OIL AND NATURAL GAS CORPORATION LIMITED URAN …environmentclearance.nic.in/writereaddata/Online/TOR/0_0_08_Dec... · Financial Analysis 142 Annexure 15.01 Plant and Machinery

OIL AND NATURAL GAS CORPORATION LIMITED

URAN

SETTING UP A 20 MLD DESALINATION PLANT AT ONGC, URAN PLANT, URAN

TECHNO ECONOMIC FEASIBILITY REPORT

FOR

SETTING UP A 20 MLD DESALINATION PLANT AT ONGC, URAN PLANT, URAN

MECON LIMITED BENGALURU-560004 KARNATAKA, (INDIA)

NO. MEC/23Q8/01/31/R1/00/00/0001/R01 Oct 2015

OIL AND NATURAL GAS CORPORATION LTD.

SETTING UP A 20MLD SWRO DESALINATION PLANT AT ONGC ,URAN PLANT,URAN


TEFR -20 MLD DESALINATION PLANT AT ONGC URAN 2015, MECON LIMITED, All rights reserved

CONTENTS

Chapter no.

Description Page no.

1. Introduction 8 2. Executive summary 10 3. Selection of technology 17 4. Desalination plant facilities & configuration 31 5. Site details 80 6. Civil & Architectural works 88 7. Steel structural works 98 8. Plant Electrics 102 9. Instrumentation & Automation 116 10. Fire fighting facilities 121 11. Hoisting and handling facilities 123 12. Laboratory 125 13. AC &Ventilation 127 14. Compressed Air system 131 15. Capital cost 132 16. Production cost 137 17. Financial Analysis 142

Annexure 15.01 Plant and Machinery 15.02 LSTK Cost 15.03 Total project cost 15.04 Cost for 7 years operation and maintenance 16.01 Year Wise Cost of production 17.01 Lifecycle cost 17.02 Estimates of working results 17.03 Cash Flow Statement 17.04 Break even capacity 17.05 Internal rate of return 17.06 Pay Back Period

Project schedule List of drawings

1. Overall plant layout MEC/23Q8/01/14/GL/0001/R01/A1 2. Plant and equipment layout MEC/23Q8/01/31/D1/00/00/0002/R01/A1 3. Process flow diagram MEC/23Q8/01/31/D1/00/00/2001/R01/A1 4. Electrical key online drawing MEC/23Q8/01/E1/D1/00/4001 Rev 01 sht 1&2





LIST OF UNITS

AFY Acre-feet per year

BWRO Brackish water reverse osmosis

BTU British thermal units

DBP Disinfection byproduct

Dth Dekatherm = 10 Therms

G Giga (109)

GT Gas Turbine

gpd Gallons per day

gpm Gallons per minute

ft/s Feet per second

Hz Hertz

HP High Pressure

HRSG Heat Recovery Steam Generator

K kilo (103)

kV Kilovolt

kVA Kilovolt-Ampere

kW Kilowatt

kWh Kilowatt-hour

LP Low Pressure

LCV Low calorific value

M Mega (106)

MED Multi Effect Distillation

MED-TVC Multi Effect Distillation with Thermal Vapour Compression

mg/L Milligrams per liter

MG Million gallons

MW Megawatt

MGD Million imperial gallons per day

MLD Million Litre per day





MSF Multi Stage Flash

MW Megawatt (106 Watts)

p.a per annum

Ppb Parts per billion

ppm Parts per million

ppt Parts per thousand

RO Reverse Osmosis

SDI Silt Density Index

STP Sewage Treatment Plant

SWRO Seawater Reverse Osmosis

TDS Total Dissolved Solids

t/h Metric Tonnes per hour

thm Therm = 100,000 BTU

TVC Thermal Vapor Compression

UAE United Arab Emirates

WHO World Health Organization

Table 1: Unit conversions for soil and water salinity

Convert… to… by multiplying with…

uS/cm mS/cm 0.001

mS/cm dS/m 0.01

ppm (mg/L) microS/cm 1.4*

m3 ML 0.001

m3 kL 1

m3 L 1000

ppm (mg/L) g/L 0.001

Bar kPa 100

Atm kPa 101

* Rule of thumb only





Glossary of terms A glossary of terms used in this study follow: Abstraction - The removal of a substance from its source to the process plant. Anti scalants - Chemicals that are used to prevent scale formation. Artesian Bores - These are devices that pump the ground water to the surface for collection or use. Back-washing Multimedia Pressure Filter - This is a filter that that has several different mediums to filter the solids and will automatically self-backwash to wash away the accumulating solids. Brackish Water - Water that has a salinity of 1000-12000 mg/L TDS. Brine - Waste water that usually has a high concentration of dissolved salts (see also Concentrate). Buffering Salts - These are salts that increase the saturation point of the solution, therefore preventing other salts from coming out of the solution. Cartridge Filters - This is a filter with a fine pore size (1-10 micron). Concentrate - The concentrated salt solution that is produced as a by-product of the desalination process (see also Brine). Desalination - The process of removing salts from saline water. Dispersants - A chemical that is used to inhibit the growth of natural organic matter. Distillation - A process of water purification whereby the feed water is heated to produce steam which is then condensed to produce water of a high purity. EDR - A membrane process of desalination, similar to electro dialysis except that several times every hour the flow through the cells is switched and the polarity of the electrodes is reversed. Then the product channel becomes the brine channel and the brine channel becomes the product channel.





Electro dialysis - A membrane process of desalination. An electric current is applied to feed water that is passing adjacent membranes. One membrane allows anions through and the other membrane allows cations through. The ions from the solution pass through the membranes allowing fresh water to be discharged as product water. Electrolytes - Compounds that when in solution conduct an electric current and are also decomposed by that current. Electromotive Force - The force that moves electrons through a membrane in the ED and EDR process. Energy Recovery System - A system incorporated in the plant to recover energy from the process to be used in other parts of the process. Feed Water - The water that is fed to the desalination equipment. This water can be already pre-treated or source water. Flocculent - This is a chemical that enables suspended particles to clump together, so that they can be settled out of the solution more easily. Freeze Desalination - A desalination process whereby salt water is frozen to the point where salt water remains in liquid form but the fresh water has frozen. The frozen water is washed to remove salts and is melted to produce product water. Fresh Water - Water that has a dissolved solids count of less than 500 mg/L TDS. Ion Exchange - A desalination process where an electric current is used to remove ions from solution. Latent Heat of Condensation - The amount of heat energy released when vapour is turned into water. Membrane Distillation - This is a form of distillation desalination that also uses membranes. Microfiltration - A low pressure membrane filtration process which only allows small soluble particles through the membrane and filters suspended & colloidal particles.





Multiple Effect Distillation (MED) - A form of distillation desalination. Evaporators are arranged in series containing hot vapor that is used to condense and produce product water. The vapour from one chamber (‘effect’) is used to heat the next effect thereby reducing overall energy requirements. Multistage Flash (MSF) - a form of distillation desalination. Feed water is heated and sent to a vessel that is slightly below saturation vapor pressure so that some of the water flashes and forms vapor. This vapor condenses and becomes product water. The salt water is sent to another vessel at a lower pressure where the flashing process is repeated. Nano - filtration - A membrane filtration process that uses loose RO membranes. These have a lower rejection capability than RO membranes and therefore leak more soluble ions, but can obtain higher recoveries. Osmosis - The natural movement of water from a diluted solution to a more concentrated solution. Osmotic Pressure - The pressure required for the osmotic process to equalise. Permeate - The purified water that membrane desalination processes produce. Photovoltaic - A type of solar panel used for collecting solar energy. Polishing - This is an end process, where product water undergoes some more processing to refine it to meet high quality product requirements. Potable Water - Water that is considered suitable for human consumption. Product Water - The fresh water that is discharged from the desalination process. Recovery - The percentage of the feed water that is recovered in the desalination process as fresh product water. Rejection - The percentage of solids that the desalination process removes from the feed water. Reverse Osmosis (RO) - A membrane desalination processes where pressure is applied to feed water so that it moves through a semi-permeable membrane.





Salinity - The measure of soluble salt (sodium chloride) in the water. Saturation Vapor Pressure - The pressure at which no more vapour can evaporate into the air. Scale - The substance that precipitates onto the equipment walls during the desalination process. Most relevant for the distillation processes. Silt Density Index - Also known as Fouling index(FI) is a good guide line to determine the colloidal fouling potential of RO feed water. Solar Humidification - A desalination process where solar power is used to heat saline water so that some of it evaporates, and the vapor is then condensed and collected as product water. Suspended Solids - Colloidal material that is suspended in water. Total Dissolved Solids (TDS) - The amount of solids that are dissolved in the water, usually measured in milligrams per liter (mg/L) or parts per million (ppm). Total Suspended Solids (TSS) - The amount of solids that are suspended in a solution. Turbidity - The clouding of the solution because suspended materials in the solution reduce the transmission of light. Ultra-filtration- This low pressure filtration process uses membranes to selectively filter molecules of a particular size and weight present in suspended or colloidal form. Vacuum Freezing - A desalination process that involves the temperature and pressure of the feed water being lowered until the water freezes. This is then washed and then melted to produce the product water. Vapor Compression (VC) - A desalination process where some of the feed water is evaporated and then compressed with mechanical or thermal energy where it condenses and is collected as product water. The latent heat released in the condensation process is used to evaporate more feed water.





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CHAPTER -1

INTRODUCTION

ONGC Uran Plant, Uran intends to set up a sea water desalination plant of 20 MLD capacity, wherein 18 MLD shall cater to the process water requirement as per the service water quality of ONGC and 2 MLD shall cater to the boiler feed water requirement having DM water quality. Based on the field studies carried out , the preferred sea water reverse osmosis desalination technology adopted, the design basis for the plant, CAPEX and OPEX has been detailed out for various units and plant facilities comprising of sea water intake, reject disposal, integrated membrane pre treatment and RO system, post treatment, chemical system, plant electrics, instrumentation and automation.

The envisaged desalination plant is based on the best available, proven reverse osmosis technology reflecting the latest innovation in the design, operation and maintenance of water treatment plants and is conceived with the contribution of multidisciplinary experiences acquired in seawater desalination.

The plant is designed to produce 18 million liters per day (MLD) capacity towards service water for in plant consumption. Additionally, the plant also envisages production of 2 MLD capacity Demineralized Water for boiler feed water after treatment in mixed bed exchanger units of the Demineralization plant. The plant considers uninterrupted production for 365 days a year.

1.1 OBJECTIVES OF THE STUDY The key objectives of the current study are as follows:

i. Selection and recommendation of the appropriate desalination technology and plant configuration by assessing various influencing cost and non cost criteria specific to the plant including raw sea water feed analysis, product water quality requirements, availability of power and energy supply options etc.

ii. Assess the land requirement for the current plant capacity of 20 MLD, preparation of General

Layout, Process Flow Diagram (PFD) and indicate the estimated requirement of auxiliary services like raw material, power and other utilities for the 20 MLD capacity desalination plant.





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iii. Prepare preliminary capital and operating cost estimates for the recommended desalination plant configuration option for 20 MLD capacity.

iv. Preparation of project Implementation schedule.

v. Financial appraisal including profitability statement, cash flow statement.





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CHAPTER-2

EXECUTIVE SUMMARY

2.1 INTRODUCTION ONGC Uran Plant, Uran intends to set up a sea water desalination plant of 20 MLD capacity, wherein 18 MLD shall cater to the process water requirement equivalent to the present service water quality of ONGC and 2 MLD shall cater to the boiler feed water requirement having DM water quality. Based on the field studies carried out, the preferred sea water reverse osmosis desalination technology adopted, the design basis for the plant, CAPEX and OPEX has been detailed out for various units and plant facilities comprising of sea water intake, reject disposal, integrated membrane pre treatment and RO system, post treatment, centralized chemical dosing & storage system, plant electrics, instrumentation and automation.

The envisaged desalination plant is based on the best available, proven reverse osmosis technology reflecting the latest innovation in the design, operation and maintenance of water treatment plants and is conceived with the contribution of multidisciplinary experiences acquired in seawater desalination.

The plant is designed to produce 18 million liters per day (MLD) capacity towards service water for in plant consumption. Additionally, the plant also envisages production of 2 MLD capacity Demineralized Water for boiler feed water after treatment in mixed bed exchanger units of the Demineralization plant. The plant considers uninterrupted production for 365 days a year.

The proposed site is about 380 meters away from the HTL along the sea-shore on the coast of Arabian sea at 18o 51’ 24.96’’ N latitude, 72o 55’ 37.28’’ E longitude and is located in the existing ONGC Uran facility, Uran.

The TEFR has been prepared based on the field studies carried out and the multidisciplinary experiences for similar reverse osmosis based sea water desalination plants.

Based on the marine bathymetry results, it is observed that the sea is shallow in nature and the water depth available below chart datum level is around 1.5 to 2m even after a





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distance of 1.5 km from the shore. Also after evaluation of the various types of aforementioned intake options , the offshore feed water conveyance for the proposed plant is carried out by an 228 m long , 2m wide closed RCC channel designed for gravity flow with sufficient slope from the onshore intake chamber into the sea. The RCC channel is followed by dredging of the sea bed to sufficient depth for an approximate distance of 1.3 km to ensure requisite surface water availability at all times by gravity into the onshore intake chamber.The intake chamber comprises of trash racks and traveling water screens for the separation of coarse particles from the feed sea surface water.

The present report envisages conservative plant design based on the field data collected for one season and the experience of similar desalination plants.

The reject of the pretreatment and RO system (desalination plant) is assumed to be carried by HDPE sub- sea pipeline and diffuser system .This will be kept separated from the intake point sufficiently to avoid short circuiting.

The feed sea water from the intake chamber will be pumped to the desalination plant by vertical turbine pumps installed in the intake chamber .The pretreatment system envisaged for plant location for the sea water reverse osmosis desalination plant comprises of DAF (Dissolve Air Floatation units) followed by Disc filter & Ultra filtration system with intermediate RCC storage tanks & pumping facilities. Considering that presence of marine activity at the location of the proposed sea water reverse osmosis desalination plant , the state–of-the-art DAF system followed by 40 micron automatic back washable disc filters coupled with ultrafiltration system is conceived to be the best suited option and will have advantage over the conventional pretreatment equipment like clarifiers, tube settlers, gravity & pressure sand filters.

Incoming power supplies for the proposed desalination plant shall be made available by ONGC from the existing 6.6kV switchgear of NBPH substation fed from from LPG-II substation , 6.6/0.433 kV, 630kVA transformer sourced from 6.6kV switchgear at LPG-II substation , 415V spare breaker panel at 13-1F1 of C71/72 MCC of LT substation. Flame proof LT motors suitable for zone 2 and Gas group IIB and IIC environment as per requirement is considered.

Instrumentation system has been envisaged with adequate measurement and control facilities with a view to attain efficient, reliable and trouble-free operation of the plant and its facilities, safety of the plant, equipment and operating personnel and user friendly man-machine communication. The PLC system shall be Safety Integrated Level-3 (SIL3) and shall be redundant.





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In developing the layout, a systematic approach is adopted to ensure that all the subsystems are optimally laid out both from the viewpoint of operational & maintenance flexibility, optimizing land requirement , capital cost as well as running costs. The layout enclosed with this document, drawing no. MEC/23Q8/01/14/GL/0001/R01/A1 is indicative . Approach roads/paving is envisaged between main building & storage tank area of the Desalination plant depending on the type of service in this area and movement of traffic. The desalination plant is approachable from the existing plant roads in the area, especially the chemical building ,bulk chemical storage & handling area and electrical & control room building, CO2 storage area, Post treatment area . Within each facility, approach to various equipments is envisaged.

The TDS data available for the proposed location varies from 32000 ppm to 35000 ppm. Considering this variation , a maximum TDS of 42000ppm has been taken into consideration for designing the proposed 20 MLD SWRO desalination plant for the desired product water quality for the TEFR purpose .All the major drives have been envisaged with VFD and accordingly the equipment rating & recovery have been envisaged for this TDS. As per available data and information ,the site lies in seismic zone III as per seismic zone mapping of India (IS: 1893 - 2005) and has the lowest seismic potential.

The altitude of the site is at safe grade elevation of 16.34 m above MSL

The subsections of this report shall give a detailed description of the each key component envisaged in the proposed desalination plant. The key components of the desalination project consist of a seawater intake system, brine disposal system and desalination (treatment) facility, plant electrics , instrumentation & automation and allied facilities.

Desalinated (product) water from the proposed desalination plant is being transferred to the existing ONGC raw water storage and DM water storage tanks located at approximately 1.5 km from the proposed desalination plant site.

2.2 Desalination Facility The process shall be based on sea water reverse osmosis. The sea water will be received through a pipeline into an onshore intake chamber from where it will be pumped to DAF units followed by Automatic back washable disc filter & Ultrafiltration skids for removal of suspended solids including Oil & grease etc. The water then be pumped at high pressure through Reverse Osmosis membrane system for separation of dissolved solids . The two pass RO system is envisaged to get the desired water quality indicated in the ONGC





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technical specification with proper blending of permeate . The dissolved solids will get concentrated in the reject stream, which will impart its energy to the RO feed water in the energy recovery device. The reject brine stream from the energy recovery device will get disposed off in to the sea through a reject disposal pipeline & diffuser system . The Permeate water to partially from RO system will be subjected to recarbonation in the post treatment section to produce service water of 18 MLD and remaining is sent to a DM water plant to produce 2 MLD DM water .The service and potable water is sent to the respective tanks existing in the ONGC Uran plant.

Chemical storage, handling, preparation and dosing facilities for storage of chemicals like ferric chloride, poly electrolyte, sodium bisulphate, sodium hypochlorite, limestone, carbon dioxide etc has been considered for sufficient storage capacity. A centralized chemical preparation & dosing system has been considered for requirement at various process stages.

All other auxiliary plant facilities like power supply & distribution, plant electrics, instrumentation and automation, air conditioning & ventilation, material handling facilities, lab facilities has been envisaged in the techno feasibility study. Non plant facilities like administrative building has been considered as the part of the plant facilities.

Low pressure piping has been assumed to be HDPE and High pressure piping to be duplex material. All valves and pumps handling seawater material of construction has been assumed to be super duplex of pitting resistance equivalent no. > 40. RO permeate piping, valves shall be of SS 316L grade. Corrosive chemicals storage shall be in GRP/FRP (glass reinforced plastic/fiber reinforced plastic) tanks and vessels.

The major plant units envisaged shall be as follows:

i. Offshore sea water intake & outfall facilities ii. Onshore intake chamber and pumping station iii. Water conditioning by dosing of chemicals iv. Pre treatment by means of DAF units , backwashable disc filter followed UF

membranes v. Desalting by two pass RO membrane , energy recovery device vi. RCC Intermediate storage tanks vii. Storage, dosing & pumping system viii. Re carbonation & Remineralisation system ix. Electrical power distribution x. Instrumentation & control xi. Allied facilities.





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2.3 Project completion period

The estimated project completion time for the above is about 26 months including construction period of 21 months and testing,commissioning and performance guarantee test period of 5 months.

2.4 Contract and Delivery models

Several contracting delivery models (project delivery methods) are available to pursue and construct the desalination facility and associated systems. The conventional delivery models are as follows:

■ Engineering, Procurement, and Construction Management (EPCM)

■ Design - Build (DB)

■ Design - Build - Operate (DBO) and maintain (DBOM)

■ Build - Own - Operate - Transfer (BOOT)

■ Build - Own - Operate (BOO)

The contract delivery model that has been used to construct several desalination projects worldwide are either DBOM or EPCM along with operation & maintenance contract which is normally for 7 years being practiced by industries.

2.5 Estimated Capital cost : The investment required for the proposed desalination plant has been estimated as Rs 313.6 Crores including a foreign exchange component of Rs 43.3 Crores.

The capital cost estimates are based on prices prevailing during the 3rd quarter of 2015.

The desalination plant solutions are location specific and cost estimation of the plant are dependent on the local factors, end user , economics of the scale of capacity of the plant ,product water quality, additional redundancy, type of tanks & buffer storage, location specific intake & outfall system , prevailing tax structures etc and therefore ,incomparable with the same capacity of the plant elsewhere.





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2.6 Operating & maintenance cost: The cost of manufacture (without interest and depreciation) per CUM of treated sea water is estimated as Rs 34.94 based on the cost of materials, consumables, labour & supervision, power and other services costs as prevailing in the 3rd quarter of 2015.

2.7 Financial analysis.

The financial analysis for the proposed plant has been carried out on the basis of capital cost and production cost as enumerated in the following chapters and selling price of Rs 92 per cum of treated water.

Sl.No. Index Unit Value

1 Life Cycle Cost, NPV at 8% Discounting

Rate

Rs Crores 640.9

2 Cumulative profit over 20 years of

operation

Rs Crores 789.9

3 Average profit per year over 20 years of

operation

Rs Crores 39.5

4 Cumulative cash surplus over 20 years of

operation

Rs Crores 1,081.2

5 Break even capacity (Average over 10

years of operation)

Conventional % 54.9





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Cash % 9.3

6 IRR (Post Tax) % 14.3

7 Payback period Years 6.3

2.8 Conclusion

The foregoing analysis reveals that installation of the proposed 20 MLD desalination plant

involving capital investment of Rs 313.6 Crores generates an average annual net profit of

Rs. 39.5 Crores and a IRR (post tax) of 14.3%. Keeping in view the socio-economic benefits

of the proposed project and water scarcity problem in future, it is recommended to

implement the project.





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CHAPTER-3

SELECTION OF TECHNOLOGY

3.1 Desalination as a source of fresh water

Of all the Earth’s water, 94 percent is salt water from the oceans and 6 percent is fresh. Of the latter, 27 percent is in glaciers and 72 percent is underground. While the Earth’s salt water resources support commercially important activities such as fishing and transport, it is typically beyond the limits to support human life or farming. Desalting techniques have therefore captured attention as an option to increase the range of water resources available for use by a community.

3.2 Worldwide Scenario

The application of desalting technologies over the last half of the 19th century has changed the way people live their lives and where they choose to live. Villages, cities and industries have now developed in many of the arid and water scarce areas of the world where sea or brackish waters (a salt level between fresh and sea water) are available and are being treated with desalting techniques. The change is most apparent in parts of the arid Middle East, North Africa, Europe, Australia. America and some of the islands of the Caribbean, where the lack of fresh water previously limited development. The requirement to provide fresh water to people in areas with little or no infrastructure was highlighted during WWII. The potential of desalination was realised during this time and the technology underwent its first intensive period of development following the war. The American government, through the creation and funding of the Office of Saline Water in the early 1960’s, and its successor organisations, led the worldwide research effort. The work of these underpins much of the knowledge and understanding that exists today. By the late 1960’s, commercial thermal approaches to desalting water were common with capacities up to 8,000 kL/day being achieved. In the 1970’s, commercial scale membrane processes such as Reverse Osmosis (RO) and Electrodialysis (ED) were introduced and used more extensively. As the technology progressed and operational experience increased through the 80’s and 90’s, the cost of construction and operation reduced significantly. Particularly the membrane technologies are considerably cheaper now for many site specific requirements than the tried and trusted thermal/distillation technologies.





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As the scarcity and price of conventional sources of fresh water rose by the passage of time, desalination as an option for supplying fresh water for human consumption and industries is becoming more predominant in India.

3.3 Potential users of desalination

The users of desalination are many and varied. For fresh water, desalination plants have the potential to supply drinking quality water and water for industries. More and more industries are coming forward to invest in the desalination plant to meet their water requirement. Earlier, the financial costs of desalination were hard to justify but with the advancements & development in desalination technology it has become an attractive option.

3.4 Salinity quality guidelines

Table -03.1

Use Rating Approximate Salinity Range (mg/L TDS)

Human consumption Excellent About 100 Human consumption Good to fair 100 - 1,000 Human consumption Poor 1,000 - 1,200 Human consumption Unacceptable > 1,200

Irrigation depending on plant Max. for healthy growth 0 - 3,500

Industry specific - Industry

3.5 Desalination technologies

Desalination is a process that removes dissolved minerals (including but not limited to salt) from feed water sources such as seawater, brackish water or treated wastewater.

The techniques for desalination may be classified into three categories according to the process principle used:

a) Process based on a physical change in state of the water - i.e. distillation or freezing; b) process using membranes - i.e. reverse osmosis or electrodialysis; and





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c) process acting on chemical bonds - i.e. ion exchange.

Of the above processes, those based on chemical bonds such as ion exchange are mainly used to produce extremely high quality water for specialised industrial and are not suited to treating seawater or brackish water. Hence, this process was not considered as terms of reference for feasibility study for the proposed desalination plant of ONGC Uran Plant, Uran.

The other two processes, based on physical change of the water and filtering via membranes, are regularly used to treat seawater and brackish water and have been developed over many years in large scale commercial applications. Hence, the choice for the sea water desalination processes to be adopted in proposed ONGC Uran Plant, Uran, were to be made from the following established commercially proven process:

3.5.1 Major Processes:

a) Membrane based process

i) Reverse Osmosis

ii) Electro dialysis

b) Distillation (thermal or enthalpy based processes)

i) Multi-Stage Flash Distillation (MSF)

ii) Multiple Effect Distillation (MED)

iii) Vapor Compression Distillation (VCD)

The most widely applied and commercially proven seawater desalination technologies are broadly categorised as either thermal (evaporative) or membrane (reverse osmosis) based methods. Various combinations of desalination technology such as thermal , membrane or hybrid (thermal and membrane) and associated energy supply exists which can be employed for the water production capacities being considered for ONGC Uran Plant, Uran

3.5.1.1 Membrane processes

Membranes are used in two commercially important desalination processes:

i) Reverse Osmosis (RO); and

Ii) Electrodialysis (ED).

Each process uses the ability of the membranes to differentiate and selectively separate salts and water. However, the membranes are used differently for each of these two





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processes. Reverse Osmosis is a (differential) pressure driven membrane separation technique. By applying a pressure difference, the permeating component(s), in most applications nearly exclusively water, are forced through the membrane. It is a membrane filtration process with a nominal membrane pore size less than 0.001 microns. The applied pressure used for separation depends on the salt content resulting to osmotic pressure, allows the water to pass through the membrane while the salts remain thereby removing suspended solids and dissolved salts. Besides its application for production of drinking water for human consumption, industry & irrigation, reverse osmosis is also applied in the treatment of effluent water and separation of organic and inorganic compounds from aqueous solution for industrial applications.

Electro dialysis is a voltage driven process, and uses the electrical potential to selectively move salts through the membrane, leaving the product water behind.EDR systems have a feed water TDS limit of 12,000 mg/L TDS and are generally considered when high scaling feed waters are present. EDR systems are therefore only economically viable over an RO system when the feed water TDS is between 3,000 mg/L to 12,000 mg/L, and the plant capacity required is greater than 100 kL/d, and the feed water is high scaling. As the proposed plant raw water TDS is anticipated to be greater than 12000 ppm, EDR process has not been evaluated further.

Based on the same, membrane based Reverse osmosis desalting process is evaluated vis- a- vis thermal process.

Thermal Process:

Thermal desalination separates salt from water by evaporation and condensation where steam is the main driver . In membrane desalination water diffuses through a membrane and the dissolved salts are almost completely retained resulting in fresh water. Electricity is the main driver in membrane process.

MSF, MED and VCD are three advanced thermal processes wherein thermal evaporation principle is used to desalinate the raw water. The MSF process operates with a top brine temperature in the range of 90-110°C while the MEE and MVC processes are operated with lower top brine temperatures in the range of 60°C -70°C. In MSF process, the seawater feed is pressurised and heated to the corresponding boiling temperature and discharged into a chamber maintained slightly below the saturation vapour pressure of the water, a fraction of its water content ‘flashes’ into steam. In Multiple effect distillation, the units operate on the principle of reducing the ambient pressure at each successive stage, allowing the feed water to undergo





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multiple boiling without having to supply additional heat after the first stage. MVC is distinguished from MSF & MED by the presence of a mechanical vapour compressor, which compresses the vapour formed within the evaporator to the desired pressure and temperature. The system also includes plate heat exchangers for preheating the feed water using heat recovered from the brine lowdown stream and the distillate product. In all these processes, exhausted brine, concentrated in salt, is pumped out and rejected to the sea.

3.6 Selection of Technology

3.6.1 Techno-Economic Considerations & Trends The energy, capital, operating costs, plant availability and reliability are the key issues of sea water desalination technology selection. Optimised process selection and choice will depend on specific conditions prevailing at site (location specific) such as existing facilities, power availability, land availability, water intake and outfall, sea conditions and it extent of variation, fluctuation in feed water conditions ,feed and product water quality & quantity to be produced, civil works.

Thermal desalination processes have been widely applied in the Middle East integrated with power plants in dual-purpose configurations i.e. for the supply of power and water. These configurations are very well suited to the simultaneous demand for water and power in this region. In addition it allows for a good overall thermodynamic efficiency, as the heat generated in the power plant can be used in the desalination plant instead of being rejected as waste heat. Thus, depending on site-specific circumstances, the total water cost may be lower than in the case of a reverse osmosis plant. As the cost of the membrane and thermal desalination technologies has decreased the desalination market has grown markedly. Seawater remains the most widely used raw water source for desalination facilities and accounts for just over half of the installed capacity. Prior to 2003, when only the seawater desalination market is considered, thermal processes accounted for 73% of the installed capacity and RO only around 27%. This was historically skewed by the large number of older seawater thermal desalination plants. When the entire desalination market of all water sources (seawater, brackish, wastewater etc) is considered, RO has been steadily increasing its market share at the expense of thermal processes. At the end of 2003 RO was the leading process accounting for 47.6% of the world’s installed desalination capacity. Other than in some parts of the Middle East, where thermal processes are favoured by extremely low energy costs as it is mostly coupled with integrated power plants, reverse osmosis is now the dominant technology for seawater desalination elsewhere. Even in the middle east, the recent desalting plants are either based on reverse osmosis or hybrid plants i.e RO +Thermal).





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Both thermal and RO desalination technologies have limitations and advantages. Factors such as source water TDS, product water use e.g. drinking water or high quality industrial water, plant production capacity and energy availability exert a strong influence on which desalting process is best suited to a particular site. The availability of cheap energy or waste heat supplies can be a deciding factor in selecting a desalination process. An overview of the energy requirements of the thermal and RO along with comparison of thermal and RO desalination technologies based on their intake volumes, suitability to plant capacity, operational and maintenance requirements etc is given in is given in Table 3.2

Table 3.2 Comparison of thermal and reverse osmosis desalination technologies is

Sl. no Parameter Thermal Reverse Osmosis 1. Process

Phase change Evaporation & condensation (liquid → vapour →liquid)

Membrane (no phase change)

2. Energy supply

MSF, MED, MED-TVC requires Thermal + electrical energy MVC requires electrical energy

Electrical energy

3. Operation temperature °C

MSF <115, MED <65, MED-TVC <65 , MVC <65,

<45

4. Form of energy, Bar (a)

MSF - Steam> 2.8, MED - Steam >0.3, MED-TVC – Steam >2.8, MVC- Electrical energy

Electrical energy

5. Average elec. energy Consumption, KWh/m3

MSF-4.0 , MED -1.9 , MED-TVC -1.9, MVC - 9 KWh/m3

3.0 to 4.5 KWh/m3

6. Typical TDS salt content of source water mg/L

30 000 to 100 000

1 000 to 45 000

7. Product water quality mg/L

< 10 <500 (single pass)

8. Current single unit capacity m3/d

MSF - 5000 to 72 000, MED - 500 to 17 500, MED-TVC - 500 to 22 500, MVC - 50 to 3000

10 to 20000

9. Intake volume requirements

High cooling water demand for MSF/MED. Seawater demand four times that of RO.

Achieve higher recoveries – lower intake





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MVC no cooling water requirement. Only make up water required. Lower recovery rates than RO leading to more expensive offshore and onshore civil works.

demand, no cooling water requirement for feedwater <45°C

10. Small plant size MVC RO 11. Large plant size MSF, MED, MED TVC RO 12. Ample supply of

waste heat available

MSF, MED

13. Electricity only MVC RO 14. Desalinated

product High quality product water (<10 mg/L TDS), Unaffected by variations in seawater salinity

First pass SWRO system < 500 mg/L. Product depends on membrane age, temperature and salinity of raw water

15. Pre-treatment requirements

Processes unaffected by typical suspended or biological matter levels in raw seawater. Filtration down to 2 – 3 mm Ion trap for aluminium heat exchange surfaces De-aeration for MSF

Critical – extent depends on seawater quality Suspended solids must be removed and biological activity controlled. Final cartridge filtration down to 1 – 10 μm SDI < 5

16. Corrosion More susceptible to corrosion. Require high grade corrosion resistant materials increases capital cost.

Less susceptible. Operational temperatures lower.

17. Scale control More severe for calcium and magnesium carbonate. Acid and anti-scalant addition

Acid and anti-scalant addition

18. Chemical consumption

Low High





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19. Safety issues High temperature and pressurised steam Corrosive chemical use

High pressure pumping Corrosive chemical use

20. Start up Start up cumbersome Start up quicker and response to load changes faster

21. Operation and maintenance

More tolerant of less than optimal operation and maintenance MSF least amount of operator attention MVC simple to operate but compressors require significant levels of maintenance

Higher than for thermal for pretreatment and membrane cleaning. Complexity determined by pretreatment Qualified personnel recommended

22. Consumables

Membranes – average lifetime 5 – 7 years depending on pretreatment Cartridge filters 2 -3 months

23. Cleaning

Operational periods of more than a year between acid cleans of heat transfer surfaces Annual shut down for repair of heat transfer systems

Typically every 3 months on first pass depending on pretreatment efficiency and control of fouling, biofouling and scaling

24. Brine/concentrate temperature

Up to 10°C above ambient seawater

Up to 2°C above ambient seawater

25. Waste disposal

Limited waste from pretreatment Acid cleaning waste disposal

Produce waste in pre-treatment that require disposal





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Membrane cleaning waste disposal

26. Post treatment requirements of product desalinated water pH and alkalinity adjustment

At TDS of <10 mg/L water tastes flat and insipid, objectionably soft . Requires more post treatment than RO Low levels of oxygen – may need re-aeration Product water temperature higher than RO, may require cooling if used for drinking water

Re-mineralisation requirement lower than thermal pH and alkalinity adjustment

Many recent and important improvements in desalination technologies are in RO systems. The total desalination capacity worldwide using RO technology is continuously increasing, even in the Arabian Gulf region where energy is cheap and raw water quality is less suitable for RO technology, requiring an advanced pretreatment scheme to protect RO membranes mainly from fouling and biofouling. The total global capacity (sea and brackish waters) of RO is the highest compared to any other process. The tremendous reduction in desalinated water cost by RO has enabled many countries to implement desalination to supply potable water for domestic and industrial use and even for agriculture purposes in some countries such as Spain There have been many developments over the last three decades that have contributed to a reduction in unit water cost of RO desalination, particularly membrane performance and reduction in energy consumption caused by more efficient energy recovery systems. The performance of the membrane materials and modules has improved with respect to increased salt rejection, increased surface area per unit volume, increased flux, improved membrane life, and capacity to work at higher pressure, and has also a decreased membrane cost. The recovery ratio increased considerably over the years due to improved salt rejection. The recovery ratio for normal seawater desalination (35,000 mg/L of salinity) was about 25% in 1980s and it increased to 35% in 1990s. Currently, it is about 45% and can reach 60% if second stage is applied. Significantly lower recoveries occur in locations where seawater salinities are usually high, such as the Arabian Gulf, the Red Sea, and the eastern Mediterranean Sea, but recoveries in these difficult areas have also historically improved. Improved recovery has facilitated a decrease of the investment cost and also operating costs. The capital cost reduction occurs because of the reduction in RO train and intake and outfall system capacities caused by the improved conversion rate of seawater to fresh water. The operating cost reduction is due to a reduction in usage of chemicals and pumping energy. Membrane costs should increase due to inflation over a period of time. The significant decrease of membrane costs of the





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last decades has contributed considerably to unit water cost reduction. Perhaps the energy component has witnessed the most dramatic improvement in RO processes. The energy is recovered from the brine side of the process through either turbo systems that include reversible pumps, Pelton turbines, turbochargers, and a hydraulic pressure booster or through volumetric systems that include the ERI pressure exchanger, DWEER (Dual Work Exchanger) Calder, or the KSB (SalTec) device. With the new energy recovery systems developed over the years, the objective of reducing energy consumption for SWRO below 3 kWh/m3 for RO section is being achieved presently. Typical energy consumption for different desalination technologies is presented in table 3.3: Energy consumption and water cost (average values) of large scale commercial desalination processes:

Table 3. 3 . Process

Thermal energy kWh/m3

Electrical energy kWh/m3

Total energy kWh/m3

Investment cost $/m3/d

Total water cost US$/m3

MSF

7.5–12 2.5–4 10–16 1200–2500 (0.8–1.5)a

MED 4–7 1.5–2 5.5–9 900–2000 0.7–1.8

SWRO – (3–4) b 3–4 900–2500 0.5–1.2

BWRO – 0.5–2.5 0.5–2.5 300–1200 0.2–0.4 a Including subsidies (price of fuel). b Including energy recovery system. The other important improvements in RO technology are: - Improvements in pretreatment processes (including microfiltration (MF)/ultrafiltration (UF) membranes). Most of the new plants are using lesser amounts of chemicals, which is more environmentally friendly and results in a great reduction in consumable costs. - Development of new intake designs, mainly subsurface beach or sea intakes in the form of conventional wells , horizontal wells or gallery intakes. These types of natural filtration systems are very suitable for treatment of difficult raw water qualities to minimize impingement and entrainment, and reduce quantities of chemicals used, especially during red tide events or high harmful algal blooms. However, beach intakes are suited for small capacity plants in India as the yield is not commensurate to large capacity plant. Gallery





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intakes require more cumbersome construction or a large area inside the sea and hence not widely preferred. For large capacity plants, surface open intakes are mostly preferred, but a more suitable pretreatment is required. Dissolved air flotation (DAF) is considered the best solution for red tides and other sea water contaminants. - Improvements in design with use of different configurations and improvements in linking processes. - Development of a high boron rejection membranes that produce an acceptable concentration in the permeate without requiring a second pass RO system - Reduction in usage of chemicals with improved membrane performance. Injection of acid and antiscalant is not always necessary. A recent study showed stable operation of a SWRO plant free of chemicals without causing any scaling. In addition, the use of low pressure membranes in SWRO pretreatment can reduce or avoid the use of coagulation agents. - Increase in plant capacity (plant size and unit size) provides a scaling factor that reduces cost, particularly capital cost per treatment capacity unit. Apart from improvements in RO technology, increases in plant capacity have also contributed to a reduction in unit water cost. The magnitude of the respective costs due to improvements in the membranes and increases in plant capacity are difficult to measure since they have both taken place simultaneously. Plant capacities increased by a factor of 10, conceived and executed between the period 1995 and 2010. The Maqtaa SWRO plant located in Algeria, which is under construction & commissioning, has a total capacity of 5,00,000 m3/d. There are other SWRO plants in Israel , Australia, USA, Mediterranean region and India which has been built over the years for large capacities ranging between 1,00,000 to 5,00,000 m3/day. Recently, even in India after the year 2010, two nos. of 100000 m3/day (Minjur & Nemmeli) SWRO plants were commissioned and are in operation.

3.6.2 Parameters influencing the desalination cost

3.6.2.1 Main parameters influencing the cost

The parameters that affect the total investment (capital) and operational costs of desalination plants are the major factors considered in selection of an appropriate desalination technology. The estimated cost of desalination with different processes is site-specific and depends mainly on the following parameters:





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- Electric power availability. If a plant is going to be a stand-alone facility powered by electricity generated at a considerable distance away, the RO process may have greater economic advantage over a thermal or hybrid process.

- Desalination process configuration, plant size and its component design. The investment cost of different commercial desalination technologies differs widely between thermal-based and membrane based technologies (Table above). For a similar plant capacity, thermal processes require larger footprints and use more costly materials and equipment than the SWRO process. Similarly, thermal processes consume higher amounts of specific energy (electrical and thermal) than RO (needs electricity only) and more chemicals are required to control scaling, corrosion and foam. However, on the other hand, thermal distillate is of higher quality than the RO product. Also, thermal processes function using nearly any quality (salinity) of feed water without extensive pretreatment. Plant capacity is also an important issue. Normally, the higher the plant capacity, the lower the total water cost and investment cost per cubic meter of product. However, political or environmental issues could be a limitation for successfully implementing such mega-projects.

- Geographical location and site-specific characteristics. Desalination plants with a required production capacity should be built in appropriate locations to avoid additional costs, such as water transfer or not running the plant under its optimal conditions. Real estate acquisition cost is also a significant factor that may require greater water transmission in locations where land cost may exhibit orders of magnitude differences in relatively short distances.

- Raw water quality, temperature, intake arrangement and required product water quality (post-treatment, blending). The plant location should be carefully selected at the best site in terms of feed water quality, elevation or currents especially for RO as the cost could be significantly affected by the quality of feed water if more advanced pretreatment is required. For example, biofouling reduces the membrane life-expectancy and increases the operation and maintenance (O&M) costs and, in some cases, has led to temporary plant shutdowns. Intake and pretreatment arrangements are designed depending on raw water quality and quantity as well as geology of the site. - Reject discharge type and product water storage. New environmental regulations continuously oblige designers and plant constructors to develop advanced methods for concentrate discharge. Concentrate salinity and chemistry, temperature (for thermal processes), and waste chemicals are the main concerns. New regulations require dilution of the concentrate in a mixing zone, reduction of brine temperature by cooling water, and removing the chemicals before discharging it into the sea (e.g., dechlorination). - Post-treatment of the product water. The pH and hardness of desalinated water require readjustments to make the water acceptable for potable use. In general, desalinated water, after post treatment, is introduced into the water distribution system.





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- On-site storage of product water. Depending on the reliability of the treatment plant infrastructure and the electric power source and the need for storage of produced water for emergency periods, on-site storage capacity can range from a few hours of plant capacity up to about 5 days of capacity. At the large desalination plants in the Middle East region, only a small amount of water is stored in tanks in case of a reduction in water production due to routine or an unexpected shut down. - Product water recovery and energy price. The energy price is included in the contract agreement for the service period as part of the total water cost. However, virtually all BOO and BOOT contracts contain an energy adjustment cost provision to cover variations (mostly increases) in electric power costs. Therefore, minimization or reduction in the facility energy consumption has a major impact on reducing the unit water cost. - Materials, equipment, chemicals and other consumables. - Financing details and amortization period as well as inflation

3.7 Conclusion

As ONGC Uran plant, Uran has no need or intention to produce electrical power by setting power plant (cogeneration plant i.e. power + water by desalination plant) and intends to set up stand alone desalination plants for process water quality (18 MLD process water+ 2 MLD DM water), it can be seen from above evaluation, comparative study & trends between various processes that desalination technology based on membrane reverse osmosis process in a stand-alone configuration having majority market share worldwide and being cost-effective technology was selected for ONGC Uran plant, Uran for carrying out further technical feasibility studies, design & costing.

Additionally, the suitability of the selected sea water reverse osmosis desalination technology over Thermal desalination technology including energy supply option for ONGC Uran plant, Uran was also evaluated and concluded based on the following site specific factors such as:

a) the salinity and quality of the water to be desalinated;

b) target water quality requirements;

c) the desired desalination plant production capacity;

d) Reliability and availability

e) the available energy supply sources for a desalination plant and associated





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costs;

f) energy usage;

g) robustness of desalination technology; h) construction timeframe;

i) Recovery and sea water intake

j) Reject outfall k) water production cost;

l) Market trend/share globally & in India for preference in technology





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CHAPTER-4

DESALINATION PLANT FACILITIES AND CONFIGURATION

4.1 General

4.1.1. Technical Fundamentals considered for Seawater Desalination at ONGC, Uran. The following points are the key technical fundamentals of seawater desalination, forming the design basis, have been considered here in preparation of the report.

1. The desalination process operates at around an overall recovery of 35 - 40%. This means that more than twice the flow of product water must be pumped from the ocean, and slightly more than the product flow must be returned. As a result the piping and pumping costs for the inlet pipeline and concentrate return pipeline are higher per km than for the delivery pipeline for final desalinated water. This means that it is more economic to site the plant as closer as possible to the ocean source.

2. The cost of piping is significant. Therefore it is preferable to locate the plant site at a point where the ocean is relatively close to the point where the water can be introduced into the system. Further, the height to which the water must be lifted to get it into the system also affects the costs and energy use. So sites that are close to points with lower lifts, are also preferred.

3. Drawing from seawater in deeper open ocean water which is unaffected by inflows from the land leads to more consistent salinity and lower suspended solids. This reduces the extent of pre-treatment required, and thus reduces plant costs and operational risks. So sites that can draw from ‘clean’ open ocean water are preferred. However, it is possible to engineer plants to use variable estuarine feed water. The consequence is increased costs and increased time to understand and manage the feed water quality variations. Thus drawing water from less pristine sources is possible, but this needs to be weighed up against other factors when selecting a site.

4. To maintain reasonable inlet water quality, it is preferable to have the inlet located in deeper water. This avoids sediments that are stirred up by wind and wave action in more shallow waters. It is also preferred to keep the inlet deep enough to avoid any interaction with boats and shipping. Further, constructing the connecting pipes or tunnels to the inlet is often costly, and minimizing this length is therefore beneficial. This means that sites where deeper water is relatively close to shore are preferred. In cases where the water depth does not increase significantly with distance from the shore it would be feasible to provide an open surface intake using open/closed channel intake system keeping in view of the hydraulic





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energy(static head) availability and the hydraulic losses therein and the pretreatment system should be designed accordingly.

5. The concentrate can be dispersed effectively using diffusers on the outlet pipeline. However, this requires a minimum depth of water. Significant local currents also assist, and reduce the need for extensive diffuser approaches. Again this means sites near deeper water are preferred.

Note that all of the points noted above can be addressed with various design approaches. Moving away from the ‘preferred’ position will impact either cost or time to implement.

A review of these considerations shows that the site earmarked by ONGC for the desalination plant in their existing Uran plant facility is near to the coast of Arabian sea is a suitable location for the proposed sea water desalination plant keeping in view of the proximity to sea and requirement of product water pumping to the existing water reservoirs of ONGC plant.

4.2 Target water quality requirements

Desalination product water quality will depend on the source of water (seawater or estuarine water), its inherent salinity, the desalination technology selected and its design, e.g. a single pass or a two-pass RO system or thermal, and the post treatment applied to the desalinated water to prevent corrosion of distribution infrastructure. The first step in designing a seawater desalination plant is to determine target water quality requirements. Several aspects need to be considered in recommending these requirements that a desalination plant in the aforesaid location will be required to meet. These include:

a) The water quality presently being supplied to ONGC for process water and the DM water

quality requirements. b) The increase in TDS and other parameters after post treatment also needs to be

considered. c) Corrosion guidelines and indices to prevent corrosion of water supply infrastructure.

The product water quality produced by RO desalination technologies is described and target water quality and post treatment processes will be recommended based on the corrosion guidelines and the quality of existing supplies.





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4.2.1. Reverse Osmosis Product Water (Permeate) Quality

The product water (permeate) from a seawater reverse osmosis plant is dependent on the inherent salinity and temperature of the feed water and design factors such as membrane selection and age, RO system recovery etc. The TDS in RO permeate will be higher for more saline feed water such as Arabian Gulf seawater with a TDS of 40,000 to 45,000 mg/L compared to that for Gulf of Khambat with a TDS of approximately 35,000 to 38000 mg/L and Bay of Bengal approx 30,000- 37000. The principal factors which determine permeate quality are the RO system recovery and the temperature of seawater. For instance, for a given membrane and seawater composition and fixed temperature, the TDS (and other ions such as chloride) in the permeate may increase by around 20% for an increase in recovery from 30% to 40%. The increase is not linear and for a further 10% increase in recovery to 50% the permeate TDS concentration may increase by a further 30%. Different ions diffuse through the membrane at different rates and these percentages are approximate and depend on the specific seawater composition, temperature etc. Similarly, as the temperature of seawater increases during summer, the salt flux increases through the RO membrane and the TDS in the permeate increases at a fixed recovery. Finally, it should be noted that RO membranes are subject to an aging process which results in decreasing permeate flux and salt rejection.

4.2.2. Water Quality of ONGC existing supply

The composition and quality of process water and Demineralised water of ONGC is summarized below in Tables 4.1 & 4.2 respectively.

Table -4.1 Process water quality

SI .No Parameter Value

1 pH 7.6

2 Turbidity NTU (5 min settled) 5.9

3 Total Suspended Solids ,ppm 5

4 Total Dissolved Solids ,ppm 150





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Table -4.2 DM water quality

SI .No Parameter Value

1. Total electrolyte not to exceed 0.1 ppm 2. Total silica not to exceed 0.01 ppm as SiO2 3. Iron content, ppm as Fe Nil 4. Free CO2 ppm as CO2 Nil 5. Total hardness, ppm as CaCO3 Nil 6. pH value 6.8 - 7.2 7. Conductivity, at 25 deg C Micromhos/cm Less than 0.15

4.3 Seawater Quality Detailed knowledge of the source seawater quality is fundamental for the design and operation of thermal and reverse osmosis seawater desalination plants, especially in this case as RO process has been preferred. The inherent quality and composition of the source seawater is a determining factor in the entire process technology of a desalination plant; from intake, pre-treatment considerations and process plant design to post treatment requirements.

5 Conductivity@25°C , umho/cm 210

6 M-Alkalinity as CaCO3 ,ppm 80

7 P-Alkalinity as CaCO3,ppm NIL

8 Ca Hardness as CaCO3,ppm 45

9 Mg Hardness as CaCO3,ppm 35

10 Total Hardness as CaCO3,ppm 80

11 Silica as SiO2 (reactive) ,ppm 17

12 Chlorides, ppm 21

13 Residual Chlorine, ppm Nil

14 Sulphates as SO4 ,mg/l 15

15 Iron ,mg/l 0.3

16 Na + K as CaCO3 44.5

17 KMnO4 at 100°C 10





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As RO is the selected desalination process, comprehensive seawater sampling and analysis programs are strongly recommended to determine water quality parameters which may have an impact on the RO process causing membrane fouling and scaling (e.g. ion composition, organic, colloidal constituents etc) or which degrade the membrane (oil, hydrocarbons). These programs would need to determine seasonal variations of water quality parameters and the effect of marine conditions. SWRO desalination plants in particular require much broader and more detailed information on seawater composition and pollution contamination than for thermal processes, as RO membranes are more susceptible to both fouling and scaling, and are significantly more sensitive to suspended solids and oil in the source water and feed water quality than thermal processes. Although, thermal systems are generally more robust and very forgiving of feed water quality some organic substances may induce foaming, lead to fouling of heating surfaces or can impair drinking water quality, while some inorganic substances may cause corrosion, such as H2S and halogen compounds.

For the purposes of techno-economic feasibility study, information on the ion composition and TDS, TSS, oil content etc. is required for the sea water at allocated site for the desalination plant of ONGC. Sea water quality parameters for the samples of sea water collected at specified locations have been analyzed by MECON. Based on the field studies and the raw water sampling analysis carried out and the desired product water quality from the desalination plant,the formulation of process design & preparation of TEFR has been carried out. The details of the sea water quality water samples are listed in the table below.

Table 4.3

Sl. No. Parameters Units RESULTS Sea shore at

proposed intake area

1.0 km inside sea from the shore

1.5 km inside sea from the shore

1 Colour Hazen units <5.0 <5.0 <5.0

2 Odour Unobj. Unobj. Unobj. Unobj.

3 Taste Agreeable Salty Salty Salty

4 Turbidity NTU 0.84 0.84 0.63

5 pH 7.97 8.00 7.97

6 Conductivity mS/Cm 54.7 50 50

7 Total Hardness mg/L 6400 6000 8000

8 Total Alkalinity mg/L 1600 800 1600

9 Carbonate mg/L 40 40 32





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10 Bicarbonate mg/L 150 200 150

11 Total Suspended Solids

mg/L 240 278 294

12 Salinity mg/L 29216 27520 27000

13 Temperature Deg.C 27.2 27.2 27.2

14 Total Dissolved Solids

g/L 35 32 32

15 COD mg/L 56.0 40.0 72.0

16 Sulphate mg/L 3400 2480 2550

17 Nitrate mg/L 9.2 8.9 8.9

18 Phenolic compounds mg/L <0.001 <0.001 <0.001

19 Fluoride mg/L 0.58 0.60 0.41

20 Chloride mg/L 18,396 18,039 17,860

21 Sulphide mg/L 0.78 0.40 0.60

22 Phosphate mg/L 5.4 6.7 7.4

23 Calcium mg/L 400 350 450

24 Magnesium mg/L 1310 1243 1668

25 Sodium mg/L 11170 9486 9140

26 Potassium mg/L 151 167 150

27 Ammonia mg/L 0.03 0.03 0.02

28 Mercury mg/L <0.0005 <0.0005 <0.0005

29 Cyanide mg/L <0.01 <0.01 <0.01

30 Aluminium mg/L <0.02 <0.02 <0.02

31 Silica mg/L 2.40 1.50 1.00

In addition to the above ,the following additional parameters have been analysed

Sl. No. Parameter Units Units Sample-1 Sample-2

1 Total Organic Carbon

mg/l 1.4 1.8

2 BOD mg/l 2.2 2.5

3 Total Oil mg/l 1.0 1.0

4 Particle size ppm 11.6 14.8





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distribution of TSS

5 Hydrogen Sulphide

ppm 0.05 0.05

6 CO2 ppm 5.0 5.0

7 Silica total (as SiO2)

ppm 0.49 0.57

8 Colloidal Silica ppm 0.02 0.02

9 Particulate Silica ppm 0.02 0.02

10 Petroleum hydrocarbon

mg/l

i. Octane μg/l 168.1 92.2

ii. Nonane μg/l 0.1 0.1

iii. Decane μg/l 0.1 0.1

iv. Undecane μg/l 6.9 3.9

v. Dodecane μg/l 0.1 0.1

vi. Tridecane μg/l 0.1 0.1

vii. Tetradecane μg/l 0.1 0.1

viii. Pentadecane μg/l 2.8 1.2

ix. Hexadecane μg/l 0.1 0.1

x. Heptadecane μg/l 0.1 0.1

xi. Octadecane μg/l 0.1 0.1

xii. Nonadecane μg/l 0.1 0.1





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xiii. Eicosane μg/l 0.1 0.1

11 PAH μg/l <0.01 <0.01

12 Detergent mg/l 0.05 0.05

13 SDI

8.5 8.7

Anions

14 Bromide mg/l 200 200

15 Residual free Cl mg/l 0.1 0.1

16 Carbonate mg/l 0.0 0.0

17 Bicarbonate mg/l 135.1 19.4

18 Boron (as B) mg/l 3.64 3.66

Cations

19 Copper (as Cu) mg/l <0.01 <0.01

20 Manganese (as Mn)

mg/l 0.008 <0.005

21 Manganese dissolved (as Mn+2)

mg/l 0.005 <0.005

22 Manganese (as Mn+3)

mg/l 0.005 <0.005

23 Iron total ( as Fe ) mg/l 0.55 0.26

24 Iron as Fe+3 mg/l 0.55 0.26

25 Iron dissolved (as Fe +2)

mg/l 0.55 0.26





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26 Barium (as Ba) mg/l 0.021 0.02

27 Strontium (as Sr) mg/l 6.601 6.646

28 Cadmium (as Cd) mg/l <0.001 <0.001

29 Selenium (as Se) mg/l <0.005 <0.005

30 Arsenic (as As) mg/l 0.005 0.005

31 Lead (as Pb) mg/l 0.005 0.005

32 Zinc (as Zn) mg/l <0.1 <0.01

33 Chromium ( as Cr )

mg/l <0.005 <0.005

34 Aluminium dissolved (as Al)

mg/l 0.02 0.02

For this study a maximum possible TDS of 42,000 mg/L was adopted for design consideration as per

the sea water analysis study results obtained and increase in TDS near the RO membrane due to the

mixing in ERD and addition of chemicals. A conservative pretreatment design has been adopted for

the design of the SWRO system considering the sea water analysis results obtained and seasonal

variations of sea water quality parameters.

4.4 SEAWATER INTAKE

4.4.1. Introduction

The type of intake is essential for delivering a consistent and reliable quality and quantity of raw water feed to the desalination plant along with minimal pre-filtration stages in the pre-treatment section thereby effectively handling less sludge (solids) quantity.

The pre-feasibility study involves a detailed site-specific evaluation of the





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site to locate a desalination facility, the marine environment for seawater intake and concentrate discharge pipelines. However, based on the field studies carried out for the existing area, a feasibility assessment for the seawater intake options that would supply feed water to the proposed SWRO desalination facility has been detailed out. The objective of this chapter is to evaluate potential constraints that would limit or eliminate options for the design and operation of the proposed desalination facility.

The three seawater intake options consist of one open-ocean intake and two subsurface intake options. A subsurface intake is defined by any intake that is located beneath the seabed, utilizing it as a natural filter. The three seawater intake options assessed in this study include:

i) Open ocean intake : a. Open-Ocean Intake: An offshore open-ocean intake using cylindrical wedge-wire

mesh screens suspended in the water column. This can either be open channel intake or pipeline intake.

ii) Subsurface intake :

a. Seabed Infiltration Gallery (SIG): An offshore shallow pipe gallery installed under

the seabed using the sand as a filter.

b. Beach (Slant) Wells drilled from onshore.

Site-specific physical characteristics of the project area are to be determined to establish the basis for identifying potential design criteria for the intake system that must be considered to minimize overall impact and ensure operational success. The following design criteria require to be addressed for each of the three potential intakes for the site.

-Impingement/entrainment,

-Intake water quantity & quality, -Benthic communities, -Biofouling,

-Hydrogeology, and

-Navigational restrictions.

Conveyance of seawater to shore from any of the intake options (except beach wells & intake channels ) would be accomplished by pipelines . Open channel Intake will be used for





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conveyance in case the sea is shallow in nature or pervious coffer dam with wave breakers is adopted for intake water collection.

4.4.2. Background

Comprehensive marine studies including bathymetry , sub bottom profile, side scan surverys and seismic studies will provide data which would describe the nature of the sea , sea bed profile w.r.t to distance from shore, high tide and low tide levels, wave patterns, seawater quality and review offshore conditions, both of which need to be considered when evaluating a seawater intake system for a desalination facility. The approximate efficiency (ratio of product water flow to total feed water flow) of a SWRO desalination process using feed water from a screened open-ocean intake is approximately 45 % in RO section first pass & 90% in RO section second pass and overall recovery of 36-38% considering losses in the pretreatment section. Therefore, a total intake flow of approximately 55.2 MLD of seawater is required for the proposed 20 MLD product water. However, depending on the efficiency (recovery) rate of the pretreatment system and the type of intake and TSS , the intake flow may slightly vary.

To assume a worst case scenario, the intake pumping volumes are based on a open-ocean intake system with a reverse osmosis (RO) recovery rate of 41 %, ( 45 % in first pass and 90 % in second pass) an ultra-filtration (UF) membrane recovery rate of 90 % and a pretreatment recovery rate of 98 % , for a total plant recovery rate of 36.2%. For a subsurface intake, the desalination process would have a RO recovery rate of 50%, and a pretreatment recovery rate of 95%; for a total plant recovery rate of 47.5%.

4.4.3. Near shore Water Quality

The SWRO process is sensitive to input water quality and therefore parameters including temperature, salinity, turbidity, dissolved solids, and silt density index (SDI) would influence the overall efficiency of the desalination process. Characterization of the water quality near the proposed project area is useful to site the intake structure and identify pretreatment requirements at the onshore facility. The following sections present data on near shore water quality parameters of interest for this project.

4.4.3.1 Temperature

Near shore , natural water temperatures fluctuate throughout the year in response to seasonal variations in currents as well as meteorological conditions such as wind, air temperature, relative humidity, cloud cover, ocean waves, and turbulence. Natural temperature is defined as "the temperature of the receiving water at locations, depths, and times which represent conditions unaffected by any elevated temperature





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waste discharge”. Previous studies have shown that natural surface temperatures may vary several degrees in a single day depending on time of day and year, as well as meteorological and oceanographic conditions.

Diurnally, natural surface water temperatures typically vary 2 to 4°C in summer and 1 to 2°C in winter. Factors contributing to rapid daytime warming of the sea surface are light winds, clear skies, and warm air temperatures. Factors that reduce diurnal temperature ranges are overcast skies, moderate air temperatures, and vertical mixing of the surface waters by winds and waves.

The region where a sharp difference between more uniform surface water and bottom water temperature exists is called a thermocline. A thermocline is a stable stratification, separating the surface layer from the subsurface layer based on a general inverse relationship between water temperature and density. Artificial thermoclines may be found in the vicinity of thermal discharges where large volumes of water at elevated temperatures result in heated water overlaying the cooler receiving water.

In the proposed site for ONGC desalination plant , the temperature data is collected and for the present study, the mean monthly temperatures ranged from a low of 24oC to a high of 32°C.

The ideal temperature for most membranes is approximately 25°C. Although siting of intake screens in warmer regions may improve operational efficiency of the RO process, the benefits of such locations may be negated by increased: (1) biofouling of the intake structure, (2) exposure of marine organisms to impingement and entrainment.

4.4.3.2 Salinity / Total Dissolved Solids (TDS)

Salinity / TDS in nearshore environments is affected by the introduction of fresh water (from land runoff and direct rainfall), upwelling and by evaporation. Offshore, salinities are fairly uniform and normally range from 33.0 to 37.0 parts per thousand (ppt). RO membranes can desalinate feed water with up to 45 ppt salinity. Similar to temperature, salinity in the near shore environment has seasonal components.

4.4.3.3 Density

Seawater density varies inversely with temperature and directly with salinity at a given pressure. The pycnocline (a region of rapid density change within a relatively small





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change in depth) is assumed to be the dominant feature observed in the vertical density profile of the water column and the major factor affecting its stability and resistance to vertical mixing . Water temperature is the major component influencing water density and density stratification because salinity is relatively uniform. As a result, large density gradients are most pronounced further offshore when spring and summer thermoclines are present. The pycnocline in the project area could be affected by the brine discharge of the desalination facility. Depending on the depth of discharge, and the temperature of the effluent, high salinity discharge water could contribute to a stronger pycnocline. The dense brine would remain in the region below the pycnocline and consequently reinforce the water column stability and effective vertical mixing (and dilution).

4.4.3.4 Dissolved Oxygen

The dissolved oxygen (DO) concentration of seawater is affected by physical, chemical, and biological variables. DO concentrations reflecting highly oxygenated water (i.e., > 5 to 6 mg/L), may be the result of cool water temperatures (solubility of oxygen in water increases as temperature decreases), active photosynthesis, and/or mixing at the air- water interface. Conversely, low DO concentrations may result from high water temperatures, high rates of organic decomposition, and/or extensive mixing of surface waters with oxygen-poor subsurface waters. A vertical DO gradient is typically seen in the water column during the summer months, while during winter DO exhibits relatively constant values throughout the water column. Dissolved oxygen typically fluctuates in the near shore temperate environment around 7.5 mg/l, with the threshold of biological concern being 5 mg/l. DO concentrations typically range from 5 to 13 mg/l.

4.4.3.5 Hydrogen Ion Concentration

In the open ocean, the hydrogen ion concentration (pH) remains fairly constant due to the buffering capacity of seawater. However, in near shore areas, pH may be more variable due to various physical, chemical, and biological influences. For instance, in areas with a large organic influx, such as bays, estuaries, and river mouths, microbial decomposition increases. Along with a reduction in DO, decomposition also results in the production of humic acids, which decrease pH. Reduced pH values may also occur in areas of freshwater influx, since fresh water usually has a lower pH than salt water. In contrast, phytoplankton blooms (red tide), which are often associated with near shore upwelling, may cause pH to increase. High photosynthetic rates increase the removal of carbon dioxide from water, thus reducing the carbonic acid concentration and raising pH. The pH in surface waters at ONGC Uran sea varies narrowly around a mean of approximately 8.0 and decreases slightly with depth.





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4.4.4. Location and Operation Considerations

4.4.4.1 Navigation / Restricted Areas

Navigational restrictions may exist in the area depending on the vessel types and frequency of maritime traffic. It is recommended to collect the data for the same before finalising the intake and outfall route alignment. The intake system and its associated conveyance system should be designed to provide adequate clearance and avoidance of marine traffic. The local Maritime Board would need to be consulted when the final intake type, depth and location is determined.

4.4.4.2 Wave Energy

The degree to which wave energy would affect structures near the seabed is directly related to the water velocity at the depth of the structure. This velocity is also a function of the wave height. Hourly data is taken to determine the dominant wave period (the period with the maximum wave energy) and significant wave height. The wave and tidal energy in the sea water leads to churning effect which affects TSS levels as sediments are unable to settle at the bottom of the seabed. These velocities and energy have a significant effect in the design of intake structure and hence a detailed data requires to be obtained for the proposed site.

4.4.4.3 Separation of Intake and Outfall Systems

Many factors affecting the design and location of the intake system are evaluated in this study. One such factor involves the assurance of adequate separation between the intake system and brine discharge. The intake system and brine discharge must be designed to prevent short circuiting & recirculation of the brine effluent and degradation of the intake water quality.

4.4.4.4 Bio fouling

All structures constructed in the ocean are subject to biofouling, or the growth of bacterial and algal microorganisms on the structure. This growth, if left unimpeded, causes blockage of screens or filter media, resulting in an increased pressure differential across the intake system. Biofouling of the intake structure increases maintenance cost and risk of failure of the feed water intake system. Biofouling would also reduce the overall efficacy of the intake since the pressure differential increases. The degree to which biofouling would occur for a certain intake or outfall structure depends heavily on its location and the material selected for its construction.

4.4.4.5 TSS/Turbidity

Solids in feed water are quantified, utilizing tests that measure total suspended solids (TSS)





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and silt density index (SDI).The SDI is a measurement of the fouling capacity of water and is generally independent of turbidity. Raw seawater SDI requires to be reduced to less than approximately 5.0 to avoid rapid fouling or clogging of the SWRO membrane. Chlorine is sometimes used as an oxidant for feed water pretreatment, however, this has been found to cause increased SDI since organic matter in the water (mainly algae) may be broken down and passed through the pretreatment system with other naturally occurring colloids. The RO process requires feed water having a maximum SDI <5.To achieve this goal, raw seawater would typically require pretreatment. Obtaining the best possible water quality from the intake system would reduce overall treatment requirements and reduce cost. Water quality of the feed water is heavily dependent on the type and location of the intake structure. Subsurface intake water, for example, has lower solids content than seawater extracted directly from the ocean. Generally, all else being equal, near shore shallow waters are typically more turbid than deeper offshore waters due to the effects from wave action and currents in shallower waters.

4.4.5. Offshore Feed water Conveyance

The type of various intake screens adopted for open intakes i.e , channel or pipeline intakes is evaluated as below.

4.4.5.1 Open-Ocean Wedge-Wire Screens

a) Description

The three offshore intake options include a screened open-ocean (wedge-wire screen) intake, a seabed infiltration gallery (SIG), and a deep infiltration gallery (DIG) collector well system. The onshore intake method being considered is a slant well intake system. Wedge-wire screens are one of the most commonly used water intake structures. They are considered passive surface water intake structures, which mean they require no moving parts and are designed to maintain a uniform low intake velocity. Wedge-wire screens consist of a large cylindrical cap on the end of an intake pipe below the water surface which is designed to diffuse the flow velocities. Wires are wrapped around the circumference of the cylinder, which have a triangular or wedge shaped cross-section to allow an increase in slot opening size from the exterior to the interior of the cylinder. Wedge-wire screens can be made in a “tee” or “drum” configuration. The material of construction of the intake screens is super duplex steel having PREN > 40.Johnson Screens® has patented a dual open pipe flow modifier system which uses two flow modifiers to distribute the flow more evenly to the wedge wire surface





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,thereby increasing total flow without increasing peak velocity .Screens has a proprietary core cylinder design which is a cylinder with perforations increasing in diameter from the center of the Tee screen, which also is an attempt to achieve uniform flow velocity.

Slot size is defined as the distance between two of the screen‘s wires and is effectively the “filter size” of the screen. Slot size is determined based on the characteristics of the installation site, including the plant and animal species expected to be present. Typical slot sizes in the screen range from 0.5 to 5 mm. The length and number of structures is determined based on diameter, slot size, and required flow capacity. Intake velocity is also a constraint with a goal of 0.16 m/s or less to reduce impingement. Wedge wire screen intakes utilize an air-burst system to clear debris that may accumulate on the outside of the screen. A package compressor and air-receiver for the system are installed onshore with a pump. When the pressure drop across the filter reaches a pre-defined threshold, a single burst of air is sent through a perforated inner cylinder at the bottom of the screen to remove debris from the wedged openings ,while the current carries the debris away. The controlled entrance velocity and the air backwash system keep the intake screen clean and operating.

b) Design Criteria

Traditional intake systems that move large volumes of seawater from the ocean through screened pipes typically experience many ecological and operational challenges. This section explores potential mitigation methods for wedge-wire screens in response to the applicable design criteria.

i. Impingement/Entrainment

The effectiveness of reducing entrainment would depend on the screen size, the slot size, and the location of the structures. Physical exclusion occurs when the slot size of the screen is smaller than the organisms susceptible to entrainment. A sufficient ambient current must also be present in the source waters to aid organisms to bypass the structure and to remove debris/organisms from the screen face. The ability to maintain clean screening surfaces would affect the biological performance of the cylindrical wire mesh. Increased fouling or impinged material would reduce the filtering area available, thus increasing intake velocity. The location and depth of installation determine the fish and invertebrate that are affected by such a system.

In 2005, the Electric Power Research Institute (EPRI) evaluated wedge-wire screens in Narragansett Bay, Rhode Island, using a specially constructed test facility. The study concluded that entrainment densities were lower with smaller slot widths.





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Additionally, larval entrainment densities increased as ambient velocity increased, though egg entrainment densities did not. Entrainment density decreased with larval length. A slot size of 0.5 mm reduces total entrainment by >72 percent compared to a control port. The 1.0 mm slot size significantly reduced entrainment in only one of three species tested by >44 percent. Egg entrainment was reduced by >92 percent at the 0.5 mm slot width, however no significant reduction in egg entrainment was observed at the 1.0 mm slot width.

ii. Intake Water Quality

Generally sea water turbidity and SDI decrease with depth. A less turbid feed water increases efficiency of the RO process. Therefore, water drawn from as deep as practical has some desirable attributes in majority of the open ocean intakes. The actual location of the intake structure is determined through a detailed marine study .

iii. Bio fouling

A screen suspended in the water column is at risk for biofouling. Biofouling of the screens is affected directly by the water quality, which means that the same conflict identified above regarding water quality is also applicable to biofouling. Generally, deeper waters below the thermocline are less biologically productive and therefore less at-risk for biofouling. This is the result of lower water temperature and reduced light penetration. Increased particulate load of phytoplankton organisms in the source water during a red tide may clog intake filters and require increased maintenance or temporary shutdown of the desalination facility during plankton blooms.

Several design considerations can help minimize biological fouling of the structure, including the material, non-toxic coatings, and/or chemical injection. These options are considered based on efficacy, cost, and durability.

Despite these mitigation techniques, the screen would inevitably accumulate debris in the slot openings. For this application, an air-burst system shall be envisaged. Additionally, divers would also be required to perform periodic manual screen cleaning. The frequency of these cleanings would depend on the severity of clogging and the effectiveness of natural wave energy clearing the screens. Clogging would increase head loss and may accelerate the corrosion process in un-clogged parts of the screen due to increased flow in those areas.

iv. Wave Energy

Static structures built in the ocean are constantly experiencing direct forces induced by





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currents, tides, and waves. The wave energy conditions are more favorable at greater depths .. The installation of an intake structure at shallower depths would require consideration of additional impacts on the structure including, scouring, structural integrity, and water quality. Local wave and seabed velocity data should be collected before design of the intake structure.

c) Conceptual Design

Based on a worst case overall plant recovery of 37 percent, an intake flow of approximately 55.2 MLD (ultimate) of seawater is required. The average velocity shall be assumed 90 percent of the maximum velocity since the velocity profile across the entire cylinder would not achieve uniformity. Screen design is based on manufacturer-specific information supplied by Johnson Screens® of New Brighton, Minnesota. Each screen would consist of a wedge-wire grid constructed of a V-shaped wire spirally wound around and welded to a cylindrical cage of longitudinally-oriented support rods with a slot width of 1.0 mm (0.04 in). The wire width is assumed 1.803 mm (0.071 in). The screens are designed based on a maximum approach velocity of 0.5 fps resulting in a maximum through-slot velocity of 0.9 fps. The diameter of the screen is assumed 5 m. The total seabed area required for the placement of the screens would depend on the final intake capacity which governs the number and dimension of the screens. Screens should be placed at least 1 meter above the seafloor to avoid pulling up sand particles which would be smaller than the slot width.

d) Conclusions

Tradeoffs exist between the consistencies of feed water quality and availability , ease of maintenance; impacts associated with water currents, and cost that need further consideration prior to selecting a final location. Placing the structure in deeper water below the thermocline would provide a more consistently clear feed water quality. The recommended depth for a surface structure should be decided according to the results obtained from the wave energy analysis; However, reaching the depths recommended to avoid some of the criteria listed above may be prohibitively expensive. Maintenance for such a deep water structure can be costly and dangerous.

Overall, screened open-ocean intakes like the wedge-wire screen are part of an existing, proven intake technology which would be able to effectively provide required source water volumes. Additionally, if costs or technical feasibility rule out the use of a subsurface intake, the wedge-wire option may still be viable. However, issues that may pose an obstacle to feasibility include navigational considerations, loss of sea floor habitat,





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continued (although minimal) impingement and entrainment losses, and potential for increased maintenance or temporary shutdown of the desalination facility during plankton blooms.

4.4.5.2 Seabed Infiltration Gallery

a) Description

An alternative to a screened open-ocean seawater intake is a subsurface intake system. One type of subsurface intake is a seabed infiltration gallery (SIG). Infrastructure for a SIG consists of a series of horizontal wells buried 6 to 14 feet deep in the subtidal zone. The system is designed as a slow underground sand filter using the media (seabed) surrounding the wells to remove suspended material. Seawater from a SIG is generally of a higher quality than seawater from surface intakes due to this natural filtration. Subsurface intakes are more stable and less affected by inclement weather since they are below surface and not affected by turbulence in the water column. They are also less visually and physically obtrusive on the beach and in the water since both the pipe gallery and the aqueduct are buried.

b) Background

The city of Fukuoka, Japan began operations of a new desalination plant in June 2005. The plant is the largest in Japan, with a fresh water production rate of 13.2 MGD and intake capacity of approximately 27 MGD. Several new technologies were featured in the Fukuoka plant to increase throughput and efficiency, including the offshore SIG intake system. Currently, the Fukuoka plant is the only large desalination facility (>5 mgd) with a SIG intake in operation. The SIG consists of an offshore network of perforated subsurface pipes. The entire footprint of the pipe gallery is approximately 5 acres. One hundred foot long, 2ft diameter HDPE, perforated infiltration pipes (laterals) are buried 10 ft under the sea floor, approximately 2,100 ft offshore at a water depth of approximately 38 feet. The laterals are installed with an external mesh layer to keep sand out of the feedwater and are arranged perpendicular to the shoreline 16.5 ft apart and stem horizontally off a header running parallel to the shore. The header is 6 ft diameter HDPE and is connected in the center to a concrete aqueduct (5 ft diameter) which leads onshore.

The Fukuoka SIG was designed to withstand a 50-year frequency wave event. The connection points between the laterals and the header were designed to withstand ground shaking and liquefaction due to earthquakes. Since operations began, the plant has been hit by an earthquake (seismic intensity of more than 5) and aftershocks





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(seismic intensity of around 4). Additionally, a typhoon passed in September 2005. The only reported effect on the intake system during these events was an increase in seawater turbidity to a maximum reading of 1.0 mg/L after the typhoon. Other smaller earthquakes have had no effect on the intake system.

c) Design Criteria

Many ecological and operational concerns invoked by the use of screened open-ocean intakes are eliminated when water is collected under the seabed. For example, the filtering action of the seabed reduces the need for feedwater pre-treatment. Additionally, fish and suspended larvae and eggs are unaffected by the subsurface pipes since no high velocity flows occur in the water column of sufficient intensity to cause entrainment or impingement.

i. Impingement / Entrainment

Impacts due to impingement and entrainment are not anticipated during operation of the SIG. The effectiveness of eliminating impingement and entrainment would depend on the type and size of material selected for the SIG, the intake velocity at the seafloor, and the location of the galleries. Infiltration galleries act on the premise that aquatic organisms would not pass through the sediment and into the intake. A successful system would provide low withdrawal velocities and exclude small marine organisms.


Feedwater quality from a submerged intake would be better than that from a surface water intake due to the substrate‘s filtering action. This reduces the costs and effort associated with the pre-treatment process. Changes in water quality characteristics in surface waters related to plankton blooms are not expected to be detected in the subsurface source water. Increased particulate load and acid concentrations in phytoplankton organisms in surface waters are expected to be filtered from the source water by overlaying sediments and should not concentrate in collection galleries even if dead organisms accumulate on the seabed above the intake, although this should be confirmed for the overlaying sediment material. Mean water temperature of feedwater from a subsurface intake would be even lower than water taken from a wedge-wire screen on the seafloor. Warmer water is more ideal for the efficiency of the RO process, however this may be a fair tradeoff since overall solids content would be significantly lower.

iii. Benthic Communities





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Assuming the SIG is designed to maintain low intake velocities to minimize impingement, the organisms which are most likely to be affected by the operation of the SIG include those which reside in or spend time in contact with the seafloor. Installation of a SIG requires excavation and modification of between 12 and 35 acres of native sediments causing a large disruption to the benthic community. While a benthic community would undoubtedly recolonize the area, changes in sediment characteristics could affect other biological communities that utilize the seafloor as habitat. The community that recolonizes the area would likely be different from the existing community because of the different substrate characteristics.

The main environmental impacts caused by shallow SIG are due to the excavation of natural seabed substrate and replacement with an engineered filter bed. In-water construction activities would increase short-term localized suspended sediment, turbidity, and possibly contaminant levels in the area surrounding the offshore construction site. The required excavation to install the SIG would result in large volumes of suspended sediments which would move with the current and be re-deposited down current . This reduced water quality in the vicinity of the construction site could disrupt migratory fish. Other habitats may also be disrupted during the construction and installation of the SIG. Disturbance of the benthic zone would disrupt food and nutrient sources for these fish.

Predicting the effect of sedimentation and turbidity on local biota requires knowledge of the sediments, duration of exposure, the type of material, the species and life stage of the organism and other factors. Sound levels attained during construction may result in avoidance or migration delays for certain species of fish and/or marine mammals. Depending on the local substrate in the area and the depth of excavation, a vibration hammer may be used during construction. Underwater sound pressure levels above 180 decibels may result in sub-lethal or lethal effects for certain species. Mitigation efforts during construction to minimize excavation and collect suspended sediment in screens would help to reduce overall impact. If benthic communities can recover after construction, the overall project impact would be greatly reduced. This would depend on the construction process and the type of fill used after the installation of the SIG.

iv. Biofouling / Siltation

Biofouling of an intake structure under the seabed is less likely; however, shallow submerged intake structures are subject to clogging by debris and silt, and recolonization of the benthic habitat by plants, microorganism and animals. This type of fouling would cause a more severe disruption to plant operations since the clearing of





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underground structures and restructuring of filter media would be a costly and involved process. To reduce the risk of siltation, the SIG should be located at a sufficient distance offshore where wave and current energy would not overly disrupt the seabed filter, but should also remain in a location which would receive some wave/current energy where the seabed is not constantly in a depositional state. Finding this equilibrium is the main challenge in siting a SIG.

v. Wave Energy

Although too much wave energy may encourage siltation of the seabed filter due to stirring of the sand and allowing the constructed grading to be re-mixed, some wave energy is beneficial for a SIG. The turbulence associated with wave action causes the sand filter to be cleaned and re-graded, making the waves an effective natural ”backwashing” system for the filter. Wave energy also ensures that the location is not entirely depositional, and some clearing of organic deposition would occur. The wave energy also helps to aerate the filter and recharge DO concentrations. This reduces biological fouling by microbial organisms. If the submerged intake is exposed to high wave energy, the filter media could be mixed, lose its grading and require reconstruction.

vi. Navigational Restrictions

Navigation restrictions may become a concern during construction and maintenance for the structure. Additionally, if the SIG is located in shallow water, the presence of certain vessels may pose a risk. The local Maratime Board should be consulted during the preliminary design phase of the project.

vii. Hydrogeology

The groundwater/seawater profile of the site alternatives would need to be assessed for a shallow SIG. This information may affect the required distance offshore or the depth to which the SIG should be buried.

d) Conceptual Design

Assuming a subsurface intake recovery rate of 47 percent, the average intake water feed rate would be 42 MLD for a 20 MLD product water capacity. Using Fukuoka‘s loading rate of 0.087 gpm/ft2, the total area of the ocean floor needed to be excavated to construct a SIG with a capacity of 20 MLD is approximately 2 acres. This estimate is based on assumptions at the site and a more detailed analysis would be required to yield accurate specifications.





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Using the same 100 ft laterals used at Fukuoka, the SIG would have a approximate width of 60 ft and a header length of 0.4 to 1.12 miles for capacities of 42 MLD. This configuration may require 4 to 10 redundant systems, each with a header and concrete aqueduct. Alternatively, longer laterals could be used with a shorter header to make the entire footprint more consolidated, spanning less shoreline To determine the optimal location of a SIG with respect to the distance from shore, years of sea level/wave data need to be analyzed to determine the optimal wave energy to naturally “backwash” the seabed. In general, the potential location of a SIG is similar as the location for the wedge-wire screen alternative. Local sensitive biological populations may prohibit certain placement configurations.

e) Conclusions

Many of the high turbidity and TSS concerns along with potential environmental concerns associated with the open-ocean wedge-wire screen alternative (e.g., impingement and entrainment) are eliminated with the SIG alternative. However, this system would raise additional environmental concerns associated with the disruption of natural bottom sediments over a much larger area than impacted by the wedge-wire screen alternative. The projected seabed area needed for the wedge-wire screen intake system is approximately 1 acre, compared to the 10 acres needed for a SIG for similar capacity . A SIG may be able to be sited closer towards shore than wedge-wire screens to take advantage of expected increased current velocity to prevent significant deposition on or in the sediment filter. This could also lower the costs for the offshore intake conveyance system. However, shallower, near-shore locations are also expected to be more turbid due to natural wave action and may result in increased logging of the sediment filter.

4.4.5.3 Beach Slant Wells

a) Description

There are two main types of beach wells: slant wells and vertical wells. Only slant wells are being investigated for this project, since vertical wells would not be adequate to provide the required feed water flow for the plant’s capacity. Slant wells are typically drilled from the beach and extend beyond the shoreline under the seabed to tap the saline aquifer under the ocean. A slant well is a combination of both vertical and horizontal directionally drilled (HDD) wells, since it is nearly horizontal, yet the construction method is similar to a vertical well. The shallow-entry dual rotary drill rig is angled approximately 15-25 degrees from the horizontal, and then drilled straight, unlike a HDD drill rig that gradually turns as it drills to achieve a horizontal well. Well





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depth, production rate, and water quality vary based on the groundwater profile and soil matrix at a particular location. Slant wells could also potentially supply feedwater to the proposed desalination facility. As with other subsurface intakes, the wells reduce or eliminate many concerns regarding feedwater quality associated with screened open-ocean intakes. The factors most affecting the feasibility of the use of slant wells as the primary intake for the proposed facility at ONGC are:

- The amount of shoreline required for the wells to produce 55 MLD of feedwater.

- The local hydrogeologic conditions, including salt and freshwater aquifer profiles.

- The potential ecological effects on the intertidal zone and the SMR Estuary. Groundwater modeling and pumping tests are required to be carried out for the feasibility of a slant well intake system .

b) Design Criteria

The benefits associated with a subsurface infiltration gallery are similar for a beach well intake. The filtering action of the seabed reduces the need for feedwater pretreatment and since the SIG is located underground; fish, suspended larvae and eggs are unaffected; biofouling is not a concern; and navigational restrictions are not a concern for subsurface intake systems. Wave energy may have an effect on the slant wells if they are not properly located. Assumed future erosion conditions must be considered when locating the slant wells onshore.

i. Impingement / Entrainment

Underground wells do not face some of the ecological issues caused by surface intakes, including impingement and entrainment of biota. However, siting a beach well should still take into consideration the presence of sensitive environmental populations in the vicinity. The wells should be located up shore and/or downshore so that salinity profiles in this area do not change.


The sand provides an effective means of pre-filtering source water to remove suspended sediments, and macro- micro-organisms. Lower TSS concentrations and SDI in beach well source water have been observed. Like with the other subsurface options, the ecological impact associated with impingement and entrainment is virtually eliminated since the seafloor and water column are left undisturbed. Turbidity and SDI offeed water





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from a beach well have been observed at levels as low as1NTU and less than 2, respectively.

A study conducted at the SWRO plant at Al-Birk on the southwestern Red Sea coast of Saudi Arabia examined the option of replacing the original surface intake system with a beach well system due to significant membrane fouling problems. Bacteriological and nutrient analysis showed that bacterial counts were one order of magnitude lower in beach well water as compared to seawater; however, beach well water showed an accelerated bacterial growth due to a significantly high concentration of inorganic nutrients as compared with the seawater.

Temperature fluctuations are buffered in beach well feedwater, however mean temperatures are typically lower than surface water temperatures. RO process efficiency increases with warmer feed water, however this potential decrease in efficiency may be mitigated by the efficiency increase associated with the high feedwater quality.

iii. Benthic Communities

Since the slant wells would be drilled underground, it is not anticipated that benthic communities would be affected. However, indirect effects of dewatering could be a concern for benthic organisms. Similarly, a change in the nearshore saltwater profile could affect sensitive species.

iv. Hydrogeology

Pumping from coastal wells could potentially invoke a negative impact on nearby fresh groundwater aquifers. Traditional onshore groundwater wells in confined coastal aquifers have increased in quantity due to rising populations. As the freshwater aquifers have depleted without being recharged through natural processes, salt water intrusion from the ocean have occurred. Desalination has often been cited as a way to reduce saltwater intrusion by producing potable water without disturbing freshwater aquifers. However, depending on the local groundwater profile, beach wells to supply the desalination plant could exacerbate intrusion problems. A site specific Hydrogeological survey needs to be carried out before a conclusion can be made on the feasibility and impact so beach wells at this site.

4.6.6 Partial list of Intakes & their types are given below:

Partial list of existing seawater desalination plants and their respective intake types:





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Table- 4.3

S.No Owner Location Intake type Capacity

1. Golden Gate State Park

San Francisco, California, USA

Beach collector well

0.1 mgd (380 m3/d)

2. Santa Catalina Island California, USA Beach wells 0.15 mgd (570 m3/d)

3. Marin Municipal Water District

Corte Madera, California, USA

Screened intake—pilot

0.2 mgd (760 m3/d)

4. Sand City Sand City, California, USA

Beach well—pilot

0.26 mgd(980 m3/d)

5. Hyatt Regency Hotel Grand Cayman Island

Beach wells 0.5 mgd (1,900 m3/d)

6. Municipal Water District of Orange

County

Dana Point, California, USA

Beach slant well—pilot

0.5 mgd (1,900 m3/d)

7. Blue Hills Nassau, Bahamas


8. Diablo Canyon Power Plant

Avila Beach, California, USA

Open intake 0.7 mgd (2,600 m3/d)

9. Marina Coast Water District

Marina, California, USA

Beach well 0.7 mgd(2,650 m3/d)

10. United Arab Emirates U.A.E. Floating intake on barge

1 mgd (3,800 m3/d)

11. Morro Bay Morro Bay, California, USA






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12. Antigua Antigua Open sea intake

2.5 mgd (9,500 m3/d)

13. N.V. Energie en Watervoorziening

Rijnland

Leiden, Netherlands

Beach collector wells

2.6 mgd (9,800 m3/d)

14. U.S. Naval Base Guantanamo Bay, Cuba

Open intake with fish trap

5 mgd (19,000 m3/d)

15. Ghar Lapsi Malta Beach wells 6.3 mgd (24,000 m3/d)

16. Veolia Kindasa, Saudi Arabia

Open intake 7 mgd (26,500 m3/d)

17. Bay of Palma Mallorca, Spain Beach wells 11 mgd (42,000 m3/d)

18. Pemex Refinery Salina Cruz, Mexico

Beach collector wells

12 mgd(45,500 m3/d)

19. Fukouka District Waterworks Agency

Fukuoka, Japan Seabed infiltration

gallery

13.2 mgd (50,000 m3/d)

20. Pembroke Malta Beach wells 14.3 mgd (54,000 m3/d)

21. Veolia Sur, Oman Open intake and beach

wells

21 mgd (79,500 m3/d)

22. Aqualectra Production Santa Barbara, Curacao

Permeable pit intake

22 mgd (83,000 m3/d)

23. Tampa Bay Water Tampa, Florida, Shared power 25 mgd





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USA plant intake (95,000 m3/d)

24. Desalcott Point Lisas, Trinidad &

Tobago

Bar screen intake

28.8 mgd (109,000 m3/d)

25. San Pedro del Pinatar Cartagena, Spain Horizontal bedrock wells

35 mgd (132,000 m3/d)

26. Public Utilities Board Tuas, Singapore Open intake 36 mgd (136,000 m3/d)

27. Sydney Water Kurnell, Australia Passive intake screen risers

66 mgd (250,000 m3/d)

28. Veolia Ashkelon, Israel Multiple-head open intakes

222 mgd (840,000 m3/d)

29. CMWSSB Nemmeli Chennai ,India

Open intake 26.5 mgd

(100,000 m3/d)

4.4.6 Intake system for the plant

Based on the marine bathymetry results, it is observed that the sea is shallow in nature and the water depth available below chart datum level is around 1.5 to 2m even after a distance of 1.5 km from the shore. Also after evaluation of the various types of aforementioned intake options , the offshore feed water conveyance for the proposed plant is carried out by an 228 m long , 2m wide closed RCC channel designed for gravity flow with sufficient slope from the onshore intake chamber into the sea. The RCC channel is followed by dredging of the sea bed to sufficient depth for an approximate distance of 1.3 km to ensure requisite surface water availability at all times by gravity into the onshore intake chamber. The onshore intake chamber is to be constructed based on the levels achieved after maintaining the appropriate gradient of the intake RCC channel for gravity flow. The intake chamber is provided with trash racks ,travelling water screens with standby provision using stop log gates during cleaning and maintenance and feed pumping facilities to desalination plant .





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4.5 Concentrate Disposal This section would determine the feasibility of an offshore ocean discharge structure designed to convey and dilute the concentrate (brine), which is a byproduct of the proposed SWRO desalination facility located at the proposed ONGC site . The outfall location with a super duplex diffuser configuration to meet dilution and water quality criteria is considered.

Data on the existing physical characteristics in the project area is used for carrying out the mathematical modeling and effective diffuser design. The physical characteristics and data required include local bathymetry, currents, tides, upwelling, sediment movement, navigation, and water quality which all help to establish a basis for identifying potential design criteria which must be considered to minimize overall impact and ensure operational success of an ocean outfall concentrate diffuser system.

The concentrate from the proposed SWRO desalination facility along with the diluted sludge in the pretreatment system shall be disposed by one no. 800 dia HDPE pipelines with diffuser system for 20 MLD plant . Diffuser parameters such as port diameter, orientation of the ports, number of ports, and the spacing between ports is determined by modeling the dilution of the waste streams discharged together (combined) and independently. Various water modeling techniques are available to determine the dilutions achieved using several alternative outfall diffuser designs.

Concentrate conveyance is achieved using pipeline , similar to the feedwater conveyance pipelines.

4.6 Pre Treatment:

Pretreatment design is crucial to the successful operation of desalination systems. Pretreatment requirements for large seawater desalination plants, be it either distillation or RO, will typically comprise of trash-racks, band-screens and filtration units.

For RO systems, the filtration requirements tend to be media type filters with a filtration down to 10-50 micron, followed by cartridge filters with a filtration typically down to 1-5 microns. Filtration systems for distillation plants tend not to be as rigorous, with filtration systems down to 80 micron being normally acceptable.





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Chemical conditioning of the feed water for scale prevention is also required for both RO and distillation processes, but the requirements tend to be much more extensive for RO systems.

Pre treatment of feed water involves following major equipment down the line . The brief description of major equipment envisaged in pre treatment section for the proposed 20 MLD SWRO desalination based on the feed water quality and product water quality are as follows: The chosen pretreatment process consists of a dissolved air flotation (DAF) system followed by disc filters and Ultra filtration.

4.6.1 Trash racks , stop logs and travelling water screens

Sea water shall be inducted into the Intake sump of the Desalination Plant through stop log followed by trash rack & Travelling water screen .One additional stop log gate is provided on the downstream of trash rack. Two parallel chambers with 100 % standby configuration of the above set of screens ,filters and stop logs are employed to enable uninterrupted supply during cleaning and maintenance of the screens.

4.6.2 DAF -Dissolved Air Flotation.

A dissolved air flotation (DAF) is a well proven device shall be selected in upstream to an UF pre-treatment and designed to remove suspended solids, oil and grease (both in emulsified and non-dissolved form) and removal of plankton organisms and algae. The expected removal rate of DAF is reported to be >90% . The DAF system employed in this plant shall be of turbulent flotation type. The cost-effective DAF process flocculates water being pretreated with coagulant. In the air injection zone of DAF unit , flocculated particles attach to micro-bubbles created by a supersaturated recycle stream, and the solids float to the water’s surface. With the solids removed periodically, the clarified water is free of solids, algae and reduced in organic matter. The DAF system applied with its patented effluent collection system creates a vortex flow pattern within the DAF basin that results in a dense air bed and increased bubble surface area for significantly higher flotation rates and has been working successfully at loading rates of 30 m/h and higher.





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4.6.3 Disc filters

Disc filters with high filtration efficiency has been envisaged with automatic backwash system. The filtration cut off selected for disc filters is 40 micron. The individual disc filters outlet are connected to a common product header which will feed the downstream Ultrafiltration skids. The highlight of the system is provision of a sufficient standby disc filtration units to compensate for the capacity requirements during maintenance of any of the working disc filtration skids . This assures that no upsets in the flow and differential pressures across the filters occur during backwash and also increased availability. Each disc filter skid has four disc filters and with suitable piping, valve, instrumentation and automation arrangement for sequential operation and to ensure maximum flexibility in operation & maintenance and achieve guaranteed production

The disc filter backwash water is taken from first pass RO reject water thereby removing the permeate loss for backwashing and achieving 100 % recovery in the disc filtration units.

4.6.4 Ultra filtration System

Ultra filtration is a filtration method in which hydrostatic pressure forces a liquid against a semi permeable membrane. Suspended solids and solute of high molecular wt. are retained while water and low molecular wt. solute pass through the membrane. Ultra filtration is applied in cross flow or dead end flow mode . Ultra filtration membranes have been successfully employed in pre-treatment of much more difficult raw waters, sea water, Brackish water and in industrial & municipal waste water for many years. The hyrophlic membrane forms a barrier against suspended particles, colloidal materials and bacteria. Therefore they guarantee a low SDI value of the RO feed water; even with strong fluctuation of raw water quality, enabling operation with a high and stable permeate flux even in long term operation. The ‘hydrophilic’ UF membrane will not foul with oil grease (limited value) or other hydrophobic substances. Due to hydrophilic characteristic , the membrane is highly attractive to water so the water molecules will push away other molecules in order to gain access to membrane. Hydrogen bonds are quite stable and reluctant to break apart once they are formed. This keep contaminants away from the membranes so it remains clean and functioning for longer period In a process using membranes in pre-treatment, the raw water is usually roughly prefiltered by a mechanical screen before it is fed to the membrane. Chemical dosing in membrane pre-treatment is significantly reduced compared to conventional pre-treatment . The filtration can be carried out either’ inside-out’ or ‘outside –





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in’ .Commercially available modules are: immersed plate, pressure driven capillary, pressure driven spiral wound and immersed hollow fiber modules their Membrane Geometries are :

o Spiral wound module: Consists of large consecutive layers of membrane and support material rolled up around a tube.

o Tubular membrane: the feed solution flows through the membrane core and the permeate is collected in the tubular housing

o Hollow fiber membrane: The modules contains several small tubes or fibers. The feed solution flows through open cores of the fibers and the permeate is collected in the cartridge area surrounding the fibers.

Fouling agents, suspended solids and bio organisms that occurs in the feed water which cause fouling layers on the surface of the membrane have to be removed. Back flushing with permeate or back flushing with chlorinated permeate combined with air sparging has been very efficient in removing particles that deposit on the membrane surface.

For TEFR purpose, UF modules with hollow fiber membranes have been considered for pretreatment system design & accounted for costing purpose .The exact configuration of ultra filtration shall be determined during the plant design stage.

4.6.5 CARTRIDGE FILTERS

Cartridge filters are normally used as polishing filter in prior to RO feed . The filter elements shall be cylindrical cartridges constructed from continuously wound polypropylene fibers, which have a 5 micron nominal 90% efficient rating. The filter elements used in the membrane cleaning system shall be identical to the filter elements used to treat the RO feed water. The feed water enters the housing and distributed evenly around the filter cartridges . Filtration takes place from outside to inside . Solids are collected on the outside of the filter cartridges and clear filtrate is collected at the outlet. Extent of filter fouling shall be identified from differential pressure drop which shall be brought down by replacing the cartridges periodically . Cartridge vessel shall be provided with pressure relief valve, drain valve and vent valve. Cartridge filter replacement influences not only it’s own cost but membrane element life and therefore membrane replacement cost. Usually, the optimal cartridge type is one that provides the lowest particle size cut-off while maintaining good dirt holding capacity

4.7 RO system: A typical RO system comprises of following set of equipment: i) RO membranes ii) High pressure pumping system





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iii) Pressure recovery device

i) RO membranes:

Reverse osmosis is a filtration method that removes many types of large molecules and ions from feed water by applying pressure to the feed water when allows to pass on one side of a selective membrane. The result is that the ions or molecules are retained on the pressurized side of the membrane and permeate passes to the other side. This membrane dose not allow large molecules or ions to pass through the pores. The membrane shall be non-telescopic, non- flexing and leak free.

Types of Reverse Osmosis membranes:

a. Asymmetric membrane – cellulose acetate( CA) membrane:

This membrane is formed by casting a thin film acetone- based solution of ‘cellulosed acetate (CA) polymers’. The CA membrane has an asymmetric structure with dense surface layer (0.1-0.2 micron meter) which is primarily responsible for salt rejection whereas the rest of the membrane which is 100-200 micron meter thick spongy & porous which supports the thin film surface layer mechanically, thus has high water permeability.

b. Thin film composite membrane(TFC) - polyamide (PA) membrane

TFC membrane consists of a porous support layer and a thin film dense layer which is crossed linked membrane skin and is formed in situ on the porous support layer, usually made of polysulfone.The thin film dense layer is a crossed linked aromatic polyamide made from interfacial polymerization reaction of a poly function amine. The TFC membrane is characterized by its higher specific water flux , higher salt rejection, Long membrane life time, operable at lower pressure, chemically and physically more stable than Asymmetric membrane , display a strong resistance to bacterial degradation, do not hydrolyse, less influenced by membrane compaction and are stable over wide range of feed pH pH (3–11) and thus widely used commercially than cellulose acetate membranes .

The feed enters the module and is partly forced through the membrane. Permeate is collected in the permeate tube, while retentate leaves the membrane elements on the





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opposite side of the feed inlet. Besides providing a flow path for the feed along the membrane leaf, feed spacers also create eddies, which reduces ‘concentration polarization’ and thus increases mass flow through the membrane. By reducing concentration polarization, feed spacers significantly reduce fouling potential and enhance critical flux . In practice, the saline feed water is pumped into a closed vessel where it is pressurized against the membrane. As water passes through the membrane, the remaining feed water increases in salt concentration. This water is discharged from the vessel in a controlled manner in order to ensure problems such as precipitation of supersaturated salts and increased osmotic pressure across the membranes does not occur in the system.

For TEFR purpose , a spiral wound SWRO membranes for first pass & BWRO membranes for second pass have been envisaged for RO system configuration design & cost of the same has been accounted for the cost estimation. The exact configuration shall be determined during the detail design stage.

ii) High Pressure pumping system :

The HP feed pump shall be of a horizontal multistage opposed impeller, volute type with axial/radially split casing type having a variable frequency drive. During operation, the energy recovery unit along with the booster pump (variable frequency drive) provides part of the flow and rest is by the high pressure pump (variable frequency drive). The high-pressure pump shall be designed not to introduce flow and/or pressure pulsation in the feed or brine stream. The reverse osmosis system has to be operated with fluctuating feed salinity and feed temperature. An appropriate regulation of the feed pressure for each reverse osmosis train separately by a corresponding design of the high-pressure pumps and automatic feed pressure control through variable frequency drive is required. Number of high pressure pumps, booster pumps and energy recovery units shall be same as that of number of RO Streams / trains plus one common standby. The high pressure pump within the RO system supplies the pressure needed to enable the water to pass through the membrane, while rejecting the salts. This pressure ranges from approx 17 to 27 bar for brackish water RO systems, and from 54 to 80 bar for seawater RO systems.

The processes of brackish water and seawater reverse osmosis are essentially identical. There are however, substantial differences in the two processes pressure requirements, as stated above, with brackish water systems requiring substantially lower operating pressures, and the rate of conversion of feed water to desalinated product water, with





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brackish water systems able to achieve higher system recoveries. In addition to the differing energy requirements of the two processes, the types of pretreatment required can also vary considerably.

iii) Pressure recovery device - Pelton turbine/ Hydraulic turbocharger/ Piston

pressure exchanger / Rotary isobaric device:

Before the conception of seawater reverse osmosis (SWRO) in the 1950’s, reducing energy consumption during desalination processes has been a primary driver of innovation and engineering development. The first large municipal SWRO, which began operating in Jeddah, Saudi Arabia in 1980, consumed about 8 kilowatt-hours per cubic meter (kWh/m3) of the water produced. This was less than half the energy required by state-of-the-art distillation processes. Yet, most of the hydraulic energy put into a SWRO process was wasted in the form of a pressurised brine waste stream discharged from the membranes. Since then, many energy recovery devices (ERDs) have been designed to prevent the wastage of energy in a SWRO process. Their effectiveness and reliability were widely considered to have made large-scale SWRO economically viable through recent advances in the energy recovery technology. The advent of efficient energy recovery devices in the last decade has been the key component which made membrane based SWRO desalination plants more competitive over the thermal desalination technologies like multistage flash evaporation (MSF) and multi effect distillation (MED).

In SWRO plants energy cost accounts for 50% to 60% of the operating cost of the complete plant including intake, pretreatment, RO section and post treatment section and balance 40% to 50% of the operational cost towards consumables such as chemicals, membranes, manpower, repair and maintenance (parts replacement) etc. Out of the 50% to 60% of the energy consumption in SWRO plant, the High Pressure pumping in reverse osmosis section accounts for 65% of the energy cost. In evaluating the life cycle costs for SWRO plants, cost towards capital expenses is 25 - 40 %, whereas operating cost is 60 - 75 % depending on plant and equipment selection.

Since the optimized RO section recovery is 45.4% meaning thereby that the useful conversion of energy for product water is only 45% and the rest 55% energy is in the brine / rejects. The challenge is to recover the high energy present in the RO reject waste with maximum efficiency so as to get the lowest operating cost.

The SWRO industry has been doing lot of research and development on the energy recovery devices and their evolution chronologically are as follows:





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Evolution of SWRO Energy Recovery Device

Pelton turbine

Turbines were the first energy recovery devices deployed in municipal-scale SWRO plants. Initially, Francis turbines were applied, but they were replaced in the 1980s by pelton turbines that operated at higher efficiency in high-head applications like SWRO. The design of the latter stems from a device patented in 1883 by Lester Pelton for gold-mining operations in California. Pelton turbines were widely accepted in SWRO because of their familiarity and proven reliability. Manufacturers of pelton turbines for SWRO include Calder AG, Sulzer Pumps, Ltd. and Grundfos A/S.

In Pelton turbines, the wheel is mounted on the high-pressure pump shaft, which together with a motor, drive the pump that pressurises the SWRO system feed.

The energy transfer efficiency of a pelton turbine recovery system is the product of the efficiencies of the nozzle(s), the turbine and the high-pressure pump. Therefore, we draw the conservative conclusion that 89% is the maximum attainable efficiency for an SWRO centrifugal pump impeller. The theoretical maximum attainable efficiency for a large, high-head, high-rpm hydraulic turbine is about 90%. Assuming 1% loss in the nozzle, the maximum possible overall energy transfer efficiency for a Pelton turbine energy recovery system is the product of these peak efficiencies: 89% x 90% x 99% = 79%.

Hydraulic turbocharger

Another type of centrifugal ERD is the hydraulic turbocharger, which has been used for SWRO energy recovery since the early 1990s in SWRO plants. Turbochargers are similar in concept to pelton turbine ERDs with a turbine and an impeller on the same shaft but they don’t have a motor. Current manufacturers of turbochargers include Pump Engineering Inc. and Fluid Equipment Development Company, USA. Pump Engineering Inc. has recently been taken over by Energy Recovery Inc., (ERI), USA

The turbocharger and the high-pressure pump are not directly connected, providing a degree of flexibility in the operation of these devices. Also, turbochargers have a relatively small footprint and are easy to install. In case of Pelton Wheel turbine, the wheel is mounted on the high-pressure pump shaft, which together with a motor drive the pump that pressurises the SWRO system and hence requires more space & less flexibility.





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The turbocharger’s impeller and turbine are close-coupled mixedtype of centrifugal elements incorporating both axial and radial flow features. The impeller of the high-pressure pump, that operates in series with the turbocharger, can be of any type and are considered to be the same as the turbocharger impeller. The maximum efficiency of each of these elements is 89% or 90%. This is slightly higher than the impeller in a pelton-turbine recovery system because the high-pressure pump in the latter operates with a higher head and therefore a slightly lower efficiency. The maximum attainable overall transfer efficiency of a large, high-rpm hydraulic turbocharger is the product of the weighted-average efficiency of the impellers, the efficiency of the nozzle(s) and the efficiency of the turbine: 90% x 90% x 99% = 80%. Turbocharger efficiency declines due to the factors associated with the centrifugal impellers or as the flow rate or pressure of the reject stream changes from the optimal. A brine control valve and/or nozzle controls can however be used to adjust performance.

Piston pressure exchanger

To avoid the efficiency losses associated with the energy-conversion steps inherent in centrifugal devices, engineers have developed positive-displacement (PD) piston isobaric devices for SWRO in the 1980s. These devices place the SWRO reject and fresh feed in contact with an intervening piston in pressure-equalising or isobaric chambers. Early versions include the Diprex by Aqua Design and a direct-piston design by Union Pump. Current manufacturers of piston isobaric devices include Calder AG, Switzerland, RO Kinetics and KSB. Among these manufacturers, the most successful of the positive displacement isobaric energy recovery devices in large SWRO plants (Above 50 MLD) is Dual Work Exchanger Energy Recovery (DWEER). In the 1990s it was developed by a company named DWEER Bermuda and licensed by Calder AG for use in the Caribbean. Subsequently, CALDER A.G, took over the complete control & license for manufacturing & sale in the entire world for the Dual work Exchanger Recovery. M/s Calder A.G, a Swiss company product line includes Pelton Turbines, Turbo Chargers and Dweer Recovery Devices. Recently, Flowserve corporation has acquired CALDER AG,

Seawater reverse osmosis (SWRO) needs high pressure and some of the reject stream can be reused by using this device. According to Calder AG, 97% of the energy in the reject stream is recovered.

Piston isobaric devices (DWEER) operate at an efficiency that is limited only by the energy loss in moving the pistons and valves and can exceed 95%. Their efficiency is relatively constant despite flow and pressure variations and is independent of device capacity. Multiple isobaric devices operate in parallel in arrays with no loss of efficiency.





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The DWEER system uses a piston dual chamber reciprocating hydraulically driven pump, and a patented valve system in a high pressure batch process with large pressure vessels, similar to a locomotive, to capture and transfer the energy lost in the membrane reject stream. Its advantage is its high efficiency rate, but it suffers from complex and large mechanical components which are susceptible to corrosion from seawater due to its metal composition.

Rotary isobaric device ( Pressure exchanger)

The high efficiency of an isobaric PD device and the operational simplicity of centrifugal ERDs are combined in the rotary isobaric device, first applied to the SWRO systems in 1997. Energy Recovery Inc (ERI, USA) is the sole manufacturer of rotary isobaric devices; with the trade name PX Pressure Exchanger. In an SWRO system equipped with a rotary isobaric device, the membrane reject is directed to the membrane feed. A rotor, moving between the high-pressure reject stream and a low-pressure seawater supply stream, removes the brine and replaces it with the seawater. Pressure transfers directly from the high-pressure reject stream to a feed stream with no intervening piston in the flow path. This results in a slightly higher degree of mixing between the streams than in a piston isobaric device (1 to 2.5%), eliminating the friction and wear that occurs on the pistons. Mixing is minimised with long, small diameter chambers and short brine-seawater contact time (0.05 seconds). The rotor spins freely, driven by the flow at a rotation rate proportional to the flow rate with no shaft or shaft seal. No controls are needed to operate the pressure transfer mechanism. The rotor and associated components are made with a ceramic material that is immune to corrosion and highly resistant to wear. Rotary isobaric devices can be used in pressure-centre designs, and unlimited capacity is achieved by arraying multiple devices in parallel. Total energy transfer efficiencies of up to 95 % are possible, and efficiency is relatively constant regardless of flow and pressure variations.

4.8 Post treatment (Potabilisation) of Desalinated Water The permeate produced by RO systems has a low TDS, pH, calcium concentration and alkalinity. Hence, the water is corrosive with a low buffering capacity. Therefore, the desalinated product water requires post treatment of the water to meet ultimate use requirements. For drinking water purposes this generally includes pH adjustment, hardness and alkalinity adjustment, disinfection and is commonly referred to as potabilisation or remineralisation. In addition to meeting health requirements, post treatment is necessary to protect downstream water supply infrastructure e.g. concrete & metallic pipes from corrosion. The aims of potabilisation of desalinated water for drinking/industrial water supply are to:

- establish the required salt content based on taste and health considerations;





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- adjust the pH and raise the calcium and bicarbonate concentration to obtain the

required calcium bicarbonate /CO2 equilibrium conditions which render the water non-corrosive and to impart rust preventive properties; and guarantee the quality of the product water from a hygienic point of view by disinfection.

4.8.1 Post Treatment Options

Typically potablisation consists of the following steps:

- Alkalisation – refers to the addition of chemicals to adjust the alkalinity and hardness of

desalinated water; - Remineralisation normally required for thermal distillate which have a lower TDS

concentration; - pH control; - addition of phosphate or other corrosion inhibitors(if applied) to protect distribution

network;

- final chlorination.

In the proposed 20 MLD ONGC Uran desalination plant , alkalisation and chlorination will be required for desalinated water for the SWRO plant.

Chlorination for final disinfection of the desalinated water can be achieved by: - dosing of liquid chlorine, by injection into the product water with suitable equipment; - dosing of chlorine generated on site by electro-chlorination; or - dosing of calcium hypochlorite or sodium hypochlorite solution.

Here, for this study, dosing of 12% sodium hypochlorite solution has been considered.





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Various combination of the following chemicals can be applied to increase the alkalinity and hardness (alkalization) of the desalinated water produced in a seawater desalination plant:

- Carbon dioxide provided by an external source and utilizing the carbon dioxide in the

permeate; - Calcium from lime water or filtering through limestone or dolomite filters; - Sodium bicarbonate or sodium carbonate; - Caustic soda addition; - Sulfuric acid dosing followed by limestone (calcium carbonate) filtration; and/or - Calcium chloride - sodium bicarbonate dosing.

The alkalisation methods listed above differ considerably in terms of chemical consumption (and hence cost). The input of chemicals is highest for alkalisation with calcium chloride and sodium bicarbonate. The lowest carbon dioxide consumption results from the reaction of calcium carbonate (limestone) with carbon dioxide. Twice the amount of carbon dioxide is needed if the carbon dioxide reacts with calcium hydroxide or sodium hydroxide, and twice the amount of limestone is needed if it reacts with sulphuric acid instead of carbon dioxide. Although, dolomite filtration is characterised both by a low carbon dioxide consumption and by requiring the smallest input of the hardness component it is prohibitively expensive for large plants. Limestone on the other hand can often be obtained from local deposits but its purity needs to be confirmed.

From the above, the use of carbon dioxide followed by the addition of calcium through addition of lime or limestone filtration are the preferred methods for alkalisation as other methods also increase the concentration of anions and final product water TDS in addition to alkalinity. The RO permeate still contains a certain amounts of alkalinity and carbon dioxide, the extent of which is dependent on the pH of the RO feed and the extent of acid dosing. For the techno-economic feasibility study for the proposed desalination plant in ONGC, post treatment system comprises of limestone filters, carbon dioxide absorbers and liquid carbon dioxide dosing from carbon dioxide storage tanks procured from external sources, sodium hypochlorite dosing as disinfectant and caustic soda dosing for final pH adjustment.





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4.9 Intermediate and final product storages and pumping system: Depending on the no of filtration stages in the pretreatment system and hydraulics of the pretreatment equipment, intermediate storages and pumping system shall be required. For this report, two stages of filtration has been envisaged considering high suspended solids. RCC intermediate storage tank with sufficient holding capacity and pumping system has been envisaged .

4.10 Bulk Chemical storage, handling, preparation and dosing facilities: Bulk chemical storage facilities for one month storage capacity as applicable has been envisaged. The chemical preparation and dosing facilities comprising of dosing tanks and pumps are envisaged in the centralized chemical preparation and dosing building.The chemical shall be stored in the chemical storage building for dosing purpose and in the bulk quantity in bulk storage tanks located in an open area with proper dyke wall & AR flooring ,sumps . The chemical building & bulk storage area have been provided with acid resistant flooring , sump for collecting chemicals spillage during maintenance or leakages during operation . The chemical like antiscalent , antioxidant , coagulant aid is received in carbouys and envisaged to be stored in the chemical building itself. However the chemicals like coagulant,acid , alkali , hypochlorite & CO2 are envisaged to be stored in the bulk storage tank kept outside in an open area , Unloading and bulk chemical transfer pumps to the respective dosing tanks are also envisaged in this TEFR.

4.11 Onshore land requirement:

The desalination plant site would need to accommodate onshore intake sump and pump house, pretreatment and RO desalination process facilities, intermediate and final product storage and pumping facilities, bulk chemical storage and dosing facilities, other utility facilities like air compressor house, control and instrumentation room, warehouse, laboratory facilities and electrical facilities. Additionally, non-plant facilities like administrative building is also envisaged. A multistoried process building housing all the major pumps indoor in the ground floor & UF & two pass RO system in first floor & electrical buildings have been conceived in preparation of plant layout so as to optimize the area requirement . All around road has been provided for easy accessibility to the equipment RCC above ground storage tanks . As shown below, the total land area earmarked for the desalination plant is approximately 9250 m2 (for the proposed plant including intake chamber ) and accordingly the plant and equipment have been optimally located.





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4.12 Process Description

The proposed desalination Plant has been broadly classified into three sections, namely:

Section-I : Pre-Treatment Section, essentially for removing Total Suspended Solids (TSS), Oil, colloidal suspended particles, BOD, COD etc.

Section-II : Reverse Osmosis Section to remove the Total Dissolved Solids (TDS)

in two passes and post treatment section for stabilization and potabilisation to make the permeate water suitable for various plant end users and Demineralization plant for Boiler feed water requirements

Section-III : Chemical solutions dosing section, describes the facilities required for

handling, storage, preparation and dosing of different chemical required in the various stages of treatment to maintain the process parameters.

SECTION-I :

PRE-TREATMENT SECTION

Pre-treatment section is the first stage of treatment of feed water and consists of equipment for removing settle-able suspended particulate matters, organic & inorganic impurities which may be harmful to the RO membranes. The pre-treatment section comprises of high rate solid contact type Dissolve Air Floatation (DAF) units with combination of flash mixer and flocculator , sludge water storage tanks & transfer pumps, filter water storage tanks, UF feed pumps, Automatic back washable disc filter with back washing system, ultra filtration system comprising of UF membranes skids with backwash pumps, UF permeate storage tank and first stage RO cartridge filter feed pumps. The chlorinated feed water having residual chlorine of 0.5 – 1 ppm is pumped by vertical turbine raw water transfer pumps from the intake sump to flash mixer where coagulant and coagulant aid is dosed and mixed rapidly. HCL acid is dosed at the static mixer provided at the common discharge header of vertical raw water transfer pumps for pH correction to obtain better settling in DAF. Online transmitters such as temperature transmitter, pH , TOC (total organic carbon content), chlorine analyzers, turbidity analyzer, conductivity meter are being installed on the common discharge header for automatic control and adjustment of pH and residual chlorine in the raw sea water which is being fed to the flash mixer.

The clarified overflow water from the DAF units is led by gravity to underground Clarified water storage tank and sludge generated is being collected in an underground sludge collection tank . In addition to flow meters at respective inlet to flash mixers, pneumatic on off





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valves & by pass valves are envisaged for feed flow control at various stages of pre-filtration.

The entire operation of filters shall be completely an automatic operation and controlled by DCS from the control room. The sludge settled at the bottom sludge collection chamber of the DAF units is being disposed to the reject outfall pipeline through vertical sludge disposal pumps installed on sludge water storage tanks. Online turbidity analysers and pH analyzer, TOC (Total organic carbon content ) shall be provided at the common inlet feed header of flash mixer, common product (overflow) outlet of DAF units. These analyzers are interlocked with chemical dosing pumps for automatic control and adjustment. Generally the analysers shall have the response time in terms of few minutes or less.

The filtered water having pH range of 5.5 to 6.5 is then pumped to ultra filtration membrane system followed by combination of Automatic back washable Disc filters of 40 microns particle size, by UF feed pumps. Before UF , a set of Disc filters with automatic sequential backwashing facilities is envisaged so as to meet consistent desired RO feed quality of an SDI<3 & turbidity less than 1 NTU.

The UF skids shall be capable of handling feed turbidity up to 50 NTU and total suspended

solid range of up to 50 ppm. The UF skids shall be envisaged and designed for nominal feed rate 2260 cum/hr at 2-2.5 bar. The total UF permeate obtained from all the skids shall be 2222 cum/hr with min. 90% recovery ,is led to UF product cum backwash tank. The reject of 95 cum/hr from second pass RO is also taken back to UF product cum backwash tank. Approximately an average of 220 cum/hr of UF permeate shall be used as UF backwash water wherein chlorine addition shall be done at the UF backwash pump discharge line through static mixer.VFD (1w + 1s) operated pumps shall be envisaged for UF back washing. The concentrate (rejects) & the backwash water is led to the reject storage tank for onward disposal into reject outfall marine pipeline. The net UF permeate capacity considering discounting the quantity required for backwash shall be 2000 cum/hr. Each train of UF skids shall be designed for fully automatic sequential operation through DCS.

SECTION-II : REVERSE OSMOSIS SECTION

Two pass RO system is envisaged to get the desired quality water as indicated in the table- 4.1 & 4.2 in this report.

The pretreated UF permeate will be pumped by Ist pass cartridge filter feed pumps at 2.5 bar pressure to the VFD controlled high pressure pumping and energy recovery device through 5-micron cartridge filters . The RO skids are envisaged in the first pass along with dedicated 5 micron cartridge filter at the upstream of high pressure pump, VFD controlled high pressure pump & booster pump, Energy recovery Device, VFD, overhead suck back tanks, degasser feed pump and degassers. Anti scalant, SBS (sodium bi-sulphite), HCL, NaOH shall be





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dosed at the common discharge header of cartridge filter feed pumps for controlling the parameters requisite for RO feed.

The booster pump receives the RO feed high pressure outlet from the PX and boost the feed water to the required differential pressure of high pressure pump outlet. The combined high pressure pump outlet and booster pump discharge is fed to the RO skid at high pressure approx.65 -70 bar. The RO permeate is collected in the suck back tank provided at top of RO skid. The permeate from the suck back tank is pumped to the first pass RO permeate tank and a partial stream of this permeate is used to blend with the second pass RO permeate to obtain the desired water quality . The RO concentrate after exchange of energy in PX is led to the reject storage tank for onward pumping and disposal.

Around 2095 cum/hr of UF product water from the high pressure pumping system and energy recovery system will be fed to the 1st pass RO membrane system for removal of total dissolved solids. In the first pass 945 cum/hr will be recovered as permeate (min. 45% recovery) having TDS < 400 ppm, The RO permeate is sent to second pass RO to further remove the TDS . The product from the second pass RO is around 850 m3/hr of which 760 m3/hr is sent to the post treatment section comprising of Lime stone filters with backwashing facilities,CO2 injection system, Degasser , pumping & product water storage tank and chemical dosing system with necessary instrumentation & automation for controlling product parameters for producing Industrial water as per the quality indicated in table 4.1 of chapter -4 . The remaining product water from the second pass RO system i.e. 88 m3/hr is sent to the MB system for DM water production. The reject from the second pass RO is utilized in the feed to first pass RO which reduces the net requirement of RO first pass feed water and improving the overall recovery of the RO system. The product from the post treatment system after consumption for backwashing requirements in post treatment section , equivalent to 750 m3/hr (18 MLD) is sent to the existing raw water water tank in ONGC plant. The DM water of 83 m3/hr (2 MLD) is sent to the existing DM water tank in ONGC plant.

DM PLANT

The DM water requirement has been considered as 2MLD. Feed water for DM plant is taken from RO plant. DM water is generated by removal/polishing of the remaining positive and negative ions (cations and anions) existing in the feed water . Feed water from the outlet of second pass degassed water of RO plant is taken to the Mixed bed of cations and anions . In the mixed bed all the remaining positive and negative ions will be absorbed by the resins. These resins will be regenerated by alkali and acid dosing during the regeneration process.





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DM Water plant consisting of 2 streams (1 Working and 1 reserve) each of 83.3-m3/hr net capacity is considered. Each stream shall consist of: i) Mixed bed exchanger ii) All necessary controls and instruments. Two nos. Horizontal centrifugal pumps (1 Working + 1 Reserve) each of 100% capacity shall be provided to pump water from MB Feed tank to the Mixed Bed unit. This plant shall be PLC controlled fully automatic. In addition to the above, the following facilities common for both streams are considered. a) Regeneration system consisting of common acid and alkali bulk storage tanks and transfer pumps (common for entire desalination plant) and Acid /alkali dosing tanks and ejectors for Mixed bed. b) 1 No. DM Water Storage Tank of capacity 85 cu meters. c) 2 Nos (1working+1standby) DM Water transfer Pump Set. d) 2 Nos. (1working+1standby) DM Water regeneration Pump Set. e) Neutralization Pit , 2Nos. neutralized effluent transfer pump f) Acid and caustic dosing tanks and pumps for Neutralisation pit. g) Air blowers (2 nos.). h) Necessary Electrics, instrumentation and A/C ventilation facilities.

Detailed System Description: Net continuous capacity of each stream shall be 83.33 m3/hr. The regeneration cycle

and back washing cycle shall be once in 3 days. Water required for internal consumption like regeneration back washing etc. shall be additional to the capacities indicated.





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The complete plant shall be designed in such a manner that it shall be monitored and controlled by means of fully automatic control system (PLC system) with necessary manual intervention. The PLC shall have provision for interfacing with the centralized control room.

The entire operation, including backwashing, air scouring and regeneration shall

be completely automatic (PLC based).The system shall be provided with pneumatically operated on-off valves for automatic sequential operation.

RO water (second pass degassed) from Desalination plant is considered as the

source of water for Mixed Bed unit. The feed water shall flow into the mixed bed exchanger for the

removal/polishing of the remaining positive and negative ions. The DM water from the mixed bed exchanger shall flow into the DM water storage tanks. From the DM water storage tanks, the demineralised water shall be pumped to the storage tank or system provided by end user.

A deration percentage of 10 in exchange capacities of the resins chosen for the mixed bed exchanger shall be adopted in the process calculations. The effluent discharged during back washing/regeneration shall be collected in a neutralisation pit lined with acid/alkali proof tiles. Chemicals, if necessary shall be added to neutralize the effluent water before it is pumped to the drain. Effluent discharged shall satisfy the State Pollution Control Norms. Hydrochloric acid and sodium hydroxide (lye) shall be used as regenerants. Regeneration system for the mixed bed shall consist of acid dosing tanks, alkali dosing tanks, ejectors, pipes, valves, flow indicators, density indicators etc. Resin traps shall be provided for the exchanger vessels. Industrial Emergency shower, eye and face wash fountain as per IS:10592-1982 (R.A. 1991) shall be provided near acid storage area. The quality of DM water shall be as per Table-4.2

For a detailed view of the various flows and the process configuration the Process flow diagram drg.no. MEC/23Q8/01/31/D1/00/00/2001/R01/A1 is provided with the document.

SECTION-III : CHEMICAL STORAGE, HANDLING, PREPARATION & DOSING SECTION

An integrated Bulk storage & chemical dosing system shall be provided for bulk chemical unloading & storage, transfer, preparation and dosing of chemical solutions for the complete





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desalination plant . A centralized chemical building shall be envisaged for entire pre-treatment section ,RO section including DM plant. The bulk storage capacity shall be envisaged to have 1 month storage capacity with the respective unloading pumping facilities. The chemical preparation and dosing tanks shall be envisaged to have 1 day capacity with dedicated pumps with necessary automation& control facilities for flow control.

4.13 Basic design parameters :

Assumption:

The proposed desalination plant is envisaged considering the following assumption & basic input data provided for feed water quality. A 20 % design margin in the operating capacity of the plant has been envisaged to address the plant availability during process upsets if any.

a) Pretreatment section inlet parameters: (plant capacity design considered for worst conditions) i) Sea water intake capacity to pre-treatment unit – 2302 m3/hr (avg)

ii) TSS (total suspended solids) of sea water feed – 200 - 400 ppm

iii) Total dissolved solids (TDS) – 33000 to 42000 ppm

iv) Temperature: 24oC (min.) , 32 oC (max.)

vi) Specific gravity – 1.03

vii) Oil & grease - 20 ppm max

viii) COD , ppm - 20 max

b) Pretreatment unit , DAF i) TSS (total suspended solids) of sea water feed – 200- 400 ppm (avg) ii) Oil content in DAF sea water feed inlet – 10 -20 ppm iii) TSS at outlet of DAF unit – <10 ppm iv) Oil &grease content in DAF outlet - <1 ppm v) COD ,pp m - < 2 ppm

c) Pretreatment unit , UF :





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i) UF feed water TSS – 50 -100 ppm avg, 200mm peak ii) UF feed water turbidity – 50 NTU ,max iii) UF permeate water quality - SDI < 3

iv) TSS – Nil

v) TDS at UF permeate outlet - 33000 to 42000 ppm,

vi) Net UF permeate Capacity – 2000 m3/hr (avg)

vii) Net permeate recovery for UF system – 88 % (min.)

d) RO first pass section inlet parameters:

i) Inlet capacity for – 2095 m3/hr distributed equally in 3 trains

ii) TDS at RO inlet - 33000 –42000 ppm

iii) Temp in deg centigrade - 24oC (min.) , 32 oC (max.)

e) First pass RO section outlet parameters

i) TDS of RO permeate ≤ 400 ppm. ii) RO recovery of each train – 45.5% (min) iii) Net permeate from each train – 315 m3/hr.

Total for 3 trains shall be 945 m3/hr.

iv) TSS < NIL. v) Net Product water Capacity measured at outlet of underground RCC product tank

– 750 m3/hr (nominal). vi) CO2 < 5 ppm.

f) RO section second pass inlet parameters: i) Inlet capacity – 945 m3/hr (nominal) distributed equally in two trains ii) TDS at RO inlet - TDS of RO permeate of first pass

g) RO section second pass outlet parameters: i) TDS of RO permeate < 20 ppm ii) TSS < NIL





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iii) Net Permeate Capacity –425 m3/hr (nominal) iv) Recovery in second pass RO skids – 90% min. v) CO2 < 5ppm

After post treatment, water quality shall be as per table 4.1. Langelier saturation index (LSI) of the product water (750 m3/hr) shall be positive 4.14 UTILITY REQUIREMENT

a) The plant power requirement is indicated in chapter -8, Plant electrics. b) The Compressed air requirement for the plant is indicated in chapter -14,

Compressed air system.

The in plant water consumption for the desalination plant is approximately 0.2 MLD which shall be met by the product water from the desalination plant.





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CHAPTER -5

SITE DETAILS

05.01 DESCRIPTION OF THE PROJECT SITE

05.01.01 Site location and its access

The project site of proposed 20 MLD SWRO desalination plant is located within the existing gas processing facility at ONGC, Uran . ONGC has earmarked an area admeasuring about 8750 m2 . The proposed site is located at about 380 meters away from the HTL along the sea-shore on the coast of Arabian sea. The location map of desalination project site is shown in the Fig. 05 - 01. The latitude and longitude of the proposed project site is given below:

Sl. No. Latitude Longitude 1 18o 51’ 24.96’’ N 72o 55’ 37.28’’ E 2 18o 51’ 23.20’’ N 72o 55’ 37.55’’ E 3 18o 51’ 23.22’’ N 72o 55’ 36.23’’ E 4 18o 51’ 25.37’’ N 72o 55’ 35.92’’ E

The site is well connected by road. The Uran town is located at a distance of 2 km in NE direction from the project site. The National Highway NH- 4B is passing in east direction at a distance of 11 km from the project site .The road connectivity map of Raigad district is shown in Fig. 05 - 02.

The nearest railway station is Panvel, which is at a distance of 30 km and nearest airport is at Chatrapathi Shivaji terminus located at about 60 km from Uran. The nearest seaport is Jawaharlal Nehru Port Trust, which is at about 18 km from project site. The satellite map of project site is shown in Fig. 05 - 03.





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Fig. 05 - 01 Location map of proposed 20 MLD SWRO Desalination plant





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Fig. 05 - 02 Road connectivity of Raigad district





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Fig. 05 - 03 Vicinity map of Project Site

05.02.01 Site description

The altitude of the site is at safe grade elevation of between 13m to 14m above MSL. The site is flat and ready for construction.

The west of the site is covered by Arabian sea and east by Dronagiri hills.

PROPSED 5 MLD

DESALINATION PLANT





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Fig. 05 - 04 shows the satellite view of the site as captured by satellite and Fig. 05 - 05 shows the general layout of proposed project. The nearest human settlement is Pirwadi village which is located at about 370m in South West direction. The proposed plant is physically isolated from surroundings by constructing compound wall on all sides and other physical protections as per safety requirements.

Fig. 05 - 04 Satellite map of the proposed project





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Fig. 05- 05 General layout of the proposed project of 20 MLD SWRO desalination plant





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05.03.01 Site selection

The main features of site including environmental considerations that make it suitable for this plan are given below:

Readily available industrial land with flat terrain. No land acquisition is involved, hence no R&R issues Nearest settlement is about 1km away from the plant site Suitable topography and geography for plant construction Good accessibility through road and rail Availability of power & raw water sources at convenient distance Suitable seismic zone From the toposheet, no reserve forests or forest land is identified in the

vicinity of project site The proposed site is not falling within the vicinity of any monument or in

an archeologically sensitive area. No declared biodiversity parks/sanctuaries are there in the surroundings

of the site.

The above features make it favorable for the proposed project. Hence, alternate sites have not been explored.

i) Seismic consideration

The site lies in seismic zone III as per seismic zone mapping of India (IS: 1893 - 2005) and has the lowest seismic potential. There is no capable fault within the study area. The seismic zone map of India is shown in the Fig. 05 - 06.





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Fig. 05 - 06 Seismic zone map of India

Proposed Project Site





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CHAPTER -6

CIVIL AND ARCHITECTURAL WORKS

6.1 Civil Works The civil engineering works at proposed site shall comprise of jungle clearance, site preparation & leveling based on site survey report, pile/raft foundations/open foundations for equipments, machinery & structures, construction of building structures based on soil investigation report of the proposed site, including roads, drains, boundary wall, underground / over ground RCC storage tanks etc., along with all finishing works, as per technological schemes. Since the proposed site is located proximity to sea, normally pile foundations are required to be provided with pile caps. However, the foundation system will be decided based on soil investigation report.

6.1.1 Major units covered are as follows:

1. Intake chamber & pump house. 2. DAF units. 3. Clarified water tank. 4. Sludge tank. 5. RO/UF & pump house building comprising the following facilities.

Ground floor units a. Pump house. b. RCC trench. c. Air Compressor room. d. DG room. e. Consumables ware house. f. C & I store. g. Workshop. h. Centralized store. i. Toilet. j. Stairwell.

First floor units

a. RO/UF skids. b. Control room. c. Shift in charge room. d. Mechanical maintenance. e. Instrumentation maintenance. f. Electrical maintenance.





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g. Laboratory. h. Visitors meeting room.

i. Workers change room /rest room. j. Toilets.

6. UF prod & backwash tank. 7. RO –I Permeate tank. 8. RO –II Permeate tank. 9. Potable water tank. 10. Bulk storage area. 11. Chemical storage and dosing building. 12. Post treatment area.

a. Lime stone recharging building. b. Sedimentation tank. c. Limestone filter area.

13. CO2 storage with perlite insulation tank. 14. CO2 Absorber. 15. Reject storage tank. 16. Administrative Building. 17. Electrical building (3 floors).

a. Cable cellar – Ground floor. b. Switch gear room –first floor. c. VFD room– third floor.

18. Anchor blocks (RCC) for outfall pipelines. 19. Roads and Drains. 20. Rainwater harvesting. 21. Site leveling. 22. Jungle clearance. 23. Pipe Supports. 24. Pipes Crossing Roads. 25. Cable Rack.

6.1.2 General Site Features: The site consists of trees and bushes with sandy soil. The terrain is undulating and hence requires cutting or filling inside the plant area in order to obtain leveled ground.

6.1.3 Type of Foundation System Soil investigation needs to be carried out before designing the civil foundations. For the purpose of estimation, based on visual observation at site as the soil appears to be sandy,





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the most likely suitable foundation system would be piles with pile caps. Piles of 500mm Dia. of 15m length, with 60T vertical load carrying capacity, 15T tensile capacity & 3T horizontal capacity are assumed for estimation. All foundations are proposed to be supported on piles and pile caps.

6.1.4 Design Aspects The civil engineering design will be based on the norms laid down in relevant specification of Bureau of Indian Standards and National Building Code. Where such norms are not available relevant international norms / standards will be adopted.

No special protective measures to the underground concrete against under ground water have been envisaged. However, this is to be reviewed after obtaining the actual characteristics of underground water during detail soil investigation work to be carried out before taking up the detailed engineering works.

6.1.5 Constructional Features

6.1.5.1 DAF Units structural shed.(Size 50.0mX25.0mX9.0m)

This will be a structural building with steel columns, structural roofing civil foundations and structural side sheeting all-round with apron and drain

6.1.5.2 RO/UF/Pump House Building .(Size 64.10 mX26.86mX15.5m)

RO/UF/Pump House Bldg. shall be two storied RCC framed structure with brick in-fill walls with civil foundation as required. Finished floor level shall be 300mm above the road top level with approach ramp, curb wall all around the building be provided. RCC equipment foundations for Pumps, DISC Filter, Skids, Cartridge filters etc shall be planned at ground floor level. Steel Doors and windows, all-round PCC apron with open RCC drains shall be considered.

6.1.5.3 Main Plant Electrical Bldg. (Size 30.0 mX16.0mX13.5.0m)

This shall be of three-storied RCC framed structure with brick in-fill walls with civil foundation as required. The ground floor shall accommodate Cable cellar, Battery room and Transformer room and staircase provision for upper floors. First floor shall accommodate Switch gear room and Second floor shall accommodate VFD Room and AC/ Ventilation Room. The approximate size of building shall be of 30.0m x 16.0m and floor-to-floor height shall be minimum 4.5 m. Roof access shall be provided by continuing the same staircase. Emergency exit staircase from second floor to ground level shall be provided on one side of the building. overhead tank of suitable capacity and 1no. septic tank and soak pit of required capacity shall also be provided. The false flooring and false ceiling for VFD room





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shall be provided. Cable trenches of suitable size & depth and for required length shall also be considered, the trench shall be covered with RCC cover slabs.

6.1.5.4 Control Room(Size 12.9 mX6.0mX7.5m)

This building shall be two storied RCC frame structure with brick in-fill walls of 5.0 m height approximately. The foundation for the building column shall be RCC. Cable trenches of suitable size & depth and for required length shall also be considered, the trench shall be covered with RCC cover slabs. False ceiling shall be considered for Control room with staircase provision. Toilet facility shall be provided for the working personnel.

6.1.5.5 Chiller Room(Size 9.70 mX4.5mX4.2m)

Chiller Room shall be of RCC structure with brick in-fill wall, approximately 9.70m x 4.50m in size and 4.20m height.

6.1.5.6 Chemical Dosing Bldg. (Size 23.50 m X 13.90mX 6.5m)

Chemical Dosing Bldg. shall be single story RCC framed structure with brick in-fill wall approximately 6.50m height with RCC flooring, Steel Doors and windows, all-round PCC apron with open RCC drains. The floor , drains & sumps shall be protected with AR lining with slope towards sump.

6.1.5.7 Chemical Bulk Storage Area: (Size 13.25 m X 15.50m)

Chemical Bulk Storage Area shall have an area of 13.250mX15.50m(Approx) with dyke wall all-round. The storage area will be an open yard. Foundation for vertical tanks will be supported on RCC open foundation. Interconnecting structural platform provided for tank tops shall be supported on structural columns with RCC foundations. The storage area shall be protected with AR lining with slope towards sump.

6.1.5.8 Limestone filter, CO2 Storage & Absorber, Degasser& Root blower :

RCC open foundation with RCC pedestals shall be provided for:

1.Lime Stone Filter(3- Nos).

2. Lime Stone Filter Recharging Pump (2- Nos)

3.CO2 Storage Tank(2- Nos)

4.Carbon Di Oxide Absorber(1-No).

5.Carbon Di Oxide Absorber Booster Pump(2-Nos).

6.Slurry Disposal Pump (2-Nos).





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7.Degasser Blower(4-Nos) and

8.Root Blower for limestone filter (2-Nos) .

6.1.5.9 MB Unit & MB Regen Unit Bldg: (Size 20.50 m X 20.0mX7.5m)

This is a RCC Bldg of approximate 7.5 M height. It has two rooms separated by full partition wall. One room is for mixed bed generation and another room for mixed bed exchangers and related pumps. The approximate area of acid/ alkali proof tiling is 17.0 m X 3.5 m.

RCC Foundation for 85 cum DM water storage tank and RCC covered underground neutralization pit of size 5.0m X 10.0m X 3.5 m depth shall be considered.

MCC Room 12.0mX7.0m of approximate height of 4.50m shall be provided at MB Area. This will be a single story RCC framed structure with brick in-fill wall approximately 4.50m height with RCC flooring, Steel Doors and windows, all-round PCC apron with open RCC drains.

6.1.5.10 Clarified Water Tank & Sludge Tank:

Clarified Water Tank & Sludge tank shall be RCC underground tank of size 17.0m X 8.0 m with height 5.8 m(approx) & 2.5m X8 m X 5.8m ( approx) respectively.

6.1.5.11 UF Product & Backlash Tank, RO-1 & 2 Permeate Tank and Reject Water Tank:

UF product & backwash Tank, RO-1 &2 permeate tank and reject tank shall be RCC above ground tank of size 17.3m X 8.0 m X 5.9 m ( approx) , 7.1m X8m X5.9m ( approx) and 12 mX8mX5.9 m ( approx)respectively.

Tank foundations in open area supported on RCC open foundation with all round PCC apron connected to open drain.

6.1.5.12 Potable Water Chamber

Potable Water Chamber shall be underground RCC tank of size 8 m X 8.0m X 5.8 m (approx) .

6.1.5.13 RCC Sedimentation Tank

RCC Sedimentation Tank shall be of RCC Construction . This is a over ground tank of size 8.0m X 4.0m x 3 m (Approx.)

6.1.5.14 Lime Stone Storage & Recharging Bldg:





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This will be a structural building with steel columns, structural roofing civil foundations and brick wall all-round with apron and drain. The size of the building of 15mX9m X10.5m ( bottom of monorail)

6.1.5.15 Intake Sump & Pump House Bldg:

Intake Sump & Pump House Bldg. shall be of RCC construction with approximate size of 21.00 m X 13.00m with bottom of Intake sump at (-) 6.50 m with a pump house size of 6.4m X 13m X 9.5 m (approx) at top with gantry arrangement with EOT crane and Hoist crane for Pump maintenance.

There will be an Electrical Building of size 15.0mX6.0m with approximate height of 4.5m. with a provision of VFD cum Switch gear room and Transformer room. This will be a single story RCC framed structure with brick in-fill wall approximately 6.50m height with RCC flooring, Steel Doors and windows, all-round PCC apron with open RCC drains.

6.1.5.16 RCC Channel Intake:

This will be RCC underground structure starting from Intake sump to a length of about 228.155 m towards sea side. Provision for necessary cofferdam, dismantling of existing shore protection & dredging of sporadic rock patches in the alignment of RCC channel shall be considered.

6.1.5.17 Plant Roads

4 m wide bituminous Plant road with 1.0 m wide berm on either side and drain arrangement along the road will be planned.

6.1.5.18 Plant Drains

Open rectangular RCC drains are planned for the plant and the township along roads. At road crossings, drains shall be taken through RCC box culverts. Discharge will suitably be connected to main outlet.

6.1.5.19 Pipe Supports

Pipe shall be laid over RCC saddle supports with open foundations.

6.1.5.20 Pipes Crossing Roads

Box culverts will be provided for road crossing of the pipelines.

6.1.5.21 Cable Rack





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RCC footings with open foundation shall be provided for cable rack supporting structures.

6.1.5.22 Laboratory

A dedicated lab facility with requisite testing equipment is envisaged for the plant.

6.1.5.23 Administrative Building (Size 20 m x 12m x 4m double storied):

Double storied RCC building with RCC frame, RCC roof and brick cladding, supported on pile foundations with RCC flooring, all-round PCC apron with open RCC drains.

6.1.5.24 Electrical Building (Size 110mx50mx6m three storied):

Three storied RCC building, with RCC frame and roof, brick cladding, supported on pile foundations with RCC flooring, all-round PCC apron with open RCC drains.

6.1.5.25 Anchor blocks:

Precast RCC anchor blocks for outfall pipeline approximately 1100 numbers of 3.8 ton each for outfall pipe.

6.1.5.26 Site leveling:

Cutting and filling considered, as the site is undulating, may be modified based on survey report.

6.1.5.27 Jungle clearance:

Jungle clearance considered as the site is covered with trees and bushes,.

6.1.6 Construction Aspects Well Point Dewatering may be required during construction of Intake Chamber & Potable Water Chamber due to high water table normally to the proximity of sea.

Locally available construction material such as sand, aggregate, brick etc. will be used for the construction work.

6.1.7 General Specification for Civil Engineering Works. a) RCC cast-in-situ construction for foundations & structures will generally be adopted. However, cover slabs for drain shall be of pre-cast construction wherever necessary.

Anchor blocks for the intake and outfall pipe shall be of pre-cast construction.

The following grades of concrete are considered.





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M-10 : For mud mat / mass filling under foundations

M-15 : Screed concrete

M-20 : For flooring and mass foundations.

M-30 : For general RCC construction & water retaining structures.

M-35 : For roads & precast anchor blocks.

b) Ordinary Portland cement conforming to IS: 12269 – 1987 & IS: 8112 – 1989 and Portland slag cement conforming to IS: 455 - 1989 considered for construction. Cement for precast concrete blocks considered is Portland slag cement conforming to IS: 455 - 1989 with 50% slag.

c) Steel for reinforcement bar will be either plain mild steel conforming to grade – I of IS: 432 - 1982 or high yield strength deformed bars conforming to IS: 1786 - 2008.

d) Brick works considered to be done with cement mortar and brick of best quality locally available bricks.

e) Storm water Drains considered are of RCC construction. Drains are considered both sides of roads, pavement yards & around buildings. At road crossings, drains are considered through RCC box culverts/pipe culverts. Discharge considered to be connected to rainwater harvesting/sea.

f) RCC roads are considered with PCC base, granular sub base. Shoulders with gavel fill, water bound macadam and precast kerb stone. RCC drains on both sides of roads.

6.2.1 General Schedule of finishes for all RCC Buildings:

a) General Points:

1) Apron of 1000 mm with drain of 300 mm with Ms/ RCC grating shall provided all around the building for plinth Protection.

2) PVC Rain water pipes of suitable diameter shall be provided at locations and quantity as per NBC guidelines with screed of slope 1:100

3) All windows shall have RCC chajja projections of minimum 600 mm depth. 4) The Canopy projections for doors except Main doors shall be minimum of 1200mm. 5) The canopy projection for main doors shall be minimum1500mm. 6) All the Ceilings except false Ceiling areas shall be coated with two coats of Acrylic oil

bound washable distemper of white shade.





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7) All window sill of Admin Building, Canteen Building, Control room, Laboratory, VFD Room, Visitors Meeting room, Shift In Charge room shall have 20 mm thick granite coping with bull nosing on exposed edges.

b) Staircase:

1) The Minimum width of stairs for any building shall be 1500 mm . 2) The size of tread shall be a minimum of 300 mm. 3) The riser height shall not exceed 175mm 4) Stainless Steel handrail of 50 mm diameter shall be provided over 1050 mm high

Mild steel grill works with 16 mm square rod of approved design. 5) The hand railing system for Admin Building staircase shall have 50 mm SS Handrail

with Stainless steel Baluster system and Stainless steel connecting rods.

c) Water Supply and Sanitary Fixtures:

All Sanitary fixtures shall be of approved make from Hindware / Parryware / jaquar or equivalent . One PVC water tank shall be provided at the terrace for supply of water.

All the waste water pipes shall be of Centrifugally Cast Iron type and water supply distribution pipes shall be Galvanised Iron Pipes. Gun metal valves of suitable diameter shall be provided at the inlet and outlet water supply pipes. Septic tank and soak pit of required capacity shall also be provided for the toilets.

d) Doors, Windows and Ventilators:

All doors, windows and ventilators shall be made of powder coated aluminium extrusions manufactured from Jindal/ Indal / Hindalco or equivalent manufacturers. The thickness of aluminum extrusions for frames shall be a minimum of 20 mm. All 2400 mm high doors shall have fanlight of 300mm and all windows of height 1500 mm shall have 300 mm fixed glazing at top. The shade of powder coating shall be as per the directions of the engineer in charge.

The Windows / Fixed Glazing provided in Control rooms and VFD rooms shall have double glazing reflective 6mm glass + 12 mm Air gap+ 6 mm glass as per Air conditioning Technical requirement.





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e) Water Proofing Treatment: The RCC roof of this building shall have 4 mm thick APP membrane as waterproofing membrane laid over cement screed sloped towards rainwater outlets. Water proofing membranes shall be extended till the top surface of parapet wall shall be continued to a minimum of 100 mm towards the external face of the parapet wall to avoid entry of rain

water through the roof/parapet joints.





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CHAPTER-7

STEEL STRUCTURAL WORKS

7.1 Design basis and General Considerations

Design of steel structures will generally be as per Indian standard IS 800 and local & state regulations governing such works.

7.2 Type of Construction

All steelwork will be of welded shop and site construction as far as practical except that site connections for secondary members like purlins, runners, rafter bracings, etc. will generally be of bolted construction.

7.2.1 Materials for Construction All structural steel plates up to and including 20 mm thickness will conform to IS :

2062 – 2006 , Fe 410WA, Grade A, and plates above 20 mm thick will confirm to Fe 410 WB OF IS:2062 –2006

Colour coated troughed steel sheets shall be used for roof & side cladding. These will be of hi-rib profiled colour coated galvalume/zincalume made of cold rolled steel of 550 MPA minimum yield strength conforming to ASTM A366 or AS 1595. Base metal thickness shall be 0.6mm and total thickness of colour coated profiled sheet shall be 0.68mm.

2 mm thk Translucent sheets shall be used on roof & sides at specified locations for natural lighting

Electrodes for mild steel will conform to IS 814 – 2004. The electrodes will be chosen according to the welding procedure to be adopted, and the quality of metal to be welded. The strength of the weld metal and of the parent metal will not be less than that of the parent metal.

Hexagonal head bolts will generally conform to the property class 4.6 as specified in IS 1367 – (Part 3) – 2002 unless otherwise noted.

Bolts and nuts of property class 4.6 will conform to IS 1363 Part 3, - 2002. Size of permanent bolts will not be less than 16 mm Minimum size of fillet weld will be as per recommendation of clause A – 2.1.8 of IS

9595 – 1996 except that leg size will not be lower than 6 mm. However for nominal fillet weld as required, for example, between chequered plates and their stiffeners or supporting members, the leg size will not be less than 4 mm.

7.3 Loads

7.3.1 Dead Loads





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Dead load on the structures will include self weight, weight of floor / roof materials including all other likely dead loads to be experienced by the structures during its lifetime and will be as per IS –875 (Part 1) - 1987

7.3.2 Live loads

The live loads will be as per IS –875 (Part 2)-1987.

7.3.3 Wind Loads

Wind Loads will be calculated as per IS 875 Part 3 – 1987 with parameters as follows:

1.1 Basic Wind speed: 44 metres/ second 1.2 Probability factor: 1.07 (for a mean probable design life of structure for

100 years 1.3 Terrain Category: 1.05 category 1 class ‘A’. 1.4 Topography factor: 1.0 1.5 Internal Pressure: As per clause 6.2.3.2 of IS 875

7.3.4 Seismic loads Seismic loads will be calculated as per provisions of IS 1893 – 1984,IS 1893 – PART 1-2002, IS 1893 – PART 4 –2005.

Zone: III

Basic Horizontal Seismic coefficient (Ah) will be as per clause no: 6.4.2

Other factors will be based on soil type.

Note: The design of structures will be done for either wind load or seismic loads. Both loads will not be considered to act at the same time.

7.3.5 Impact factors

For design of monorails: 1.25

For design of crane girders supporting EOT cranes above 10 tonnes capacity : 1.25

For design of crane girders supporting EOT cranes less than 10 tonnes capacity : 1.10

7.3.6 Load combinations

The worst load combinations due to dead load, live load, crane loads, equipment load, wind / seismic load, belt tension etc. will be considered as follows:





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Dead load + Live Load + Crane load + Equipment load

Dead load + Live Load + Crane load + Equipment load + (either wind or seismic Load)

0.8 x Dead Load + wind Load or 0.8 x Dead load + Seismic load for maximum uplift for foundation bolts only)

Equipment load and belt tension loads will be considered as separate load cases and considered in other combination of loads

7.4 Deflections

The deflection of various structural members will not impair the smooth working of building units and will not also not exceed the following limits:

Floor / Roof beams of buildings in general, and walkway beams of Galleries: Span /325

Floor beams directly supporting drive machinery, motor and gear boxes: Span / 500 Beams supporting brick walls: Span / 400 Monorail track beams: span / 500.

7.5 Fabrication, erection and inspection

Fabrication and erection will conform to IS:800, IS:7215, IS:7205 and other relevant standards referred to herein. Standard tolerances for fabrication and erection as set out in relevant IS codes will apply. Where no IS Standards exists, American, British or German Standards will apply.

All steel structural work will be subject to inspection by the owner/ engineer before erection. All butt welds will be tested ultrasonically. Additionally 2 % of the butt welds will be tested radio graphically.

7.6 Painting system

Surface preparation: Sa 2½ according to Swedish Standard SIS 055900

1 First Coat (Primer) : Epoxy Zinc phosphate

50 microns DFT





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2 Second Coat (Intermediate) : Epoxy polymide micaceous iron oxide 75 microns DFT

3 Third Coat (Finishing) : High Build Epoxy polymer

90 microns DFT

4 Fourth Coat (Finishing) : Epoxy polyurethene

35 microns DFT

Total Thickness : 250 Microns

Painting system conforming to IS: 2932-2003





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CHAPTER-8

PLANT ELECTRICS

8.1 INTRODUCTION:

Incoming power supplies for the proposed desalination plant shall be made available by

ONGC from the existing substation. The total estimated power requirement of the

proposed plant is approximately 5MW. For preliminary Power distribution network of the

proposed plant refer, Drawing No: MEC/23Q8/01/E1/D1/00/4001, Rev-01. Details of

source of incoming power supply for the main plant area & intake pump house are

indicated below:

a) Main plant area:

Incoming power supply for 6.6kV switchgear envisaged at electrical building of main

plant area shall be extended from existing 6.6kV switchgear of NBPH substation

which in turn is being fed from LPG-II substation situated at 1050Mtrs (approx.) away

through 3 runs (3Cx300) Sq.mm XLPE, Aluminium cable.

Additional VCB panel shall be provided on each bus section of existing 6.6kV

switchgear (totally 2Nos. similar to Jyoti power Ltd., make) of NBPH substation

including alignment of new VCB panel with existing Bus, interconnection with existing

bus supply & laying of power & control cables.

Additional No. of runs (3Cx300) Sq.mm 11kV (E), XLPE Aluminium cable as per the

voltage drop calculation (however minimum 2 run per feeder) shall be provided

between existing 6.6kV switchgear of LPG-II substation and NBPH substation. Cables

shall be laid in existing overhead cable trays /underground (at gas pipe line /road

crossings) as per site conditions. Accordingly cable trays shall be extended by

providing additional tier on existing overhead cable trestle. Existing supports/arms

shall be strengthened suitably.

6.6kV supply is further stepped down to 415V using 6.6/0.433kV transformer to meet

the LT power requirements of Desalination plant





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b) Intake pump house:

LT switchgear at intake pump house shall be provided with 2 incomers & buscoupler.

One incoming 415V supply for the above LT switchgear shall be made available

through 6.6/0.433 kV, 630kVA transformer which in turn is sourced from spare motor

feeder panel of existing 6.6kV switchgear at LPG-II substation. Spare motor feeder at

existing 6.6kV switchgear of LPG-II substation shall be converted into a transformer

feeder with necessary modifications. Numerical relay (similar to model no. ARGUS-1

DCD 424C of easun Reyrolle make) shall be provided for the same including supply&

installation of CT of proper ratio inside the 6.6KV panel, supply & laying of 2 Runs

(3Cx240 Sq.mm), 11kV (E) XLPE, Aluminium power and12Cx1.5Sq.mm &

3Cx2.5Sq.mm 1.1kV grade, XLPE Copper control cables.

Second 415V incoming supply shall be extended from existing 415V spare breaker

panel at 13-1F1 of C71/72 MCC of LT substation. Retrofitting of the panel shall be

made with ACB having microprocessor based releases (similar to Seimens make,

ACB model no. 3WL I 1600A with release ETU27B). Also suitable size 1.1kV grade,

XLPE Aluminium Power cable of proper size as per Electrical Design Basis & 12Cx

1.5 Sq.mm, 1.1kV grade, XLPE Copper control cables shall be supplied & laid for

the same.

Incoming cables shall be laid in overhead trays to the extent possible. Hume pipes /

culverts shall be provided at road crossings. Supply & installation of the cable tray

shall be in bidder’s scope.

8.2 APPLICABLE STANDARDS :

Design of the electrics for the Plant shall comply with IE Rules, BIS and safety

standards as per OISD norms.

8.3 POWER DISTRIBUTION SYSTEM:

The design of power distribution system and selection of equipment shall be based

on the main consideration of simplicity, safety and reliability, ease of operation &

maintenance. 100% redundancy is envisaged in the power distribution system to

provide continuous and reliable operation.





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The equipment shall conform to relevant IS/IEC specifications and codes of

practice to meet the operational requirements and to ensure reliable and safe

operation. Generally, all electrical equipment shall be of type tested design.

8.4 DESIGN PARAMETERS :

S.No Description

1. Ambient temperature for design 40 deg C

2. Height above MSL less than 1000M

3. Incoming Power supply 6.6kV, 3ph, 50Hz

4. Utilisation Voltage 415V , 3 ph, 50 Hz

5. Permissible variations:

a) Voltage b) Frequency c) Combined Variation

+6% , -6%

±3%

Any combination of above

6. Control power supply:

a) AC b) DC

240V, 1 ph,50 Hz

110V supply through Battery and DCDB fed for HT Switchboard

7. Illumination voltage 240V, 1 ph,50 Hz

8. System earthing:

a) 6.6 kV b) 415V

Resistance earthed

Effectively earthed

9. Maximum Symmetrical Short Circuit level considered for the system:

a) 6.6kV bus b) 415V bus

40KA for 3 sec

63kA for 1 sec

10. Cable sizing Based on Rated current carrying capacity, derating factors, short circuit capacity, Voltage drop etc.





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11. Internal Illumination Suitably rated 433/415 V isolation transformer shall be considered to feed lighting loads through MLDB, LDB, SLDBs.

Flameproof fixtures /lamps shall be considered suitable for Gas group-IIA,IIB as per requirement.

12. External Illumination Street lighting fixtures shall be provided with MH lamps suitable for gas group IIA/IIB as per requirement

13. PLC Power Supply 110V, 1 Phase, 2 Wire, 50Hz A.C – UPS

14. Earthing System To comply with IS 3043

15. Lighting protection system To comply with IS 2309

16. Critical lighting of switchgear & control room.

Through DC system

Major electrical equipment considered essential for the smooth and safe

operation:

6.6kV switchboard

6.6/0.433kV distribution transformers catering to 415V loads.

6.6/0.72 kV converter duty transformers catering to process VFDs.

415V and 690V Variable frequency drives

Flame proof LT motors suitable for zone 2

and Gas group IIB and IIC environment as per requirement.

Inverter duty motors

415V and 690V switchboards (PCC, PMCC, MCC, PDB,AC DB)

Internal & external Illumination through Lighting distribution boards

being fed from 433/415V lighting transformers.

HT/LT power & control Cables and accessories

LT capacitor bank for Power factor improvement.





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Earthing and Lightning Protection Systems

Refer drg no : MEC/23Q8/01/E1/D1/00/4001 for the overall power distribution

scheme.

8.5 6.6KV SWITCHBOARD:

6.6kV switchboard shall be located in substation building near main plant pump

house.

The 6.6 kV switchgear shall be of type tested design, indoor, sheet metal clad,

horizontal draw out type, with Vacuum circuit breakers, in IP 4 X enclosure,

suitable for short circuit current of 40 kA ( 3 sec) and 800A rated current as

required for the project. The switchgear shall be provided with aluminium/copper

busbars.

The protection for various feeders shall be achieved through numerical relays.

The switchgear shall be provided with necessary control gear, metering and

audio-visual alarm annunciation system.

Quantity : 1 set

8.6 DC SYSTEM:

DC system consists of one no float and one no float cum boost charger, battery

bank & DC distribution board in sheet metal enclosed, multi-tier,

compartmentalized design with enclosure class of protection IP-42.

One battery bank comprising of 55 cells of tubular SLA batteries is envisaged as

DC source.

DC distribution board distributes DC control supply to 6.6 kV switchboards.

Quantity: 1 set.

8.7 DISTRIBUTION TRANSFORMERS:

6.6kV power supply received from nearby existing substation shall be stepped

down to 415V using 6.6/0.433kV, three phase dry cast resin type, indoor

copper/aluminium foil wound distribution transformers. The insulation class of the





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transformers shall be Class F restricted to Class B. Degree of enclosure

protection shall be IP-3X.The transformer shall be provided with Cable Boxes

with disconnecting chamber on HV and Cable Box with disconnecting chamber /

Busduct flange on LV side depending on the KVA rating of the transformer.

Core shall be made up of stacked laminations of low loss CRGO silicon steel

sheets with lamination thickness not exceeding 0.3 mm.

Off circuit tap-changer with rotary tap switch shall be provided for distribution

transformers. The range of variation shall be +5 % to -5 % in steps of 2.5 % each.

Bushings shall be suitable for atmosphere present in the place of installation.

Total creepage distance shall not be less than 25 mm/kV of highest system

voltage.

Clearances in air between live conductive parts and live conductive part to

earthed structure shall be as per CBIP manual for transformer.

The transformer design shall ensure that the efficiency of transformers is

compliant with CBIP Guidelines for energy efficient transformers .

Quantity:

Intake pump house:

6.6/0.433 kV, 630kVA distribution transformer - 1 No.

Substation near Main plant pump house:

6.6/0.433 kV, 2500kVA distribution transformer- 2 Nos.

8.8 CONVERTER DUTY TRANSFORMERS:

6.6kV power supply received from nearby existing substation shall be stepped

down using 6.6/0.72kV, three phase dry cast resin type, indoor copper/aluminium

foil wound distribution transformers. The insulation class of the transformers shall

be Class F restricted to Class B. Degree of enclosure protection shall be IP-

3X.The transformer shall be provided with Cable Boxes with disconnecting





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chamber on HV and Cable Box with disconnecting chamber / Busduct flange on

LV side depending on the KVA rating of the transformer.

Core shall be made up of stacked laminations of low loss CRGO silicon steel

sheets with lamination thickness not exceeding 0.3 mm.

The converter transformers shall be designed to take care of harmonic currents

generated by the downstream systems as well as to minimize noise, heating and

vibration. Electrostatic shielding shall be provided between the primary and

secondary windings.

Off circuit tap-changer with rotary tap switch shall be provided for distribution

transformers. The range of variation shall be +5 % to -5 % in steps of 2.5 % each.

Bushings shall be suitable for atmosphere present in the place of installation.

Total creepage distance shall not be less than 25 mm/kV of highest system

voltage.

Clearances in air between live conductive parts and live conductive part to

earthed structure shall be as per CBIP manual for transformer.

The transformer design shall ensure that the efficiency of transformers is

compliant with CBIP Guidelines for energy efficient transformers .

Quantity:


6.6/0.72 kV, 3150kVA converter duty transformer- 2 Nos

8.9 LT BUSDUCT:

LT Busducts shall be 415V/ 690V rated, non segregated phase type, with 3 mm

thick aluminium enclosure, aluminium conductor of grade 63401-WP II bus duct

for interconnection between 6.6/0.433kV transformer, 6.6/0.72kV transformer &

respective LT Switchboards envisaged at switchgear room for transformers rated

1000KVA & above.





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The enclosure class of the bus duct shall be IP 54/55 for indoor/outdoor areas

respectively. Standard accessories shall include rubber elbows, vertical and

horizontal bends, transformer and switchgear lead-in sections, etc.

8.10 LT SWITCHBOARDS (PCC/PMCC/MCC):

The LT switchboards shall be in draw out, single/double front, multi tier,

compartmentalized, type tested design and shall be fabricated from sheet steel

with 2 mm thickness for load bearing members and 1.6 mm thickness for non-

loading bearing members.. The enclosure class shall be IP 42 or better. The form

of construction shall be 3b as per IS 8623.

LT switchboards shall comprise of 3 pole air circuit breakers at the incoming

feeder and TP ACB/MCCBs as outgoing feeders as per respective SLDs.

The ACBs shall be provided with microprocessor based releases with LSIG

features. The ACBs shall be provided with electrical and mechanical anti-

pumping interlocks. The ACBS shall be of motorized spring charged, stored

energy operating mechanism.

Motors of rating below 90kW shall be controlled from MCC through MCCB /

MPCB and contactors.

Motors rated 90kW & above shall be controlled from PMCC through ACB feeders

with comprehensive motor protection relay.

Three phase and neutral main busbars shall be provided in a separate

compartment running at the top. Vertical busbars shall be provided for the

outgoing feeders and they shall be either in a separate compartment or shall be

suitably shrouded. Main busbars shall be of Aluminum grade 63401-WP II. In

addition, earth busbar of Aluminium of cross section not less than 300 sq mm

shall be provided running through out the length of the switchboard.

Automatic Power factor improvement capacitor banks with APFC (Automatic

power factor compensation) feature shall be provided in PMCC for achieving 0.95

PF (lag).





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690V PCC at substation building near main plant pump house to feed power

supply to the First pass RO high pressure pump VFDs.

415V PCC at substation building near Intake Pump House is envisaged to feed

power supply to the LT loads/VFDs.

415V PMCCs at substation building near main plant pump house is envisaged to

feed power supply to Motor control centre/power distribution boards/ large motors

as per requirement.

Quantity :

Substation near Intake pump house:

415V Power control centre (PCC) - 1 No.


690V Power control centre (PCC)- 1 No.

415V Power cum motor control centre (PMCC)- 1 No.

415V Motor control centre (MCC)- 1 No.

MCC room near MB area:

415V Motor control centre (MCC)- 1 No.

8.11 MOTORS:

415V AC motors shall be provided as per system requirement.

Motors shall be preferably squirrel cage induction type.

690V Motors for high pressure RO pumps shall be controlled through VFD fed

from converter duty transformers as per standard design of the manufacturer.

Inverter duty motors shall be provided for all VFD operated motors.

All motors shall be flame proof type suitable Zone-2 & gas group-IIA and IIB.

8.12 HT/LT CABLES:

11 kV (E) cables for the 6.6 kV system shall be heavy duty type with stranded,

shaped circular, compact, Aluminium conductor, XLPE insulated, conductor &





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insulation screened with combination of extruded semi-conducting compound and

annealed copper tape, PVC type ST2 extruded inner and outer sheathed,

galvanised Steel Strip (Single Layer) armoured conforming to IS-7098 Part-2.

6.6kV cable shall be unearthed type suitable for resistance earthed system

LT power and control cables shall be 1100 V grade, heavy duty,

aluminium/copper conductor, multi core, XLPE insulated, galvanized steel

strip/round wire armoured, extruded PVC type ST-2 inner and outer sheathed

type conforming to IS-1554. LT power cables shall be provided with aluminium

conductors for cross sectional areas greater than 10 sq mm and with copper

conductor for cross sectional areas of 10 sq mm or lesser . The control cables

shall be provided with copper conductor having cross sectional area of 1.5 sq

mm; cables for CTs shall be 2.5 sq mm. Colour coding shall be acceptable for all

cables up to 5 cores. Cable with more than 5 cores shall have Hindu Arabic

numerals printed on each core. The printing shall be reversible. Spare cores shall

be provided for all control cables as below:

Up to 5 core cables : 1 core

7 Core and 10 Core cables: 2 cores

14 Core to 19 Core cables : 3 cores

Greater than 19 core cables : 4 cores

The power cables shall be sized taking into account the derating factors

applicable for ambient temperature, grouping factor, voltage drop considerations,

short circuit withstand capability etc.

8.13 CABLE CARRIER SYSTEM:

FRP / GRP cable Trays shall be provided.

Cable trays shall be of prefabricated ladder type and with associated accessories

such as coupler plates, tees, elbows, etc.,

Hardware (bolds, nuts, washers, coupler plate etc,) used for the cable trays shall

be stainless steel grades.

8.14 ILLUMINATION :





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The design of the lighting system shall be in accordance with relevant IS

standards and suitable energy saving light fixtures for buildings are considered.

For supply of various illumination loads, main lighting distribution boards (MLDBs)

have been considered. The power supply for the MLDBs shall be fed from the

433/415V isolation transformers.

LDBs/SLDBs shall be installed in respective area to feed lighting loads.

8.15 MAIN LIGHTING BOARDS/ LIGHTING BOARDS /SUB LIGHTING BOARDS:

The MLDBs shall be in sheet steel enclosed, multi tiered, and compartmentalized

design with separate compartments for each feeder in floor mounted free

standing design. The incoming feeder shall be 4 pole MCCB and the outgoing

feeders shall be 4 pole MCCBs/ MCBs as per requirement.

The MLDB shall be provided with TPN aluminium busbars in separate

compartment.

The LDB/SLDBs shall be in sheet steel enclosed, compartmentalized design

suitable for wall/structure mounting.

Critical lighting system:

Critical lighting at electrical premises shall be provided through DC system.

8.16 AREA AND ROAD LIGHTING

Area lighting is envisaged using feeder pillars and steel tubular street lighting

poles with MH lamps .

8.17 CONTROL OF LIGHTING CIRCUITS

Automatic switching ON/OFF of external area lighting shall be done through

programmable astronomical switches & contactors.

8.18 LUMINAIRE:





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All luminaires shall be flameproof suitable for gas group-IIA/IIB environment.

Luminaires shall be integral type including electronic ballast and power factor

correction capacitor to improve PF upto 0.95.

Live parts shall be provided with suitable shrouds to prevent accidental contacts.

8.19 EARTHING :

Earthing system shall be designed in accordance with the provision of IS 3043 –

1987. The type of earthing system foreseen is TN-S. The design of protective

earth conductors shall be done for 50 kA considering a fault clearing time of 1

second.

The resistance of earth grid shall be less than 1 ohm.

Parts of all electrical equipment and machinery not intended to be alive shall

have two separate and distinct earth connections.

All joints of bare earth strips shall be welded / braced to form a rigid earthing ring.

All the earth electrodes in the site will be interconnected by galvanized strip

earthing conductors buried directly in ground. In switchgear rooms earthing flats

will be run along walls, column, horizontal and vertical structural members using

clamps.

8.20 LIGHTNING PROTECTION :

The design of the lightning protection system shall be in accordance with IS:

2309-1989.

All buildings and structures vulnerable to lightning strokes owing to their height or

exposed situation or conditions of use shall be protected against atmospheric

flash-overs and lightning strokes.

The system shall consist of air terminations, horizontal roof conductors, down

conductors and earth pits. Down conductor shall have a testing point adjacent to

the earth electrode. Each down conductor shall be terminated to individual earth

pit. All earth termination shall be interconnected. The lightning protection system

pits shall be further interconnected to the plant earthing system.





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8.21 SUBSTATION LAYOUT CONSIDERATIONS:

The layout of the substations shall take into account the requirements of IE

Rules, Indian Standards, manufacturer’s recommendations and Codes of

Practice.

The electrical building shall be of RCC construction with brick masonry walls. The

switchgear room shall be provided with fire resistant doors to meet 2 hour rating.

The windows and frames shall be of steel construction.

For all electrical equipment minimum clear head room of 500mm shall be

provided inside the substation.

Clearances considered shall be as follows while planning equipment layout in the

substation:

i) Two switchboards facing each other. 2000 mm

ii) Between front of switchboards to wall of

the room

2000 mm

iii) Between two switchboards installed in a

row

1000 mm

iv) Back to back clearance Between Two

switchboards

1000 mm

v) Back of one switchboard facing front of

another switchboard

2000 mm.

vi) Clearance between the bottom of the

ventilation duct and top of the electrical

equipment

500 mm.

vii) Clearance between switchgears to wall 1000mm





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viii) Top of switchgear 500 mm

ix) Between two battery banks facing each

other.

800 mm





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CHAPTER-9

INSTRUMENTATION AND AUTOMATION

9.1 Process Control System Overview

The Instrumentation & Process Control system shall be designed for safe, reliable, efficient and smooth operation of the plant and its associated auxiliaries with minimum intervention of the operating personnel during normal working of the plant.

A latest state of art PLC system is envisaged for plant monitoring and control. The PLC system shall be Safety Integrated Level-3 (SIL3) and shall be redundant. SIL-3 is adopted to reduce the failure rate and redundancy is adopted to increase the availability of the control system. The PLC shall have hot redundancy in processor, power supply, communication modules and communication networks. Redundant modules shall be installed on a different rack in the panel. All IOs shall also be redundant.

For automation of the plant, three sets of redundant SIL-3 PLCs are envisaged. Process Safety, sequencing, process protection shall be implemented in one PLC, VFD control & protection in another PLC and process control & monitoring through another PLC.

Each PLC receives the field signals and performs the necessary interlocks, protection, sequence and control operations. Both the PLCs shall be networked on redundant communication link and communicate with each other for necessary interlocking, between the areas.

The plant shall be operated and controlled from PLC with all closed-loop set in auto-mode. Sequencing, interlocking and logic functions shall be implemented in the PLC.

Operation of entire plant shall be from the Desal Plant Control Room. The Desal Plant Control Room shall be located on the first floor and annexed to the UF RO premises. The control room shall have aluminum-glazed partitions to install the PLC, UPS, HMI stations and other associated equipment. The control room shall be air-conditioned. The console desks shall be with aesthetic arrangement and orientation in the control room.

The field IOs shall be brought to the control room and interfaced to the PLC through the local junction boxes and marshalling rack, segregating analog and digital signal. In normal operating conditions the plant shall be operated and controlled from PLC with all closed-loop set in auto-mode. Sequencing, interlocking and logic functions shall be implemented in the PLC. The control system shall have provisions to allow





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the operator interventions such as change-over of stream, valve operations, etc. from the control room.

RIO units are envisaged in the electrical room of intake pump house. The field signals associated to the intake area shall be connected to these RIO units. The RIO shall be on redundant link to the PLC using optic fiber cable.

Operator’s interface to the plant and process is through PC based Human Machine Interface (HMI) stations. HMI stations will comprise of 4 Nos. Operator Workstations & 3 Nos. Engineering Workstation (1No. for each PLC), 1 No. Sequence of Event (SOE) station for VFD control PLC, 2nos. of 72” large video screen for monitoring process alarm and consequent corrective action. HMI stations shall be located in the Desal Plant Control Room. Engineering stations and SOE station shall be located in the Engineering Room within the Control Room. Rooms shall have provision of sitting arrangement, at for engineers and operators within the control room.

Additionally 1 No. HMI station shall be installed at existing main C2C3 Control room providing the facility to monitor the Desal Plant parameters. The C2C3 control room and Desal Plant control room are about 2km distance and linked using optic fiber cable. The existing route facilities & structures shall be used to lay the connectivity cable.

The HMI stations shall have latest Windows operating system. All software supplied with the HMI station shall be with license. Demo version software is not accepted. Driver software of all supplied printers shall be provided. License key for PLC diagnosis and modification in block/element/ladder/ logic also to be provided.

The power supply to the PLC, workstations, field instruments shall be through UPS. The UPS shall be parallel redundant load sharing mode of sufficient capacity with PDB. Panels of PLC, UPS, DB shall be similar to electrical panel.

The motorized valves shall be interfaced to the PLC on Modbus / Profibus communication link through data concentrator / master station for operation and control.

Numerical relays and multi-function meters in switchgear and MCC shall be interfaced to the PLC on Modbus / Profibus communication link for recording the parameters.

VFD shall be interfaced to the PLC on Profibus communication link for recording the parameters. However the control and feedback signals shall be on hardwired IOs.

The measurements, controls and protections envisaged for the plant are indicated in P&IDs.





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Earthing for the system shall be as per IS: 3043. Protective Earthing and Technical Earthing are envisaged for the Process Control System.

Safety barriers shall be with one input and two output type for proper isolation between hazardous and non-hazardous area for analog loops. In case of digital signals intrinsically safe barriers shall be provided. Control output to input shall also be through safety barrier. All barrier shall be active type.

Switches are derived from transmitters. Safety interlocks shall follow 2-out-of-3 logic.

9.2 Field Instrumentation

Transmitters shall be 2-wire type with built-in digital indicators calibrated in engineering units and shall have 4-20 mA DC output, SMART/ HART.

Magnetic flow meters shall be 4-wire with remote transmitters.

Temperature transmitters shall be used for RTD type temperature measurement.

Level Transmitter shall be Radar / Ultrasonic / DP type and shall have separate LCD display as field indicators, if required.

The wetted parts of the instruments shall be best suited to the process fluid, which shall be corrosion resistant.

Instruments shall be designed for continuous operation in dusty, wet atmosphere containing grit and micron size dust particles. Enclosure shall be IP-65 or better and shall be weatherproof and corrosion resistant. Field Instruments shall be IP65 or better. Transmitter shall be IP66 or better.

Analyser shall be intelligent microprocessor based, online sampling type with 4-20mA output. Analyser shall have calibration facility from the front panel. Self diagnostics features provide the status and fault indications.

All field transmitters, like pressure / level / temperature / flow etc. shall be intrinsically safe for gas group IIa/IIb or class I Div I group C& D hazardous area.

Analysers and Junction boxes shall be of flame proof suitable for gas group IIa & IIb. SOV shall be flame proof suitable for gas group IIa & IIb.

The pneumatic operated Control valves shall be complete with pneumatic actuator and accessories such as SMART electro-pneumatic positioner with position feedback, air filter regulator with pressure gauges, hand wheel, etc.





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The pneumatic operated On-Off valves shall be complete with pneumatic actuator and accessories such as solenoid valve, position switches, air filter regulator with pressure gauges, hand wheel, etc.

Electric actuators shall have inbuilt position switches, torque switches and shall be used for On-Off purposes only. Electric actuators shall be flame proof suitable for gas group IIa & IIb.

The Control valve / On-Off valve on failure shall move to safe position as per process requirement.

Impulse tubing to the instruments shall be of Duplex SS 2507 material. Pneumatic tubing to the valves shall be of Duplex SS 2507 material.

Signal cables shall be individually & overall screened and single pair cable shall be 1.0 mm2 and multi-pair cable shall be 0.75 mm2. Control cable shall be 1.5 mm2 and Power cable shall be 2.5 mm2. All field cables shall be armoured. Cable shall be laid through trays. Conduits shall be used if required.

9.3 Telephone Network

In the Desal Plant, Telephone Network is envisaged for communication. Telephone network of the Desal Plant covers telephones with associated cables and telephone JBs only. The Desal plant Telephone network shall be linked to the Uran Plant EPABX System.

The Uran Plant EPABX system is located at 1st floor of Old Fire Station. From the existing MDF of EPABX system, armoured PIFJ telephone cable shall be laid to the Desal Plant for Plant Telephone Network.

Telephones are envisaged in the manned Electrical premises of MB Area, Intake Area, Main Electrical Building and Control Room.

PIJF Telephone cables shall be of size 0.63mm, Armoured and shall conform to DOT/TEC specification GR/CUG-01/03 Aug 2003 with latest amendment.

PVC Insulated, PVC Sheathed Telephone Cable shall be of size 0.5mm and shall conform to DOT/TEC specification no: GR/WIR 06/03 dated March 2002 with latest amendment.

9.4 Fire Detection and Alarm System

Fire Detection and Alarm system is envisaged in the electrical premises of MB Area, Main Electrical Building and Control Room.





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Fire Detection and Alarm system detects and alerts people through audio appliances when smoke/fire is present. These alarms are activated from smoke detectors or heat detectors which are automatic or from a manual fire alarm pull station.

The FDA system shall include the following:

* Microprocessor based intelligent addressable Fire Alarm Control Panel * Smoke Detector / Heat Detector / Combo Detectors. * Manual call points * Hooters * Fault Isolation Modules * Operator HMI Station * Associated cables

The stand alone Fire Alarm Control Panel shall be located in the Control Room of Desal Plant. Fire Alarm Repeater Panel shall be installed at the existing main C2C3 Control room and at the New Fire Station. The panels shall be linked using optic fiber cable.

The distance between Desal Plant control room to New Fire Station through C2C3 control room is about 3km. The existing route facilities & structures shall be used to lay the connectivity cable.





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CHAPTER-10

FIRE FIGHTING FACILITIES

10.1 General Some of the working premises of the proposed Desalination Plant have hazardous and fire prone environment. To protect the working personnel, equipment and machineries, adequate safety and fire fighting measures have been planned for the proposed 20 MLD desalination plant

10.2 Design Basis For Fire Fighting System In order to combat any occurrence of fire in plant premises, the following fire protection facilities have been envisaged for the various units of the plant.

Fire hydrant system Portable fire extinguishers Personal safety appliances

Extension of fire hydrant network including associated valves and pipes, electrics are envisaged for fire hydrant system.

All plant units, office buildings, stores, laboratories, etc will be provided with adequate number of portable fire extinguishers to be used as first aid fire appliances.

To protect the working personnel, equipment and machineries, adequate safety and fire fighting safety appliances have been planned for the proposed Desalination plant.

10.3 Fire protection facilities

In order to combat any occurrence of fire in plant premises the following fire protection facilities have been envisaged for the various units of the plant.

Fire hydrant system Portable fire extinguishers Industrial safety equipments

10.3.1 Hydrant system A fire hydrant network system has been envisaged for the plant. Internal hydrants will be provided at suitable locations and at different levels inside the major plant units. Yard





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hydrants will be provided normally along the road and in the close vicinity of the units to meet the additional requirement of water for extinguishing fire. Hydrant system shall have dedicated pump house, pumps, water storage and piping network etc.

10.3.2 Portable fire extinguishers

All plant units, office buildings, stores, laboratories, etc will be provided with adequate number of portable fire extinguishers to be used as first aid fire appliances. The distribution and selection of extinguishers will be done in accordance with the requirement of Bureau of Indian Standard: 2190-92.

10.4 Industrial safety To protect the working personnel, equipment and machineries, adequate safety and fire fighting measures have been planned for the proposed Desalination plant.

10.5 Safety of personnel

All workmen employed in hazardous working conditions will be provided with adequate personal safety appliances like

Safety Shower Safety helmets Self contained Breathing Apparatus Hand gloves Stretcher First Aid Box Fire suit Respirators Explosimeters





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CHAPTER-11

HOISTING AND HANDLING FACILITIES

Following are the material handling systems envisaged:

1. Limestone recharging system 2. One no. 7.5T electric hoist in RO building 3. Two no. 5T electric hoist RO building 4. One no. 2T electric hoist RO building 5. One no. 6T electric hoist intake pump house 6. One no. 6T x ~7m span under slung EOT crane in intake sump 7. One no. of 8 passenger lift in the electrical building.

11.1 Limestone recharging system:

A Limestone recharging system is envisaged for charging lime stone into the system. The above system consists of the following equipment:

a. Main Loading hopper b. Isolating valve below the main loading hopper c. Two way diverting chute with gate d. Screw conveyors e. Filling hoppers f. Inter connecting chutes g. Dust extraction system for main Loading Hopper h. Structural supports for hopper/equipment, platform, ladder, etc. Equipment in Limestone recharging system shall be designed considering the following characteristics of Limestone: a. Particle size : 2 – 5 mm b. Bulk density : 1.45 t / cu.m c. Moisture : 0.3% (approx.) Brief technical parameters of various equipment envisaged in Limestone recharging system are as follows:

Sl. No. Equipment Description Eqpt. No. Technical details Qty. (Nos.) 1. Main Loading Hopper LH-01 ~5.1 cu.m steel hopper 1

2. Isolating Valve IV-01 ---- 1

4. Two Way diverting chute with gate

DG-01 ---- 1

3. Screw Conveyors SC-01 & 02 5 t/hr. & ~ 4.0 m long 2





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5. Filling hoppers FH-01 & 02~0.38 cu.m steel

hopper 2

6. Inter connecting chutes CH-01 --- 1 Lot

7. Dust extraction system for main loading hopper

DE-01 To suit the system

requirement 1 Lot

The general arrangement of Limestone recharging system is shown in the enclosed drawing no. MEC/23Q8/01/17/D3/00/00/7001/R0/A2. The limestone bags received by trucks will be unloaded and stored in Limestone Recharge System building. These bags will be lifted using an electric hoist and unloaded manually into main loading hopper. Limestone from main loading hopper will be fed to any one of 2 nos. screw conveyors through a two way diverting chute with gate. Screw conveyor will discharge Limestone into filling hoppers. Limestone from the above hoppers will be fed to Lime stone ejector for further conveying into the system. A dust extraction system is envisaged for the main loading hopper. A control panel will be provided for operation of the dust screw conveyor, motorized diverting gate, extraction system, etc.

11.2 Cranes and hoists:

One no. 6T under slung EOT crane is envisaged in intake sump for handling stop logs and trash racks.

Electric hoists of various capacities are envisaged in RO building and intake pump house for handling of pumps, motors, etc.





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CHAPTER-12

LABORATORY

12.1 INTRODUCTION

The laboratory will cater the need of chemical analysis of water. Equipments like Ph meter, temperature gauge, ORP meter, TDS meter, pipettes, etc. are proposed The laboratory equipments are housed in a building measuring 15m X 6.5 m x4m . The equipments proposed are listed in the table-1.

Table-1. List of Laboratory Equipment

SL No

Equipment Qty

1. Surface temperature and dew point measuring gauge 1

2. Digital hygrometer 1

3. Hot plate –2kw 1

4. Digital p H meter 1

5. Digital conductivity meter 1

6. Chlorine analyzer 1

7. ORP meter 1

8. Turbidity meter 1

9. Silt density measuring kit 1

10. Salinity measuring instrument 1

11. Drying oven 1

12. TDS meter 1

13. Microscope 1

14. Laboratory flocculator 1

15. Portable autoclave 1

16. Colony counter 1

17. Colorimeter 1

18. Colorimeter Comparators 1

19. Digital Electronic Chlorine residual meter 1





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20. Electronic Physical balance 1

21. Portable pipe corrosion meter 1

22. PC System with software & hardware, Printer and LAN facilities for lab data entry ,storage, Communication with centralized communication.

1 set

23. Laboratory furniture including

Instrument table , work desk ,vertical drawer cabinet, anti vibration table glass ware drying table, tall cabinet, trolleys 2 each

Revolving chair 8 nos

Computer table and chair 1 set

24.

Laboratory glassware full set (like aspirator bottle, burette, conical flask, pipette ,test tube, measuring flask, glass dishes, bottles, Funnel, beaker, pipette stand, tripod stand, wire gauge, porcelain crucible, Bunsen burner, test tube holder, burette clamp, vacuum pump etc –50 Nos.each)

5 LOT

25. Atomic absorption spectrometer 1 no

26. Ion analyser 1 no

27. True double beam UV-visible Spectrophotometer 1 no 28. Total Organic Carbon Analyser 1 no. 29. BOD Analyzer 1 no. 30. COD Analyzer 1 no.





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CHAPTER-13

AC & VENTILATION FACILITIES

13.1 Air-conditioning Facilities

13.1.1 Air-conditioning facilities are envisaged for electrical premises to remove heat generated from panels & to maintain design requirement for efficient functioning of electrical equipment.

13.2 The design basis for calculating the Air-conditioning System capacities are as given below:

i. Outdoor design conditions

Season DB (0F)* WB (0F)* RH (%)*

Summer 95 83 60

Monsoon 85 82 88

Winter 65 58 65

* As per ISHRAE Handbook

ii. Inside design conditions to be maintained

Temperature (0C) : 23 + 2

Relative humidity (%) : 55 + 5

Filtration : 90% down to 10 microns

13.3 The capacity of Air-conditioning (AC) system shall be arrived based on equipment heat loads, sensible heat loads, latent head loads, lighting loads etc. The selection of AC units depends on the specific requirement of cooling capacity, temperature,





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humidity and freedom from dust. The capacity of the equipment selected shall be 20% more than the calculated capacity.

13.4 Air-conditioning system considered for various premises are as detailed below:

Sl. No.

Premises Equipment Proposed

1 VFD Room at Main Plant Electrical Building

Air-cooled Precision Type Air-conditioners

2 VFD cum Switchgear Room at Intake Pump House

Air cooled VRF type System, Ductable IDUs

3 Control Room & Laboratory Air cooled VRF type System, Ductable IDUs

4

Visitors Room, Officer (Mech) Room, Officer (Elec) Room, Officer (Inst) Room, Plant in-charge Room & Meeting Room in Administration Building

Air cooled VRF type System, Cassette type Split IDUs

13.5 VENTILATION FACILITIES

13.5.1 Pressurized Ventilation / Exhaust Ventilation facilities are envisaged for the premises as per design requirement for efficient functioning of electrical equipment.

13.5.2 The design basis for calculating Ventilation Systems are as given below:

i. Pressurized Ventilation Systems

Temperature : Inside design temperature shall not exceed more than 5°C over and above the prevailing ambient temperature.

Pressure : Positive Pressure of minimum 3 mmWc shall be maintained inside the premises.





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ii. Exhaust Ventilation Systems

Temperature : Not more than 50C rise above ambient temperature (maximum) shall be maintained.

13.5.3 The capacity of Ventilation systems shall be arrived based on equipment heat loads, lighting loads etc. or based on minimum 20 air-changes, whichever is higher. The capacity of the equipment selected shall be 20% more than the calculated capacity.

13.5.4 Ventilation Systems considered for various premises are as detailed below:

Sl. No.

Premises Equipment Proposed

1 Mixed Bed Regeneration Room at DM Water Plant Building

Propeller type Exhaust Fans

2 Mixed Bed Room at DM Water Plant Building

--- do ---

3 Pump House at RO/UF Building --- do ---

4 RO/UF/DF Skids House --- do ---

5 Chemical Building --- do ---

6 Intake Pump House --- do ---

7 MCC / Electrical Room at MB Area --- do ---

8 Cable Cellar at Main Plant Electrical Building

--- do ---

9 Battery Room at Main Plant Electrical Building

--- do ---

10 Switchgear Room at Main Plant Electrical Building

Ventilation AHU with centrifugal Fan, Filters, ducting, electrics, etc.





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13.6 DUST EXTRACTION SYSTEM

13.6.1 Dust Extraction System is envisaged to remove the dust generated during transfer of limestone into the Hopper thereby eliminating the flying dust & dust accumulation on the surrounding parts of the Hopper area / premises.

13.6.2 Cassette type Bag Filter with necessary ducting / stack, ID Fan (Centrifugal Fan), instruments, support structures etc have been considered for completing the system.

13.6.3 De-dusting System is considered for the following area:

Sl. No.

Premises System description

1

Limestone Recharging System:

Limestone Hopper

Dust Extraction system with Cassette type Bag Filter, ID Fan, support structures, instrumentation and Electrics including Cabling, Earthing, Controls etc.

13.7 LIST OF CODES & STANDARDS

All equipment, systems and works for air conditioning & Ventilation facilities shall comply with all currently applicable statutes, regulations and safety codes in the locality where the equipment shall be installed and the following publications, norms / guidelines, standards, acts and rules shall be followed.

- Publications of Bureau of Indian Standards (BIS).

- ASHRAE & ISHRAE

- American Conference of Governmental Industrial Hygienists (ACGIH) publications, U.S.A.

- VDI stipulation for vibration level.

- Handbook of Air Conditioning System Design by ‘Carrier Air Conditioning Company’.

- Sheet Metal & Air-conditioning Contractors National Association (SMACNA)





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CHAPTER-14

COMPRESSED AIR SYSTEM

The instrument air and plant air requirement for the desalination plant shall be met by the existing compressed air network system available in the ONGC plant premises.

GI piping shall be carried out from the existing nearest available point of the compressed air network system of ONGC to the desalination plant units .

The estimated compressed air requirement are as follows

a. Instrument air - 640 m3/hr. @ 7 bar

b. Plant air – 1. DAF system - 132 m3/hr @ 7.5 bar 2. UF system - 8 m3/hr @ 1 bar 3. Miscellaneous – 20 m3/hr @ 7 bar





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CHAPTER-15

CAPITAL COST

15.1. Introduction

ONGC Uran Plant, Uran intends to set up a sea water desalination plant of 20 MLD capacity, wherein 18 MLD shall cater to the process water requirement as per IS 10500 and 2 MLD shall cater to the boiler feed water requirement having DM water quality. Based on the preferred sea water reverse osmosis desalination technology the has been estimated for various units and plant facilities comprising of sea water intake, reject disposal, integrated membrane pre treatment and RO system, post treatment, chemical system, plant electrics, instrumentation and automation.

15.2. Scope of work

The scope of work comprises of construction of complete sea water reverse osmosis desalination plant facilities for 20 MLD capacity in the existing premises of ONGC Uran plant, Uran.

15.3. Estimated project cost

The investment required for the proposed desalination plant has been estimated as Rs 313.61 Crores, including a foreign exchange component of Rs 43.32 Crores. The summary of estimated capital cost is given in Table 15.01.

Table 15.01

Summary of the estimated cost of the project

Unit: Rs S.No DESCRIPTION

FC IC TOTAL

1 EPCC cost 433,204,574 2,553,579,635 2,986,784,210

SUBTOTAL (1) 433,204,574 2,553,579,635 2,986,784,210





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2 ENGINEERING COSTS

LICENSE AND BASIC ENGINEERING

Excluded

PMC 149,339,210 149,339,210 SUBTOTAL (2) 149,339,210 149,339,2103 SITE RELATED FACILITIES

LAND Existing SITE DEVELOPMENT Included in

Civil

CONSTRUCTION SITE ACTIVITIES

Included in PMC cost

INFRASTRUCTURE FACILITIES

Existing

TOWNSHIP Excluded SUBTOTAL (3) 0 0 0 4 OTHERS

GENERAL FACILITIES Excluded OWNERS CONSTRN.

PERIOD EXPENSES Excluded

OWNERS STARTUP AND COMMISSIONING EXPENSES

Excluded

SUBTOTAL (4) 0 0 05 OWNERS CONTINGENCY Excluded

SUBTOTAL (1+2+3+4+5) 433,204,574 2,702,918,846 3,136,123,4206 INTEREST DURING

CONSTRUCTION Excluded

SUBTOTAL (1+2+3+4+5+6) 433,204,574 2,702,918,846 3,136,123,420 7 MARGIN MONEY FOR

WORKING CAPITAL Excluded





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SUBTOTAL (1+2+3+4+5+6+7) 433,204,574 2,702,918,846 3,136,123,420 TOTAL COST 433,204,574 2,702,918,846 3,136,123,420

The details of plant & machinery, LSTK cost and project cost are given in Annexure-

15.01, Annexure-15.02 and Annexure-15.03 respectively. In addition O&M cost for the first seven years of operation is given in Annexure-15.04.

The cost towards major facilities include intake screens and stop logs, DAF units, disc filters, ultra filtration membranes, cartridge filters, RO membranes, energy recovery devices, pressure vessels, pumps, blowers, tanks and vessels, CO2 system, marine intake and outfall, DM plant, and related service facilities like electrical, instrumentation and automation systems, piping and valves, material handling facilities, AC & ventilation system, laboratory equipment, repair services shop etc.

15.4. Civil and structural works including site development

The cost of civil and structural works including site development have been estimated on the basis of preliminary layouts and designs of facilities and the derived rates for civil works applicable in the region. The facilities included in the estimates are site development, factory buildings covering main plant & auxiliary units.

15.5. Plant and machinery

The cost towards major facilities include intake screens and stop logs, DAF units, disc filters, ultra filtration membranes, cartridge filters, RO membranes, energy recovery devices, pressure vessels, pumps, blowers, tanks and vessels, CO2 system, marine intake and outfall, DM plant, and related service facilities like electrical, instrumentation and automation systems, piping and valves, material handling facilities, AC & ventilation system, laboratory equipment, repair services shop etc.

The estimates are generally based on budgetary quotations & in-house data. The costs have been estimated based on prices of similar equipment installed in other projects. The estimated costs include provision towards ocean freight & marine insurance on imported equipment, sales tax on indigenous equipment, inland freight for indigenous and imported supplies.

It has been assumed that, the project is exempted from service tax.

Provision has been made towards commissioning spares in the estimate.





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Provision has also been made in the estimate for installation charges for plant and machinery.

Provision has been made for third party inspection, design & engineering, construction supervision and startup and commissioning expenses.

15.6. Contingencies

Contingencies at the rate of 5% of the total capital cost have been provided to cover unforeseen aspects of the estimate.

15.7. Assumptions

The assumptions made while estimating the capital costs are enumerated below:

- The capital cost estimates are based on prices prevailing during the 3rd quarter of 2015 and no provision has been made for future escalation.

- Cost data for major plant and equipment are based on offers received / under consideration and budgetary quotations. Wherever quotations are not available, costs are based on broad estimates.

- Foreign exchange rates have been considered as given below:

a) US Dollar 1 = Rs 63.00 - The cost of civil engineering works is based on indications available regarding

local labour rates and prices of construction materials, prevailing in the area.

- Indirect costs

i. Ocean freight & Marine insurance-5.5% on FOB cost of imported equipment

ii. Port handling charges-1% of FOB cost of imported equipment iii. Inland freight-1.75% FOB cost of imported equipment and ex-works

cost of indigenously sourced equipment. iv. Insurnace-0.5% of FOB cost of imported equipment and ex-works cost

of indigenously sourced equipment. - Statutory taxes & duties

i. Customs duty- 26.69% of CIF (7.5% Basic customs duty + 1.0% landing charges + 12.5% CVD + 3.0% Education Cess on customs duty + 4% SAD)

ii. Excise duty- 12.5% iii. CST-2% iv. VAT-5%





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Cost estimate does not consider any CENVATABLE benefits, if available.

- No provision has been made for Royalty, know-how, process design & basic engineering in the estimate.

- Project management and consultancy services has been considered at 5%.

- Existing land will be used.

- Existing infrastructure facilities shall be used.

- No cost provision has been made for township.

- No additional provision has been made for owner’s construction period expenses.

- No additional provision has been made for general facilities.

- Owner’s contingency has been excluded.

- No provision has been made towards margin money for working capital as the same will be met from the internal resources.

- No provision has been made towards financing of the project as the same will be met from the internal resources.





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CHAPTER -16

PRODUCTION COST

16.1. General

The proposed desalination plant envisages production of 20 MLD of treated water

and it has been assumed that, the plant will achieve 85% capacity in 1st year, 95%

capacity in 2nd year, and 100% capacity utilisation in 3rd year and onwards.

16.2. Annual production cost

The proposed desalination is designed for a capacity of 7.37 million cum of water.

The costs of desalination from the proposed plant has been estimated on an annual

basis based on various technological parameters and specific consumption of raw

materials & various services dealt with in earlier chapters and are given in Table-

16.01.

Table 16.01

Sl.No. Item Unit Rate

Rs/unit

Annual

requirement

Cost

Rs Lakhs

1 Chemicals

a) HCl (33%) t 6,000 553 33.2

b) Anti-Scalant t 92,000 55 50.4

c) Antioxidant-Sodium Bisulphite

(60%) t

32,000 91 29.2

d) Lime Stone (90%) t 9,000 718 64.6

e) Sodium hypochlorite (12%) t 8,000 304 24.3

f) Caustic Soda (33%) t 25,000 111 27.7





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Rs/unit

Annual

requirement

Cost

Rs Lakhs

g) Carbon dioxide t 11,000 504 55.4

h) Coagulant-Ferric chloride (40%) t 9,000 1,004 90.3

i) Coagulant aid (polyelectrolyte) t 220,000 53 116.4

Subtotal (Chemicals) 491.5

2 Consumables

a) Hydrophilic UF Membranes 127.1

b) Cartridge Filters 36.9

c) Sea Water RO Membranes 136.2

d) Media for on-shore intake filter &

Other Misc. consumables

11.1

Subtotal(Consumables) 311.2

3 Power

'000

kwh

4,000.0 33,399.7 1,336.0

4 Labour

94.4

5 Overheads

a) Repair & maintenance 266.8

b) Lease rent, insurance, taxes,

water cess etc.

39.0





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Rs/unit

Annual

requirement

Cost

Rs Lakhs

c) Administrative expenses 3.0

d) Sales expenses 33.9

Sub total (Overheads) 342.7

Total cost of manufacture 2,575.8

The cost of manufacture (without depreciation) per CUM of treated sea water is

estimated as Rs 34.94 based on the cost of materials, consumables, labour &

supervision, power and other services costs as prevailing in the 3rd quarter of 2015.

An escalation of 6% per annum has been considered on the operation and

maintenance cost. The year wise cost of production and cost of production including

depreciation per CUM of treated sea water over the life span of project are shown in

Annexure-16.01.

The various assumptions made in working out the production cost are given in the

following paragraphs

16.3. Utilities

The unit rates for utilities and services adopted for calculation of production

costs are indicated in Table 16.02.

Table 16.02

Unit rates of utilities

Sl. No Item Unit Rate (Rs / Unit)

1 Electric Power kWh 4.00





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16.4. Labour and supervision

The cost estimated under labour and supervision includes salaries and other applicable

fringe benefits for various categories of operation and maintenance personnel

deployed in the plant. Annual pay structure including all fringe benefits considered

for calculation of labour cost and the estimated annual wage bill is given in Table

16.03.

Table 16.03

Salaries and wages

Sl.No Grade No. of

persons Salary, Rs/annum

Annual wage bill, Rs

Lakh

A) Main plant

1 Sr. Executives 1 1,800,000 18.0

2 Executives 2 1,200,000 24.0

3 Highly Skilled 3 960,000 28.8

4 Skilled 12 120,000 14.4

5 Semi skilled 5 108,000 5.4

6 Unskilled 4 96,000 3.8

Total 27

94.4

B) Administrative

1 Semi skilled 1 108,000 1.1

2 Unskilled 2 96,000 1.9

Total 3

3.0

TOTAL 30

97.4





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16.5. Overheads

Under this head, overheads include provision for repair & maintenance, lease rent of the

land, taxes, water cess, insurance & miscellaneous expenses, administrative salaries and

sales expenses.

Provision for repair & maintenance include cost of stores & spares, repair & maintenance

of plant & machinery and buildings including monitoring of environmental control

equipment.

Provision towards administrative expenses includes administrative salaries.

Provision made towards sales expenses includes expenses towards sales promotion,

agency commission, etc.

16.6. Depreciation

Provision for depreciation shown under production costs has been worked out on

straight-line basis





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CHAPTER -17

FINANCIAL ANALYSIS

17.1 General

The financial analysis for the proposed plant has been carried out on the basis of

capital cost and production cost as enumerated in the previous chapters and selling

price of Rs 92 per cum of treated water.

The salient techno economic indices are given in Table-17.01.

Table 17.01

Salient financial indices

Sl.No. Index Unit Value

1 Life Cycle Cost, NPV at 8% Discounting

Rate

Rs Crores 640.9

2 Cumulative profit over 20 years of

operation

Rs Crores 789.9

3 Average profit per year over 20 years of

operation

Rs Crores 39.5

4 Cumulative cash surplus over 20 years of

operation

Rs Crores 1,081.2

5 Break even capacity (Average over 10

years of operation)

Conventional % 54.9

Cash % 9.3

6 IRR (Post Tax) % 14.3





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7 Payback period Years 6.3

17.2 Life Cycle Cost

Life Cycle Cost has been calculated by finding out NPV at a discount rate of 8%of

cost of construction for initial 2 years and cost of operation and maintenance for 20

years. The details are given in Annexure-17.01.

17.3 Estimates of working results and Cash Flow statements

Estimates of working results and cash flow statement for the proposed facility have

been worked out for 20 years of operation. The details are given in Annexure-17.02

and Annexure-17.03 respectively.

17.4 Break Even capacity

The break even capacity for the proposed plant (average over 10 years of

operation) works out to 54.9% of the rated capacity of the plant on conventional

basis and 9.3% on cash basis. The details of the working are given in Annexure-

17.04.

17.5 Internal Rate of Return (IRR)

Based on the cash flow statements for 20 years of operation, the IRR has been

calculated. The IRR after tax works out to 14.3% and on pre-tax basis works out to

17.4%. The details of the workings are given in Annexure-17.05.

17.6 Pay Back Period

The pay-back period for the proposed project i.e. the period required for recovering

the original investment outlay through cash accruals, works out to 6.3 years from

the start of operation. The details of working are given in Annexure-17.06.

17.7 Assumptions

The following assumptions have been made while carrying out the financial

analysis.

- Net sales realisation for the product has been considered as Rs 92/ cum

- Depreciation has been considered as follows:





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Category of Asset

For tax

purposes on

WDV method

For profit & loss

account on

straight line method

Buildings 10% 3.17%

Plant and machinery 80% 11.88%

Miscellaneous fixed

assets

80% 11.88%

- It has been assumed that the plant would be able to achieve a

capacity utilisation of 85% capacity in 1st year, 95% capacity in 2nd

year, and 100% capacity utilisation in 3rd year and onwards.

- Corporate tax has been considered at the rate of 30% of the taxable

profit with a surcharge of 10% and education cess of 3% thereon.

- An escalation of 5% per annum has been considered on selling prices

17.8 Conclusion

The foregoing analysis reveals that installation of the proposed 20 MLD desalination

plant involving capital investment of Rs 313.6 Crores generates an average annual

net profit of Rs. 39.5 Crores and a IRR (post tax) of 14.3%. Keeping in view the

socio-economic benefits of the proposed project and water scarcity problem in

future, it is recommended to implement the project.

Annexure‐15.01

S.No DESCRIPTION

FC IC SC TOTAL

A MAJOR ITEMS

1 INTAKE SCREENS AND STOP LOGS 43,585,868 43,585,868

2 DAF UNITS 44,734,486 44,734,486

3 DISC FILTERS 21,394,754 21,394,754

4 ULTRA FILTRATION MEMBRANES 63,535,936 63,535,936

5 CARTRIDGE FILTERS 9,308,979 9,308,979

6 RO MEMBRANES 68,076,965 68,076,965

7 ENERGY RECOVERY DEVICES 60,773,697 60,773,697

8 PRESSURE VESSELS 14,589,371 14,589,371

9 PUMPS 47,953,417 126,069,357 174,022,775

10 BLOWERS 916,918 916,918

11 TANKS AND VESSELS 17,124,367 17,124,367

12 CO2 SYSTEM 12,812,154 12,812,154

13 MARINE INTAKE AND OUTFALL 405,772,285 405,772,285

14 DM PLANT 22,382,679 22,382,679

SUBTOTAL (A) 305,320,638 247,938,311 405,772,285 959,031,234

B BULK MATERIALS

1 PIPING AND VALVES 83,800,850 402,790,776 486,591,625

2 ELECTRICAL 94,997,035 94,997,035

3 INSTRUMENTATION 145,918,615 145,918,615

4 LABORATORY 10,000,000 10,000,000

5 MATERIAL HANDLING 4,244,991 4,244,991

6 AC & VENTILATION 16,242,987 16,242,987

SUBTOTAL (B) 83,800,850 674,194,404 757,995,254

C SPARES 2,996,051 2,996,051

D LIMESTONE AND PACKING MEDIA 573,460 573,460

SUBTOTAL (A+B+C+D) 389,121,488 925,702,226 405,772,285 1,720,595,999

E ERECTION

MECHANICAL 80,543,105 80,543,105

ELECTRICAL 7,124,778 7,124,778

INSTRUMENTATION 10,943,896 10,943,896

SUB TOTAL ( E ) 98,611,778 98,611,778

F CIVIL & STRUCTURAL WORKS INCLUDING SITE DEVELOPMENT 184,905,111 184,905,111

SUB TOTAL (A TO F) 389,121,488 925,702,226 689,289,175 2,004,112,888

G INDIRECT COSTS

1 OCEAN FREIGHT & MARINE INSURANCE @ 5.5% 21,401,682 21,401,682

2 CUSTOMS DUTY @ 26.01% 110,607,199 110,607,199

3 EXCISE DUTY @ 12.5% 115,712,778 115,712,778

4 SALES TAX @ 2% 20,828,300 20,828,300

5 PORT HANDLING @1% 3,891,215 3,891,215

6 INLAND TRANSPORTATION 23,009,415 23,009,415

7 INSURANCE 6,574,119 6,574,119

8 VAT 115,306,880 115,306,880

9 SERVICE TAX 0 0

SUBTOTAL (G) 21,401,682 395,929,906 0 417,331,587

H ESCALATION DURING EXECUTION

TOTAL COST 410,523,169 1,321,632,131 689,289,175 2,421,444,476

Cost estimate Pg.1of1

All right reserved@2015


SETTING UP A 20 MLD DESALINATION PLANT AT ONGC ,URAN PLANT,URAN BASIC ENGINEERING DESIGN PACKAGE

PLANT AND MACHINERY

PRICE IN RS.

Annexure‐15.02

S.No DESCRIPTION

FC IC SC TOTAL

1 DESALINATION PLANT PACKAGE 410,523,169 1,321,632,131 689,289,175 2,421,444,476

2 THIRD PARTY INSPECTION 2,052,616 6,608,161 8,660,777

3 DESIGN AND ENGINEERING 173,215,530 173,215,530

4 CONSTRUCTION SUPERVISION 34,464,459 34,464,459

5 STARTUP AND COMMISSIONING 20,678,675 20,678,675

SUB TOTAL (1 TO 6) 412,575,785 1,501,455,822 744,432,309 2,658,463,916

7 CONTINGENCY 20,628,789 75,072,791 37,221,615 132,923,196

SUBTOTAL (1 TO 7) 433,204,574 1,576,528,613 781,653,924 2,791,387,112

8 EPCC MARGIN

FINANCING 55,827,742 55,827,742

PROVISION FOR LIABILITIES 0

PROFIT 139,569,356 139,569,356

SUBTOTAL (8) 0 195,397,098 0 195,397,098

TOTAL EPCC COST 433,204,574 1,771,925,711 781,653,924 2,986,784,210



PRICE IN RS.



LSTK COST ESTIMATE

Annexure‐15.03

S.No DESCRIPTION

FC IC TOTAL

1 EPCC cost 433,204,574 2,553,579,635 2,986,784,210

SUBTOTAL (1) 433,204,574 2,553,579,635 2,986,784,210

2 ENGINEERING COSTS

LICENSE AND BASIC ENGINEERING Excluded

PMC 149,339,210 149,339,210

SUBTOTAL (2) 0 149,339,210 149,339,210

3 SITE RELATED FACILITIES

LAND Existing

SITE DEVELOPMENT Included in Civil

CONSTRUCTION SITE ACTIVITIES Included in PMC cost

INFRASTRUCTURE FACILITIES Existing

TOWNSHIP Excluded

SUBTOTAL (3) 0 0 0

4 OTHERS

GENERAL FACILITIES Excluded

OWNERS CONSTRN. PERIOD EXPENSES Excluded

OWNERS STARTUP AND COMMISSIONING EXPENSES Excluded

SUBTOTAL (5) 0 0 0

5 OWNERS CONTINGENCY Excluded

SUBTOTAL (1+2+3+4+5+6) 433,204,574 2,702,918,846 3,136,123,420

6 MARGIN MONEY FOR WORKING CAPITAL Excluded

SUBTOTAL (1+2+3+4+5+6+7) 433,204,574 2,702,918,846 3,136,123,420

7 INTEREST DURING CONSTRUCTION Excluded

SUBTOTAL (1+2+3+4+5+6+7+8) 433,204,574 2,702,918,846 3,136,123,420

TOTAL COST 433,204,574 2,702,918,846 3,136,123,420





PROJECT COST ESTIMATE

PRICE IN RS.

Annexure‐15.04

a Total plant operating capacity ,avg

b Base year

c Power tariff considered

d

Wages ,chemical cost and membrane replacement

costs,spares,overheads and profits etc. worked out for the

project.

e Escalation considered in operating cost including power tariff

f Escalation considered in selling price

Year of operation Power Cost

Others

excluding power

(chemicals,spares,

wages,maintenance)

Total Cost

1 O&M Cost for first year 116,564,918 111,142,180 227,707,098

2 O&M Cost for second year 135,596,061 127,401,075 262,997,136

3 O&M Cost for thirdyear 150,111,567 140,429,112 290,540,679

4 O&M Cost for fourth year 159,118,261 149,494,598 308,612,859

5 O&M Cost for fifth year 168,665,356 159,176,306 327,841,662

6 O&M Cost for sixth year 178,785,278 169,519,373 348,304,651

7 O&M Cost for seventh year 189,512,394 180,572,578 370,084,972

Total Cost for seven years O&M 1,098,353,835 1,037,735,222 2,136,089,057



Cost in Rupees



Rupees Two hundred thirteen Crore sixty lakh eighty nine thousand fifty seven only

Cost estimate Basis

6%

March ‐2015

COST ESTIMATE FOR 7 YEARS OPERATION AND MAINTENANCE

20 MLD (18 MLD service water as per IS 10500 +

2 MLD DM water)

Rs. 4/‐ per unit

Rs.16.82/‐ per m3

5%



Annexure-16.01

Unit: Rupees LakhsSl.No. Item / Year 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Capacity utilization 85% 95% 100% 100% 100% 100% 100% 100% 100% 100% 100% 100% 100% 100% 100% 100% 100% 100% 100% 100%Production (lakh cum / year) 62.7 70.0 73.7 73.7 73.7 73.7 73.7 73.7 73.7 73.7 73.7 73.7 73.7 73.7 73.7 73.7 73.7 73.7 73.7 73.7

A Chemicals & Consumables1 Chemicals 417.8 495.0 552.3 585.4 620.5 657.8 697.2 739.1 783.4 830.4 880.2 933.1 989.0 1,048.4 1,111.3 1,178.0 1,248.6 1,323.6 1,403.0 1,487.12 Consumables 264.5 313.3 349.6 370.6 392.8 416.4 441.4 467.9 495.9 525.7 557.2 590.7 626.1 663.7 703.5 745.7 790.4 837.9 888.1 941.4

Sub total - A 682.3 808.3 901.9 956.0 1,013.4 1,074.2 1,138.6 1,206.9 1,279.3 1,356.1 1,437.5 1,523.7 1,615.1 1,712.0 1,814.8 1,923.6 2,039.1 2,161.4 2,291.1 2,428.6

B Utilities1 Power 1,165.6 1,356.0 1,501.1 1,591.2 1,686.7 1,787.9 1,895.1 2,008.8 2,129.4 2,257.1 2,392.6 2,536.1 2,688.3 2,849.6 3,020.5 3,201.8 3,393.9 3,597.5 3,813.4 4,042.2

Sub total-B 1,165.6 1,356.0 1,501.1 1,591.2 1,686.7 1,787.9 1,895.1 2,008.8 2,129.4 2,257.1 2,392.6 2,536.1 2,688.3 2,849.6 3,020.5 3,201.8 3,393.9 3,597.5 3,813.4 4,042.2

C Labour and Supervision 94.4 105.1 117.0 130.2 144.9 161.3 179.5 199.8 222.4 247.5 275.5 306.6 341.3 379.8 422.8 470.5 523.7 582.9 648.7 722.0

D Overheads1 Repair & maintenance 258.8 280.0 299.8 317.8 336.8 357.0 378.5 401.2 425.2 450.8 477.8 506.5 536.9 569.1 603.2 639.4 677.8 718.4 761.5 807.2

2Insurance, rent, taxes, water cess etc. 39.0 41.3 43.8 46.4 49.2 52.2 55.3 58.6 62.2 65.9 69.8 74.0 78.5 83.2 88.2 93.5 99.1 105.0 111.3 118.0

3 Administration salaries 3.0 3.3 3.7 4.1 4.6 5.1 5.7 6.3 7.1 7.9 8.8 9.7 10.8 12.1 13.4 14.9 16.6 18.5 20.6 22.94 Sales expenses 33.9 36.0 38.1 40.4 42.8 45.4 48.1 51.0 54.1 57.3 60.7 64.4 68.2 72.3 76.7 81.3 86.2 91.3 96.8 102.6

Sub total-D 334.7 360.6 385.4 408.7 433.5 459.7 487.6 517.2 548.5 581.8 617.1 654.6 694.4 736.7 781.5 829.1 879.6 933.3 990.3 1,050.8

Total O & M Cost 2,277.1 2,630.0 2,905.4 3,086.1 3,278.4 3,483.0 3,700.8 3,932.7 4,179.6 4,442.5 4,722.6 5,021.1 5,339.1 5,678.1 6,039.5 6,425.0 6,836.3 7,275.1 7,743.5 8,243.5

E Depreciation 3,542.0 3,542.0 3,542.0 3,542.0 3,542.0 3,542.0 3,542.0 3,530.3 66.9 66.9 66.9 66.9 66.9 66.9 66.9 66.9 66.9 66.9 66.9 66.9

Total Cost of Production 5,819.1 6,172.0 6,447.4 6,628.2 6,820.5 7,025.1 7,242.9 7,463.1 4,246.5 4,509.4 4,789.5 5,087.9 5,405.9 5,744.9 6,106.4 6,491.9 6,903.1 7,341.9 7,810.3 8,310.4

Total cost of production (Rs / cum) 92.9 88.1 87.4 89.9 92.5 95.3 98.2 101.2 57.6 61.2 65.0 69.0 73.3 77.9 82.8 88.0 93.6 99.6 105.9 112.7

Year Wise Cost of Production

Page 1 of 1

© 2015 MECON Limited. All rights reserved



Annexure 17.01

Unit: Rupees Lakhs

1 2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

I Capital cost 12,544.5 18,816.7

II O & M Cost

1 Chemicals & Consumables 682.3 808.3 901.9 956.0 1,013.4 1,074.2 1,138.6 1,206.9 1,279.3 1,356.1 1,437.5 1,523.7 1,615.1 1,712.0 1,814.8 1,923.6 2,039.1 2,161.4 2,291.1 2,428.6

2 Power 1,165.6 1,356.0 1,501.1 1,591.2 1,686.7 1,787.9 1,895.1 2,008.8 2,129.4 2,257.1 2,392.6 2,536.1 2,688.3 2,849.6 3,020.5 3,201.8 3,393.9 3,597.5 3,813.4 4,042.2

3 Labour and supervision 94.4 105.1 117.0 130.2 144.9 161.3 179.5 199.8 222.4 247.5 275.5 306.6 341.3 379.8 422.8 470.5 523.7 582.9 648.7 722.0

4 Overheads 334.7 360.6 385.4 408.7 433.5 459.7 487.6 517.2 548.5 581.8 617.1 654.6 694.4 736.7 781.5 829.1 879.6 933.3 990.3 1,050.8

Total O & M cost 2,277.1 2,630.0 2,905.4 3,086.1 3,278.4 3,483.0 3,700.8 3,932.7 4,179.6 4,442.5 4,722.6 5,021.1 5,339.1 5,678.1 6,039.5 6,425.0 6,836.3 7,275.1 7,743.5 8,243.5

Total Annual Cost 12,544.5 18,816.7 2,277.1 4,572.1 2,905.4 3,086.1 3,278.4 3,483.0 3,700.8 3,932.7 4,179.6 4,442.5 4,722.6 5,021.1 5,339.1 5,678.1 6,039.5 6,425.0 6,836.3 7,275.1 7,743.5 8,243.5

Life Cycle Cost, NPV @ 8% 64,089 Rupees Lakhs

Life Cycle Cost, per m3 Rs 869.2

Life Cycle Cost

Sl.No Item/ yearOperation PeriodConstruction period

Page 1 of 1© 2015 MECON Limited. All rights reserved



Annexure 17.02

Unit: Rupees Lakhs

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

1 Cost of manufacture 2,277.1 2,630.0 2,905.4 3,086.1 3,278.4 3,483.0 3,700.8 3,932.7 4,179.6 4,442.5 4,722.6 5,021.1 5,339.1 5,678.1 6,039.5 6,425.0 6,836.3 7,275.1 7,743.5 8,243.5

2 Expected sales 6,356.7 7,459.7 8,245.0 8,657.2 9,090.1 9,544.6 10,021.8 10,522.9 11,049.1 11,601.5 12,181.6 12,790.7 13,430.2 14,101.7 14,806.8 15,547.1 16,324.5 17,140.7 17,997.7 18,897.6

3 Gross Profit before Depreciation 4,079.6 4,829.8 5,339.6 5,571.1 5,811.7 6,061.5 6,321.0 6,590.2 6,869.4 7,159.0 7,458.9 7,769.6 8,091.1 8,423.6 8,767.2 9,122.1 9,488.2 9,865.6 10,254.3 10,654.1

4 Depreciation 3,542.0 3,542.0 3,542.0 3,542.0 3,542.0 3,542.0 3,542.0 3,530.3 66.9 66.9 66.9 66.9 66.9 66.9 66.9 66.9 66.9 66.9 66.9 66.9

5 Profit/loss before taxation 537.6 1,287.7 1,797.5 2,029.1 2,269.6 2,519.5 2,778.9 3,059.9 6,802.6 7,092.1 7,392.1 7,702.8 8,024.3 8,356.8 8,700.4 9,055.2 9,421.4 9,798.8 10,187.4 10,587.2

6 Tax 107.6 257.6 359.6 406.0 454.1 504.1 1,012.3 2,205.7 2,304.1 2,405.6 2,510.3 2,618.4 2,729.9 2,845.0 2,963.6 3,085.8 3,211.8 3,341.4 3,474.7 3,611.6

7 Profit after tax 430.0 1,030.1 1,437.9 1,623.1 1,815.5 2,015.4 1,766.6 854.1 4,498.5 4,686.5 4,881.8 5,084.4 5,294.3 5,511.8 5,736.8 5,969.4 6,209.6 6,457.4 6,712.8 6,975.6

8 Retained profit 430.0 1,030.1 1,437.9 1,623.1 1,815.5 2,015.4 1,766.6 854.1 4,498.5 4,686.5 4,881.8 5,084.4 5,294.3 5,511.8 5,736.8 5,969.4 6,209.6 6,457.4 6,712.8 6,975.6

Add: Depreciation 3,542.0 3,542.0 3,542.0 3,542.0 3,542.0 3,542.0 3,542.0 3,530.3 66.9 66.9 66.9 66.9 66.9 66.9 66.9 66.9 66.9 66.9 66.9 66.9

Net cash accruals 3,972.0 4,572.1 4,979.9 5,165.1 5,357.6 5,557.4 5,308.7 4,384.5 4,565.4 4,753.4 4,948.6 5,151.2 5,361.2 5,578.6 5,803.7 6,036.2 6,276.5 6,524.3 6,779.6 7,042.4

Estimates of Working Results

Sl.No Item/ year

Page 1 of 1© 2015 MECON Limited. All rights reserved



Annexure - 17.03

Unit:Rupees Lakhs

1 2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20A Source of funds

1 Equity 9,220.6 22,140.72 Pre tax Profit 537.6 1,287.7 1,797.5 2,029.1 2,269.6 2,519.5 2,778.9 3,059.9 6,802.6 7,092.1 7,392.1 7,702.8 8,024.3 8,356.8 8,700.4 9,055.2 9,421.4 9,798.8 10,187.4 10,587.23 Depreciation & prel. Expenses 3,542.0 3,542.0 3,542.0 3,542.0 3,542.0 3,542.0 3,542.0 3,530.3 66.9 66.9 66.9 66.9 66.9 66.9 66.9 66.9 66.9 66.9 66.9 66.9

TOTAL - A 9,220.6 22,140.7 4,079.6 4,829.8 5,339.6 5,571.1 5,811.7 6,061.5 6,321.0 6,590.2 6,869.4 7,159.0 7,458.9 7,769.6 8,091.1 8,423.6 8,767.2 9,122.1 9,488.2 9,865.6 10,254.3 10,654.1

B Disposition of funds1 Capital expenditure 9,220.6 22,140.72 Tax 107.6 257.6 359.6 406.0 454.1 504.1 1,012.3 2,205.7 2,304.1 2,405.6 2,510.3 2,618.4 2,729.9 2,845.0 2,963.6 3,085.8 3,211.8 3,341.4 3,474.7 3,611.6

TOTAL -B 9,220.6 22,140.7 107.6 257.6 359.6 406.0 454.1 504.1 1,012.3 2,205.7 2,304.1 2,405.6 2,510.3 2,618.4 2,729.9 2,845.0 2,963.6 3,085.8 3,211.8 3,341.4 3,474.7 3,611.6

Opening balance 3,972.0 8,544.2 13,524.1 18,689.2 24,046.8 29,604.2 34,912.9 39,297.3 43,862.7 48,616.1 53,564.8 58,716.0 64,077.2 69,655.8 75,459.4 81,495.7 87,772.1 94,296.4 101,076.0Net surplus/ defecit 3,972.0 4,572.1 4,979.9 5,165.1 5,357.6 5,557.4 5,308.7 4,384.5 4,565.4 4,753.4 4,948.6 5,151.2 5,361.2 5,578.6 5,803.7 6,036.2 6,276.5 6,524.3 6,779.6 7,042.4Closing balance 3,972.0 8,544.2 13,524.1 18,689.2 24,046.8 29,604.2 34,912.9 39,297.3 43,862.7 48,616.1 53,564.8 58,716.0 64,077.2 69,655.8 75,459.4 81,495.7 87,772.1 94,296.4 101,076.0 108,118.4

Sl.No Item/ year

Cash Flow Statement

Construction period Operation period

Page 1 of 1




Annexure - 17.04

Sl.No. ItemValue

(Rs Lakhs)

1 Net sales realisation 8,245.0

2 Variable expenses Manufacturing expenss 1,991.6

Total variable expenses 1,991.6

3 Contribution 6,253.4

4 Fixed expenses Manufacturing expenss 584.2 Depreciation (average over 10 years) 2,845.8

Total fixed expenses 3,430.0

Break even capacity,% Conventional 54.9 Cash 9.3

(Average over initial 10 years of operation)Break Even Capacity

Page 1 of 1




Annexure - 17.05

Unit:Rupees Lakhs

1 2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

1 Gross profit before interest 4,079.6 4,829.8 5,339.6 5,571.1 5,811.7 6,061.5 6,321.0 6,590.2 6,869.4 7,159.0 7,458.9 7,769.6 8,091.1 8,423.6 8,767.2 9,122.1 9,488.2 9,865.6 10,254.3 10,654.1

2 Tax 107.6 257.6 359.6 406.0 454.1 504.1 1,012.3 2,205.7 2,304.1 2,405.6 2,510.3 2,618.4 2,729.9 2,845.0 2,963.6 3,085.8 3,211.8 3,341.4 3,474.7 3,611.6

3 Capital Cost 9,220.6 22,140.7 (2,234.5)

4 Margin after tax [1 - (2+3) (9,220.6) (22,140.7) 3,972.0 4,572.1 4,979.9 5,165.1 5,357.6 5,557.4 5,308.7 4,384.5 4,565.4 4,753.4 4,948.6 5,151.2 5,361.2 5,578.6 5,803.7 6,036.2 6,276.5 6,524.3 6,779.6 9,276.9

5 Margin before tax [ 1 - 2 ] (9,220.6) (22,140.7) 4,079.6 4,829.8 5,339.6 5,571.1 5,811.7 6,061.5 6,321.0 6,590.2 6,869.4 7,159.0 7,458.9 7,769.6 8,091.1 8,423.6 8,767.2 9,122.1 9,488.2 9,865.6 10,254.3 12,888.5

IRR (After Tax), % 14.3

IRR (Before Tax), % 17.4

Sl.No Item/ year

Internal Rate of Return (IRR)

Construction period Operation period

Page 1 of 1




Annexure 17.06

Total capital cost 31,361.2 Rupees Lakhs

Unit:Rupees Lakhs

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

1 Gross profit before interest 4,079.6 4,829.8 5,339.6 5,571.1 5,811.7 6,061.5 6,321.0 6,590.2 6,869.4 7,159.0 7,458.9 7,769.6 8,091.1 8,423.6 8,767.2 9,122.1 9,488.2 9,865.6 10,254.3 10,654.1

2 Tax 107.6 257.6 359.6 406.0 454.1 504.1 1,012.3 2,205.7 2,304.1 2,405.6 2,510.3 2,618.4 2,729.9 2,845.0 2,963.6 3,085.8 3,211.8 3,341.4 3,474.7 3,611.6

3 Cash accrual (1+2-3-4) 3,972.0 4,572.1 4,979.9 5,165.1 5,357.6 5,557.4 5,308.7 4,384.5 4,565.4 4,753.4 4,948.6 5,151.2 5,361.2 5,578.6 5,803.7 6,036.2 6,276.5 6,524.3 6,779.6 7,042.4

4 Cumulative cash accrual 3,972.0 8,544.2 13,524.1 18,689.2 24,046.8 29,604.2 34,912.9 39,297.3 43,862.7 48,616.1 53,564.8 58,716.0 64,077.2 69,655.8 75,459.4 81,495.7 87,772.1 94,296.4 101,076.0 108,118.4

5 Pay back period 6.3

Pay back period, years 6.3

Pay Back Period

Sl.No Item/ yearOperation

Page 1 of 1


Remarks

A SITE MOBILISATION 0.5Demolishing existing structure , site developement in ONGC scope .

B OFF SHORE MARINE WORKS 15 MONTHS

B.1 INTAKE & OUTFALL SYSTEM 15 MONTHS CONCURRENT ACTIVITY WITH SL. NO. B

C ONSHORE WORKS

C.1

ELECTRO- MECHANICAL COMPLETION ,DETAIL ENGINEERING , APPROVAL , SUPPLY , ERECTION , INSPECTION

21 MONTHS CONCURRENT ACTIVITY WITH SL. NO. B

C.2TESTING, PRECOMMISSIONING & COMMISSIONING , PG Test

5 MONTHS

26 MONTHS

Page 1 of 1

TOTAL MONTHS



Project scheduleAll right reserved@2015

140

CONSTRUCTION ACTIVITY

1

PROJECT SCHEDULE IN THE FORM OF BAR CHART

S.L NO.

159 105 6 7 8 18

DURATION IN MONTHS

11 123 4 19 2013 21 22 23 24 25 262 16 17

CHECKED

APPROVED

DIVISION

DRAWN

DESIGNED

& VERIFIED

©2015

DATE

SCALE : SHEET 1 OF 1

M & C

VINAY

S KARTHIK

P K SINHA

MANOJ KR.

10/02/15

©2015

LEGEND

CL. 0.5

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1000A, 415V, 50Hz, 50 kA, 1 Sec.,TPN,Bus Section-1 1000A, 415V, 50Hz, 50 kA, 1 Sec.,TPN,Bus Section-2

4P, LSIG

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AT

OR

-1

0.75K

W-(W

OR

KIN

G)

1st P

AS

S R

O C

LE

AN

IN

G

TA

NK

A

GIT

AT

OR

-1

0.75K

W-(W

OR

KIN

G)

2nd P

AS

S R

O C

LE

AN

IN

G

DA

F D

RIV

E M

EC

HA

NIS

M-1

0.55K

W-(W

OR

KIN

G)

DA

F D

RIV

E M

EC

HA

NIS

M-2

0.55K

W-(W

OR

KIN

G)

DA

F M

IX

ER

A

GIT

AT

OR

-1

1.5K

W-(W

OR

KIN

G)

AG

IT

AT

OR

-1

0.55K

W-(W

OR

KIN

G)

DA

F F

LO

CC

ULA

TO

R

DA

F M

IX

ER

A

GIT

AT

OR

-2

1.5K

W-(W

OR

KIN

G)

AG

IT

AT

OR

-2

0.55K

W-(W

OR

KIN

G)

DA

F F

LO

CC

ULA

TO

R

RE

CY

CLE

P

UM

P-1

22K

W-(S

TA

ND

BY

)

SLU

DG

E D

IS

PO

SA

L A

ND

RE

CY

CLE

P

UM

P-2

22K

W-(W

OR

KIN

G)

SLU

DG

E D

IS

PO

SA

L A

ND

CO

2 T

RA

NS

FE

R P

UM

P-1

3K

W-(W

OR

KIN

G)

CO

2 T

RA

NS

FE

R P

UM

P-2

3K

W-(S

TA

ND

BY

)

CO

MP

RE

SS

OR

-1

22K

W-(W

OR

KIN

G)

IN

ST

RU

ME

NT

A

IR

CO

MP

RE

SS

OR

-2

22K

W-(S

TA

ND

BY

)

IN

ST

RU

ME

NT

A

IR

SP

AR

E F

OR

0.75kW

)

SP

AR

E F

OR

3kW

SP

AR

E F

OR

2.2kW

SP

AR

E F

OR

11kW

SP

AR

E F

OR

15kW

SP

AR

E F

OR

22kW

SP

AR

E F

OR

1.5kW

)

SP

AR

E F

OR

55kW

SP

AR

E F

OR

75kW

SP

AR

E F

OR

0.55kW

)

SP

AR

E F

OR

0.75kW

)

SP

AR

E F

OR

3kW

SP

AR

E F

OR

2.2kW

SP

AR

E F

OR

11kW

SP

AR

E F

OR

15kW

SP

AR

E F

OR

22kW

SP

AR

E F

OR

1.5kW

)

SP

AR

E F

OR

55kW

SP

AR

E F

OR

75kW

SP

AR

E F

OR

0.55kW

)

AI

3

AI

3

AI

3

AI

3

NTS

SATISH SHANDRA

MURALY.P / Y.M

P.M / Y.M

FOR TENDER PURPOSE ONLY

SATISH SHANDRA

OIL AND NATURAL GAS

CORPORATION LTD.

4P, LSIG

400A

4P, LSIG

1000A 1000A

M

1st PASS RO HIGH PRESSURE

PUMP-2 (VFD CONTROLLED)

900 KW - WORKING

1250A

800A

BUSCOUPLER

11kV

FUSE

110V

33

3

3

CL. 0.5

15VA

5P20

800A/1A

800A/1A

30

86

95

51

51N

57N 51G

110V

3

NR

FUSE

3

3

NR

51 51G

NR

3

3

AI

MULIFUNCTION

METER

FROM NBPH

R Y BR Y B

SA

3

3

ASS A

CL. 0.5

1250A

CL.0.5/3P,100 VA

MULIFUNCTION

METER

SA

3

3

ASS A

SA

3

3

ASS A

SA

3

3

ASS A

CL. 0.5

SA

3

3

ASS A

CL. 0.5

1250A

SA

3

3

FR

OM

RE

SP

EC

TIV

E

BU

S P

T

50

94

NR

ASS A

CL. 0.5

7.5VA

400/1A

5P20

7.5VA

400/1A

100VA

800A/1A

5P20

50VA

800A/1A

CL. 0.5 CL. 0.5

BUS PT

110V6.6KV

3

3

110V

3

CL.0.5/100VA

CL 3P,100VA

BUS PT

110V6.6KV

3

3

110V

3

CL.0.5/100VA

CL 3P,100VA

DWTP : 6.6KV SWGR

11kV110V

33

110V

3

800A, 6.6KV, 50Hz, 40 kA, 3 Sec.,TP,Bus Section-2

800A, 6.6KV, 50Hz, 40 kA, 3 Sec.,TP,Bus Section-1

10

1112

432

LOC : SS-1

13

1

DMP-TR #3

M

3P,1000A

900 kW



900 KW - WORKING

3

IA

PS

20VA

4000/1/1/1A

CL:1

20VA

Y

5P20

20VA

2000/1A

PS

4000/1A

3

I

CL:1

20VA

4000/1A

A

BUS COUPLER

3

CL 0.5, 50VA

I A

I V

PS

20VA

4000/1/1/1A

CL:1

20VA

Y

5P20

20VA

2000/1A

PS

4000/1A

R Y B


LSIG

415V110V

33

MLD

B

3P+N,400A

SP

AR

E

M

SUBSTATION- FEEDER-1

M

VFD

3P,3500A

M



900 KW - STANDBY

DMP-TR #4

M



900 KW - WORKING

DMP-PMCC

LOC : SS-1

M

VFD

M

SP

AR

E

SP

AR

E

SP

AR

E

DR

Y T

YP

E, 6

.6

/0

.7

20

kV

31

50

KV

A

CO

NV

ER

TE

R D

UT

Y

DR

Y T

YP

E, 6

.6

/0

.7

20

kV

31

50

KV

A, D

d0

CO

NV

ER

TE

R D

UT

Y

DMP-TR #1

DMP-TR #2

50 kA/1 Sec.,TP Bus

3500A, 690V, 50Hz

50 kA/1 Sec.,TP Bus

3500A, 690V, 50Hz

5

6 7

8

9

94

59 2

27 2

30

86

95

51

51N

57N 51G

94

59 2

27 2

51

86 94 30

51N

51

49X

30

49Y

8664R

MCB

MPCB

(Near Main Plant Pump House)

(Near Main Plant Pump House)

SP

AR

E

SP

AR

E

6.6kV INCOMING SUPPLY

CL.0.5/3P,100 VA

1250A 1250A 1250A 1250A 1250A

7.5VA

400/1A

7.5VA

400/1A

7.5VA

400/1A

7.5VA

400/1A

7.5VA

400/1A

5P20

7.5VA

400/1A

5P20

7.5VA

400/1A

5P20

7.5VA

400/1A

5P20

7.5VA

400/1A

5P20

7.5VA

400/1A

95

FR

OM

RE

SP

EC

TIV

E

BU

S P

T

50

94

NR

51N

51

49X

30

49Y

8664R 95

FR

OM

RE

SP

EC

TIV

E

BU

S P

T

50

94

NR

51N

51

49X

30

49Y

8664R 95

FR

OM

RE

SP

EC

TIV

E

BU

S P

T

50

94

NR

51N

51

49X

30

49Y

8664R 95

FR

OM

RE

SP

EC

TIV

E

BU

S P

T

50

94

NR

51N

51

49X

30

49Y

8664R 95

FR

OM

RE

SP

EC

TIV

E

BU

S P

T

50

94

NR

51N

51

49X

30

49Y

8664R 95

LSIG

3P,3500A

LSIG

3P,3500A

LSIG

LSIG

3P,1000A

LSIG

3P,1000A

LSIG

3P,1000A

LSIG

VFD

900 kW

VFD

900 kW

VFD

900 kW

VFD

27B

2

27A

2

3P+N,4000A

LSIG

3P+N,4000A

R Y B

LSIG

3P+N,4000A

CL 0.5, 50VA

IV

415V110V

33

MCB

MPCB

27B

2

27A

2

LSIG

LSIG

3P+N,630A

LSIG LSIGLSIG LSIG LSIG

LSIGLSIGLSIG LSIG LSIG

CL. 0.5

*VA

*A/1A

3

AASS

CL. 0.5

*VA

*A/1A

3

AASS

CL. 0.5

*VA

*A/1A

3

AASS

CL. 0.5

*VA

*A/1A

3

AASS

CL. 0.5

*VA

*A/1A

3

AASS

CL. 0.5

*VA

*A/1A

3

AASS

CL. 0.5

*VA

*A/1A

3

AASS

CL. 0.5

*VA

*A/1A

3

AASS

CL. 0.5

*VA

*A/1A

3

AASS

CL. 0.5

*VA

*A/1A

3

AASS

CL. 0.5

*VA

*A/1A

3

AASS

CL. 0.5

*VA

*A/1A

3

AASS

CL. 0.5

*VA

*A/1A

3

AASS

CL. 0.5

*VA

*A/1A

3

AASS

CL. 0.5

*VA

*A/1A

3

AASS

CL. 0.5

*VA

*A/1A

3

AASS

3P+N,400A

3P+N,400A 3P+N,400A

5P20

*VA

*A/1A3

5P20

*VA

*A/1A

3

5P20

*VA

*A/1A3

5P20

*VA

*A/1A3

98M

47 48 49

5051LR

50G

66

98M

47 48 49

5051LR

50G

66

98M

47 48 49

5051LR

50G

66

98M

47 48 49

5051LR

50G

66

DR

Y T

YP

E, 6

.6

/0

.4

33

kV

25

00

KV

AD

yn

11

DIS

TR

IB

UT

IO

N T

RA

NS

FO

RM

ER

DR

Y T

YP

E, 6

.6

/0

.4

33

kV

25

00

KV

A, D

yn

11

DIS

TR

IB

UT

IO

N T

RA

NS

FO

RM

ER

CL. 0.5

15VA

5P20

800A/1A

800A/1A

PD

B

M

CC

M

CC

MA

IN

P

LA

NT

M

CC

CH

EM

IC

AL M

CC

M

CC

CH

EM

IC

AL M

CC

M

CC

MA

IN

P

LA

NT

M

CC

PD

B

MLD

B

3500A,NON-SEGREGATED PHASE

40

00

A, N

ON

-S

EG

RE

GA

TE

D P

HA

SE

L

T-B

US

DU

CT

40

00

A, N

ON

-S

EG

RE

GA

TE

D P

HA

SE

L

T-B

US

DU

CT

LT BUSDUCT

3500A,NON-SEGREGATED PHASE

LT BUSDUCT

VFD-PCC

LSIGLSIG

LSIG

LSIG

3P+N,630A 3P+N,630A 3P+N,630A 3P+N,630A 3P+N,630A 3P+N,630A 3P+N,630A

3P+N,630A

3P+N,630A 3P+N,630A3P+N,630A

FROM NBPH

SUBSTATION- FEEDER-2

6.6kV INCOMING SUPPLY

M

LIM

ES

TO

NE

R

EC

HA

RG

IN

G

30K

W-(S

TA

ND

BY

)

BO

OS

TE

R P

UM

PS

AI

3

M

LIM

ES

TO

NE

R

EC

HA

RG

IN

G

30K

W-(W

OR

KIN

G)

BO

OS

TE

R P

UM

PS

AI

3

M

I

3

M

I

3

DU

ST

E

XT

RA

CT

IO

N S

/M

55K

W-(W

OR

KIN

G)

FO

R LR

S

DU

ST

E

XT

RA

CT

IO

N S

/M

55K

W-(S

TA

ND

BY

)

FO

R LR

S

M

LIM

ES

TO

NE

D

IV

ER

TE

R

1.5K

W-(S

TA

ND

BY

)

A

M

LIM

ES

TO

NE

D

IV

ER

TE

R

1.5K

W-(W

OR

KIN

G)

A

M

LIM

ES

TO

NE

D

IV

ER

TE

R

2.2K

W-(S

TA

ND

BY

)

SC

RE

W C

ON

VE

YO

RS

M

LIM

ES

TO

NE

D

IV

ER

TE

R

2.2K

W-(W

OR

KIN

G)

SC

RE

W C

ON

VE

YO

RS

MM

DE

WA

TE

RIN

G P

UM

PS

3.7K

W-(W

OR

KIN

G)

FO

R M

AIN

P

LA

NT

P

H

DE

WA

TE

RIN

G P

UM

PS

3.7K

W-(S

TA

ND

BY

)

FO

R M

AIN

P

LA

NT

P

H

1. RATING OF DRIVES SHALL BE FINALIZED DURING DETAILED ENGINEERING

A

V

KW

KWH

IC

AMMETER

VOLTMETER

KILLO-WATT-METER

KILO-WATTHOUR-METER

INTELLIGENT CONTROLLER

HRC FUSE

CONTACTOR

MOTOR

THREE PHASE

MCCB

M

AIR CIRCUIT BREAKER

(Fully draw out)

ISELECTOR SWITCH

MPCB

VACUUM CIRCUIT BREAKER

(Fully draw out)

CONVERTER DUTY

ASS

AMMETER SELECTOR

27 UNDER VOLTAGE RELAY

30 AUXILIARY RELAY

51.G IDMT EARTH LEAKAGE RELAY

51.N IDMT EARTH FAULT RELAY

57.N RESIDUAL OVER VOLTAGE RELAY

59 OVER VOLTAGE RELAY

60 NEUTRAL DISPLACEMENT RELAY

64.R

EARTH FAULT RELAY

RESTRICTED

86 MASTER TRIP RELAY

46 CURRENT BALANCE

66 STARTS/HOUR

47 SINGLE PHASING

48 EXCESSIVE LONG START

37 UNDER CURRENT

38 RTD RELAY 87 DIFF. PROTECTION

18 RE-ACCELERATION

32P REVERSE POWER RELAY

67 WATTMETRIC

81U UNDER FREQUENCY

DLS DOOR LIMIT SWITCH

EPB EMERGENCY PUSH BUTTON

50

OVER CURRENT RELAY

INSTANTANEOUS

49.X WINDING TEMPERATURE ALARM

49.Y WINDING TEMPERATURE TRIP

51 IDMT OVER CURRENT RELAY

49 THERMAL O/L RELAY

50P

PHASE OVER CURRENT RELAY

INSTANTANEOUS

50N

EARTH FAULT

INSTANTANEOUS

50BF CB FAILURE

25C SYNCHRO CHECK RELAY

51L/R LOCKED ROTOR RELAY

51N

NEUTRAL DISPLACEMENT RELAY

INVEISE TIME VOLTAGE

95

TRIP SUPERVISION RELAY

98M MOTOR PROTECTION RELAY

51P TIME DELAYED PHASE OVERCURRENT

59N RESITUAL OVER VOLTAGE RELAY

50.G

EARTH LEAKAGE RELAY

INSTANTANEOUS

RELAYS

2 TIMER

15 REVERSING DEVICE

VACUUM CONTACTOR UNIT

OLR OVER LOAD RELAY (ELECTRONIC)

5 STOPPING DEVICE

57

GROUNDING DEVICE

SHORT-CIRCUITING OR

SWITCH FUSE UNIT

SWITCH

TRANSFORMER

TRANSFORMER

(Fully draw out)

(Fully draw out)

SURGE ARRESTER

RDOL STARTER

KEY ONE LINE DIAGRAM

M

VFD

LSIG

CL. 0.5

*VA

*A/1A

3

AASS

3P+N,400A

UF

B

W P

UM

P

200kW

(W

)

M

VFD

LSIG

CL. 0.5

*VA

*A/1A

3

AASS

UF

B

W P

UM

P

200kW

(S

)

M

VFD

LSIG

CL. 0.5

*VA

*A/1A

3

AASS

DA

F R

EC

YC

LE

P

UM

P

110kW

(S

)

M

VFD

LSIG

CL. 0.5

*VA

*A/1A

3

AASS

DA

F R

EC

YC

LE

P

UM

P

110kW

(W

)

M

VFD

LSIG

CL. 0.5

*VA

*A/1A

3

AASS

Ist P

AS

S C

AT

RID

GE

F

ILT

ER

FE

ED

P

UM

P 350kW

(W

)

M

VFD

LSIG

CL. 0.5

*VA

*A/1A

3

AASS

Ist P

AS

S C

AT

RID

GE

F

ILT

ER

FE

ED

P

UM

P 350kW

(S

)

M

CL. 0.5

*VA

*A/1A

3

AASS

3P+N,400A

5P20

*VA

*A/1A3

98M

47 48 49

5051LR

50G

66

LSIG

3P+N,250A3P+N,630A 3P+N,400A 3P+N,250A 3P+N, 630A

RE

JE

CT

D

IS

PO

SA

L

PU

MP

160kW

(W

)

M

CL. 0.5

*VA

*A/1A

3

AASS

5P20

*VA

*A/1A3

98M

47 48 49

5051LR

50G

66

LSIG

RE

JE

CT

D

IS

PO

SA

L

PU

MP

160kW

(S

)

M

CL. 0.5

*VA

*A/1A

3

AASS

3P+N,630A

5P20

*VA

*A/1A3

47 48 49

5051LR

50G

66

LSIG

2nd P

AS

S R

O H

IG

H P

RE

SS

.

PU

MP

250kW

(W

)

M

CL. 0.5

*VA

*A/1A

3

AASS

5P20

*VA

*A/1A3

47 48 49

5051LR

50G

66

LSIG

2nd P

AS

S R

O H

IG

H P

RE

SS

.

PU

MP

250kW

(S

-1)

M

CL. 0.5

*VA

*A/1A

3

AASS

5P20

*VA

*A/1A3

47 48 49

5051LR

50G

66

LSIG

2nd P

AS

S R

O H

IG

H P

RE

SS

.

PU

MP

250kW

(S

-2)

M

3

AASS

3

98M

47 48 49

5051LR

50G

66

LSIG

Ist P

AS

S R

O C

LE

AN

IN

G

PU

MP

90kW

(W

)

3P+N,400A 3P+N,400A 3P+N,630A 3P+N,630A

M

3

AASS

3

98M

47 48 49

5051LR

50G

66

LSIG

Ist P

AS

S R

O C

LE

AN

IN

G

PU

MP

90kW

(S

)

3P+N,400A

M

VFD

LSIG

CL. 0.5

*VA

*A/1A

3

AASS

UF

F

EE

D P

UM

P

250kW

(W

)

3P+N,630A

M

VFD

LSIG

CL. 0.5

*VA

*A/1A

3

AASS

UF

F

EE

D P

UM

P

250kW

(S

)

3P+N,630A

M

3

AASS

3

98M

47 48 49

5051LR

50G

66

LSIG

PO

RT

AB

LE

W

AT

ER

T

RA

NS

FE

R

PU

MP

110kW

(W

)

3P+N,400A

M

3

AASS

3

47 48 49

5051LR

50G

66

LSIG

PO

RT

AB

LE

W

AT

ER

T

RA

NS

FE

R

PU

MP

110kW

(S

)

3P+N,400A

SP

AR

E

SP

AR

E

SP

AR

E

SP

AR

E

M

3

AASS

3

47 48 49

5051LR

50G

66

LSIG

3P+N,400A

M

3

AASS

3

47 48 49

5051LR

50G

66

LSIG

3P+N,400A

M

VFD

LSIG

CL. 0.5

*VA

*A/1A

3

AASS

3P+N,630A

SP

AR

E

SP

AR

E

SP

AR

E

M

3

AASS

3

47 48 49

5051LR

50G

66

LSIG

3P+N,400A

M

3

AASS

3

47 48 49

5051LR

50G

66

LSIG

3P+N,400A

M

VFD

LSIG

CL. 0.5

*VA

*A/1A

3

ASS

3P+N,630A

SP

AR

E

SP

AR

E

SP

AR

E

M

DE

WA

TE

RIN

G P

UM

PS

3.7K

W-(W

OR

KIN

G)

FO

R R

CC

T

RE

NC

HE

S

M

AI

3

DE

WA

TE

RIN

G P

UM

PS

3.7K

W-(S

TA

ND

BY

)

FO

R R

CC

T

RE

NC

HE

S

NE

UT

RA

LIZ

AT

IO

N P

IT

0.75K

W-(W

OR

KIN

G)

AC

ID

D

OS

IN

G P

UM

P

NE

UT

RA

LIZ

AT

IO

N P

IT

0.75K

W-(S

TA

ND

BY

)

AC

ID

D

OS

IN

G P

UM

P

NE

UT

RA

LIZ

AT

IO

N P

IT

0.75K

W-(S

TA

ND

BY

)

CA

US

TIC

D

OS

IN

G T

AN

K

NE

UT

RA

LIZ

AT

IO

N P

IT

0.75K

W-(W

OR

KIN

G)

CA

US

TIC

D

OS

IN

G T

AN

K

M

MB

R

EG

EN

ER

AT

IO

N

PU

MP

-1

5.5K

W-(W

OR

KIN

G)

(F

OR

V

EN

TIL

AT

IO

N &

M

H L

OA

DS

)

(F

OR

V

EN

TIL

AT

IO

N &

M

H L

OA

DS

)

5P20

20VA

1200/1A

PS

1200/1A

3

3

CL 0.5, 100VA

I A

I V

PS

1200/1/1/1A

CL:1

7.5VA

5P20

7.5VA

415V 110V

33

MCB

MPCB

630A

M

3P+N, LSIG

125A

PDB

3P+N, LSIG

100A

SLDB

3P+N, LSIG

100A

3P+N, LSIG

100A

SPARE SPARE

SPARE

433/415V

15 KVA

LPG-II S/S

PURCHASER FEEDER FROM

1250A, LSIG

3P+N,1250A

50

NR

51N51

49X3049Y

8664R

95

DRY TYPE, 6.6/0.433kV

DISTRIBUTION TRANSFORMER

630 KVA, Dyn11

3P+N, LSIG

630A

3P+N, LSIG

630A

3P+N, LSIG

250 kW

SEA WATER FEED PUMP

ISOLATION

TRANSFORMER

PUMP MOTOR-1 (W)

VFD

250kW

1200A, 415V, 50Hz, 50 kA, 1 Sec.,TPN,Bus

M

630A

3P+N, LSIG

250 kW

SEA WATER FEED PUMP

PUMP MOTOR-1 (S)

VFD

250kW

SPARE

3

CL 0.5, 100VA

I A

I V

CL:1

7.5VA

415V 110V

33

MCB

MPCB

1250A, LSIG

3P+N,1250A

OF PURCHASER LT S/S

FEEDER NO. 13-1F1 OF C71/72 MCC

1250A, LSIG

3P+N,1250A

415V - PCC

LOC : INTAKE PUMP HOUSE

A2

OIL AND NATURAL GAS

CORPORATION LTD.

1200A, 415V, 50Hz, 50 kA, 1 Sec.,TPN,Bus

KEY ONE LINE DIAGRAM

6.6kV

LBS

(FOR VENTILATION & MH LOADS)

M

7.5 kW

SCREEN WASH PUMP FOR

TRAVELING WATER SCREEN-1 (W)

M

7.5 kW

SCREEN WASH PUMP FOR

TRAVELING WATER SCREEN-2 (W)

MPCB

32A

A

A

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OIL AND NATURAL GAS CORPORATION LIMITED URAN …environmentclearance.nic.in/writereaddata/Online/TOR/0_0_08_Dec... · Financial Analysis 142 Annexure 15.01 Plant and Machinery