Presentation on Conservation and Revival of Powai Lake

by Shri M.R. Sohoni Dy. Municipal Commissioner (Special Engineering) Municipal Corporation of Greater Mumbai Conservation of Powai Lake by Using Bioremediation Technique BRIEF HISTORY Powai lake was created in 1891 by constructing dam between two hillocks across Mithi River. Catchment area of the lake is about 600 hectors and water spread area at full supply level is 220 hectors. Top level of the dam is at 195 Feet T.H.D. level. Length of the dam is about 110 mtrs.and height is varying from 6 mtrs. (maximum ht.) to 3mtrs. (minimum ht.) Lake is deteriorated due to accelerated growth of residential, commercial and industrial area around the lake & quarrying activity in the catchment area. The lake water is not used for drinking purposes but for non potable purposes i.e. gardening and industrial use. This lake was included in "National Lake Conservation Plan" by MoEF, GoI in the year 1991. Conservation of Powai Lake by Using Bioremediation Technique (Contd.) In the year 1995, B.M.C. prepared and submitted D.P.R. for these works to GoI but the same was not approved. In the month of March 2001, M/s. Wockhardt Co. submitted DPR with an estimated cost of Rs. 10.51 Crores for conservation, as well as beautification of lake. In June 2001, GoI approved DPR and sanctioned Rs. 6.62 crores for "Conservation of Powai Lake" with its allied works. Scope of Work

The scope of work consists of the following activities for improving the quality of Powai Lake Water by using BIOREMEDIATION TECHNIQUE to bring the values of various parameters of the lake water upto the values required for maintaining Eco-balance. 1. The base line data collection and continuous monitoring of lake water and sludge and submission of monthly report to BMC. 2. Removal of water hyacinth and other unrooted weeds from lake water surface and transporting the same to a 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 necessary corrective measures shall be taken to maintain quality of water as desired. 6. Parameters to be monitored.

For Lake water For Sludge 1.Physio-Chemical Analysis 1. Chemical Analysis of sludge and bottom sediments. i. Turbidity in NTU i. Organic contents in sludge. ii. Total suspended solids ii. Organic Nytrate iii. D.O. iii. Total Phosphates iv. C.O.D. iv. Ash content v. Phosphates v. pH vi. Nitrate Nitrogen vi. Sludge Mineralization vii. Total Kjeldahl Nitrogen vii. Nitrate Nitrogen viii.pH ix. B.O.D. Scope of Work (Contd.)

For Lake water For Sludge 2. Bacteriological Analysis of -- Sewage Ingress i. M.P.N. ii. Faecal Coligorm iii. Faecal Streptococcus 3. Biological Analysis of Fauna & -- Flora i. Chloropyll a ii. Chloropyll b iii. Chloropyll c iv. Chloropyll d 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 samples are fixed. Samples at these points are collected and tested per month. Removal of Floating hyacinth Floating hyacinth from lake water surface are removed and transported. However, this is repeated activity as the hyacinth grows again and again. The growth will be 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 proposed to use 7 compressors of varying capacity as follows (as per the requirement and site conditions) (5+5+25+40+30+7.5+7.5) totalling 120 HP with total 200 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 of Compressors)

NNoo.1.1:: 55HHPPCCoommpprreessssoorr NNoo.2.2:: 55HHPPCCoommpprreessssoorr NNoo.3.3::2255HHPPCCoommpprreessssoorr NNoo.4.4::4400HHPPCCoommpprreessssoorr NNoo.5.5::3300HHPPCCoommpprreessssoorr

No.1 No.3

No.4 &5 No.2 Analytical Progress

Water samples: For collection of water samples, 10 locations are fixed. 10 samples from top and 10 samples from bottom are collected every month and tested for various parameters. Location of samples is shown in the next slide and the results of major parameters such as D.O., C.O.D., Phosphates and Nitrate-Nitrogen are shown in further slides (from May-2002 till Nov.2002). Map of Powai Lake (Location of Water & Sludge samples)

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2 3 D.O. at Top Level

Table Showing Values of D.O. at Top Level of Powai Lake Value for Maintaining Eco Balance >5 mg/l Sample May June July August Sept. Oct. Nov. 1 3.5 2.9 2 9.3 7.1 7.4 7.6 2 2.1 4 3.8 7.5 8 8.1 6.6 3 2.9 3 4 12 8.2 8 6.4 4 2.5 0.2 2 6.9 6 7.2 4.3 5 2.1 0 3.9 5.7 5.4 6 6.2 6 3.2 0.3 2.9 7.3 7.3 7.5 5 7 2.8 0.6 2.6 7.8 7.2 7.5 7.3 8 3.1 0 2.5 7.2 7.5 7.5 7.1 9 3.3 0 2.3 7.6 7.9 8.2 7.2 10 3.2 0.8 2.2 8.2 7.4 7.6 6.8 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

10 1 2 8 3 4 6 5 6 4 7

2 8 9 0 10 May June July August Sept. Oct. Nov. Months D.O. at Bottom Level

Table showing Values of D.O. at Bottom level of Powai Lake Value for Maintaining ECO Balance >2mg/l Sample May June July August Sept. Oct. Nov. 1 2.2 1.3 1.7 7.4 7 6.8 6.6 2 0 0.2 1.2 9.8 6.2 6.2 7.3 3 1.2 0 1.3 6.2 6 3.8 6.4 4 0.8 0 1.4 6.6 3.3 6.1 5.6 5 0 0 1.8 5.2 5.6 4.1 7.8 6 1.8 0 1.5 7.1 6.8 5.8 6 7 2.5 0 1.5 5.2 4.7 4.8 6.2 8 1.4 0 1.6 7.1 4 5.2 7.8 9 1.7 0 1.2 7 5.3 5.6 7 10 1.4 0 1.4 4.8 6.2 6.8 6.2 D.O. at Bottom Level (Contd.)

Graph showing Valuesof D.O.at Bottomlevel of Powai Lake Value forMaintaining ECO Balance >2mg/ l

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6 4 5 6 4 7 8 9 2 10

0 May June July August Sept. Oct. Nov. Months C.O.D. at Top level

Table showing Values of C.O.D. at Top level of Powai Lake Value for Maintaining ECO Balance <10-30mg/l Sample May June July August Sept. Oct. Nov. 1 40 64 36 48 32 32 28 2 72 68 32 42 66 32 26 3 52 88 36 38 68 42 30 4 62 140 28 56 62 32 32 5 73 200 36 36 68 32 26 6 42 208 20 56 68 40 28 7 54 116 32 38 94 32 48 8 58 260 40 48 96 32 36 9 42 264 40 47 58 36 38 10 39 156 40 37 32 32 42 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

300

250

200

1 150 2 3 4 100 5 6 7 50 8 9 10 0 May June July August Sept. Oct. Nov. Months C.O.D at Bottom Level

Table showing Values of C.O.D. at Bottom level of Powai Lake Value for Maintaining ECO Balance <10-30mg/l Sample May June July August Sept. Oct. Nov. 1 92 84 28 36 92 44 32 2 180 172 40 62 64 40 32 3 88 164 40 56 34 44 32 4 146 100 32 46 60 36 28 5 186 300 36 48 94 38 34 6 72 76 28 42 62 40 38 7 94 304 36 44 32 38 42 8 0.19 252 44 44 64 48 32 9 74 248 48 57 62 35 64 10 88 252 29 52 62 64 32 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

350

300 1 2 250 3 4 200 5 6 150 7 8 100 9 50 10

0 May June July August Sept. Oct. Nov. Months Phosphates at Top Level

Table showing Values of Phosphates at Top level of Powai Lake Value for Maintaining ECO Balance 10-35mg/m3 Sample May June July August Sept. Oct. Nov. 1 2.723 4.407 0.36 0.42 0.092 0.15 0.006 2 6.618 6.504 0.28 0.37 0.18 0.18 0.018 3 2.532 3.475 0.29 0.29 0.17 0.16 0.01 4 3.51 4.854 2.92 0.38 0.18 0.17 0.018 5 6.432 5.893 0.68 0.68 0.23 0.39 0.011

Values are in mg/l in are Values 6 2.171 6.432 0.66 0.44 0.191 0.61 0.011 7 4.192 7.484 0.69 0.35 0.18 0.12 0.009 8 4.18 4.56 0.47 0.66 0.179 0.62 0.011 9 3.918 6.533 0.5 0.52 0.185 0.25 0.012 10 3.43 7.276 0.66 0.42 0.183 0.24 0.009 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) 8

1 5 2 3 4 4 5 3 6 7 2 8 9 1 10

0 May June July August Sept. Oct. Nov. Months Phosphates at Bottom Level

Table showing Values of Phosphates at Bottom level of Powai Lake Value for Maintaining ECO Balance 10-35mg/m3 Sample May June July August Sept. Oct. Nov. 1 4.326 4.504 0.28 0.35 0.187 0.23 0.011 2 11.46 12 0.37 0.45 0.2 0.26 0.005 3 4.425 7.082 0.52 0.48 0.21 0.22 0.009 4 5.692 5.694 0.26 0.56 0.22 0.24 0.004 5 10.295 12.985 0.29 0.37 0.21 0.32 0.11

Values are in mg/l in are Values 6 3.598 8.839 0.78 0.22 0.23 0.12 0.13 7 5.765 9.553 0.83 0.26 0.23 0.19 0.004 8 2.77 6.577 0.89 0.37 0.21 0.32 0.009 9 3.93 4.781 0.75 0.49 0.24 0.21 0.005 10 3.925 8.577 0.89 0.31 0.15 0.45 0.008 Phosphates at Bottom Level (Contd.)

Graph showing Values of Phosphates at Bottom level of Powai Lake Value for Maintaining ECO Balance 10-35mg/m3 (values in table are in mg/l)

12 1 2 10 3 4 8 5 6 6 7 4 8 9 2 10 0 May June July August Sept. Oct. Nov. Months Nitrate-Nitrogen at Top Level

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

Sample May June July August Sept. Oct. Nov. 1 1.432 1.418 1.14 1.36 2.6 0.3 2.2 2 3.38 3.592 0.52 0.65 3.3 0.9 1.1 3 1.332 1.89 0.53 0.63 2.96 0.32 1.4 4 1.85 2.07 0.15 0.18 2.81 0.24 2.8 5 3.29 4.816 0.094 0.13 3.6 0.11 3.6 6 1.181 1.134 0.45 0.54 2.8 0.31 4.2 7 2.18 2.647 0.189 0.22 2.7 0.95 3.8 8 2.15 2.08 0.265 0.32 2.2 0.36 6.9 9 2.03 1.985 0.28 0.34 1.99 1.3 3.2 10 1.81 1.512 0.18 0.21 1.72 0.2 2.7 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

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0 May June July August Sept. Oct. Nov. Months Nitrate-Nitrogen at Bottom Level

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

Sample May June July August Sept. Oct. Nov. 1 2.24 2.269 0.48 0.57 3.2 0.4 2.2 2 5.74 6.145 0.38 0.48 2.96 0.7 1.5 3 2.31 3.78 0.44 0.52 3 1.2 2.2 4 2.95 6.618 0.44 0.52 4.2 1.2 2.8 5 5.28 6.148 0.46 0.52 4.6 0.9 2.9 6 1.92 1.89 0.189 0.22 4 0.95 1.2 7 2.98 2.741 0.37 0.44 4.7 0.94 1.7 8 1.4 5.29 0.55 0.66 4.92 0.22 4.9 9 2.06 2.06 0.47 0.37 3.16 0.7 5 10 2.06 2.08 0.48 0.57 4.78 1.4 3 Nitrate-Nitrogen at Bottom Level (Contd.)

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

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0 May June July August Sept. Oct. Nov. Months TTHHAANNKK YYOOUU