Water balance Point from Minutes of meeting: “Quantity of fresh water consumption will be reduced after recycling of treated effluent. Water balance need to be reassessed” Overall water balance for the expansion and zinc project have been reassessed as per the directions of the ministry and the details regarding the same are as follows. A) Water inputs to the Unit The total water requirement for the proposed expansion and zinc project will be 494 KLD. There will not be any usage of ground water. Fresh raw water of 308KLD will be received from the Chennai Metro Water Supply and Sewerage Board (CMWSSB) and the balance 186 KLD will be catered by the recycle of treated water from the RO plant. Comparison of water inputs to the unit between existing vs proposed expansion & zinc project is shown in the following table. Consumption KLD S. No Description Source Existing Expansion & plant Zinc project Chennai Metro Water Supply and 1 Fresh raw water 175 308 Sewerage Board (CMWSSB) Effluent Treatment Plant(ETP) - 2 Recycle water Further treatment done in Reverse 79 186 Osmosis(RO) plant Total water 3 ** 254 494 inputs to the unit B) Water usage in the Unit The total water requirement for plant usage for the proposed expansion and zinc projectwill be 444 KLD which covers the water requirements for cooling tower, boiler & DM plant and process plants.Regarding water requirement for plant usage, 42 KLD water will be used for caustic dilution & other process requirements, 227 KLD water will be used as compensation for cooling tower blow down, evaporation & drift losses and 175 KLD water will be required for boiler feed water generation & compensation for blowdown. The total water usage for domestic purpose for the proposed expansion and zinc project is 50 KLD which covers the drinking & washing requirements of personnel and canteen usage as well. Comparison of water usage for the unit between existing plant vs proposed expansion & zinc project is shown in the following table. Consumption KLD S.No Description Purpose Expansion & Existing plant Zinc project For caustic dilution & other process 1 Process Usage 15 42 requirements Page 1 of 6 Consumption KLD S.No Description Purpose Expansion & Existing plant Zinc project Make up water for compensation of 2 Cooling towers 99 227 evaporation, drift and blowdown losses Boiler feed water generation& 3 Boiler/DM plant 110 175 compensation for blowdown Total Plant 4 As mentioned above 224 444 Usage (1+2+3) Drinking & washing requirements of 5 Domestic Usage 30 50 personnel, canteen usage etc. Total water 6 usage of unit Domestic & plant requirements 254 494 (4+5) C) Unrecoverable water & Effluent generationin the Unit The total quantity of water which is unrecoverable in the proposed expansion and zinc project is 184 KLD. Evaporation & drift losses in cooling towers account for 149 KLD and 30 KLD of water used in process gets mixed along with the product. Around 5 KLD water as domestic consumption is also unrecoverable. The total trade effluent that will be generated for the proposed expansion and zinc project will be 265 KLD. The sources of generation of trade effluent are cooling tower blow down, boiler blowdown, DM plant regeneration water and water from process plant.Regarding trade effluent generation, 78 KLD trade effluent will be generated due to cooling towers blowdown, 32 KLD trade effluent will be generated due to boiler blowdown & DM plant regenerations, 143KLD trade effluent will be generated due to water &steam condensate from Steam jet ejectors, steam tracings etc. and 12 KLD trade effluent will be generated from process. The total sewage generated by the unit will be 45 KLD. The sourcesof sewage generation are wash rooms and canteen. The total effluent (Trade effluent + Sewage) generated by the unit is 310 KLD. Comparison of unrecoverable water &effluent generated in the unit between existing plant vs proposed expansion & zinc project is shown in the following table. Consumption KLD S.No Description Source Expansion & Existing plant Zinc project I. Unrecoverable water in the unit 1 Evaporation & Drift losses Cooling Towers 69 149 2 Water mixed with product Raw water 15 30 3 Domestic consumption Raw water 3 5 Page 2 of 6 Consumption KLD S.No Description Source Expansion & Existing plant Zinc project Total unrecoverable water As mentioned 4 87 184 in the unit above II. Total Effluent Generation 5 Cooling towers blow down water Cooling Towers 30 78 Boiler blow down water/DM 6 Boiler/DM plant 26 32 plant regeneration water Steam jet ejectors, 7 Water & Steam condensate steam tracing systems 84 143 etc. 8 Water from process Process plant -- 12 9 Trade effluent (5+6+7+8) As mentioned above 140 265 Washrooms & 10 Sewage 27 45 Canteen Total Effluent generated Trade effluent + 11 167 310 (9+10) Sewage III. Total water usage Unrecoverable 12 Total Water usage(4+11) water + Effluent 254 494 generated D) Treated Effluent Recycle / Gardening Usage The trade effluent generated in the proposed expansion and zinc project will be treated in the Effluent treatment plant (ETP) available in the unit. The treated trade effluent meeting the quality standards prescribed will be partially used for gardening and green belt maintaining/development purposes and the balance will be recycled back for plant usage after further treatment through Reverse Osmosis (RO) plant. 79 KLD of treated trade effluent will be used for gardening and green belt maintaining/development purposes and the balance 186 KLD of treated trade effluent will be recycled for plant usage after further treatment in RO plant. Around 70% of the trade effluent generated will be recycled for plant usage to reduce the fresh raw water intake. The sewage generated in theproposed expansion and zinc project will be treated in the Sewage treatment plant (STP) available in the unit. The treated sewage meeting the quality standards prescribed will be used for gardening and green belt maintaining/development purposes. 45KLD treated sewage will also be utilized for gardening and green belt maintaining/development purposes. The total water requirement for gardening and green belt maintaining/development purposes is 124 KLD. Water requirement of ~3.5 litres per sq. m per day envisaged for gardening and green belt maintaining/development for the proposed expansion & zinc project. Page 3 of 6 Green belt area => 8.56 acres =>34641 sq.m Water requirement (theoretical) for green belt development: 34641 × 3.5 Water requirement = = ~121퐾퐿퐷 1000 Comparison of distribution treated of effluent in the unit between existing plant vs proposed expansion & zinc project is shown in the following table. Consumption KLD S. No Description Source Existing Expansion & plant Zinc project Effluent treatment 1 Treated trade effluent for gardening 61 79 plant (ETP) Sewage treatment 2 Treated sewage for gardening 27 45 plant (STP) Total water usage for As mentioned 3 88 124 gardening(1+2) above Recycle water - Further treatment Effluent 4 done in Reverse Osmosis(RO) treatment plant 79 186 plant (ETP) Total Water (3+4) - Used for 5 ETP/STP 167 310 gardening + Recycle for plant use Overall around 37% of the total water requirement of the expansion & zinc project will be catered through recycled water and the balance 63% requirement will be handled using fresh raw water supply from CMWSSB. Recycle of 70% of trade effluent generated for plant usage is envisaged in the expansion & zinc project which is app 15% higher than the existing plant recycle water quantities. Water balance flow diagrams of existing plant & proposed expansion & zinc project areattached below. Page 4 of 6 i) Water BalanceFlow Diagram – Existing Plant OVERALL WATER BALANCE - EXISTING Raw water from CMWSSB - 175 KLD 175 Recycle water from RO plant - 79 Total Water usage - 79 KLD 254 KLD 99 110 15 30 Cooling Tower(CT) Boiler/DM plant feed Process Usage Domestic Usage-30 KLD 15 3 CT Evaporation / Drift Blowdown / Condensate from Water consumed - CT Blow down Water mixed with losses - 69 KLD 69 Regeneration Ejectors/others process - 15 KLD 3 KLD 30 26 84 27 Effluent Treatment Plant - 140 KLD Sewage Treatment Plant - 27 KLD 79 79 61 27 Gardening & Green Belt RO Plant development - 88 KLD Pl Note: All values are in KLD Page 5 of 6 ii) Water Balance Flow Diagram – Expansion & Zinc Project OVERALL WATER BALANCE - EXPANSION & ZINC PROJECT Raw water from CMWSSB - 308 KLD 308 Recycle water from RO plant - 186 Total Water usage - 186 KLD 494 KLD 227 175 42 50 Cooling Tower(CT) Boiler/DM plant feed Process Usage Domestic Usage-50 KLD 30 5 CT Evaporation / Drift Blowdown / Condensate from Water from Water mixed with Water consumed - CT Blow down losses - 149 KLD 149 Regeneration Ejectors/others Process process - 30 KLD 5 KLD 78 32 143 12 45 Effluent Treatment Plant - 265 KLD Sewage Treatment Plant - 45 KLD 186 186 79 45 Gardening & Green Belt RO Plant development -124 KLD Pl Note: All values are in KLD Page 6 of 6 VOC in indoor air quality Point from Minutes of meeting: “VOC to be monitored in the Indoor air quality” The unit handles solvents like Mono ethylene glycol (MEG), 2-Ethyl hexanol (2 EH) &Isodecyl alcohol (IDA) as raw materials for the process. The unit has VOC sensors installed at Process plant & Tank farm for VOC online monitoring and they are also hooked up to Care Air Centre (CAC), Tamil Nadu Pollution Control Board (TNPCB) & Central Pollution Control Board(CPCB) for continuous monitoring. Particulars of the VOC analysers installed in the unit are as follows. PRINCIPLE OF DESCRIPTION MAKE MODEL LOCATION MEASUREMENT ION VOC ANALYSER - 1 PHOTOIONISATION DETECTION TVOC PHENATE PLANT SCIENCE 600 SERIES VOC ANALYSER -2 IGD PHOTOIONISATION DETECTION TOCSIN903 TANKFARM Page 1 of 7 Recent trend details of VOC analysers in the unit attached as follows… I.