. Sulphate (mg/l) 9.9 10.55 9.71 12.25 400 16. Hardness (mg/l) 24.51 34.22 9.8 14.71 300

17. Calcium (mg/l) 5.89 11.79 3.93 1.96 80.10

18. Magnesium (mg/l) 2.38 1.2 Nil 1.6 24.28 19. Nitrate (mg/l) 0.12 0.48 0.29 0.23 20

20. Nitrite (mg/l) 0.72 0.28 0.09 0.06 -

21. Ammonia (NH3 -N) (mg/l) 1.11 2.32 0.80 6.4 1.2

22. Phosphate (mg/l) 0.018 0.021 0.025 0.04 - 23. Arsenic (mg/l) Nil Nil Nil Nil 0.05

24. Chloride (mg/l) 26.52 20.1 31.34 14.15 250

S13 : East Side of Amar Sagar, Udaipur, South Tripura. S14 : East Side of Amar Sagar, Udaipur, South Tripura. S15 : East Side of Amar Sagar, Udaipur, South Tripura. S16 : East Side of Amar Sagar, Udaipur, South Tripura 6.0 Conclusion :

The above findings indicate that Amar Sagar is highly polluted by continuous inflow of a large amount of untreated domestic sewage discharged into Amar Sagar by five drains. The domestic sewages were heavily loaded with organic matter, ammonia, pathogens etc. and are producing severe environmental stress on aquatic life.

From the observed value of Bio-Chemical Oxygen Demand, it may safely be concluded that the bacteriological load in Amar Sagar is very high. From the observation it is also seen that the Ammonical Nitrogen was much higher than the standard limit. This is also a bad indication.

It may hence be concluded that the water of Amar Sagar is not suitable for drinking, bathing and fishing purposes.

7.0 Recommendations :

 All the five sewage inflows should be diverted immediately through a circular cannel.

 Dumping of solid waste including polythene on the banks of Amar Sagar should be stopped immediately.

 The piggery should be removed from the west bank of Amar Sagar.

 Continuous monitoring should be required.

Tripura State Pollution Control Board 9