Presentation on Conservation andRevival of Powai Lake

byShri M.R. Sohoni

Dy. Municipal Commissioner (Special Engineering)Municipal Corporation of Greater Mumbai

Conservation of Powai Lake by UsingBioremediation Technique

BRIEF HISTORY� Powai lake was created in 1891 by constructing dam

between two hillocks across Mithi River. Catchment areaof the lake is about 600 hectors and water spread area atfull supply level is 220 hectors. Top level of the dam is at195 Feet T.H.D. level. Length of the dam is about 110mtrs.and height is varying from 6 mtrs. (maximum ht.) to3mtrs. (minimum ht.)

� Lake is deteriorated due to accelerated growth ofresidential, commercial and industrial area around thelake & quarrying activity in the catchment area.

� The lake water is not used for drinking purposes but fornon potable purposes i.e. gardening and industrial use.

� This lake was included in "National Lake ConservationPlan" by MoEF, GoI in the year 1991.

Conservation of Powai Lake by UsingBioremediation Technique (Contd.)

� In the year 1995, B.M.C. prepared andsubmitted D.P.R. for these works to GoI but thesame was not approved.

� In the month of March 2001, M/s. WockhardtCo. submitted DPR with an estimated cost ofRs. 10.51 Crores for conservation, as well asbeautification of lake.

� In June 2001, GoI approved DPR andsanctioned Rs. 6.62 crores for

� "Conservation of Powai Lake" with its alliedworks.

Scope of Work� The scope of work consists of the following

activities for improving the quality of PowaiLake Water by using BIOREMEDIATIONTECHNIQUE to bring the values of variousparameters of the lake water upto the valuesrequired for maintaining Eco-balance.1. The base line data collection and continuous

monitoring of lake water and sludge and submissionof monthly report to BMC.

2. Removal of water hyacinth and other unrooted weedsfrom lake water surface and transporting the same toa suitable place as directed by the Corporation.

3. Aeration of lake with Compressors &diffusers etc.4. The biological treatment to lake water with speciality

bio-product.

Scope of Work (Contd.)5. Monitoring of the quality of lake water during

maintenance period of 36 months and necessarycorrective measures shall be taken to maintain qualityof water as desired.

6. Parameters to be monitored.

1. Chemical Analysis of sludgeand bottom sediments.

i. Organic contents in sludge.ii. Organic Nytrateiii. Total Phosphatesiv. Ash contentv. pHvi. Sludge Mineralizationvii. Nitrate Nitrogen

1.Physio-Chemical Analysis

i. Turbidity in NTUii. Total suspended solidsiii. D.O.iv. C.O.D.v. Phosphatesvi. Nitrate Nitrogenvii. Total Kjeldahl Nitrogenviii.pHix. B.O.D.

For SludgeFor Lake water

Scope of Work (Contd.)

--3. Biological Analysis of Fauna &Flora

i. Chloropyll aii. Chloropyll biii. Chloropyll civ. Chloropyll d

--2. Bacteriological Analysis ofSewage Ingress

i. M.P.N.ii. Faecal Coligormiii. Faecal Streptococcus

For SludgeFor Lake water

Physical Progress (Upto 31.12.2002)� Baseline Data Collection

� Water spread area, area of visible eutrophication,depth of water at various locations are ascertained.

� Points for collecting water samples and sludge samplesare fixed. Samples at these points are collected andtested per month.

� Removal of Floating hyacinth� Floating hyacinth from lake water surface are removed

and transported. However, this is repeated activity asthe hyacinth grows again and again. The growth willbe reduced after bio remediation treatment.

Physical Progress Upto 31.12.2002(Contd.)

� Aeration of lake� In financial “PACKET B" Contractors proposed to use

15 compressors of 5 H.P. each. ( i.e. total 75 H.P.)with 120 diffusers.

� After collection of baseline data contractors proposedto use 7 compressors of varying capacity as follows (asper the requirement and site conditions)(5+5+25+40+30+7.5+7.5) totalling 120 HP with total200 Nos. of diffusers.

� Contractors have installed 5 compressors(5+5+25+40+30) totalling 105 HP with(10+10+45+45) 110 nos. of diffusers.

Map of Powai Lake (Location ofCompressors)

No.1

No.2

No.3

No.4 &5

No.1 : 5 HP CompressorNo.2 : 5 HP CompressorNo.3 : 25 HP CompressorNo.4 : 40 HP CompressorNo.5 : 30 HP Compressor

No.1 : 5 HP CompressorNo.2 : 5 HP CompressorNo.3 : 25 HP CompressorNo.4 : 40 HP CompressorNo.5 : 30 HP Compressor

Analytical Progress� Water samples:

� For collection of water samples, 10 locations are fixed.10 samples from top and 10 samples from bottom arecollected every month and tested for variousparameters. Location of samples is shown in the nextslide and the results of major parameters such asD.O., C.O.D., Phosphates and Nitrate-Nitrogen areshown in further slides (from May-2002 till Nov.2002).

Map of Powai Lake (Location of Water & Sludgesamples)

1

23

4

5

6

7

8

9

10

D.O. at Top Level

6.87.67.48.22.20.83.210

Table Showing Values of D.O. at Top Level of Powai LakeValue for Maintaining Eco Balance >5 mg/l

7.28.27.97.62.303.39

7.17.57.57.22.503.18

7.37.57.27.82.60.62.87

57.57.37.32.90.33.26

6.265.45.73.902.15

4.37.266.920.22.54

6.488.212432.93

6.68.187.53.842.12

7.67.47.19.322.93.51

Nov.Oct.Sept.AugustJulyJuneMaySample

D.O. at Top Level (Contd.)Graph Showing Values of D.O.at Top Level of Powai Lake

Value forMaintaining Eco Balance >5 mg/ l

0

2

4

6

8

10

12

14

May June July August Sept. Oct. Nov.Months

12345678910

D.O. at Bottom Level

6.26.86.24.81.401.41075.65.371.201.797.85.247.11.601.486.24.84.75.21.502.5765.86.87.11.501.867.84.15.65.21.80055.66.13.36.61.400.846.43.866.21.301.237.36.26.29.81.20.2026.66.877.41.71.32.21Nov.Oct.Sept.AugustJulyJuneMaySample

Table showing Values of D.O. at Bottom level of Powai LakeValue for Maintaining ECO Balance >2mg/l

D.O. at Bottom Level (Contd.)Graph showing Values of D.O.at Bottomlevel of Powai Lake

Value forMaintaining ECO Balance >2mg/ l

0

2

4

6

8

10

12

May June July August Sept. Oct. Nov.

Months

12345678910

C.O.D. at Top level

42323237401563910

3836584740264429

3632964840260588

4832943832116547

2840685620208426

2632683636200735

3232625628140624

304268383688523

263266423268722

283232483664401

Nov.Oct.Sept.AugustJulyJuneMaySample

Table showing Values of C.O.D. at Top level of Powai LakeValue for Maintaining ECO Balance <10-30mg/l

C.O.D. at Top Level (Contd.)Graph showing Values of C.O.D. at Top level of Powai Lake

Value for Maintaining ECO Balance <10-30mg/l

0

50

100

150

200

250

300

May June July August Sept. Oct. Nov.

Months

12345678910

C.O.D at Bottom Level

32646252292528810

6435625748248749

32486444442520.198

4238324436304947

384062422876726

34389448363001865

28366046321001464

3244345640164883

32406462401721802

324492362884921

Nov.Oct.Sept.AugustJulyJuneMaySample

Table showing Values of C.O.D. at Bottom level of PowaiLake Value for Maintaining ECO Balance <10-30mg/l

C.O.D at Bottom Level (Contd.)Graph showing Values of C.O.D. at Bottom level of Powai Lake

Value for Maintaining ECO Balance <10-30mg/l

0

50

100

150

200

250

300

350

May June July August Sept. Oct. Nov.Months

12345678910

Phosphates at Top Level

0.0090.240.1830.420.667.2763.43100.0120.250.1850.520.56.5333.91890.0110.620.1790.660.474.564.1880.0090.120.180.350.697.4844.19270.0110.610.1910.440.666.4322.17160.0110.390.230.680.685.8936.43250.0180.170.180.382.924.8543.5140.010.160.170.290.293.4752.53230.0180.180.180.370.286.5046.61820.0060.150.0920.420.364.4072.7231Nov.Oct.Sept.AugustJulyJuneMaySample

Table showing Values of Phosphates at Top level of PowaiLake Value for Maintaining ECO Balance 10-35mg/m3

Valu

es

are

in m

g/l

Phosphates at Top Level (Contd.)Graph showing Values of Phosphates at Top level of Powai

Lake Value for Maintaining ECO Balance 10-35mg/m3

(Values in table are in mg/l)

0

1

2

3

4

5

6

7

8

May June July August Sept. Oct. Nov.

Months

12345678910

Phosphates at Bottom Level

0.0080.450.150.310.898.5773.925100.0050.210.240.490.754.7813.9390.0090.320.210.370.896.5772.7780.0040.190.230.260.839.5535.76570.130.120.230.220.788.8393.59860.110.320.210.370.2912.98510.29550.0040.240.220.560.265.6945.69240.0090.220.210.480.527.0824.42530.0050.260.20.450.371211.4620.0110.230.1870.350.284.5044.3261Nov.Oct.Sept.AugustJulyJuneMaySample

Table showing Values of Phosphates at Bottom level ofPowai Lake Value for Maintaining ECO Balance 10-35mg/m3

Valu

es

are

in m

g/l

Phosphates at Bottom Level (Contd.)

Graph showing Values of Phosphates at Bottom level of Powai LakeValue for Maintaining ECO Balance 10-35mg/m3

(values in table are in mg/l)

0

2

4

6

8

10

12

14

May June July August Sept. Oct. Nov.

Months

12345678910

Nitrate-Nitrogen at Top Level

2.70.21.720.210.181.5121.81103.21.31.990.340.281.9852.0396.90.362.20.320.2652.082.1583.80.952.70.220.1892.6472.1874.20.312.80.540.451.1341.18163.60.113.60.130.0944.8163.2952.80.242.810.180.152.071.8541.40.322.960.630.531.891.33231.10.93.30.650.523.5923.3822.20.32.61.361.141.4181.4321Nov.Oct.Sept.AugustJulyJuneMaySample

Table showing Values of Nitrate-Nitrogen at Top level ofPowai Lake Value for Maintaining ECO Balance <0.1mg/l

Nitrate-Nitrogen at Top Level (Contd.)Graph showing Values of Nitrate-Nitrogen at Top level of Powai Lake

Value forMaintaining ECO Balance <0.1mg/ l

0

1

2

3

4

5

6

7

8

May June July August Sept. Oct. Nov.Months

12345678910

Nitrate-Nitrogen at Bottom Level

31.44.780.570.482.082.061050.73.160.370.472.062.0694.90.224.920.660.555.291.481.70.944.70.440.372.7412.9871.20.9540.220.1891.891.9262.90.94.60.520.466.1485.2852.81.24.20.520.446.6182.9542.21.230.520.443.782.3131.50.72.960.480.386.1455.7422.20.43.20.570.482.2692.241Nov.Oct.Sept.AugustJulyJuneMaySample

Table showing Values of Nitrate-Nitrogen at Bottom level ofPowai Lake Value for Maintaining ECO Balance <0.1mg/l

Nitrate-Nitrogen at Bottom Level(Contd.)

Graph showing Values of Nitrate- Nitrogen at Bottomlevel of Powai LakeValue for Maintaining ECO Balance <0.1mg/ l

0

1

2

3

4

5

6

7

May June July August Sept. Oct. Nov.

Months

12345678910

THANK YOUTHANK YOU