Environment Pollution

Air Pollution


Water Pollution


Noise Pollution


Soild Waste


Hazardous Waste


Bio-medical Waste

Sikkim State Pollution Control Board (SPCB) has a regular Ambient Air and Water Quality Monitoring Programme to assess the status of pollution in the natural environment. These monitoring programme are funded by the Central Pollution Control Board, Ministry of Environment & Forests, Government of India.


Air Pollution

 

To prevent, control and abate air pollution in the country, the Government of India enacted Central legislation called the Air (Prevention & Control of Pollution) Act, 1981 (referred to as the Air Act, 1981). Every polluting industry must obtain a consent from the State Pollution Control Board for the discharge of air pollut­ants in any form through chimney or otherwise. The State Board may lay down suitable conditions while giving consent to discharge air pollutants in the light of emission standards developed by the Central Board, subsequently notified through the rules framed under the Environment (pro­tection) Act, 1986 Rules.

 

Ambient Air Quality Monitoring

 

The air quality surveillance and monitoring is under taken to detect any deterioration in air quality arising from industrial, vehicular, residential and natural sources of pollution, as there are large seasonal variation in the concentration of various air pollutants. Air quality monitoring is the measurement of various pollutants to study the pattern and movement of air masses and deterioration of air quality. Monitoring programme helps in estimating the dynamic concentration levels of various pollutants from time to time, based on dispersal mode of original concentration at sources and at receptor end.

 

Air Quality of Gangtok, Sikkim

 

Ambient Air Quality in and around Gangtok (Yearly Avg) in (mg/m3)

SL.No

Name of sites

Category

SPM

SO2

NO2

1

Tadong

Residential

108

16.2

15.7

2

Indira bye –pass

Commercial

137

17.4

22.6

3

Deorali

Residential

118

18.6

16.1

4

Bazar area (near Metro Point)

Commercial

145

22.3

20.4

5

Hospital point

Sensitive

122

19.6

18.6

6

Zero point

Sensitive

98

10.2

12.3

 

Oxides of Sulphur

Eight hourly Sulphur dioxide concentration of the sample shows that Bazar area with 22.3 μg/m3 has highest concentration on yearly average while the zero point shows minimum concentration with 10.2 Μg/m3. The other stations viz: Tadong (16.2 Μg/m3), Indira bye-pass (7.4 Μg/m3), Deorali (16.1 Μg/m3), and Hospital Point (18.6 Μg/m3). All the values are, however, within the prescribed limit.

 

Oxides of Nitrogen

 

The Eight hourly averages of Nitrogen oxides samples were collected and further analyzed in the lab. The result is presented in the table above. The highest concentration of oxides of Nitrogen as NO2 was recorded from Indira Bye-pass with 22.6 Μg/m3 followed by Bazar area (20.4 Μg/m3, Hospital Point (18.6 Μg/m3, Deorali (16.1 Μg/m3, Tadong (15.7 Μg/m3 and lowest was recorded from zero point with 12.3 Μg/m3. All the val­ues are however, within Indian standard.

 

Suspended Particular Matter (SPM)

 

The yearly average of suspended particulate matter is pre­sented in table above. It can be inferred that Bazar area (near metro point) with 145 Μg/m 3 of SPM has highest concentration while zero point with 98 Μg/m3 shows minimum concentration of SPM. The highest value in Bazar area is mainly due to heavy vehicular movement in this area. Tadong monitoring site recorded 108 Μg/m3 of SPM and like-wise Indira bye-pass (137 Μg/m3, Deorali (118 Μg/m3) and Hospital point (122 Μg/m3).


Go to TOP


Water Pollution

 

The Central Pollution Control Board, Delhi initiated the National Water Quality Monitoring Programme to consistently monitor the water quality in a systematic manner to know the nature and extent of water quality degradations and the exist­ing quality of water in the water bodies. The national programme is also termed as Monitoring of Indian National Aquatic Resources (MINARS). Under the MINARS programme the State Pollution Control Board, Sikkim collects water samples from River Teesta and its tributaries at nine stations. This program is totally funded by Central Pollution Control Board. The details of sampling Stations are as follows:

 

Sl. Name of Station (Station Code)    Location

1. Chungthang (1801)  Lat.88°39'0" Long. 27°36'0"

2. Dikchu (1802) Lat.88°31 '30" Long. 27°23'44"

3. Burtuk (1803) Lat. 88°31 '30" Long. 27°21 '30"

4. Adampool (1804) Lat. 88°35'15" Long. 27°18'30"

5. Ranipool (1805) Lat. 88°35'45" Long. 27°17'15"

6. Singtam (1806) Lat. 88°29'45" Long. 27°13'45"

7. Singtam D.S (1807) Lat. 88°29'44" Long. 27°13'44"

8. Rangpo (1808) Lat. 88031'45" Long. 27°10'8"

9. Melli (1809) Lat. 88°37'30" Long. 27°5'15"

 

WATER QUALITY OF LAKES

            

Sikkim is bestowed with abundant hydrological resources pri­marily because of its geomorphology and its location in the Eastern Himalayas. The Himalayas obstruct the rain bearing winds of the south-west monsoon resulting the Himalayas to receive annual rainfall which ranks as the highest in the world, making the Himalayas a source of a large number of mighty rivers perennial streams and snow cover mountains.

 

The geomorphological conditions providing high amount of rainfall has gifted the state of Sikkim with abundant wetlands. The state presents a picturesque panaroma of about 150 lakes situated at different altitudes with varying shape, size and depth. Most of the lakes are regarded highly sacred and attract a large number of tourist and pilgrims.

 

Of all the Lakes of Sikkim the study on the Environment sta­tus of the three revered lakes of East Sikkim, Viz., Changu, Menmoitso, & Kupuk Lakes have been carried out under the Central sponsored scheme Prevention & Abatement of Pollu­tion. The Changu, Menmoitso, Kupuk Lakes are regarded as extremely sacred & are places of Tourist interest besides mili­tary base is situated in their vicinity. These lakes form an im­portant stopover for various ducks besides being home to resi­dent brahminy ducks (Tendora ferruginea). These lakes also form the habitat for introduced browntrout (Salmo trattafario).

 

The scenic beauty and sanctity of these holy lakes have been drawing large number of tourists and pilgrims. There is heavy movement of different vehicles and also there is biotic interfer­ence . Keeping these activities in mind the study was conducted to assess the status of these fragile eco-systerns, which fall under the category of high altitude lakes as all of them lie 2500 mtr. above mean sea level belonging to the category of wetland type 14 according to Directory of Indian wetlands 1993. Classification. Comparative Water analysis of lakes is shown in the following table:

Comparative Study of Physico- Chemical parameters of Three lakes

Sl.

No

Parameters

CHANGU

MENMOISTO

KUPUP

Ave

Range

Ave

Range

Ave

Range

1

pH

5.8

5.0-6.4

6.7

6.1-7.4

6.8

6.1.-7.2

2

Dissolved Oxygen (mg/l)

6.00

3.7-8.6

9.2

6.1-14.1

12.41

7.6-8.2

3

Calcium mg/l

1.57

.890-2.125

1.890

1.025-2.225

1.73

1.00-3.00

4

Sodium mg/I

0.011

0.003-0.022

0.012

0.002-0.037

0.013

0.002-0.023

5

Potassium mg/l

0.023

0.002-0.132

0.069

0.016-0.146

0.039

0.009-0.146

6

Nitrate mg/l

0.966

0.911-14

1.290

0.900-2.025

1.08

0.750-1.475

7

Phosphate mg/l

1.023

0.113-1. 720

0.750

0.250-1.025

1.67

0.500-1.800

8

B.O.D mg/l

13.90

8.6-18.6

7.00

4.6-9.2

4.98

6-7.2

9

C.O.D mg/I

56.58

23.1-90.4

27.37

16.10-14.20

34.69

22.5-47.2

10

Total Solid mg/l

484.80

270.1-673.4

328.90

142.10-473.8

299.8

255.9-298

11

Total Kjeldahl Nitrogen mg/l

0.021

0.011-0.037

0.018

0.006-0.025

0.029

0.015-0.050

12

Sulphate mg/l

ND

ND

ND

ND

ND

ND

13

Water Temp °C

3.9°C

2°C-6°C

6.1°C

3°C-8°C

3.4°C

2°C-4°C

14

Air Temp °C

9.7°C

3°C-14°C

5.7°C

1°C-9°C

-

1 °C-8°C

 

 

COMPARATIVE STUDY OF THE THREE LAKES

 

>>    The pH- The annual average pH of Changu was lowest with 5.8 compared to Menmoitso and Kupup which had aproximately the same value in average. Lower pH value in Changu may be attributed to religious offerings and the impact of flow of tour­ists during tourist season whereas in Menmoitso and Kupup flow of tourist is comparatively low:

 

 

>>  Dissolved oxygen: The highest annual average of dissolved oxygen was observed at Kupup with 12.41 mg/l and the lowest no. at Changu with 6.00 mg/I. The low no Value of Changu shows the tendency towards eutrophic condition of the lake. In all the sites no content shows a marked seasonality with oxygen levels decreasing during winter months which might be due to cumulative influence of low insulation, low tempera­ture, over turn of lake water and minimal photo synthetic ac­tivity.

 

 

>>  Calcium, Sodium, Potassium, Nitrate and Phosphate values are apprpximately same in all the study sites. The average calcium value of Changu was 1.57 mg/l as that of 1.890 mg/l in Menmoitso and 1.73 mg/l in Kupup. It has been found that calcium concentration increased from summer to winter. Phos­phate concentration was highest in Kupup with 1.67 mg/l in average whereas in Menmoitso mg/l and 1.023 mg/l in Changu.

 

 

>>   B.O.D & C.O.D: The annual average B.O.D value of Changu was 13.9 mg/l which is comparatively higher than other two study sites. Menmoitso shows 7.00 mg/l whereas lowest ROD. value was observed in Kupup with 4.98 mg/I. More or less the same pattern was followed by C.O.D Changu showed C.O.D 56.5 mg/l followed by Kupup 34.6 mg/l and Menmoisto 27.2 mg/I. Maximum values of B.O.D and C.O.D  was observed during rainy season which may be due to heavy input of Vari­ety of nutrients along with eroded material and prevalence of favourable environmental conditions for microbial activities. The highest total solids was found in Changu with 484.8 mg/l followed by Menmoisto 328.9 mg/l and Kupup 299.8mg/I. Total Kjeldal Nitrogen was approximately same at all sites. The higher B.O.D and C.O.D values infer to the pollution potential. Thus it can be inferred that Changu lake has suffered undesir­able changu than the other two lakes.

 

 Drinking Water

 

 The surveillance and monitoring of water and waste water qual­ity is very important to evaluate their adverse effect on human health and surrounding' environment. The available water may be unfit for drinking purpose due to chemical and micro- bio­logical contaminations and therefore apart from MINARS the SPCB, Sikkim monitors drinking water of Gangtok along with water quality of some high altitude lakes and hot waste springs and water quality of streams encompassing Gangtok town. The drinking water source of Gangtok is Tarnzey at an alti­tude of 14,000ft. above mean sea level. The Public Health En­gineering Department supplies and maintains the drinkingwater supply to Gangtok. The water from the source Tamzey is stored at 10th & 4th mile Rateychu tank and before distribution it is stored and chlorinated at salap tank (6000 ft.).From this stor­age and chlorination point water is distributed to Gangtok as per the detailed network.

 

>>    Drinking water quality

           

Water is the fundamental basis of life. The drinking water has a direct impact on human health and considering this fact the regular monitoring of drinking water supplied to Gangtok town at different localities reveals the following facts. A detail study under taken by Pollution Control Board assesses the quality of the urban water supply network. As a very little work has been carried out on the water quality of the other parts of the State hence the information's provided under are based on the detail study of the water quality of the capital town only. Drinking water is supplied to Gangtok town by the Public Health and Engineering Department. The source of drinking water is at Tamzey at an altitude of 14,000ft. above mean sea level. An army base camp is also situated besides this stream. The water from Tamzey is stored at 10th mile and 4th mile Rateychu tanks and before distribution it is stored at Salep tank(6,000ft.) where chlorination takes place after which the water is supplied through pipeline network to different parts of the capital town Gangtok. The water quality is under continuous monitoring at various points from where it is used for consumption and for this pur- 530 pose seven localities have been identified by SPCB which are designated as follows:

 

Zone 1: Deorali: (Syari,Panihouse, Deorali bazaar).

Zone 2: Lall Market(Lall market, Sundari gaon, Old Secretariat, Bishal gaon).

Zone3: New Market:(Nam Nang, New Market area and Kazi Road).

Zone 4: Old Market:(Arithang, Old Market area and Kazi Road).

Zone 5: Hospital Point:(Hospital complex, Diesel Power House,Palzor Stadium complex).

Zone6: Development Area:(Residential area, TNHS Road, Shopping complex).

Zone7: Balwakhani Area (Vajra complex, Forest Colony, P&T Colony, Zero point area).

       Drinking water samples are collected from the zones specified by State Pollution Control Board (SPCB). At least three samples are collected from each zones on weekly basis. The methodol- 14 ogy for laboratory analyses of the parameters are adopted from the "Standard methods for Examination of water and waste water" 12 18th Edition 1992 prepared and published by American Public Health Association, American Water Works Association and 10 Water Pollution Control Federation. The collected samples after 8 necessary analysis in the water lab of SPCB reveals.....

>>        pH: pH is the negative logarithm of hydrogen ion concentration. pH is used to measure the alkalinity and acidity of water. The pH values of all the stations lie within the Indian standard of 6.5 to 8.5. The pH value is between 6.4 to 8.2. The zone V (Hospital point) shows minimal pH (6.4) whereas in zone IV (old market) pH is 8.2.

 

>>        Conductivity:    The highest conductivity of 540 umhos/ cm2 was observed at zone I and zone VII whereas zone V shows lowest.

 

>>        Dissolved Oxygen: The collected samples are analyzed within 24hrs of collection in lab. of SPCB. The lowest no value was recorded in 11.2 mg/ltr. at zone VI while the highest 13.4 mg/ltr. was observed at zone III. The dissolved oxygen of all the samples is above 6mg/ ltr. Which is the prescribed value.

 

>>        B.O.D (Biochemical Oxygen Demand): The highest B.O.D value was found to be 2.2 mg/ltr. at zone I and lowest 1.8mg/ltr. at zone V & VI .Three study zones viz zone I, zone II and zone VII shows B.O.D value more than prescribed limit of 2mg/Itr. And other zone lie within the per­missible limit. The quality of water is determined by B.O.D value, the higher the value of B.O.D worse the quality of water.

 

>>        Nitrate (NO3): All the study zones show that the values of nitrate fall within the prescribed level of 45 mg/ltr. With the lowest nitrate value of 26 mg/ltr. at zone III and highest 4lmg/ltr.at zone

 

>>        Magnesium: The national standard for Magnesium concentration is 30 mg/ ltr. Two study zones viz zone I and zone IV shows concentra­tion more than national standard whereas other zone lies be­low standard. The highest Mg-concentration of 35 mg/ltr. was recorded at zone IV while lowest 23mg/ltr. at zone III.

 

>>        Free CO2 The lowest free Co2 was recorded at zone III with 0.7 mg/ ltr. and highest 1.2 mg/ltr. at zone IV.

 

>>        Chlorides (as chlorine): The chlorides concentration in all the zones were below the national standard of 250 mg/ltr. The highest concentration of cWoride was found to be l27mg/ltr at zone VI whereas the lowest was recorded at zone I with 105 mg/ltr.

 

>>       Sulphate (SO4) : The highest Sulphate content was recorded at zone V (24mg/ ltr.) while lowest value was observed at zone I (l6mg/ltr.). The sulphate content of zone II, zone III, zone V, zone V, zone VI, Zone VII were found to be 19 mg/ltr. 18mg/ltr, 22 mg/ltr 24mg/ltr,18mg/ltr and 17 mg/ltr respectively.

 

>>        Total Hardness (as CaC03): The total hardness value of all the study zones lie within the prescribed national standard of 300 mg/ltr. With highest at zone V(105mg/ltr.) and lowest concentration of 77 mg/ltr. at zone III. In other study zones viz ; zone II, zone Iv, zone VI, and zone VII, 95mg/ltr, 92mg/ltr., 98mg/ltr., 96mg/ltr., and 91mg/ ltr. were observed respectively.

 

>>              Calcium as CaC03 The national standard for calcium is 75mg/ltr. In all the study zones the calcium concentration was found to be within the national standard. The highest calcium concentration with 68 mg/ltr. was recorded at zone VI and lowest concentration of 54 mg/Itr. at zone III.

 

>>       T.D.S & T.S.S: The national standard of total dissolved solids is 500mg/Itr. The total dissolved solids value is the highest in the zone VII with 43 mg/ltr. and lowest at zone III with total dissolved sol­ids value of 26 mg/ltr. Similarly, total suspended solids concentration lies highest at zone II, zone IV, zone VII with 104 mg/ltr. and lowest 1.1 mg/ ltr. at zone I. The analysis of drinking water of Gangtok town shows varia­tion in concentration of some parameters in different study zones. This can be attributed to chances of leakage due to rust­ing and improper fitting of pipeline network passing through the drains.

 

 

STREAM/JHORA WATER QUALITY

 

A preliminary study on the encompassing, Gangtok was carried out in collaboration with the Department of Zoology, Sikkim Govt. College and the re­sult of is shown in the following tables.

 

 

Physical analysis of water quality of streams and jhoras

Source

Name

Source

Set.

Temp.

Ai

Temp.

wi

pH

Cond

Sal

Odr.

Cor.

Goshkhan ihora

Spring

12.10(pm)

13.5 °C

1tC

5.3

650

0.5 %

Toxic

Blackish

Hospital jhora

Spring

12.20(pm)

10.5 °C

10°C

5.S

300

 

Toxic

Muddy

Paljor Stadium ihora

Spring

12.10(pm)

17 °C

Wc

5.5

200

 

Toxic

Yellowish

Fisheries ihora.

Spring

1.00(pm)

15 °C

15°C

5.4

200

 

Toxic

Darkish

Rani Khola

Stream

1.35(pm)

19 °C

12.5°C

6.1

60

5.3

-

Clear

Adam Pool Khola

Stream

3.10(pm)

19 °C

17'C

6.3

100

5.3

Toxic

Muddy

  

Chemical Analysis of Water Quality of Streams and Jhoras

Source Name

Source

D.O

D.C02

Cl.

Alk

Aci.

Hard.

Goshkhan ihora

Spring

5.332

89.34

4.496

201.83

49.67

199.460

Hospital jhora

Spring

8,532

20.66

2.596

118.67

15.17

93.476

Paljor Stadium ihora

Spring

8.132

27.34

1.659

84.67

11.33

68.260

Fisheries ihora.

Spring

8.468

7.34

11.418

72.33

4.33

75.436

Diesel Power House jhora

Spring

7.868

11.34

18.907

58.67

6.83

63.844

Rani Khola

Stream

8.468

4.34

6.624

16.33

1.33

14.164

Adam Pool Khola

Stream

6.868

9.34

8.269

20.67

5.33

12.884

 

METAL ANALYSIS

Source

Name

Source

Ca

Mg

Fe

Na

K

GJ

Spring

38.613

ND

2.120

51.155

92.902

H.J

Spring

28.320

ND

0.008

35.478

57.322

P.S.J

Spring

22.709

ND

0.179

41. 749

33.603

F.J

Spring

27.118

ND

0.024

37.046

37.556

D.J

Spring

24.713

ND

0.204

28.977

37.556

R.KH.

Stream

4.545

ND

0.139

13.036

9.883

A.KH.

Stream

8.954

ND

10.351

29.868

17.790

Compound Analysis

P04

N03

SiO4

T.S

T.D.S

T.S.S

67.101

0.0002

25.252

428.0

332.600

95.400

4.111

0.0154

18.499

455.2

384.200

71. 000

7.921

0.013

11.601

240.2

202.000

38.200

6.542

0.009

10.997

104.7

83.700

20.660

4.195

0.010

12.952

23008.1

22629.500

378.600

0.248

0.001

13.720

563.0

455.600

107.400

2.431

0.003

131. 940

531.6

302.200

229.400

 

 


Go to TOP


Noise Pollution

 

Noise has rapidly become a source of environmental pollution with increasing industrialization, urbanization and the rapid expansion of the means of transportation. The ambient noise level termed as the total noise associated within a given environment and usually comprise of sounds from many sources both near and far.

 

Noise Monitoring Locations In Gangtok

 

The measurement of ambient noise level is being using sound Level Meter 2031 A(Cygnet). The measurements which were taken for seven consecutive days in each sites were in three slots i.e., morning 8.00 a.m.-10.00 a.m., afternoon 14.00 p.m.­16.00p.m., and night 18.00-20.00p.m. The average measurements are reflected below:

 

 

Average Ambient Noise Level at Various Places in Gangtok.

Sl. No.

Place

Day Average leg. in dB (A)

Night Average leg in dB (A)

SILENCE ZONE

1.

Hospital Point

62

63

2.

District Court

50

44

RESIDENTIAL ZONE

1.

Tadong

61

58

2.

Deorali Govl. Quarter

61

57

3.

Development Area

66

50.7

COMMERCIAL ZONE

1.

M.G. Marg

70

62

2.

Indria Bye-Pass

73

69
 

 


Go to TOP


Soild Waste

Under Construction

 

Hazardous Waste

Under Construction

 

Bio-medical Waste

 

Under Construction