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Environmental Impact Assessment _____________________________________________________

For

Jebel Ali Power and Desalination Station M

April 1, 2009

Prepared for:

Prepared By:

Environmental International ConsultanEnvironmental International ConsultanEnvironmental International ConsultanEnvironmental International Consultantstststs

Office: P.O. Box 123401, Dubai, UAE

Tel: 04-3357044, Fax: 04-335733

http://www.eicon.ae

Table of Contents

1

EIA study for the proposed Jebel Ali Power and Desalination Station M

EXECUTIVE SUMMARY

CHAPTER 1 INTRODUCTION

1.1 Preamble 1-1

1.2 Objective of the study 1-2

1.3 Objective of the Project 1-2

1.4 Location and Accessibility 1-3

1.5 Methodology of EIA study 1-7

1.6 Approach of the EIA study 1-7

1.7 Structure of Report 1-8

CHAPTER 2 POLICY AND LEGAL FRAMEWORK

2.1 Preamble 2-1

2.2 Guidelines 2-1

2.3 Standards 2-3

2.3.1 Ambient Air Quality Standards 2-3

2.3.2 Ambient Noise Level 2-4

2.3.3 Wastewater Discharge Limits 2-5

2.3.4 Solid Waste 2-8

2.4 ISO 14000 2-10

CHAPTER 3 PROJECT DETAILS

3.0 Project Characteristics 3-1

3.1 Outline and Rationale of the Project 3-1

3.2 Plant Layout and Land Requirement 3-1

3.3 Project Description – Power Plant (2000 MW) 3-2

3.3.1 Main Systems / Components 3-3

3.3.2 Modes of Operation 3-4

3.3.3 Abnormal Operating modes 3-5

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3.4 Project Description – Desalination plant 3-6

3.4.1 Details of Proposed Desalination Plant 3-9

3.5 Operational Features of the Project 3-11

3.5.1 Fuel 3-11

3.5.2 Chemicals 3-14

3.6 Water System 3-15

3.7 Wastewater Treatment System 3-16

3.7.1 The Treatment for the Oily Wastewater 3-18

3.7.2 Treatment for Chemical Wastewater 3-19

3.8 Details of Sewage Water Treatment System 3-23

3.9 Sources of Pollution 3-25

3.9.1 Air Environment 3-26

3.9.2 Water Environment 3-27

3.9.3 Solid waste 3-27

3.9.4 Noise Levels 3-28

CHAPTER 4 BASELINE ENVIRONMENTAL STATUS

4.1 Preamble 4-1

4.2 Climatology and Meteorology 4-1

4.2.1 General 4-1

4.2.2 Temperature 4-2

4.2.3 Relative Humidity 4-2

4.2.4 Atmospheric Pressure 4-3

4.2.5 Rainfall 4-3

4.2.6 Annual Wind Pattern 4-4

4.3 Sea Surface Water Treatment 4-6

4.4 Landuse 4-7

4.5 Regional Geology 4-8

4.6 Existing Baseline Air Quality 4-8

4.7 Biological Features 4-11

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4.7.1 General 4-11

4.7.2 Birds 4-12

4.7.3 Fauna, Wildlife 4-12

4.8 Soil, Geology and Geomorphology 4-13

4.8.1 General 4-13

4.8.2 Regional geology and Hydrogeology 4-13

4.9 Shoreline, Water Courses and Discharges 4-14

4.10 Cultural Heritage 4-15

4.11 Lanscape and Topography 4-15

4.12 Surrounding Recreational Land uses 4-15

4.13 Population 4-16

4.14 Water Quality 4-16

4.14.1 General Characteristics of the Arabian Gulf 4-17

4.14.2 Water Quality of the Gulf 4-18

4.14.3 Environmental threats of the Gulf 4-18

4.14.4 Water Quality off DEWA Station M 4-18

4.14.5 Results and Discussion 4-20

4.15 Marine Ecology 4-23

4.15.1 The Arabian Gulf Marine Environment 4-25

4.15.2 Objective of the Marine Study 4-26

4.15.3 Data Collection and Monitoring Stations 4-26

4.15.4 Strategy of Selecting Biological Variables 4-27

4.15.5 Methodology of Sampling and Analysis 4-30

4.15.6 Phytoplankton 4-31

4.15.7 Macro – Benthos 4-33

4.15.8 Conclusion 4-34

4.16 Terrestrial Ecology 4-37

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CHAPTER 5 ENVIRONMENTAL IMPACT ASSESSMENT

5.1 Preamble 5-1

5.2 Impacts during Construction Phase 5-4

5.2.1 Impact on Air Quality 5-4

5.2.2 Impact on Water Quality 5-5

5.2.3 Impact on Noise Level 5-6

5.2.4 Impact on Landuse 5-7

5.2.5 Assessment of Works, Health and Safety 5-7

5.3 Impacts during Operation Phase 5-8

5.3.1 Impact on Ambient Air Quality 5-8

5.3.2 Impact on Water Quality 5-12

5.3.3 Impact of Brine from Desalination Plant 5-14

5.3.4 Impact on Noise Levels 5-18

5.3.5 Impact on Social Life 5-20

5.3.6 Impact on Cultural Heritage 5-21

5.3.7 Impact on Terrestrial Ecology 5-21

5.3.8 Solid Waste 5-21

CHAPTER 6 PROPOSED MITIGATION MEASURES

6.1 Preamble 6-1

6.2 Mitigation Measures during Design and Construction 6-1

6.2.1 Dust Emissions 6-1

6.2.2 Noise Emissions 6-3

6.2.3 Flora and Fauna 6-3

6.2.4 Traffic and Transport 6-4

6.2.5 Socio – economic effects 6-4

6.2.6 Archaeology 6-5

6.2.7 Solid wastes during Construction 6-5

6.2.8 Occupational Health and Safety 6-6

6.3 Mitigation Measures during Operation 6-7

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6.3.1 Introduction 6-7

6.3.2 Air Quality during operation 6-8

6.3.3 Noise Emissions during Operation 6-8

6.3.4 Flora and Fauna during Operation 6-9

6.3.5 Visual Impact during Operation 6-9

6.3.6 Solid Waste Impacts during Operation 6-9

6.3.7 Health and Safety during Operation 6-10

6.4 Environment Monitoring Program 6-11

6.5 Hazard Protective Measures 6-15

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LIST OF TABLES

Table 2.1 Ambient Air Quality Standards 2-3

Table 2.2 Standards For Ambient Noise Levels 2-4

Table 2.3 Limits for Discharges into the Marine Environment 2-5

Table 2.4 Dubai Municipality Wastewater Discharge Standards 2-6

Table 2.5 Limits of Trace Metals in Sludge intended for Disposal on Land 2-8

Table 2.6 Land Contamination Indicator Levels 2-9

Table 3.1 Parameters for the Calculation of Emissions 3-2

Table 3.2 Natural Gas Analysis 3-11

Table 3.3 The Typical Diesel Oil Analysis 3-12

Table 3.4 Quality of the Wastewater Prior to the Treatment 3-17

Table 3.5 Details of Stack and Gaseous Emission 3-25

Table 4.1 Climatological Data – Dubai International Airport – 2008 4-3

Table 4.2 Monthly Sea Temperature Variation for the Year 2007 4-6

Table 4.3 Jebel Ali Village Air Quality Monitoring 4-10

Table 4.4 Background Heavy Metals in Soil in Dubai 4-14

Table 4.5 Selected Water Quality Parameters and Their Test Methods 4-19

Table 4.6 Distribution of Phytoplankton Cell Counts (NO/L) Along

Different Stations

4-35

Table 4.7 Distribution of Macro-Benthos Biomass (gm/m2) and Population

(no/m2)

4-36

Table 5.1 Impact Rating Assessment Matrix 5-2

Table 5.2 Impact Rating Assessment Matrix 5-3

Table 5.3 Source Data of the proposed ‘M’ Station Desalination Plant 5-10

Table 5.4 Predicted 24-Hourly short term Incremental Concentrations of

NOx

5-11

Table 5.5 Quality of Wastewater 5-13

Table 5.6 Predicted Noise Levels Plant Boundary 5-19

Table 6.1 Role and Responsibilities of the Project Proponent 6-2

Table 6.2 Responsibilities of Environmental Team during Operational 6-7

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Phase

Table 6.3 Environmental Monitoring During Construction Period 6-12

Table 6.4 Environmental Monitoring During Operation Period 6-13

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LIST OF FIGURES

Figure 1.1 Proposed Project site 1-4

Figure 3.1 Process Flow Diagram of MSF with Brine Circulation 3-7

Figure 4.1 Annual Windrose of Dubai International Airport – 2008 4-5

Figure 4.2 Monthly Sea Water Temperature 4-7

Figure 4.3 Marine Water Quality Monitoring 4-20

Figure 4.4 Monitoring Stations Along Coastal Environment of DEWA 4-27

Figure 4.5 Marine Environment of DEWA showing outfall Locations 4-29

Figure 4.6 Distribution of Macro-Benthos Biomass (gm/m2 ) and

Population (no/m2)

4-37

Figure 5.1 Noise Dispersion Contours 5-20

LIST OF APPENDICES

Appendix 1 Layout Plan of the Desalination plan

Appendix 2 Main Stack and Bypass Stack

Appendix 3 Wastwater Treatment P & I Diagram

Appendix 4 Sewage Treatment Plan

Executive Summary

E-1


M/s Fisia Italimpianti, Gruppo Impregilo & M/s Doosan are the main

contractor for the execution of the project, retained M/s. Environmental

International Consultants, Dubai to carry out the Environmental Impact

Assessment (EIA).

The EIA has been carried out as per the ETG 53 prescribed by Dubai

Municipality for getting environment clearance. EIA report has been prepared

in accordance with the Guidelines of Local Order 61 of 1991 published by

Dubai Municipality (DM). The environmental impacts of the proposed project

for the activities during construction as well as operation phase. As far as

possible, these evaluations are quantitative and based on comparisons with

relevant available standards specified by Dubai Municipality and International

Organizations (WHO, World Health Organization, World Bank).

Location of the project:

Proposed project is located in Dubai, U.A.E and is about 0.5 km from west of

the Dubai-Abu Dhabi highway and adjacent to Jebel Ali Free Zone. The

proposed site is at the existing Jebel Ali Power Station Complex. The project

location is already owned by DEWA. The project site is located along the

shore of the Arabian Gulf and adjacent to existing Jebel Ali ‘L’ power station.

The new desalination plant will be part of the Jebel Ali Power Station.

Project description:

The project consists of gas-based power plant to generate 2000 MW of

electricity and desalination plant of 140 MIGD capacities to produce potable

water.

Executive Summary

E-2


The seawater desalination plant shall consist of eight desalination units

having capacity of 17.5 MIGD each. This will result in total desalination plant

capacity of 140 MIGD.

1 Power Plant

To meet the continuously growing requirement for power in the emirate of

Dubai, UAE, the Dubai Electricity and Water Authority (DEWA) has planned to

install 2000 MW power plant.

The power plant of Jebel Ali ‘M’ station extension includes a total of six Gas

Turbines (GTs), equipped with Heat Recovery Steam Generators (HRSG)

comprising duct burners for supplementary firing, 3 condensing extraction

Steam Turbines (STs), and 2 Auxiliary Boilers (ABs). All considerations in the

present Report are based on this configuration.

In order to achieve a gross output of 2000 MW, six gas turbines will be

installed in ‘M’ station. The GTs will be equipped with dry low NO2 combustion

chambers for natural gas and Diesel oil fuel operation. No injection water or

steam injection facilities will be foreseen for NO2 reduction in case of Diesel oil

operation (only emergency cases).

2 Desalination Plant

The proposed desalination plant will be operated on Multi Stage Flash (MSF)

process.

Each distiller unit consists on a multistage flash evaporator chamber with its

auxiliary and ancillary equipment.

Executive Summary

E-3


The evaporator is a Multi Stage Flash type (MSF) with brine recirculation and

of cross tube single tier design. An anti scale system is used to treat the

recirculating brine in the whole temperature operating range of the evaporator.

The distillate produced by the eight desalination units is sent to the product

water system and blending plant. Each Unit can be subdivided from the

functional point of view in the following sections:

• Brine Heater Section;

• Heat Recovery Section; and

• Heat Reject Section.

Sources of Pollution:

1 Air emission:

In the proposed project the air emissions will be from the six stacks of power

plant and two stacks of auxiliary boilers in desalination plant. Since the power

plant and boilers will be fired on natural gas, the gaseous emissions will

comprise of NOx. These power units will be provided with stacks of adequate

height for the wider and quicker dispersion of the gaseous emissions.

The maximum incremental concentrations of NOX will be 8.6 µg/m3 and

occurring at a distance of about 3.0 km in southeast direction from the plant,

which are well within the stipulated standards of Dubai Municipality.

2 Wastewater

The wastewater generated in the project consists of;

• Oily Wastewater from service area of the power plant;

Executive Summary

E-4


• Chemical dosing area of power plant;

• Condensate discharge from the steam generator;

• Closed cooling water system;

• Brine from desalination plant; and

• Sewage from the restrooms.

The wastewater generated in the power plant shall be treated in the Effluent

Treatment Plant before sending it to desalination plant. The quality of the

discharge shall comply with Dubai Municipality regulation applicable for the

discharge into sea. The quality of condensate and discharge from closed

cooling water system will be similar to sea water quality except for the higher

temperature. These wastewater discharges shall be mixed with brine before

discharging into sea through out fall point.

The domestic wastewater shall be treated in the Sewage Treatment Plant and

treated wastewater shall be utilized in the landscaping.

3 Noise

The major noise generating equipment in the proposed facility will be pumps

used in pumping of seawater and brine. These pumps will be designed for

noise levels <85 dB (A) at 1 m from the equipment. These pumps will be

provided with pump house with adequate acoustic to attenuate the noise

levels. The noise levels shall fall below 70 dB (A) outside the pump house.

4 Solid waste

The solid waste shall be generated at the screening unit, where the debris

from the seawater will be screened out. The solid waste will be sent to the

Executive Summary

E-5


solid waste shall be non-hazardous in nature and disposed off as per Dubai

Municipality guidelines.

5 Salinity

Salt concentrations of the final effluent are above those of the receiving

waters, and will be consistently between 1 and 2.5 ppt above the existing

seawater background levels. In normal and minimal conditions, the salinity of

the effluent at the exit of the outfall (end-of-pipe) will be less than a 5%

increase above background seawater salinity. It is expected that at the edge

of the mixing zone, the Dubai Municipality (DM) Marine Standard (no more

than 5% in background concentration) would be respected at all conditions.

6 Chlorine

A chlorine generating system will produce the 0.1 to 0.15% sodium

hypochlorite solution from seawater feed. This solution will be injected into the

cooling tower and MED makeup streams on a continuous basis for a chlorine

residual of 0.5 ppm in these flows.

7 Oxygen

The DEWA effluent will be aerated in a way that the dissolved oxygen (DO)

concentration at the exit of the aeration basin would be at least 3 mg/l and at

the edge of the mixing zone, the dissolved oxygen levels should be close to

the background dissolved oxygen levels. The DO concentrations in the

effluent should not cause any mortality and should not affect the marine

organisms.

Executive Summary

E-6


8 Anti-scaling and antifoaming agents

Use of anti-scaling agents may lead to formation of orthophosphates from

hydrolysis of polyphosphates. Orthophosphates are a macronutrient that may

enhance biological growth (e.g. red and green algae). Polymeric additives

based on polyacrylate or polycarboxylic acids prevent this problem, and are

biodegradable and certified non-toxic.

Similarly, antifoaming agents are also degradable and non-toxic. Therefore

anti-scaling and antifoaming agents will be selected to avoid polyphosphate

formation and their impact on the marine environment will be considered

negligible.

9 Heavy Metals

Discharged brine contains low concentrations of metal ions resulting from

corrosion, namely copper, nickel, chromium and iron. These concentrations

are profoundly increased with acid cleaning of the plants, which occurs once

or twice per year.

Bioaccumulation of heavy metals in benthic fauna around the outfall could, in

theory, occur. Nevertheless, heavy metal concentrations at the outfall would

be very low due to the cooling water dilution, and below DM regulations.

These metals are also normal constituents of the sea (even if in low

concentrations) and are not of great concern except in extreme occurrences.

If bioaccumulation would occur, it would be locally.

Executive Summary

E-7


10 Thermal Impacts

The use of seawater will result in a discharge seawater temperature will

comply DM Standards. This small change in seawater temperature should not

be of concern for the marine environment, keeping in mind the choice of the

outfall location and design for the initial dilution

11 Socio economic

The new power plant will create new employment opportunities for

approximately 200 qualified employees, who will most likely be living in

downtown Dubai. Therefore the corresponding effect on population around

the project area will not be significant.

CHAPTER 1

Introduction

1-1


1.1 Preamble

The demand of power and water is rapidly increasing in Dubai Emirates due

to growing industrial activities in the region. To meet the growing demand of

waster and power, Dubai Electricity and Water Authority (DEWA) is proposing

the Jebel Ali Power and Desalination Station ‘M’ in addition to the existing

power project located adjacent to the project site. The project consists of

power plant with capacity of 2000 MW, 140 MIGD desalination plant and 400

kV substation.

The Environmental Impact Assessment is carried out for the proposed project

consisting of power having capacity of 2000 MW and 140 MIGD capacity

desalination plant. The desalination plant shall cater the requirement of power

plant and fulfill the water demand of Dubai city.

The power plant will be planned and built by M/s Doosan Heavy

Industries & Construction Company. The Desalination plant shall be

designed and constructed by M/s Fisia Italimpianti, Gruppo Impregilo.

Both these companies retained M/s. Environmental International

Consultants, Dubai to carry out the Environmental Impact Assessment (EIA).

The EIA shall be carried out as per the ETG 53 prescribed by Dubai

Municipality for getting environment clearance. EIA report has been prepared

in accordance with the Guidelines of Local Order 61 of 1991 published by

Dubai Municipality (DM). The environmental impacts of the proposed project

for the activities during construction as well as operation phase. As far as

possible, these evaluations are quantitative and based on comparisons with

relevant available standards specified by Dubai Municipality and International

Organizations (WHO, World Health Organization, World Bank).

CHAPTER 1

Introduction

1-2


1.2 Objective of the Study

EIA is a tool to assess the sustainability of the project with respect to benefits

of the project and environmental issues. The objective of EIA is to improve the

decision making process and to ensure that the project options under

consideration are environmentally sound and sustainable. EIA identifies the

ways to minimize the adverse impacts and identify the ways to improve the

environment.

The advantages of an EIA are:

• It allows project designers and implementing agencies to address

environmental issues in a timely and cost effective manner;

• Reduces the need for the project conditionality since appropriate steps can

be taken in advance or incorporated into project design or alternatives to

the proposed project can be considered; and

• Helps to avoid costs and delays in implementation due to unanticipated

environmental problems.

The basic objective of conducting an EIA study for the proposed project is to

rationalize the procedure for an effective environmental management plan,

leading to an improvement in environmental quality as a result of constructing

this power station.

1.3 Objective of the Project

Desalination capacities offered by the project are of basic importance for the

future water supply needs of the Dubai. Therefore, type, size and location of

the plant as well as the fuel to be used have been determined to meet

necessary development in energy supply as well as the limitation or

environmental impacts resulting from the plant.

CHAPTER 1

Introduction

1-3


To meet the continuously growing requirement for water in Dubai, UAE, the

Dubai Electricity and Water Authority (DEWA) is planning to extend the

existing Jebel Ali Power and Desalination unit to have an additional installed

capacity of 2000 MW power with 140 MIGD desalination plant.

1.4 Location and Accessibility

Proposed project is located in Dubai, U.A.E and is about 0.5 km from west of

the Dubai-Abu Dhabi highway and adjacent to Jebel Ali Free Zone. The

present location of the proposed project is shown in Figure 1.1.

The proposed site is at the existing Jebel Ali Power Station Complex. The

project location is already owned by DEWA.

The project site is located along the shore of the Arabian Gulf and adjacent to

existing Jebel Ali ‘L’ power station. The new desalination plant will be part of

the Jebel Ali Power Station.

Jebel Ali Power complex consist of the following operating units:

• Station ‘D’ Phase I, was built between 1976 and 1980. The plant consist

of five steam turbine generators each of 68 MW capacity and five

desalination plants producing in total 14.38 MIGD of water. During the

years 1982 and 1983, two gas turbines each with a summer site rating

capacity of 42.50 MW were added.

• Station ‘D’ Phase II, was built between 1981 and 1984. It consists of

three steam turbine generators each of 75 mw capacity and three

desalination plants producing in total 17.16 MIGD of water.

CHAPTER 1

Introduction

1-4


FIGURE 1.1

PROPOSED PROJECT SITE

CHAPTER 1

Introduction

1-5


• Station ‘E’, consisting of three gas turbine generating plants each of 84

MW capacity (gross) at 50o C and four desalination plants producing 24

MIGD, was commissioned between 1989 and 1991. The station was

extended by two gas turbine generators with a total site summer output of

around 180 MW (gross). These two units were commissioned in 1992. The

extension part was converted to combined cycle operation by adding heat

recovery systems and a steam turbine generator of around 112 MW

(gross) capacity, these being finally commissioned in 1996

• Station ‘G’, consisting of four gas turbine generators having a total

capacity of 457 MW (gross) and eight desalination plants producing 60

MIGD of water, was commissioned between 1993 and 1994.

• Station ‘G’ extension consists of one gas turbine generator and one

WHRB of the same type as for Station ‘G’. The gas turbine generator has

a capacity during summer of 121 MW (gross). In addition, the station

possess two backpressure steam turbines each with a capacity of 71 MW

and a further backpressure steam turbine with a capacity of around 58 MW

located at E station. The units were commissioned between 1996 and

1997.

• Station ‘K’ Phase I plant was awarded at the beginning of 1999 and has

two desalination units (10 MIGD each) associated with blending plant,

potable water reservoir, and potable water pumps etc. The steam supply

for these two desalination units was sourced from existing auxiliary boilers

at ‘G’ Station until the new power plant ‘K’ Station Phase II took over the

steam supply for the desalination units of Phase I & II.

• Repowering of ‘D’ Station Phase II was awarded in 1999 and comprises

self contained gas turbine generator units (GT) having a total capacity of

approximately 400 MW at 50o C ambient temperature net of all auxiliary

power demands and losses, exporting to the existing Dubai grid and

CHAPTER 1

Introduction

1-6


equipped with Waste Heat Recovery Boilers (WHRB) to generate steam

by utilising all the waste heat available in Gas Turbine exhaust gas and

supply steam to the existing three 75 MW steam turbines and three 5.75

MIGD desalination plants of Station ‘D’ Phase II plant.

• Station ‘K’ Phase II, was built between 2000 and 2003 and consists of

three gas turbine generators with WHRB, two pressure steam turbines

having a total capacity of 835 MW (gross) as well as three desalination

plants producing 40 MIGD of water. The combined cycle power plant also

supply low pressure steam for Station ‘K’ Phase I.

• Station ‘H’, Phase I, consisting of six simple cycle Gas Turbines suitable

for quick starting & Peak shaving operations having a total capacity of 607

MW at 50° C ambient temperature, was commissioned between 1998 and

1999.

• Phase II, consisting of three simple cycle Gas Turbines suitable for quick

starting & Peak shaving operations having a total capacity of 800 MW, to

be commissioned between May 2006 and June 2006.

• Phase III, consisting of four simple cycle Gas Turbines suitable for quick

starting & Peak shaving operations having a total capacity of 800 MW, to

be commissioned by April 2008.

• Station ‘L’, Phase I, consisting of three Gas Turbines, three Waste Heat

recovery Boilers, two Auxiliary Boilers, two Back Pressure Steam turbines

and three Desalination Plants with a total capacity of 850 MW and 70

MIGD of water, to be commissioned between December 2005 and

February 2006.

CHAPTER 1

Introduction

1-7


• Station ‘L’, Phase II, consisting of four Gas Turbines, four Waste Heat

Recovery Boilers. Two Auxiliary Boilers, two Condensing Steam Turbines

and four Desalination Plants with a total capacity of 1200 MW and 55

MIGD of water to be commissioned between April 2007 and April 2008.

In total the Jebel Ali Power and Desalination Station has at the moment

without the installation for ‘M’ Station a total installed capacity of 3833 MW

power generation plus 188 MIGD water productions. Layout plan of the

proposed Desalination plant is shown in Appendix 1.

1.5 Methodology of EIA study

The proposed Desalination project is designated to be developed under the

Local Order 61/1991 of Environmental Protection and Safety Section, which is

guided by Technical Guideline 53 for Environmental Impact Assessment

Procedure by Dubai Municipality.

This report presents the results of the EIA process, which is intended to:

• Establish and review existing conditions pertaining to the plant site and

surrounding areas;

• Identify and assess the environmental impacts during construction phase

and subsequently during operation phase; and

• Advise and assist in identifying appropriate measures to mitigate adverse

impacts to be adopted under Environment Management Plan (EMP) for all

specified significant environmental impacts likely to emerge.

1.6 Approach of the EIA study

EIC has adopted stepwise screening procedures for environmental impacts

identification and assessment. This report on EIA is based on the

observations made by the EIC team during visits to the study area and

CHAPTER 1

Introduction

1-8


collection of available environmental data from secondary sources. Literature

has also been reviewed and relevant information has been collected for

environmental and social baseline. Reconnaissance surveys have been

conducted to identify the major environmental and safety issues from the

proposed project.

EIC has followed the standard EIA methodology and technique during the

entire study and whenever necessary it has used its own judgment based on

its own experience and knowledge. During the entire study appropriate quality

checks have been taken into consideration and best management practices

have been followed for a quality output.

Impacts are identified based on the actual and foreseeable events, including

operational events and typical events of the proposed expansion. Processes

that may create risks to the natural environment are considered in terms of

key potential environmental impacts. Mitigation measures to be adopted

under Mitigation Management Plan for all specified significant environmental

impacts likely to result during the construction and subsequently during

operation, is also a part of the EIA report. The likely impacts identified and

recommended mitigation measures are based on the following:

• Project information provided by project proponent;

• Baseline information and reconnaissance survey of the study area;

• EIC’s past experience on similar projects; and

• Standard National/International environmental management guidelines/

practices.

1.7 Structure of Report

This report is structured based on the table of contents suggested in ETG 53

by Dubai Municipality. A brief description of each chapter is presented below;

CHAPTER 1

Introduction

1-9


Executive Summary Presents significant findings and

recommended actions.

Chapter 1 Introduction Presents, an introduction along with scope

and objective of this EIA study.

Chapter 2 Policy and Legal

Framework

Presents, Policy, legal, and administrative

framework applicable to the proposed

project.

Chapter 3 Project

Description

Presents, project details with regards to the

proposed project.

Chapter 4 Baseline Study Presents, description of existing

environment based on monitoring /

collection and evaluation of baseline data.

Chapter 5 Environment

Impact

Assessment

Presents, the significant environment

impacts of proposed project with respect to

air, water, soil, noise, solid waste and

Terrestrial and Marine ecological

environment.

Chapter 6 Mitigation

Measures

Presents, the followings:

• Mitigation Management Plan during

construction and operation of the

proposed project.

• Environmental Monitoring Plan

Appendices

CHAPTER 2

Policy and Legal Framework

2-1


2.1 Preamble

The proposed power plant and desalination plant is designated to be

developed under the Local Order 61/1991 of Environmental Protection and

Safety Section.

The environmental health and safety department, Dubai Municipality has

developed environmental control rules, standards and guidelines for air, water

pollution management, dangerous/hazardous materials, solid wastes, noise

control for environmental management. These requirements are finalized in

close coordination with Federal Environmental Agency or Federal

Environmental law would be dealt with penalties as per EHS rules.

These guidelines give the authority to:

Issue environmental permits to the entity responsible for undertaking any

enterprise;

• Issue permits for discharge of trade waste/hazardous waste water,

domestic and hazardous solid waste;

• Request information as the authority thinks fit;

• Request Environmental Impact Assessment report containing relevant

information;

• Request information on pollution control activities;

• Issue an annually renewable Operation Fitness Certificate (OFC);and

• Revoke or suspend permits.

2.2 Guidelines

The owner of a works shall use the Best Practicable Environmental Option

(BPEO) for preventing the discharge of noxious or offensive substances into

CHAPTER 2


2-2


environment from the premises and for rendering harmless and inoffensive

such substances as may be so discharged. Whether or not a substance is

noxious or offensive shall be in the judgement of the authority and shall

include gases, vapours, smoke, grit, fume, noise, solid and liquid wastes etc.

The EHS department, Dubai Municipality has prepared Environmental

Technical Guidelines (ETGs) for specific facilities and concerns which need to

be addressed. The following EHS guidelines shall be applicable for the

proposed facility during operation:

• ETG 53, Environmental Impact Assessment Procedure by Dubai

Municipality;

• ETG 1, Application for waste discharge permits to sewer, land and marine

environment by Dubai Municipality;

• ETG 3, Guidelines for safety audit report by Dubai Municipality;

• ETG 7, Heat Stress at Work by Dubai Municipality;

• ETG 8, Entry into Confined Space by Dubai Municipality;

• ETG 10, Guarding of Dangerous Machinery by Dubai Municipality;

• ETG 13, Industrial Wastewater Disposal by Dubai Municipality;

• ETG 14 - 21, Personal Protective Equipments by Dubai Municipality;

• ETG 25, First aid requirements by Dubai Municipality;

• ETG 26, Application for approval of disposal of hazardous wastes by

Dubai Municipality;

• ETG 27, Annual approval for hazardous waste disposal by Dubai

Municipality;

• ETG 28, Waste minimization by Dubai Municipality;

• ETG 29, Requirements for the Discharge of Waste Gases, Fumes and

Dusts to the Atmosphere by Dubai Municipality;

• ETG 34, Requirement for the use of Waste Oil in Boilers and Furnaces;

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• ETG 37, Transport of Non-hazardous wastewater by tanker vehicles by

Dubai Municipality;

• ETG 40, Examination and Certification of Boilers and Pressure Vessels;

• ETG 44, Requirement for Reduction of Construction/demolition noise;

• ETG 45 , Requirements for the Control of Entertainment Noise by Dubai

Municipality;

• ETG 49, Hazardous waste exemption policy by Dubai Municipality;

• ETG 50, Requirements for transport of hazardous waste by Dubai

Municipality;

2.3 Standards

The following EHS standards are / shall be applicable during the construction

and operation of proposed desalination plant project:

• Environmental Standard and Allowable Limits of Pollutants on Land, Water

and Air environment (May, 2003) by Dubai Municipality; and

• Final Air Pollution Law, 2006 by FEA.

2.3.1 Ambient Air Quality Standards

The ambient air quality standards are given in Table-2.1.

TABLE-2.1

AMBIENT AIR QUALITY STANDARDS

Allowable Limit (max.) Sn Pollutant

µg/m3 ppm

Average Time

350 0.13 1 hour

150 0.06 24 hours 1 Sulphur Dioxide (SO2)

50 0.02 1 year

23000 20 1 hour 2 Carbon Monoxide (CO)

10000 7 8 hours

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Allowable Limit (max.) Sn Pollutant

µg/m3 ppm

Average Time

290 0.15 1 hour 3 Nitrogen Dioxide (NO2)

110 0.06 24 hours

160 0.08 1 hour 4 Ozone (O3)

120 0.06 8 hours

230 - 1 hour 5 TSPM

90 - 24 hours

300 - 1 hour

150 - 24 hours 6 PM10

0.5 600 3 months

Prescribed by FEA.

2.3.2 Ambient Noise Level

The standards are presented in Table- 2.2.

TABLE-2.2

STANDARDS FOR AMBIENT NOISE LEVELS

Allowable Limits for Noise

Level dBA* Sn Area

Day

7 a.m-8 p.m

Night

8 p.m-7 a.m

1 Residential areas with light traffic 40-50 30-40

2 Residential areas in downtown 45-55 35-45

3

Residential areas which includes

some workshops & commercial

business or residential areas near

highways

50-60 40-50

4 Commercial areas & Downtown 55-65 45-55

5 Industrial Areas Fence lines (Heavy

industry) 60-70 50-60

*Prescribed by FEA.

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2.3.3 Wastewater Discharge Limits

Permissible limits for aqueous discharges to land and into the sea are listed in

Table-2.3 and Table-2.4 respectively.

TABLE 2.3

LIMITS FOR DISCHARGES INTO THE MARINE ENVIRONMENT

Parameter Units Permissible Emission Limit to

Marine Environment

pH - 6 – 9

Suspended Solids mg/l 25

Turbidity NTU 75

B.O.D. mg/l 20

C.O.D. mg/l 125

Oil and Grease mg/l 10

Phenols mg/l 0.1

Ammonia as N mg/l 2.0

Total Organic Carbon mg/l 75

Sulphides as S mg/l 0.1

Cyanides as CN mg/l 0.1

Residual Chlorine mg/l 1.0

Cadmium (Cd) mg/l 0.05

Chromium (Cr) mg/l 0.50

Copper (Cu) mg/l 0.50

Iron (Fe) mg/l 2.0

Lead (Pb) mg/l 0.10

Mercury (Hg) mg/l 0.001

Nickel (Ni) mg/l 0.10

Selenium (Se) mg/l 0.02

Silver (Ag) mg/l 0.005

Zinc (Zn) mg/l 0.10

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Parameter Units Permissible Emission Limit to

Marine Environment

Faecal Coliforms MPN/ 100 ml 1000

Source : Federal Regulation of Law No. 24, 1999.

TABLE 2.4

DUBAI MUNICIPALITY WASTEWATER DISCHARGE STANDARDS

Maximum Allowable Limits

Discharged to

Land as for

Irrigation

Sr.

No. Parameters Unit

Sewerage

System Drip Spray

Physical-Chemical

1 Biochemical Oxygen

Demand Mg/l 1000 20 10

2 Chemical Oxygen

Demand Mg/l 3,000 100 50

3 Chlorides Mg/l - 500 350

4 Chlorine – residual Mg/l 10 Not less than 0.5 mg/l

after 30 min contact time

5 Cyanides as CN Mg/l 1 0.05 0.05

6 Detergents Mg/l 30 - -

7 Fluorides mg/l - 1 1

8 Nitrogen, ammoniacal Mg/l 40 5 1

9 Nitrogen, organic

(Kjeldhal) Mg/l - 10 5

10 Nitrogen, total Mg/l - 50 30

11 Oil & Grease – Emulsified Mg/l 150 - -

12 Oil & Grease – Free oil Mg/l 50 5 5

13 pH (range) units 6 – 10 6.0–8.0 6.0–8.0

14 Pesticides, non-

chlorinated Mg/l 5 - -

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Discharged to

Land as for

Irrigation

Sr.

No. Parameters Unit

Sewerage

System Drip Spray

15 Phenols Mg/l 50 0.1 0.1

16 Phosphorous (P) Mg/l 30 20 20

17 Sulfates, total Mg/l 500 200 200

18 Sulfides as S Mg/l 10 0.05 0.05

19 Surfactants Mg/l - - -

20 Suspended Solids (SS) Mg/l 500 50 10

21 Temperature 0C 45 or > 5 of

ambient - -

22 Total Dissolved Solids Mg/l 3,000 1,500 1,000

Metals

23 Total Metals Mg/l 10 - -

24 Aluminum (Al) Mg/l - 2 2

25 Arsenic (As) Mg/l 0.50 0.05 0.05

26 Barium (Ba) Mg/l - 1 1

27 Beryllium (Be) Mg/l - 0.1 0.1

28 Boron (B) Mg/l 2.0 2.0 2.0

29 Cadmium (Cd) Mg/l 0.3 0.01 0.01

30 Chromium (Cr) Mg/l 1.0 0.1 0.1

31 Cobalt Mg/l - 0.1 0.1

32 Copper (Cu) Mg/l 1.0 0.2 0.2

33 Iron (Fe) Mg/l - 2.0 2.0

34 Lead (Pb) Mg/l 1.0 0.5 0.5

35 Magnesium (mg) Mg/l - 100 100

36 Manganese (Mn) Mg/l 1.0 0.2 0.2

37 Mercury (Hg) Mg/l 0.01 0.001 0.001

38 Molybdenum (Mo) Mg/l - 0.01 0.01

39 Nickel (Ni) Mg/l 1.0 0.2 0.2

40 Selenium (Se) Mg/l - 0.02 0.02

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Discharged to

Land as for

Irrigation

Sr.

No. Parameters Unit

Sewerage

System Drip Spray

41 Silver (Ag) Mg/l 1.0 - -

42 Sodium (Na) Mg/l - 500 200

43 Zinc (Zn) Mg/l 2.0 0.5 0.2

Bacteriological

44 Fecal Coliforms MPN/100

ml. 500 20 -

2.3.4 Solid Waste

The standards are applicable for different usages of solid wastes (hazardous

and non-hazardous) are given in Table 2.5.

TABLE 2.5

LIMITS OF TRACE METALS IN SLUDGE INTENDED FOR DISPOSAL ON LAND

Sn Contaminant Maximum Limit

(mg/kg)

10 year cumulative

loading on land

(kg/hectare)

1 Cadmium 30 20

2 Chromium 1,000 200

3 Cobalt 100 30

4 Copper 1,000 50

5 Lead 1,000 125

6 Mercury 10 5

7 Molybdenum 20 5

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Sn Contaminant Maximum Limit

(mg/kg)

10 year cumulative

loading on land

(kg/hectare)

8 Nickel 200 100

9 Zinc 1,000 250

Note

* Where disposal is for the purpose of soil conditioning as in the use of compost or

fertilizer for agricultural activity. In any case, disposal to land must have prior written

approval from EPSS.

The indicator levels are adopted as the objectives for contaminants not to

exceed for the land environment due to impact of human activities are given in

Table 2.6.

TABLE 2.6

LAND CONTAMINATION INDICATOR LEVELS

Sn. Parameter Acceptable Level (mg/kg)

1 Arsenic 50

2 Barium 400

3 Cadmium 5

4 Chromium 250

5 Copper 100

6 Lead 200

7 Manganese 700

8 Mercury 2

9 Selenium 2

10 Zinc 500

11 Cyanide 10

12 Fluoride 500

13 Phenols 1

14 Benzene 1

15 Chlorinated Hydrocarbons 1

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16 Pesticides (Total) 2

17 Polychlorinated Biphenyls (PCBs) 0.5

18

Total Petroleum Hydrocarbons

<C9

>C9

1000

10000

19 BTEX (Total) 100

Note

** Depending on the source, location and intended land use, the EPSS may specify

stringent level where the health of expected receptors will be at risk or to maintain the

background quality of the site.

2.4 ISO 14000

DEWA, the owner and operator of Jebel Ali Power Station, is an ISO 14001

certified company (Environmental Management System). Further, proposed

project shall also comply with the ISO 14001 requirements.

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3.0 Project Characteristics

3.1 Outline and Rationale of the Project

The proposed Power plant of 2000 MW and Desalination plant of 140 MIGD

capacity is of basic importance to meet the increased demand of power and

drinking water requirement of UAE. Therefore, type, size and location of the

plant have been determined to meet both, the necessary development in

public water and energy supply as well as the limitation or environmental

impacts resulting from the plant.

3.2 Plant Layout and Land Requirement

The proposed desalination plant is located along the shore and power plant is

located adjacent to the desalination plant.

The total land required for the project is about 218250 m2. The water supply

pipelines and brine discharge pipelines are laid along the length of the plant

boundary parallel to sea shore.

The desalination plant is part of the Power Station ‘M’, therefore it is located

near the power station and no alternate site was identified.

All considerations made in this report regarding environmental impact are

based on the power plant of 2000 MW capacity and desalination plant of 140

MIGD capacity.

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3.3 Project Description – Power Plant (2000 MW)

The power plant of Jebel Ali ‘M’ extension includes three modules and each

module consist of two gas turbines, two heat recovery steam generators

(HRSG) and one steam turbine. All considerations in the present report are

based on this configuration.

The gas turbines can be operated with supplementary firing into the HRSG for

additional steam production. For supplementary firing, solely natural gas will

be used.

The gas turbines will also be operated with natural gas supplied by gas

pipeline connection. In emergency cases and for the unlikely event of a

natural gas shortage, the gas turbines can also be operated with Diesel oil.

Table 3.1 presents the reference parameters for the calculation of emissions

represent the worst case normal operation scenario at full plant load firing

natural gas in summer (ambient Temperature 50° C) with full supplementary

firing.

TABLE 3.1

PARAMETERS FOR THE CALCULATION OF EMISSIONS

S.

No. Operation Condition

Parameters for the

Calculation of Emissions

1 Exhaust gas mass flow related to each gas

turbine 608.33 kg/s

2 Exhaust gas emission temperature after

HRSGs 118.4°C

3 Residual oxygen concentration in exhaust gas 11.5 vol %

4 Guaranteed NOX emission level in gas turbine

exhaust gas 25 ppm, dry, at 15 % O2

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S.

No. Operation Condition

Parameters for the

Calculation of Emissions

5 Guaranteed CO emission level in gas turbine

exhaust gas 15 ppm, dry, at 15 % O2

6 Particulates (ash) content of natural gas fuel Negligible

7 Exhaust gas density 0.9 kg/m3

8 Exhaust gas velocity at stack mouth 17.5 m/s

Diesel oil will only be used as backup fuel in emergency cases, during

temporary failure of the natural gas supply. Therefore operation on diesel oil is

not considered as normal operation and the detailed investigation of

environmental impacts will focus on operation with natural gas fuel. Due to

new gas supply agreements recently made with suppliers from outside UAE, a

failure of the gas supply in the future is considered very unlikely.

The operation of the plant on Diesel oil will be minimized and restricted to

emergency cases, considering the fact that higher emissions of NOX and SOX

are present in this case. However, in view of change in diesel fuel

specifications by the UAE government restricting the sulphur content to a

maximum of 0.05% the sulphur emission is expected to comply with DM

regulations on stack emissions.

3.3.1 Main Systems / Components

In order to achieve a net Output of approximately 2000 MW, six gas turbines

will be installed in M station. The GTs will be equipped with dry low NO2

combustion chambers for natural gas and Diesel oil fuel operation. No

injection water or steam injection facilities will be foreseen for NO2 reduction in

case of diesel oil operation (only emergency cases).

The auxiliary boilers and the supplementary firing facilities will be also

equipped with low NO2 combustion facilities.

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Each of the gas turbines (GTs) will be equipped with an individual Heat

Recovery Steam Generator (HRSG) adequately sized for the related GT, so

that identical HRSGs, will be installed. The GTs will be provided with bypass

stacks to allow GT operation independent from the operation of the HRSG in

emergency cases.

All gas turbines have to be equipped with air inlet cooling system. The

plant/unit capacity at 50o C shall be achieved at normal GT Turbine Inlet

Temperature (TIT) and not of increased TIT (peak load operation). The heat

of the exhaust gases shall be utilized in the respective heat recovery steam

generators.

The heat of the exhaust gases will be utilized in the respective heat recovery

steam generators. The HRSGs will be of two pressure type with

supplementary firing and shall be designed for an optimum utilization of the

exhaust heat. The summary of operating conditions at main stack and bypass

stack is attached as Appendix 2.

3.3.2 Modes of Operation

The plant shall be designed to ensure flexibility of operation, a high level of

fault tolerance and ease of maintenance. It shall meet the following

operational and design requirements.

• Each gas turbine generator shall be capable of operating in open cycle

independent of the steam generation plant;

• Each HRSG shall be capable of being started up as the first and

subsequent steam generator from any condition of GT loading within

predetermined thermal stress margins an a run up time to full load agreed

as being operationally acceptable;

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• Each GT/HRSG unit shall be capable of being operated at part load in

conjunction with other units operating at full or near full load continuously

without detriment to plant life expectancy;

• Each HRSG or GT/HRSG unit shall be capable of independent shut down;

• Each steam turbine shall be capable of operating from minimum load up to

maximum load. In the event of a steam turbine trip, the unit is to transfer to

steam turbine by-pass mode automatically without loss of water

production;

• The duct burners shall cut in automatically in case of steam generated in

the HRSG from waste heat in the gas turbine exhaust is not sufficient to

maintain steam turbine output.

3.3.3 Abnormal operating modes

The plant will be designed to operate satisfactorily under automatic control

without undo perturbation of the steam temperature and pressure under all

normal operational transients arising, for example, from the bringing into or

out of service of a gas turbine, HRSG unit or a steam turbine. Furthermore,

the Station shall satisfactorily run under automatic control and without direct

operator intervention during such fault conditions which be reasonably

anticipated, including the following:

• A trip of one power plant block from full or part load;

• A gas turbine generator trip from full or part load when either operating in

open or closed cycle;

• A HRSG trip any load with or without auxiliary firing;

• When auxiliary firing is tripped and HRSG is still in service;

• A steam turbine trip from full or partial load;

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• The loss of the normal fuel gas supply to the Station and transfer to the

diesel oil stand-by system;

• In the event of full or partial load rejection of single GT unit, that unit shall

continue to operate at synchronous speed, feeding its own auxiliaries. The

unit shall be capable of resynchronized and reloaded to MCR at the

maximum loading rate.

In the event of a trip of a gas turbine and/or a HRSG, the associated steam

turbine shall continue to operate at reduced output. If applicable (for example

only one GT/HRSG was in operation) trip of the steam turbine shall be

delayed as much as possible after the GT trip. The steam turbine shall be

restarted using steam generated once the required steam conditions have

been established.

The impact on plant operation of any other major fault conditions shall be

minimized and the control strategy of the plant shall ensure an orderly and

effective recovery from such conditions.

3.4 Project Description – Desalination Plant

The seawater desalination plant shall consist of eight desalination units

having capacity of 17.5 MIGD each. This will result in total desalination plant

capacity of 140 MIGD.

The proposed desalination plant will be operated on Multi Stage Flash (MSF)

process. In this process, two types of operations are available i.e.

1 Multi Stage Flash Once through desalination process; and

2 Multi Stage Flash process with brine recirculation.

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The proposed plant will be operated on Multi Stage Flash with brine

circulation process.

Multi Stage Flash Process with Brine Circulation

In Multi Stage Flash process, an evaporator consists of several consecutive

stages (evaporating chambers) maintained at decreasing pressures from the

first stage (hot) to the last stage (cold). Sea-water flows through the tubes of

the heat exchangers where it is warmed by condensation of the vapour

produced in each stage. Its temperature increases from sea temperature to

inlet temperature of the brine heater. The sea water then flows through the

brine heater where it receives the heat necessary for the process (generally

by condensing steam). At the outlet of the brine heater, when entering the first

cell, sea water is overheated compared to the temperature and pressure of

stage 1. Thus it will immediately "flash" i.e. release heat, and thus vapour, to

reach equilibrium with stage conditions. The produced vapour is condensed

into fresh water on the tubular exchanger at the top of the stage. The process

takes place again when the water is introduced into the following stage, and

so on until the last and coldest stage. The cumulated fresh water builds up the

distillate production which is extracted from the coldest stage. Sea water

slightly concentrates from stage to stage and builds up the brine flow which is

extracted from the last stage. The typical drawing process flow diagram of

MSF is given in Figure-3.1.

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FIGURE 3.1

PROCESS FLOW DIAGRAM OF MSF WITH BRINE CIRCULATION

The desalination units shall be of the Multi Stage Flash type with brine

recirculation of cross tube and single deck design.

The once-through flash type evaporator uses the sea-water flow both for

purposes of cooling (sea-water is introduced into the evaporator at the sea

temperature and is rejected at the brine temperature) and production of

distillate (by flashing from the outlet temperature of the brine heater to the

brine extraction temperature). This has two consequences on plant design:

• The whole sea water flow being heated to high temperature, it has to be

treated with anti-scale which increases operating costs.

• As the sea water flow cannot be decreased below values allowing safe

working conditions, the stages must be designed for winter operation,

leading to an increased evaporator volume and thus increased investment

costs.

These two points have led to the separation of the two functions (cooling and

production).

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The cooling sea-water flows through the condensers of the two (or generally

three) last stages, named "heat reject section". Upon leaving the evaporator,

part of the warmed water is rejected to sea; part is used as the make-up for

the plant. Only this part of the water is treated instead of the whole cooling

water. The production is insured by the brine recycling flow that is drawn from

the last stage towards the condensers of the other stages, named "heat gain

section", and then to the brine heater.

The warmed water leaving the heat reject section may be used in winter to

warm up the cooling sea-water, thus enabling the evaporator volume to be

designed for a reasonably high temperature.

MSF plants with brine recycling are widely used all over the world. Once-

through desalination plant should only be used for small plants (when the cost

of the chemicals is not of great importance) and in areas where the

temperature of the sea-water remains approximately constant throughout the

year.

3.4.1 Details of Proposed Desalination Plant

Each distiller unit consists on a multistage flash evaporator chamber with its

auxiliary and ancillary equipment.

The evaporator is a Multi Stage Flash type (MSF) with brine recirculation and

of cross tube single tier design. An anti scale system is used to treat the

recirculating brine in the whole temperature operating range of the evaporator.

The distillate produced by the eight desalination units is sent to the product

water system and Blending Plant. Each Unit can be subdivided from the

functional point of view in the following sections:

• Brine Heater Section;

• Heat Recovery Section; and

• Heat Reject Section

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The process is based on the recycle of the brine in the recovery section where

the latent heat of condensing vapour is recovered by increasing the

temperature of the brine recirculating in the condensers tubes. The heat input

to the system is supplied by the low pressure steam coming from the Power

Station (Package P) and the Auxiliary Boilers System to the Brine Heater in

which the brine flowing in the tube side is heated up to Top Brine

Temperature. One evaporation unit will be operated on steam procured from

existing Power Station ‘L’. The heated brine then passes through all the

stages where it flashes because of the higher temperature in respect of the

brine flowing inside the tube bundle.

This “flashed off” vapour rises through the tube bundle and condenses on the

tubes surface. The condensed water, called distillate, falls into a dedicate tray

and it is collected together with distillate coming from the other stages and

then sent to the distillate extraction pumping system.

The salt concentration of the recirculating brine is kept at the required value

by a continuous blow down of the concentrated brine and a congruent feed of

make-up sea water, which is deareted and treated with antifoam additive prior

entering the evaporator. Sodium Sulphate is also used as oxygen scavenger

in brine recycle line to recovery section. Most of the evaporator chambers

operate under vacuum; in order to maintain the vacuum condition, leakages

and non-condensable gases released from feed sea water are purged to

atmosphere by a dedicated vacuum system (ejectors and condensers

system).

• Discharge System

The discharge system includes one barometric pit system and one drain pit

for each distiller and the outfall system with provisions for the eight units of M

Station and all Power Plant discharges. For each unit, the relevant barometric

pit collects all condensate discharges and drains from the three exchangers of

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the vacuum system and it is equipped with of two sump pumps one on duty

and one in stand by mode to send the vacuum system discharges to drain pit.

The drain pit collects the discharges from the distiller and the M. P. steam

condensate from the steam trap on the vacuum system steam supply line.

The discharges of two units are collected together and sent to outfall.

3.5 Operational Features of the Project

3.5.1 Fuel

At present DEWA utilizes Natural Gas (NG) as primary fuel and Diesel Oil

(DO) as secondary fuel. The natural Gas fuel is arranged by Dubai Supply

Authority (DUSUP) from different sources.

For the Jebel Ali ‘M’ project natural gas shall be used as primary fuel and

diesel oil shall serve as back up fuel. The gas turbines and the heat recovery

steam generators will be operated with natural gas as a main fuel. The gas

turbines and the auxiliary boilers will be able to use Diesel oil if required while

the duct burners of the HRSG’s (for supplementary firing) will be designed for

natural gas operation only.

The gas supply system will be designed to handle the fuel demand when the

gas turbine and the supplementary burning system are operating at maximum

consumption.

The Diesel oil storage tank capacity will be sufficient for 8 days continuous

operation of the plant considering full load of the gas turbines with condensing

steam turbine at design conditions. When the supplementary firing is out of

service, the auxiliary boilers will be operated to produce the additional steam

flow required for 100% water production. As the auxiliary boilers are also

equipped with low NOX combustion facilities, the specific pollutant emission

rates at auxiliary boiler operation will be similar as with supplementary firing.

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The Characteristics of Natural Gas and Diesel is given in Table-3.2 and

Table-3.3.

TABLE 3.2

NATURAL GAS ANALYSIS

S.No Component Unit Value

1 Nitrogen Mole % 0.408

2 Methane Mole % 90.09

3 Carbon di oxide Mole % 4.257

4 Ethane Mole % 3.669

5 Propane Mole % 1.186

6 I – Butane Mole % 0.211

7 N – Butane Mole % 0.249

8 I – Butane Mole % 0.054

9 N – Butane Mole % 0.038

10 H2S content (maximum 250 ppm)

ppm 135

11 Ideal relative density (air 1) Kg/m3 0.63394

12 Ideal Gas Density @ 14.696 Psia & 60o F

Ib/ft3 0.04838

13 Ideal Net Calorific Value at 14.696 Psia & 60o F

BTU/ft3 921.15

14 Ideal Total Calorific Value at 14.696 Psia & 60o F

BTU/ft3 1020.92

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TABLE 3.3

THE TYPICAL DIESEL OIL ANALYSIS

Description Unit Specification Typical

Low Heating Value (LHV) MJ/kg min 42.3 42.7

High Heating Value (HHV) MJ/kg min 45.0 45.7

Specific gravity at 60°F - 0.83 – 0.8 0.85

API gravity deg min 30 35.5

Flash point °C min 65 69

Pour point °C max -3 -

Kinematic Viscosity at 50° C cSt 2.0 – 5.5 2.8

Kinematic Viscosity at 37.8°C cSt 3.2 - 5.8 3.8

Distillation

• I.B.P. °C - 155

• 10% evaporated °C - 231

• 20% °C - 264

• 50% °C - 292

• 90% °C - 338

• FBP °C - 369

• Residue % - 1.0

• Loss % - <0.5

Water wt% max 0.05 < 0.05

Sediment wt% max 0.01 0.005

Sulphur, Total wt% max 0.25 0.25

Mercapatan sulphur ppm - 25

Aromatics vol% - 18

Olefins vol% - Nil

Asphaltene wt% Nil <0.05

Carbon residue on 10% residue wt% max 0.1 0.035

Diesel index - min 55 -

Cetane index - min 50 -

Copper strip corrosion (3 h.v. at

100°C) - - No. 1

Ash ppm max 100 25

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Description Unit Specification Typical

Calcium ppm - 1

Lead ppm - Nil

Sodium & Potassium ppm max 1.0 -

Vanadium ppm max 0.5 -

Total carbon wt% - 85.85

Hydrogen wt% - 13.25

3.5.2 Chemicals

Small amounts of dosing and treatment chemicals will be stored in the

chemical stores for operation of the power facilities. Dosing quantities are

manually regulated as per results of the water sample analyses.

Trisodiumphosphate (Na3PO4) solution will be dosed into the boiler drums to

prevent the precipitation of carbonate hardness traces within the boiler water

and for pH adjustment.

Ammonia (NH3) will be dosed into the boiler feed water as volatile alkalizing

agent for pH adjustment and corrosion inhibition. The pH of the process water

will be adjusted to 8.5 – 9.0 which will prevent corrosion within the

water/steam cycle.

A corrosion inhibitor (e.g. NaOH) will be dosed into the closed cooling system

to ensure an adequate pH value in the system water which prevents material

corrosion.

All dosing devices will be placed in the turbine house building and will

comprise chemical unloading facilities, chemical storage tanks, transfer and

dosing pumps, dosing pipelines, injection facilities and control equipment.

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A suitable amount of all chemicals needed for the operation of the Jebel Ali

‘M’ CCPP will be stored inside a separate storage building at site (chemical

storage building) Ammonia and Hydrazine will be stored as aqueous solutions

with a chemical content of approx. 25 % wt.

3.6 Water System

The project consists of many units which are discussed in subsequent

sections:

1 Seawater Screening System

The seawater received from transition bay from the intake channel shall be

passed through screening trains installed in the screening and pumping

station to remove all kinds of debris having particle size larger than 2 mm.

Each screening train shall be divided into two sections;

• Bar Screen with revolving rake;

• Traveling band screen with spray water system.

The debris collected in the screening plant shall be transported with spray

water via a conveyor through and special sluice gates to trash containers

equipped with dewatering sieve. The wastewater collected from the

containers shall be pumped back to sea via the discharge culverts/outfall

structure. The debris collected shall be transported to disposal area.

The clear seawater shall be treated by hypochlorite solution to control organic

substances and the growth of mussels, barnacles etc. Dosing shall take place

continuous (0.5 to 1.0 ppm) and shock dosing (5 ppm) behind the bar screens

and in the seawater pumped streamlines to the individual plants.

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Project Details

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2 Seawater Filtration and Chlorination

The seawater from the screen unit shall be passed through gravel filters of 2 x

100% for automatic operation and backwash.

The filtered water shall be treated with chlorine to disinfect before routing it to

desalination plant.

3 Water Intake

The total water requirement of the desalination plant shall be 310,000 m3/hr

and same shall be met from the sea. The water intake point is about 500 m

from the plant and water shall be transported through channel. The existing

water intake structure of Package L shall be augmented for the purpose of

proposed desalination plant by adding water channel, pumping system and

screening unit etc.

4 Outfall unit

The total expected brine generation shall be 197,392m3/hr from the

desalination plant i.e. 24674 m3/hr from each 17.5 MIGD unit. The brine shall

be transported through pipeline to outfall point, which is located in SW of the

project.

3.7 Wastewater Treatment System

The wastewater originating from the power plant only, can be classified into

two categories such as oily wastewater and chemical wastewater.

The oily wastewater will be collected from the following location.

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• Oily water from oily wastewater disposal system - About 15 m3/hr of

wastewater will be generated in the power plant.

The chemical wastewater will be collected from the following locations of the

power plant area.

• Chemical wastewater from chemical waste water disposal system.

• Chemical wastewater from fire water collection basin.

The total chemical wastewater generation in the proposed power plant will be

20 m3/hr.

The treated oily wastewater and chemical wastewater will be routed to the

waste water collecting and monitoring basin for the final discharge. The

quality of the wastewater prior to the treatment is given in Table- 3.4.

TABLE 3.4

QUALITY OF THE WASTEWATER PRIOR TO THE TREATMENT

Sr. No. Parameters Oily wastewater Chemical

wastewater

1 Flow 15 m3/hr 20 m3/hr

2 pH 6 – 8 2 – 12

3 COD 100 100

4 Oil 100 100

5 Suspended Solids 100 200

The proposed wastewater treatment P & I diagram is attached as Appendix-

3.

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3.7.1 The Treatment for the Oily Wastewater.

1 Portable Oil Skimmer

The initial suspended oil will be drawn by rotating high adhesive nitrite belt

equipped in oil skimmer that is located on the oily water collecting basin.

The skimmed oil gravitates to the skimmed oil tank while the separated

excess water drop back to oily water collecting basin, flow quantity is

controlled by the oil dam equipped in oil skimmer.

Once oil skimmer is started, it always works except for the case of shut down.

2 Oil Water Separator

The oily water transfer pump shift the composite homogenized oil-water

emulsion to the oil water separator at the constant rate, so as to separate the

residual tiny oil in the water that is not removed with oil skimmer.

The oily water flows into the EPS oil water separator that consist of number of

corrugated plate mounted parallel to each other at a space. When the raw

waste water containing the oil passes between the plates (laminar flow is

mandatory for the proper functioning of the operation) in the course of passing

from EPS pack inlet to EPS pack outlet, the oil float upwards into the top of

EPS pack and rise up the incline of the plates to the surface of the system

where it can be removed by pipe oil separator.

The treated water will be overflowed to the waste water collecting and

monitoring basin by gravity after the oil content is reduced to less than 5ppm.

The skimmed oil shall be collected in the skimmed oil tank for disposal by

truck. The oil sludge is displaced to the oil sludge tank periodically by the

operator.

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3.7.2 Treatment for Chemical Wastewater

1 Chemical Wastewater Buffer Basin

The chemical wastewater from acid dosing, NaOH dosing, alum dosing and

polymer dosing units will be collected in the buffer basin. This basin is to

collect and store chemical wastewater from chemical wastewater disposal

system and fire water collecting basin. The first operation is to provide

adequate flow to compensate the daily fluctuation of chemical wastewater

from the various sources.

By means of air blower, scour air keep steering the liquid to prevent settling of

denser material inside the basin. Also, scour air also helps in removing the

volatile substance present in wastewater.

By means of two numbers of chemical w/w transfer pump that are controlled

by the level transmitter, chemical wastewater is transferred to reaction basin.

This contain following functions:

• To provide adequate flow to compensate the daily fluctuation of chemical

wastewater from the sources.

• To homogenize chemical wastewater from the sources.

2 Reaction Basin and Flocculation Basin

This is main equipment in wastewater treatment system. The debris and

dense material is removed by means of chemical cohesion. The pumped raw

chemical wastewater initially enters a reaction basin at the constant rate

where it is mixed with the injected chemicals from chemical dosing equipment

by mix on the basin.

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Because zeta potential is reduced and cohesion is increased by chemicals,

colloidal pollutions are cohered rapidly. Commonly alum is used and the

reaction of cohesion is as following:

Al2 (SO4)3 · 18 H2O + 3 Ca (HCO3)2 → 2Al (OH)3↓ + 3CaSO4 + 6CO2 + 18H2O

The formed floc in the reaction basin overflows to flocculation basin where it

grows big and heavy by reacting with the polymer from polymer dosing

equipment. The function of flocculation basin is to remove colloidal pollutions

by means of chemical cohesion.

3 Sedimentation Basin

The mixed liquor is now flow to sedimentation basin, the velocity is reduced

and the activated sludge is separated from the secondary effluent.

The secondary effluent discharge from the sedimentation basin via an over

flow weir into the waste water collecting and monitoring basin.

The sludge is settled and stored up in the centre of hopper by means of

rotating scraper, from where it is shifted by gravity to sludge thickening basin.

The function of sedimentation basin is to separate water and sludge by means

of the difference of specific gravity.

4 Sludge Thickening Basin

The collected sludge is disposed in the sludge storage tank. When it is filled,

the sludge is discharged by means of thickened sludge pumps. Scour air keep

steering the liquid to prevent settling of denser materials inside the tank. The

function of the sludge thickening basin is to store and thicken the sludge.

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5 Wastewater Collecting and Monitoring Basin

The final treated water from sedimentation basin, cooling water, final filter for

sewage treatment system, neutralisation tank of demineralisation plant and

boiler blowdown overflows to waste water collecting and monitoring basin.

By means of analyser, the value of pH and temperature shell be constantly

monitored.

6 Hydrochloric Acid (HCL) Dosing System

HCL dosing system consists of following main components:

• One number HCl dosing vessel of a capacity of 2㎥

• Two numbers HCl dosing pumps.

• One number level transmitter (Ultrasonic Type).

• One number calibration column.

• Four numbers pressure gauges in suction line and discharge line

• Piping system

Operation: It is charged from demineralisation plant to HCl dosing vessel by

means of unloading pump. 33% hydrochloric acid is used to wastewater

treatment system. HCl dosing pump feed to reaction basin at the preset value,

to keep the pH level in the basic region.

7 NaOH Dosing System

NaOH dosing system consists of following main components:

• One number NaOH dosing vessel of a capacity of 2㎥

• Two numbers NaOH dosing pumps



• Four numbers pressure gauges in suction line and discharge line

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3-22


• Piping system

Operation: It is charged from demineralisation plant to NaOH dosing vessel by

means of unloading pump. 50% caustic soda is used to wastewater treatment

system. NaOH dosing pump feed to reaction basin at the preset value, to

keep the pH level in the basic region.

8 Alum Dosing System

Alum dosing system consists of following main components:

• One number alum dosing vessel of a capacity of 5㎥.

• Two numbers alum dosing pumps.



• Four numbers pressure gauges in suction line and discharge line.

• One number drum pump to charge alum.

• Piping system.

Operation: It is charged from alum drum to alum dosing vessel by means of

drum pump. About 10% alum is used in wastewater treatment system. In

charging, operator keeps a watch level gauge to prevent over flow. Alum

dosing pump feed to flocculation basin at the preset value, to get the best

cohesion in the basic region.

9 Polymer Dosing System

Polymer dosing system consists of following main components:

• One number polymer auto dissolving unit of a capacity of 1㎥

• Two numbers polymer dosing pumps.


• Four numbers pressure gauges in suction line and discharge line.

• Piping system.

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Operation: The system feed water from service water source and by solid

polymer from Vinyl pack. The polymer auto dissolving unit is equipment for

inserting good quality solution after complete dilution of polymer at fixed

degree of density continuously in order to supply fully maturated cohesion

material and needs to be charged carefully. Polymer dosing pump feed to

flocculation basin at the preset value, to get the best cohesion in the basic

region.

3.8 Details of Sewage Water Treatment System

The sewage wastewater of 75 m3/day will be generated in the plant from the

rest rooms will be treated in Sewage Treatment Plant. The quality of the

untreated sewage wastewater will be:

BOD : 300 mg/l

SS : 300 mg/l

pH : 6.5 ~ 7.5

The proposed sewage P & I diagram is attached as Appendix 4. The sewage

treatment plant will consist the following units:

1 Screen Tank

In the preliminary treatment, the suspended debris and coarse material will be

removed in the screen tank. The sewage wastewater will be passed through

screen tank in which auto bar screens are installed to remove coarse material.

In addition, parallel separate channel will be provided with manual bar

screens, which will be operated in case of maintenance of auto screen tank.

2 Grit Chamber

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The grit is accumulated at the bottom of chamber and the collected grit is

removed by operator manually & on demand.

3 Equalization Basin

This under ground Equalization Basin takes all the sewage that is free from

debris and grit. In equalization tank, the submersible mixer keep steering the

liquid inside the tank to prevent settling of denser material.

4 Aeration Tank

The pumped raw sewage water initially enters an aeration tank for the

removal of BOD. The tank requires sufficient contact time between the

wastewater and heterotrophic micro organisms, and sufficient oxygen and

nutrients.

In aerobic oxidation, the conversion of organic matter is carried out by mixed

bacterial cultures in general accordance with the stoichiometry shown below.

- Oxidation and synthesis:

Bacteria

COHNS + O2 + Nutrients CO2 + NH3 + C5H7NO2 + (Other end-products)

Organic Matter New cells

- Endogenous respiration:

Bacteria

C5 H7 NO2 + 5O2 5CO2 + 2H2O + NH3 + (Energy)

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For carbonaceous removal, pH in the range of 6.0 to 9.0 is tolerable, while

optimal performance occurs near a neutral pH. The dissolved concentration

0.2 mg/l is commonly maintained in the aeration tank.

5 Clarifier Tank

After aeration, the liquor is sent to clarifier tank, for settling of the sludge. In

the clarifier, velocity is reduced to give sufficient time for settlement of sludge.

Then the effluent will be discharged from the settlement tank via an over flow

weir into the disinfection tank, where the NaOCl is added at the preset value

for the disinfection of the system. The sludge is collected from the bottom

(Hopper) of clarifier tank, where the two Sludge Transfer Pumps operate to

shift the sludge in two parts:

• Return activated sludge to aeration tank via V- notch for the improvement

of the system biology.

• Excess sludge to Sludge Holding & Thickening Basin for its further shifting

to sludge tank for the final disposal.

6 Sludge Holding & Thickening Basin

Excess sludge shall be sent to sludge holding & thickening basin. The basin

will be equipped with baffles at the inlet point to reduce the velocity of the

flow. This will provide sufficient time for the settlement of sludge.

3.9 Sources of Pollution

While designing the proposed project, number of measures have been

incorporated to minimize the adverse impacts on the surroundings. In order to

achieve this, lot of process based precautions have been integrated in the

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basic design itself as described earlier. An attempt has been made here to

identify and quantify the sources of final emissions/discharges/solid wastes

etc. based on the process design.

3.9.1 Air Environment

The gaseous emissions form the project will be from six stacks of Power plant

and two stacks of auxiliary boilers of desalination plant. The turbines and

boilers shall be operated on the clean fuel i.e. natural gas. The details of the

stacks and emissions are given in Table-3.5.

TABLE-3.5

DETAILS OF STACK AND GASEOUS EMISSION

Details Sr.

No.

Parameters Unit

Power

Station M

Power

Station L

Desalination

Plant

1 Stack height m 60 60 75

2 Number of Stacks M 6 7 2

3 Stack diameter m 7 7 3.4

4 Flue Gas velocity m/s 17.5 17.5 18

5 Exit flue gas

Temperature

°C 118.4 118.4 204

6 Volumetric flow Nm3/s 512 512 102.1

mg/Nm3 51 51 51 7 Emission rate of NOx

from each stack gm/s 26 26 5.2

The adequate stacks will provided for wider and quicker dispersion of the

gaseous emissions. The turbines and boilers shall be provided with low NOx

burners to control the NOx emissions.

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3.9.2 Water Environment

The wastewater generated in the power plant shall be treated in oil water

separator, effluent treatment plant. The domestic wastewater shall be treated in

the Sewage Treatment Plant.

The treated domestic wastewater shall be utilized in landscaping and the

excess quantity shall be supplied to Dubai Municipality.

The trade wastewater of power plant along with hot water shall be mixed with

brine generated in desalination plant. The brine shall be discharged in sea

through outfall point located about 0.5 km away from the site.

The wastewater generated from the desalination plant is called Brine, which is

a high in salt concentration and alkaline in nature. The quality of the brine is

almost like sea water.

The domestic wastewater generated in the restroom and canteen will be about

20m3/day. This wastewater shall be sent to Dubai Municipality for the disposal.

3.9.3 Solid waste

The solid waste shall be generated at the screening unit, where the debris

from the seawater will be screened out. The solid waste will be sent to the

solid waste shall be non-hazardous in nature and disposed off as per Dubai

Municipality guidelines.

The sludge from the settling tank of potable water treatment plant shall be

sent to sludge drying bed located within the plant facility.

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3.9.4 Noise Levels

The major noise generating equipment in the proposed facility will be pumps

used in pumping of seawater and brine. These pumps will be designed for

noise levels <85 dB (A) at 1 m from the equipment. These pumps will be

provided with pump house with adequate acoustic to attenuate the noise

levels. The noise levels shall fall below 70 dB (A) outside the pump house.

CHAPTER 4

Baseline Environmental Status

4-1


4.1 Preamble

This chapter describes in detail the current/existing environmental conditions

at the proposed project site. Jebel Ali desalination plant is located 25 km

southwest of the city centre of Dubai and 7 km Northeast of Jebel Ali Port.

Southwest of the site is a wide intertidal area with a variety of productive

biotopes such as fringing strips of mangrove etc. Northeast of the site up to

the Dubai Creek is a 25 km long beach shoreline (small sand dunes) which

represents a wide intertidal area and are intensively used for tourism and

recreational purposes.

4.2 Climatology and Meteorology

The meteorological data is necessary for the proper interpretation of baseline

information of ambient air quality and other environmental attributes. It is

important to understand the meteorological conditions of the study area for

the evaluation of impacts of the proposed project. Historical data on

meteorological parameters also plays an important role in identifying the

synoptic meteorological regime of the region.

4.2.1 General

Dubai climate is an arid subtropical climate due to Dubai being located within

the Northern desert belt. The skies over Dubai are generally blue with little

cloud cover. Dubai has a typical desert climate with very hot summers and

warm winters. The low precipitation falls almost exclusively between

December and April. Despite of the missing rainfall humidity of the air is

relatively high, due to its proximity to the Arabian Gulf. Especially in the

summer months the humidity is often very high.

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4-2


Strong Northwesterly ‘Shamals’ can occur quite suddenly and associated with

squalls caused by cold front pressure troughs. In summer, these Shamals are

associated with dry air, cloudless skies and dust haze.

Dust haze is common in the summer months with visibility being generally

restricted to less than 10 km. Sandstorms occur occasionally, when strong

south easterly winds transport sand from the interior to the coastal region.

These sandstorms lead to a build up of sand on highways and alongside

buildings. They also significantly affect visibility.

The local climate is broadly characterized by two seasons. There are distinct

summer and winter weather patterns, with spring and autumn as transitional

periods lasting approx. one month.

4.2.2 Temperature

January is the coolest month of the year 2008 with the maximum temperature

around 28.9°C and minimum of 11.6°C. The period from March to May is the

"spring" months in Dubai when the temperature begins its steady climb

towards the summer peaks.

During summer season the maximum temperature (July) is observed to be

45.6 °C with the minimum temperature of 25.5°C (September). During autumn

season the maximum temperature (October) is observed to be 38.9°C with

the minimum temperature of 13.8°C (December). The monthly variations of

temperatures are presented in Table-4.1

4.2.3 Relative Humidity

The air is generally very humid in the region, the maximum relative humidity is

observed to be around 83 and minimum 26%. The monthly mean variations in

relative humidity are presented in Table-4.1

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4-3


4.2.4 Atmospheric Pressure

The atmospheric pressure observed is in the range of 995.6 to 1019.3 mb,

with the maximum pressure (1019.3 mb) occurring during the winter season,

in the month of December and January. The monthly variations in the

pressure levels are presented in Table-4.1

TABLE - 4.1

CLIMATOLOGICAL DATA - DUBAI INTERNATIONAL AIRPORT - 2008

Temperature (0C)

Relative

Humidity

(%) Month

Atmospheric

Pressure

(Mb) Max. Mean. Min. Max. Min.

Rainfall

(mm)

January 1019.3 28.9 18.2 11.6 83.0 44.0 15.6

February 1012.5 31.7 21.3 13.8 83.0 41.0 25.0

March 1012.5 36.7 24.7 15.0 82.0 37.0 21.0

April 1009.1 40.0 29.3 16.6 76.4 30.1 7.0

May 1005.8 42.8 33.5 23.8 72.5 26.0 0.4

June 995.6 45.0 35.3 28.8 79.0 28.3 0.0

July 995.6 45.6 35.1 28.8 76.0 30.3 0.8

August 999.0 45.0 36.3 30.5 75.0 30.0 0.0

September 1002.4 43.9 34.7 25.5 80.6 30.4 0.0

October 1012.5 38.9 30.6 21.6 81.3 33.1 1.2

November 1015.9 33.9 25.2 17.7 80.0 38.0 2.7

December 1019.3 30.0 22.4 13.8 82.6 43.7 14.9

4.2.5 Rainfall

Short and irregular rainfalls occurred in 2008. Most of the rainfall occurs

between December and March. The total rainfall observed in year 2008 is

88.6 mm. Annual and monthly variations in the rainfall are given in Table-4.1

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4.2.6 Annual Wind Pattern

A review of the wind rose diagram shows that predominant winds are mostly

from W and WNW directions followed by S direction (Figure-4.1).

Predominant winds from W direction were observed for 11.2% of the total

time, with wind speeds (% frequencies) in the range of 5.1-11.0 kmph (0.6),

11.1-19.0 kmph (5.1%) and >19.01 kmph (5.5%). In the S direction winds

were observed for 10.9% of the total time, with wind speeds (% frequencies)

in the range 5.1-11.0 kmph (4.1%), 11.1-19.0 kmph (5.8 %) and >19.01 kmph

(0.9%). Whereas for WNW direction the winds were observed for 10.1% of the

total time with wind speeds and frequencies in the range of 1.0-5.0 kmph

(0.2%), 5.1-11.0 kmph (0.9%), 11.1-19.0 kmph (4.8 %) and >19.01 kmph

(4.3%).

In other directions, the percentage frequencies observed were N (4.9%), NNE

(3.0%), NE (4.4%), ENE (6.1%), E (9.3%), ESE (3.5%), SE (3.5%), SSE

(5.5%), SSW (3.1%), SW (2.1%), WSW (4.1%), NW (9.4%), and NNW (6.5%).

Calm conditions prevailed for 2.21% of the total time.

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4-5


FIGURE - 4.1

ANNUAL WINDROSE OF DUBAI INTERNATIONAL AIRPORT – 2008

CHAPTER 4


4-6


4.3 Sea Surface Water Temperatures

The maximum, minimum and mean seawater temperatures recorded at Jebel

Ali Port of the year 2007 recorded to be 34.6oC (August), 17.7oC (February)

and 26.5oC respectively. The monthly variations in sea temperatures are

given in Table-4.2. This is in contrary to the normal year where in minimum

occurs in winter and maximum in summer.

The monthly-recorded seawater temperatures of the year 2007 at Jebel Ali

are shown in Figure 4.2. The ground water table corresponds with the sea

water and is established at an average elevation of approx. +1.6 m, which is

approx. 4.4 m below the ground level of the existing stations. The ground

water table is subject to seasonal variation and dewatering in the site vicinity.

TABLE – 4.2

MONTHLY SEA TEMPERATURE VARIATION FOR THE YEAR 2007

Sea Temperature Month

Mean Max Min

January 20.9 23.0 19.0

February 20.7 23.0 17.7

March 22.3 24.3 18.0

April 25.0 29.0 24.0

May 28.5 32.0 24.0

June 31.2 32.0 22.0

July 32.2 34.0 30.0

August 32.9 34.6 25.0

September 31.9 32.0 28.0

October 29.9 32.0 27.0

November 27.0 29.0 26.0

December 23.4 27.0 24.0

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4-7


DUBAI INTERNATIONAL AIRPORT

SEA TEMPERATURE – JEBEL ALI PORT 2007

0

5

10

15

20

25

30

35

40

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

MONTH OF THE YEAR

DE

GR

EE

(0C

)Monthly Mean 2007

Monthly Max 2007

Monthly Min 2007

FIGURE 4.2

MONTHLY SEA WATER TEMPERATURE

4.4 Landuse

The proposed project site is currently undeveloped desert land. The area

comprises low-lying, sandy, extensive flat, stony and gravel plains. The

topography is mainly gently undulating sandy slopes, with occasional Sabkha

flats. The height of ground varies from 33.0m to 62.0 m above sea level. The

surrounding area is in the process of large-scale development for a variety of

uses.

The nature of surrounding land use will therefore change significantly in the

future, as large-scale infrastructure projects, including the new Jebel Ali

Airport City, Techno Park and Dubai Waterfront, Dubai Industrial city, develop

in the next few years. The proposed project will change the present

undeveloped desert land to industrial land use.

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4-8


4.5 Regional Geology

The general geology of the UAE has been substantially influenced by the

deposition of marine deposits associated with the continuous sea level

changes during the relatively recent geological time. Moreover, with the

existing mountainous geology across the UAE the country is considered to be

of relatively low-laying area.

The geological conditions in Dubai essentially consist in general of a linear

coastline dissected by creeks. Superficial deposits consisting of beach dune

sands with marine sands and silts. Furthermore, erosion, capillary rise

phenomena as well as evaporations have led to extensive silt deposits in

some areas especially near to the creeks. These superficial underlined by

altering layers of calcarenite, carbonate sandstone, sand as well as cemented

sand layers.

4.6 Existing Baseline Air Quality

Apart from the existing power production facilities at Jebel Ali Power Station

the nearest major point source of atmospheric pollutants to the project site is

the Dubal Aluminum Factory adjacent to the southwestern border of the Jebel

Ali Site. At Dubal, several power plants are installed for the production of

electricity which is required for the electrolytic aluminum smelting process.

The ambient air impacts of the existing industrial facilities in the vicinity of the

project site are reflected, by the results of regular ambient air quality

measurements, which are available from DM environment department for the

locations Jebel Ali Village and Jebel Ali Port.

In accordance with the requirement of the Environmental Protection and

Safety Section of the Dubai Municipality (E.P.S.S.), the air quality impact

assessment in this report focuses on the additional impact of the new project

which has to be added to the existing ambient air pollutant levels which are

CHAPTER 4


4-9


measured regularly at two monitoring stations in Jebel Ali Village and at Jebel

Ali Port.

The E.P.S.S carries out hourly measurements of NO2 and SO2 and Ozone

(O3) at Jebel Ali Village. At Jebel Ali Port hourly measurements of SO2 and

Ozone at four monitoring stations. The closest station to the project site is 2

km south-south-east in Jebel Ali Village. The station is influenced by traffic on

the Sheikh Zayed Road, which runs between the project site and Jebel Ali

Village.

The second measuring station is located approx. 4 km southwest of the

project site at Jebel Ali Port. This location is also influenced by the Sheikh

Zayed Road and by the installations at Dubal.

The air quality monitoring results from these sites are summarized in the

Table 4.3 for the period 2008.

At all sites the highest 1 hour and 24 hour Nitrogen Dioxide concentrations

are well below the corresponding Dubai, World Bank and WHO air quality

standards.

At all sites the highest 1 hour and 24 hour Nitrogen Dioxide concentrations

are well below the corresponding Dubai, World Bank and WHO air quality

standards.

The highest 1 hour average concentrations measured for SO2 are well below

the Standards of Dubai, World Bank, and WHO (350 µg/m³) considerably.

A similar situation is present for Ozone At all sites the highest 1 hour and 24

hour O3 concentrations are well below the corresponding Dubai, World Bank

and WHO air quality standards.

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4-10


Ozone levels are of interest for this project because the NOX emitted by the

plant is a precursor of Ozone in the atmospheric chemistry involving NO, NO2,

Hydrocarbons, and solar irradiation, where the nitrogen oxides act as a

catalyst of Ozone formation in the troposphere

Besides from the existing power plant of the Jebel Ali Power Station the main

ambient air pollution source in the area is Dubai Aluminum factory adjacent to

the south-western border of the Jebel Ali Site.

The only air pollutants to be considered with plant operation on natural gas

are NOX and CO. Due to the fact, that only very small traces of sulphur and

particulates are contained in the natural gas, the corresponding SO2 and

particulate matter emissions are negligible. Consequently only emissions of

NOX and CO are considered in detail.

The background NOx and SO2 concentrations were taken from the online

recording done by Dubai Municipality. The monitoring location located at

Jebel Ali village which is the nearest monitoring station to the proposed power

project site. The recorded concentrations are hourly concentrations of NOx

and SO2 collected for the period of two months from March and April 2008.

The 24 hourly concentrations were calculated based on these hourly values.

TABLE 4.3

JEBEL ALI VILLAGE AIR QUALITY MONITORING RESULTS 2008

Monitoring Site Maximum Minimum

Nitrogen Oxide Concentration

1 Hourly (Limit – 290 µg/m3) 121.0 74.6

24 hourly (Limit – 110 µg/m3) 46.6 28.7

Sulphur dioxide Concentration

1 Hourly (Limit – 350 µg/m3) 5.3 3.0

24 hourly (Limit – 150 µg/m3) 2.0 1.2

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4-11


The gas turbine emission concentrations of CO are in the same order of

magnitude as those of NOX. However, the toxicity of NOX exceeds the toxicity

of CO by a factor of more than 100, which corresponds in the much higher

emission limits set for CO. Therefore, the only air pollutant of significance with

regard to air quality impact is NOX.

Consequently the only air pollutant which was considered in the air dispersion

calculation and in the assessment of ambient air quality is NOX.

4.7 Biological Features

4.7.1 General

Due to the desert climate there is only very few natural vegetation in the

project area. However the coastal region is heavily irrigated using water from

desalination plants and re-used treated wastewater. The main vegetation

growing in the irrigated area land are palm trees, grass and shrubs.

The Gulf coasts of the Arabian countries do not vary grossly in their

geomorphologic structures. Nevertheless, there is a rich diversity of biotopes,

some of international nature protection interest. Sensitive marine Gulf-specific

biotopes are e.g. shallow bays, coral reefs, seaweed meadows, intertidal

sand- and mudflats. Sensitive coastal biotopes are mangrove areas,

saltmarshes, rocky shores, bird islands, coastal sabkhas, cyanobacterial

mats, sand beaches and beachrock flats. Accompanying this variety of

biotopes is a rich diversity of species.

Use of natural marine resources belongs to the biological context. The Gulf is

a productive sea and a rich source of fish and shrimps. Even if fishery is

negligible within the gross domestic product, it is present all along the Gulf

coast and supplies the food of high quality and variety. The number of people

engaged in traditional and modern fishery should not be underestimated.

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Conflicts between interests of desalination industry and fishery can be

expected wherever desalination plants are erected or enlarged. Productive

fishery is a good indicator for a healthy marine ecosystem.

4.7.2 Birds

The UAE Golf coast is rich of `Important Bird Areas (IBA's)'. In general, the

UAE Golf coast has functions for birds such as:

Flyways: For waders and other species from Eurasia / West Asia to Africa and

vice versa, mainly during April/May and July/November. Probably more than

250,000 waders are recorded `at any one time' during the migration period. At

the same time the Gulf coast works as a

Resting/Feeding Place: Several million shore birds are dependent on the

nutritious intertidal mudflats all year.

Wintering: For instance, the Crab Plover' and Great Knot' are dependent on

places such as Khor al Beidah.

Breeding; Up till now, there are various bird Priority Species' (Aspinall, 1996)

such as the Socotra Cormorant' (Endemic to Arabia), `Western Reef Heron'

the `Crab Plover and Kentish Plover (throughout UAE) recorded, ussing parts

of the shoreline as a breeding site.

In general, among others, 61 species of water birds alone were counted along

the Golf shoreline of the UAE.

4.7.3 Fauna, Wildlife

The most frequent animals in Dubai are camels and goats. Indigenous fauna

includes the Arabian Leopard and the Ibex, but sightings of them are

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extremely rare. Other desert life includes the sand cat, sand fox and desert

hare, plus gerbils, hedgehogs, snakes and geckos.

No wildlife is present at the selected project location which is situated in a

fenced industrial area

4.8 Soil, Geology and Geomorphology

4.8.1 General

Borings performed in previous projects at the project site showed non

homogeneous surface layers of loose to medium sand with a variable

concentration of seashell fragments. Approx 10 meters below the

unconsolidated soil strata, layers of weak, fine to medium grained calcareous

sandstone (occasionally with layers of limestone and conglomerate) were

encountered.

4.8.2 Regional geology and Hydrogeology

Geologically, the UAE occupies a corner of the Arabian Platform, a body of

continental rock that has remained relatively stable since the Cambrian

Period-more than 500 million years ago. Ancient sediments over time,

accumulated on the coast of UAE including Dubai and continental shelf that

was to become the UAE. The geology in Dubai and environs is essentially

unconsolidated desert plain deposits of sandy silt to fine sand followed by

bedrock. Locally Dubai is built on two major geological and geo-

morphological units.

• Desert plain deposits consisting of sand and silt, form low flying flat or

gently undulating surface with isolated dunes

• Coastal Sabkah: calcareous silt, muddy sand with considerable salt

content, salt crusts flooded by storm

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Regionally ground water flow from South East to North West. Ground water

quality along the coast of Dubai is brackish to saline and shallow water level

conditions (water level is 3.0 to 12 meters below ground level depending on

ground elevation).

A study on the background heavy metals data in Dubai was conducted in

1995 by Dubai Municipality EPSS section and following are the soil

background concentrations observed in Dubai as shown in Table 4.4

TABLE 4.4

BACKGROUND HEAVY METALS IN SOIL IN DUBAI

Parameter Mean value(µg/g or mg/kg) Ranges (µg/g or mg/kg)

Copper 10 5 -24

Zinc 23 7-129

Cadmium 2 0.2 to 8

Lead 22 5 to 23

Nickel 27 2 to 62

Chromium 27 5 to 50

Manganese 165 33 to 253

4.9 Shoreline, Water Courses and Discharges

Dubai has an almost linear coastline to the Arabian Gulf, which is interrupted

by the Dubai Creek and some other bays. Presently there are several projects

which will change the natural coastline. In the vicinity of the project area a

marina is constructed for which an artificial creek was created by excavation

of land. Furthermore two artificial Palm Island projects are being built close to

the shoreline.

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Dubai is lacking of natural freshwater resources which is overcome by use of

desalination plants. The desalination installations at Jebel Ali are the largest in

Dubai. By the evaporation process utilized in the desalination plants large

amounts of sea water are taken from the gulf and discharged again with

increased temperature and salinity. The natural cooling down of the

discharge water by mixing with colder sea water from the open sea will be

considerably hindered by the construction of the two palm islands.

The ground water table corresponds with the sea water and is established at

an average elevation of approximately + 1.6 m, which is approx. 4.4 m below

the ground level of the existing stations.

The ground water table is subject to seasonal variation and dewatering in the

site vicinity

4.10 Cultural Heritage

The project area is assigned for industrial use. No items of special cultural

heritage are present within a radius of 10 Km around the projected plant.

4.11 Landscape and Topography

The topography in the region consists of flat, barren coastal plain merging into

rolling sand dunes of vast desert land in the south.

4.12 Surrounding Recreational Land uses

The coastline east of the project area is strongly utilized for recreational and

tourist purposes and will be more extended by future developments, such as

the two very large `Palm Islands Projects'.

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4.13 Population

The total population of the UAE was estimated in 2001 to be 2,407,460. The

population of Dubai was 1,241, 000 in the year 2006. Of the total population,

73 per cent or 911,000 are male and 27 per cent or 330,000 are female.

Within a radius of 10 km around the plant area, which has been defined as

area of investigation for the atmospheric dispersion calculations, there are

several locations of considerable population density.

Situated approx. 5 km south of the Project Site (minimum distance) are Jebel

Ali Industrial Village and Dubai Investment Park with a population of approx.

3800. Approx. 3 km north of the site is a major residential community in Dubai

Marina and Jumeirah Lake towers with an expected population of 120000, 10

km north-east of the site are Al Mina Al Seyahi, Al Safouh and Palm Jumeirah

future development area with a total population of approx. 80000. Situated

approx. 3 km south-east is Jebel Ali Village and gardens with a population of

around 12000.

Further the industrial areas of Jebel Ali Port and Dubal Aluminium are located

within the zone of potential ambient air impact from the project.

4.14 Water Quality

Oceans, seas and coastal waters have an important influence on our lifestyle.

These ecosystems provide mankind with food, transport and recreation, but

also ultimately receive our waste. The major source of marine pollution is from

land-based human activities, these anthropogenic sources being responsible

for around 77% of the pollutants that enter the oceans and seas. Shockingly,

some 6500 x106 tonnes of litter find their way into the oceans and seas each

year and ocean currents transport pollutants considerable distances.

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Chemical pollutants entering marine systems are divided into 2 broad groups

of compounds: inorganic (phosphates, nitrates, metals etc.) and organic

substances (pesticides, hydrocarbons etc.). These pollutants interact with the

other components of seawater, which is a complex conglomeration of animal,

vegetable and mineral matter widely dispersed within a saline-water-matrix .

The full spectrum of organic species is presented from the smallest bacteria,

algae, diatoms and plankton through the full diversity of plant and animal life.

All oceans and seas (especially the Atlantic Ocean, North Sea and

Mediterranean Sea) are now experiencing serious threats due to pollution .

Marine water quality has therefore become a matter of serious concern for

mankind because of its effects on human health and aquatic ecosystems,

including the rich array of marine life that is often exploited for human use.

Water quality characteristics of an aquatic environment are of great

significance for the proper understanding of distribution, growth and

physiological function of the biotic community inhabiting the area.

4.14.1 General characteristics of the Arabian Gulf

The Arabian Gulf covers an area of 226 000 km2 and has a mean depth of 35

m. The Gulf is nearly 1000 km long, with a maximum width of around 370 km.

The coastline along its south-western side is low, whilst the Iranian side is

mountainous. Due to its enclosed and shallow nature, the Gulf is particularly

subject to the accumulation of anthropogenic contaminants. There is only a

very narrow exchange through the Strait of Hormuz into the Gulf of Oman,

which means that the time required for all of the Gulf’s water to come within

the influence of the open sea is 2.4 years or an actual flushing time of 3 -5.5

years .

The Arabian Gulf is mainly a sedimentary environment with a predominantly

soft substrate benthos. Sediments of biogenic carbonates predominate

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(derived mainly from micro-fauna), but strong terrigenous influences are

apparent at the northwest end where the Shatt El-Arab discharges to the

Arabian Gulf.

4.14.2 Water quality of the Gulf

Limited information is available on the water quality of the Arabian Gulf. The

Regional Organization for the Protection of the Marine Environment (ROPME)

is currently collecting environmental statistics from the member countries

(ROPME 2000).

4.14.3 Environmental threats of the Gulf

The Arabian Gulf is a unique biotope, distinct from other tropical and

subtropical systems (Rao & Al-Yamani 1999). The Gulf has experienced

severe environmental disturbances, most notably the leakage of an estimated

10.8 x106(1.7x106 m3) barrels of oil into the marine environment during the

1991 Gulf War and the deposition of an estimated further 8.0 x106 (1.3 x106

m3) barrels of oil fallout from the smoke plumes of the well blowouts and fires

in Kuwaiti oil fields (Al-Ghadban et al 1998).

4.14.4 Water quality off DEWA station M

The water quality monitoring survey involved the collection of marine water

samples from 2 sampling locations and results which are illustrated in Figure

4.3. The survey sites were selected to provide data for the water quality in

order to reflect the changes and variations in water quality between sampling

locations. Table 4.5 provides a detailed list of the parameters analyzed.

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TABLE 4.5

SELECTED WATER QUALITY PARAMETERS AND THEIR TEST METHODS

Parameters Test Methods Unit Sampling Depth

Station 1 Station 2

Surface Bottom Surface Bottom

Water temperature In-situ oC 30.2 31.6 30.4 31.2

pH In-situ Unit 8.2 8.3 8.2 8.2

Salinity In-situ ppt 42.2 42.0 41.9 42.0

Dissolved Oxygen In-situ mg/L 6.2 6.0 6.0 5.9

Total Phosphate As P APHA 4500 P B+E mg/L 0.03 0.03 0.03 0.03

Nitrate As N APHA 4500 NO E mg/L 0.05 0.05 0.05 0.05

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FIGURE 4.3

MARINE WATER QUALITY MONITORING STATIONS

4.14.5 Results and Discussion

Understanding of water quality characteristics of a marine environment is of

great importance. The water quality of the sea is not static even in the

absence of anthropogenic influences and is subjected to changes due to a

number of factors which are often natural. Such changes can be on short

time-scale days and seasons or long time-scale. Near shore and shelf waters

that are more biologically productive and influenced by terrestrial run off,

anthropogenic activities and atmospheric fall out often reveal seasonal

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changes in water quality. Coastal waters particularly those receiving

anthropogenic inputs and stagnation, variations in water quality are possible

even with the state of the tide.

The following provides a summary of the results taken from the 10 water

quality monitoring stations.

Temperature

Generally, the temperature variation in the tropical region is limited. As

expected for dynamic shallow coastal areas, the water temperature varies in

accordance with the air temperature. The observed range of water

temperature at station 1 and 2 during the present study is well comparable

with the earlier records of temperature in the temperature records of the

ROPME Sea Area (ROPME 2000).

pH

Unpolluted natural waters show a pH range from 3.0 to 11.0; those lying

between 5.0 and 9.0 generally supporting the most diverse assemblage of

species. The pH of coastal water varies in a narrow range (7.8-8.3) due to the

presence of buffer (CO32- -HCO3

- - CO2).

External factors such as pollutants, algae growth or bacteria may cause rapid

changes in pH unless it is buffered. The pH of coastal waters can also be

affected by changes in DO, alkalinity, hydrogen ion concentration and

temperature. The magnitude of any change varies with salinity because of

the concentrations of the various ions involved in acid-based reactions.

The pH range found within the survey stations was 8.2-8.4 with an overall

average of 8.3. The ranges found within the survey stations indicate little

variation between the sites. In general the levels of Ph were higher in the

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lagoon (8.9) as compared to coastal waters (8.2). Levels are conducive to the

growth of marine organisms.

Dissolved Oxygen

DO is a measure of the amount of oxygen dissolved in water. It is essential to

aquatic life and is a good indicator of water quality and the presence (or lack

of) of pollutants in the water column. The DO content of natural water can

vary with temperature, salinity and biological activity. For example, DO

decreases with the increase in temperature, salinity and biological activity.

Waste discharges containing high amounts of organic matter and nutrients

can reduce DO as a result of increased biological respiration (bacteria in the

water degrade the organic pollution utilizing dissolved oxygen).

Variation in DO levels were in the range of 5.9-6.1. The average DO level

recorded 6.0 mg/L. These figures show that the levels of DO are comparable

to the average of the Arabian Gulf region, which fluctuate between 4.8-6.5mg/l

depending on salinity and temperature.

Salinity and Conductivity

Conductivity is the ability of a medium to support the flow of an electric current

and can be used as a measure of the salinity of seawater. Seawater contains

about 3.5% dissolved salts and its conductivity is primarily due to these

charged solute ions. Conductivity of sea water varies predictably with

temperature and total ionic concentration. Hence, Salinity is the amount of

salt dissolved in seawater. Moreover, measurements of conductivity and

temperature can be used to calculate the salinity of the seawater. The results

indicate a range in the salinity shows normal values

Inorganic Nutrients

Dissolved inorganic phosphorous and nitrogen compounds play an important

role in controlling the production at primary level. Dissolved nitrogen and

phosphorous compounds are present in low concentrations in seawaters.

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Nitrogen is mainly present as nitrate with low concentrations of nitrite and

ammonia, while the major inorganic species of phosphorous is phosphate. High

concentrations of these nutrients in water however can lead to excessive

growth of algae resulting in eutrophication in extreme cases.

Nitrogen in the seawater is mainly present as nitrate with low concentrations

of nitrite and ammonia. High concentrations of nitrogen in water however can

lead to excessive growth of algae resulting in eutrophication in extreme cases.

Generally, the nutrient increases in the marine waters due to stagnation of

water quality. PO4 -P concentration of 0.3 mg/L will support plankton growth,

while concentrations of 1.0-3.2 mg/L PO4-P will trigger blooms.

The phosphate ion is a polyatomic ion (PO4 -P) and the term ‘phosphates’

refers to salts of phosphoric acid. Phosphates occur naturally in geological

features and play an important role in biological systems. It is generally non

toxic to aquatic organisms, however, conditions can exist such that excessive

growth of algae (which may have toxic components) can occur, referred to as

harmful algal blooms (HABs). Excessive levels in the environment are

therefore not desirable.

Levels of nitrate and phosphate were found in the normal range as observed

in the Arabian Gulf.

4.15 Marine Ecology

The coastal waters have been extensively utilized for sea transport,

desalination, fish harvest and culture, dredging and reclamation and dumping

of domestic wastes. Offshore waters have been extensively used for fish

harvest, sea transport & exploration and exploitation of oil and natural gas at

certain places. Apart from these certain areas along the sea bed used for

desalination for fulfilling the water demand. Overall, the near shore waters

play an important role in the production, maintenance and protection of

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potential biological habitat of fish and wildlife. Although much of the direct

deleterious impacts due to environmental degradation have been mitigated in

cases where commercially important species have been threatened.

It has been recognized, however that effective management of coastal is

accomplished at the level of community and habitat. It is at community level

that ecological relationship among biotic-abiotic factors can be interpreted in

terns of the functional process, however the knowledge of ecosystem at

species and taxa level ultimately determines the resistance of an ecosystem

and its components to natural and man induced alterations.

The living community of an ecosystem comprises of consumers, producers

and decomposers and related non-living constituents interacting together and

interchanging materials as a whole system. The basic process in an aquatic

ecosystem is its primary productivity. The transfer of energy from the primary

source through a series of organisms is defined as the food chains which are

of two basic types; the grazing food chain and the detritus food chain. The

stress may cause the communities to exhibit low biomass and high

metabolism. In addition, due to depressed functions of less tolerant

predators, there may be also a significant increase of dead organic matter

deposited in sediments of ecosystems modified under stress. Depending

upon the type, strength and extent of a stress factor, the ecosystem will react

to either reestablish the previous equilibrium or establish a new one, or it may

remain under prolonged disequilibrium.

The biological parameters considered for the present study are phytoplankton

cell counts, and their species diversity, and macro-benthos (biomass,

population and total faunal groups). The first one reflects the productivity of a

water column at the primary level. Benthic organisms being sedentary animals

associated with bed, provide information regarding the integrated effects of

stress, if any, and hence are good indicators of early warnings of potential

damages.

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4.15.1 The Arabian Gulf Marine Environment

Project area being an integral part of the Gulf, its ecology is controlled by the

dynamics of the Gulf. Hence, knowledge about the general environmental

setting of the Gulf is necessary for comparing the site-specific environmental

conditions with that of the surroundings.

The Arabian Gulf, or al-Khaleej al-Arabi in Arabic, lies between the Arabian

Peninsula and Southwest Asia. It is connected by the Straits of Hormuz to the

Arabian Sea, the northwest part of the Indian Ocean. The Gulf is some 615

miles long and has a maximum width of 210 miles, with an area of about

93,000 square miles. Gulf bordering Iran, Iraq, Kuwait, Saudi Arabia, Bahrain,

Qatar, United Arab Emirates and Oman, with an area of 240,000 km², a

maximum depth of 90 meters, and an average depth is 50 meters. In Western

countries it is called Persian Gulf; in most Arab countries it is called Arabian

Gulf.

The length is 1,000 km, and the maximum width is 370 km. To the south, the

coast line is flat, while the coast on the Iranian side is mountainous. The

temperatures are high, and the salt level is as high as 40%, which results from

an evaporation higher than the supply of fresh water. The main fresh water

source is from Iraq, through the Shatt El Arab, the confluence of the rivers

Euphrates, Tigris and Karun.

Through the Strait of Hormuz, the gulf is connected to Gulf of Oman and the

Arabian Sea. There have been serious incidents that have affected the

environment of the gulf in recent years. While oil spills from the heavy traffic of

oil tankers over years have been serious enough, oil spills from 1983, during

the Iran-Iraq War, and in 1991, during the Gulf War, have been catastrophic.

The area of the Arabian Gulf has slowly decreased during the last 6,000

years, when most of Kuwait and lower Iraq were part of the total basin. This

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process continues still as sediment from the Shatt El Arab enlarges the delta

area and reduces the area of the gulf.

The coastal configuration is very irregular with numerous islands, creeks and

bays. Besides, there are a number of eroded shallow banks, many of which

harbor living corals. The intertidal region is sandy and rocky.

Sand storms disturbances strike southern coast of the Gulf regions,

periodically. These disturbances generally originate over the Arabian Gulf.

4.15.2 Objective of the Marine Study

The following objectives are identified for the baseline condition of the Jebel

Ali power and desalination station “M”.

• To assess the biological characteristics at primary as well as secondary

trophic level;

• To establish the baseline conditions and ecological characterization of the

area.

4.15.3 Data Collection and Monitoring Stations

Field data collection with respect to flora and fauna for baseline investigation

were collected at three locations in a distance of 500 m from the shoreline

starting from the proposed location of the outfall for Jebel Ali Station ‘M’ in

western direction and shown in Figure 4.4.

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FIGURE 4.4

MONITORING STATIONS ALONG COASTAL ENVIRONMENT OF DEWA

4.15.4 Strategy of Selecting Biological Variables

Evaluation of biological sensitivity of the area is an integral part of the

ecological assessment. The baseline information on the biological

characteristics has been evaluated based on the qualitative and quantitative

data on organisms representative of different trophic levels. The parameters

selected during the present study were phytoplankton for covering the

biological productivity and ecological characteristics respectively at primary

levels while the benthic data were collected to ensure the life at the bottom of

the area.

It is inevitable that a marine structure in the coastal zone would cause certain

environmental impacts, the intensity of which would vary depending on

several factors such as prevailing dynamics of the area and its ecological

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sensitivity. Assessment of probable impacts of a development in the coastal

zone therefore needs the site-specific information on components of the

marine environment especially biological characteristics of the area likely to

be influenced.

Published scientific literature and available technical reports indicated that

apart from studies conducted by Environment International Corporation (EIA)

the information related to the ecology of the UAE water was rather scanty in

this area. The available information for the UAE water was assessed to plan

field data acquisition for the present study. Accordingly, two sub-tidal stations

near discharge point and associated coastal water was considered adequate

to describe the prevailing environment of the project site.

Coastal waters often reveal significant seasonal changes in ecology. These

variations should be clearly understood for assessing the prevailing status of

a water body. However due to limited scope of work only one time data

collection was considered adequate for establishing the prevailing ecology of

the project area (Figure 4.5).

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FIGURE 4.5

MARINE ENVIRONMENT OF DEWA SHOWING OUTFALL LOCATIONS

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4.15.5 Methodology of Sampling and Analysis

The sampling was done at three locations as mentioned in Figure 4.4 at

500±25 meter away from the shoreline for phytoplankton, zooplankton and

Macro-benthos.

Four samples for phytoplankton were collected from surface using Niskin

water sampler (General Oceanic) once during sampling period, preserved

with formaldehyde lugol’s solution till further analysis.

Two grabs of sediment samples from each station were collected with van

Veen type of grab (Hydro-bios), sieved through 500 micron sieve. The

material retained on sieve was collected in polythene bag, stain with rose

Bengal and preserved with 5% formaldehyde solution.

Phytoplankton samples were collected from surface, mid and bottom depth

using Niskin water sampler of 1.7 liters capacity during both the tides. The

samples were collected and preserved in 500 ml of HDPE bottles, preserved

with formaldehyde lugol Iodine solution till further analysis.

Phytoplankton samples were allowed to settle for minimum 96 hrs, decant the

supernatant solution and made the volume of 50 ml, then 1 ml of sample was

taken in Sedgwick-Rafter slide (1 ml capacity) with the help of glass dropper.

Initially the sample was examined for the qualitative analysis, and then the

different genera/species were counted. The same procedure was repeated

thrice or four times. Every time fresh aliquot of sample was examined to

minimize the variability in the phytoplankton cell counts. The identification of

the phytoplankton up to species was done using many international

phytoplankton references with the help of compound microscope. The 100

times magnification (10x eyepieces and 10 x objective) was normally used for

the counting, whereas 400 times magnification (40x eyepiece and 10x

objective) was used for the identification of certain species of phytoplankton.

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The number of phytoplankton present in 1 ml of sample was multiplied for the

total aliquot of sample and then converted in to number per liter. For the final

counting, an average of 3 to 4 (each with 1 ml of sample) counting was

considered.

The identification of the phytoplankton up to species was done using many

international phytoplankton references with the help of compound microscope.

Samples were washed again in laboratory in running water using sieve of 500

µm mesh size to remove excess of Rose Bengal and formaldehyde, Sorting of

the fauna was done under binocular Stereo microscope using 20 times

magnification (20x eyepiece and 1x objective). Specimen belonging to a

particular species or taxon has been enumerated individually. Fragments

were counted only after ascertaining that they belong to a single organism.

After enumeration, the specimens were stored in separate containers. Data

on enumeration was used to study the distribution, abundance and population

dynamics.

4.15.6 Phytoplankton

Phytoplankton cell counts between different stations (Station 1 & 2) showed

fluctuating due to variability in the phytoplankton species. Highest population

was recorded at station 1 (surface) whereas the lowest population was

noticed in station 2 (bottom). Dominant groups of phytoplankton were

recorded in all two stations were diatoms followed by dinoflagellates.

Nitzschia followed by the Rhizosolenia and Ceratium were the major species

in both stations at surface and bottom. These species are generally observed

in the offshore marine environment of Dubai. Vertical variations in terms of

species composition and population were not significant due to shallow water

in the sampling region. All species were seen as healthy conditions.

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The effects of temperature changes on marine life are greater than those of

salinity. In general, water temperatures over 34oC suppress the rate of

phytoplankton photosynthesis and can disrupt the survival and normal

metabolism of plankton. Temperatures exceeding 33o to 35oC may result in

the large-scale destruction of algae, and while benthonic organisms can

tolerate temporary water temperatures of roughly 33o to 36oC, fish can only

withstand temperatures of around 34oC.

Increases in salinity may also affect marine life, in so far as changes in salinity

disturb the equilibrium between the osmotic pressure of body fluid and the

surrounding seawater. There is also a close relationship between the

respiration and excretion of several species of marine life and the salinity of

their surrounding environment.

Research indicates that the tolerance of plankton to salinity changes is fairly

strong, though its growth rate drops dramatically in waters of greater than

40ppt salinity. While intertidal algae can tolerate environmental salinity

variations of 0.1 to 0.3 times normal, tidal algae can only survive within a

range of between 0 and 1.5 times normal levels. The sensitivity of benthonic

animals towards interrelated variations in temperature and salinity is generally

greater than that of benthonic plants. Invertebrates living in intertidal and sub-

tidal bands of several meters deep are more adaptable than euryhaline

organisms in their capacity to withstand a greater range of salinity variations

through the physiological process of osmotic pressure regulation. In addition

to the self-regulation of osmotic pressure, fish can also adapt to

environmental changes through migration.

Information with regards to the phytoplankton cell counts in the Arabian Gulf is

very few to absent. We compared our data and found that cell counts of

30x103l-1 have been reported in the coastal waters of India (Qasim, 1979).

However we found very low species richness as compared to the coastal area

of India. Despite possibilities of nutrient limitation for the primary productivity

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in the Arabian Gulf (Kimor, 1979), 400 phytoplankton species including 225

diatoms and 152 dinoflagellates were recorded (Dorgham and Mufatah, 1986,

Dorgham et al 1987). In our study we found only 9 species during sampling

period which clearly shows the impact of thermal discharge on the

phytoplankton species. Planktonic organisms have been recognized as

indicators of water masses and their movements (Raymont, 1963). It is also

reported that the coastal zone throughout the Arabian Gulf coast is already

exposed to major conflict on resources utilization (MEPA, 1992). Studies

along the offshore marine environment of desalination outfall off Jubail,

Arabian Gulf shows seasonal changes in the phytoplankton community and

their population abundance during summer (Abdul-Aziz, 1998) associated

with phytoplankton blooms during August and May. Another study from the

same location indicates that seawater temperature and salinity did not

impact on the abundance of the phytoplankton (Abdul-Aziz, 2003). Although

phytoplankton blooms and harmful algal bloom of red tide in the Arabian Gulf

are quite common (Rao et al, 1999) and exposed to fish kill in mass (Gilbert et

al 2001), we did not find any algal bloom in the present studied area.

Overall present assessment (Table 4.6) suggests low cell counts and diversity

possibly associated with harsh environment associated with thermal

discharge in the close vicinity. The dominant species of phytoplankton

existing in this area were Ceratium and Nitzschia.

4.15.7 Macro-Benthos

Macro-benthic biomass of 12.4 – 18.6 gm/m2, (Table 4.7) at station 1 and 2 is

slightly lesser then the biomass of northern Arabian Gulf environment

(Sheppard et al, 1992). The low biomass at station 1 and 2 possibly

associated with harsh environmental conditions and thermal discharges from

the outfalls located along DUBAL and DEWA.

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Salinity and sediment particle are the two parameter effect benthic community

of the Arabian Gulf (Stephens and McCain 1990). In-faunal abundance

commonly increases with decreasing particle size and reduced of benthic

organism by increasing salinity has been quantitatively observed in the gulf at

salinities above 45 ppt in the gulf of Swah and Abu Dhabi barrier island (Clark

and Keij 1973, Evans et al 1973).

The present results shown in the tables are an average values of two samples

collected from each station. The two samples were collected from two

directions of each station location. These stations are mainly dominated by

polychaetes and crustaceans. The polychaetes species mainly comprised of

Nephthys sp, Eunice sp., Ammotrypane sp., Glycera sp., Lumbrineris sp.,

Scoloplos sp. and Sthenelais sp recorded at these stations. The crustaceans

were mainly dominated by amphipods, and cumaceans. The molluscans were

mainly dominated by Tellina sp., Chama sp., Cerathium, Bellusina and

Mactra sp (Table 4.7 and Fig 4.6).

4.15.8 Conclusion

Overall, the baseline study along the stretch of Jebel Ali Station ‘M’ envisaged

the following:

• Phytoplankton assessment shows low diversity at station 1 & 2 possibly

associated with harsh environment and thermal discharge in the close

vicinity.

• Benthic biomass at station 1 and 2 were observed slightly lesser than the

recorded biomass of the northern Arabian Gulf environment. However

biomass does not shows any impact of heated brine, quantitative

estimation of the biomass of macro-benthos was similar to the Northern

Arabian Gulf. Although heated brine from adjacent outfalls from DEWA

and DUBAL may disturb the balance of marine ecosystem in the vicinity of

station 1 and 2, however their impacts could not be identified. Similar to

CHAPTER 4


4-35


our results the impacts due to heated brine on the marine environment is

not yet established in Saudi Arabia (LBA –Saudi Arabia, 1999).

TABLE 4.6

DISTRIBUTION OF PHYTOPLANKTON CELL COUNTS (NO/L) ALONG

DIFFERENT STATIONS

Phytoplankton Surface Bottom Surface Bottom

Chaetocerose sp 40 40 40 40

Coscinodiscus sp 40 40 30 40

Cyclotella 20 20 20 20

Guinardia delicatula 80 80 40 80

Melosira sp. 40 60 40 40

Nitzschia spp 980 880 780 840

Pleurosigma sp 20 20 20 20

Rhizosolenia sp 540 480 400 340

Synedra alna 140 20 80 40

Thalassionema nitzschioides 80 80 40 40

Ceratium sp. 720 780 640 620

Peridinium sp 640 540 740 640

No. of species 12 12 12 12

Total Cell counts 3340 3040 2870 2760

CHAPTER 4


4-36


TABLE 4.7

DISTRIBUTION OF MACRO-BENTHOS BIOMASS (gm/m2) AND

POPULATION (no/m2)

Species/Groups Station 1 Station 2

Amphipods - 120

Cumaceans - 40

Nephthys paradoxa 520 210

Glycera sp. 220 240

Eunice sp. 200 80

Ammotrypane sp. 2420 1160

Nereis sp. 200 240

Sthenelais boa 40 20

Strombus sp. 100 40

Cymatium sp. - 80

Cerithium sp 120 320

Mitrella blanda 80 80

Tellina sp. 120 400

Timoclea arkana 40 40

Mactra sp. 40 40

Bellucina semperiana 120 320

Biomass (g/m2; wet wt) 12.6 18.2

Population 3600 3190

CHAPTER 4


4-37


0

500

1000

1500

2000

2500

3000

3500

Am

phip

ods

Cum

aceans

Nephth

ys

para

doxa

Gly

cera

sp.

Eunic

e s

p.

Am

motrypane

sp.

Nere

is sp.

Sth

enela

is

boa

Strom

bus s

p.

Cym

atium

sp.

Cerith

ium

sp

Mitre

lla

bla

nda

Tellina s

p.

Tim

ocle

a

ark

ana

Mactra s

p.

Station 1 Station 2

FIGURE 4.6

DISTRIBUTION OF MACRO-BENTHOS BIOMASS (gm/m2 ) AND

POPULATION (no/m2)

4.16 Terrestrial Ecology

The natural surface comprises an area of sand sheets, low dunes, and

ridges and small gravel plains. The site lies in the geomorphological

region VI, the Gulf Coast, as recognized to Dubai Emirates. The pale

sand typical of coastal areas along the UAE Gulf Coast, is relatively

coarse and is rich in calcium carbonate. The site has low, parallel WNW-

ESE oriented sand ridges and interdune plains.

CHAPTER 5

Environmental Impact Assessment

5-1 EIA study for the proposed Jebel Ali Power and Desalination Station M

5.1 Preamble

Actual and foreseeable events, including operational and typical events are

discussed in this chapter. Processes that may create risks to the environment

are considered and are analyzed in terms of key potential environmental

impacts.

Generally, the environmental impacts can be categorized as either primary or

secondary. Primary impacts are those, which are attributed directly by the

project and secondary impacts are those, which are indirectly induced and

typically include the associated investment and changed patterns of social

and economic activities by the proposed actions. In this chapter, only

significant direct and indirect impacts have been considered. The details of

criteria opted for impacts assessment are as per described hereunder.

The environmental impacts may include all those that are beneficial or

adverse, short or long term (acute or chronic), temporary or permanent, direct

or indirect and local or regional. The adverse impacts may include all those

leading to harm to living resources, damage to human health, hindrance to

other activities, impairment of quality for use, reduction of amenities, damage

to cultural and heritage resources and damage to physical structures. For

each identified potential environmental impact, the associated environmental

risk is assessed based on its likelihood and significance. The impacts

assessment is being performed in three steps:

Step 1 : Identification of interactions between activities and

environmental receptors

Step 2 : Identification of potentially significant environmental impacts

Step 3 : Evaluation of all significant environmental impacts

CHAPTER 5



In Step 1, based on the project description and environmental baseline

description, a detailed matrix of activities and environmental receptors is

prepared. Then based on the legal framework and baseline environment data,

it is determined whether an interaction exists between an activity and a

receptor.

In Step 2, based on the interactions identified in Step 1, potentially significant

impacts due to the proposed changes are identified. The impacts may be

beneficial/ adverse, direct / indirect, reversible / irreversible and short-

term/long-term as per criteria given in Table 5.1.

TABLE 5.1

IMPACT RATING ASSESSMENT MATRIX

Impact Criteria

Beneficial Positive Nature of

impact Adverse Negative

Short term Impacts shall be confined to a stipulated time Duration of

impact Long term Impacts shall be continued till the end of plant life

Localized Impacts shall be confined within 5 km radius Impacted Area

Regional Impacts shall be continued beyond 5 km radius

In Step 3, all the potentially significant impacts are evaluated and a qualitative

evaluation is made. An impact level is rated as “low”, “medium” or “high”. The

impact rating is based on two parameters i.e. the “severity of impact” and the

“likelihood of occurrence of impact”.

• Impact Severity: The severity of an impact is a function of a range of

considerations including impact magnitude, impact duration, impact extent,

legal and guideline compliance and the characteristics of the receptor/

resource; and

CHAPTER 5



• Likelihood of Occurrence: How likely is the impact (this is a particularly

important consideration in the evaluation of unplanned / accidental

events).

The significance of each impact is determined by assessing the impact

severity against the likelihood of the impact occurring as summarized in the

impact significance assessment matrix provided in Table 5.2.

TABLE 5.2

IMPACT RATING ASSESSMENT MATRIX

Impact Likelihood

Impact

Severity

Unlikely (e.g. Not

expected to occur

during project

lifetime)

Low Likelihood

(e.g. may occur

once or twice

during project

lifetime)

Medium

Likelihood (e.g.

may occur every

few year)

High Likelihood

(e.g. Routine,

happens several

times a year)

Slight Negligible

Impact

Negligible

Impact

Negligible

Impact

Negligible

Impact

Low Negligible

Impact

Negligible

Impact

Negligible to

Minor Impact

Minor Impact

Medium Negligible

Impact

Minor Impact Minor–Moderate

Impact

Moderate

Impact

High Minor Impact Moderate Impact Major Impact Major Impact

Notes:

Negligible Impact : Defined as magnitude of change comparable to natural variation

Minor Impact : Defined as detectable but not significant

Moderate Impact : Defined as not insignificant; amenable to mitigation; should be mitigated

where practicable

Major Impact : Defined as significant; amenable to mitigation; must be mitigated

CHAPTER 5



The proposed project is likely to create impact on the environment in two

distinct phases:

• Construction phase

• Operational Phase

The construction and operation of the proposed project comprises of various

activities, each of which will have some impact on one or more environmental

parameters. The identification, prediction and evaluation of the associated

and potential impacts are presented as under:

5.2 Impacts during Construction Phase

Generally, impacts during the construction phase are temporary. The impacts

are localized in nature and limited to work area. The construction activities

include excavation, leveling, erection and construction. The major impacts

during construction phase on various attributes of environment are described

below;

5.2.1 Impact on Air Quality

Impact on the ambient air quality occurs during construction phase due to

vehicular traffic, leveling of the site, grading earthwork, foundation work. Mainly

fugitive dust is emitted during construction activities.

Vehicular emissions and emissions from other diesel operated equipment

during construction phase are likely to contribute to the higher concentration

of gaseous pollutants like Oxides of Nitrogen (NOX), Carbon Monoxide (CO)

and Hydrocarbons. The impact will, however, be marginal in nature.

CHAPTER 5



The impact of such activities would be temporary. The impact will be confined

within the project boundary and is expected to be negligible outside the plant

boundaries. However, proper upkeep and maintenance of vehicles, sprinkling

of water on roads and construction site are some of the measures that would

greatly reduce the impacts during the construction phase. Moreover, the site

is already leveled and the dust generation will be substantially low. Based on

the above discussion, the overall is rated as per given below;

Impact Rating Air Quality

Nature of impact Adverse

Duration of impact Short term

Impacted Area Localized

Likelihood of occurrence Low

Severity of impact Very Low

Significance of impact Insignificant

5.2.2 Impact on Water Quality

The construction work mainly consists of fabrication, erection and assembly

where water requirement is very small. The main source of water pollution will

be from loose soil at the construction site.

Make shift sanitary facilities will have to be set up for disposal of sanitary

waste generated by the labours at work place. The wastewater from the

sanitary facilities will be collected in the tanker and disposed as per Dubai

Municipality regulations.

Impact Rating Water Quality



CHAPTER 5







5.2.3 Impact on Noise Level

The major noise generating sources during the construction phase are

vehicular traffic, construction equipment like dozers, scrapers, concrete

mixers, cranes, generators, compressors etc. The operation of these

equipments will generate noise ranging between 75 – 85 dB (A). All the

machinery will comply with the relevant international noise protection

standards. As far as necessary, times and conditions of operation will be fixed

in detail in co-operation with the competent authorities.

The nearest residential area are approximately 3 km from the edge of the

proposed desalination plant. There are existing power stations adjacent to the

proposed desalination plant station ‘M’ and Sheikh Zayed Road which

contribute to the background noise.

Although the existing noise levels have not been monitored, measurements

conducted in similar areas show levels to be typically about 50 to 55 dB (A)

during the day time, falling to between about 35 and 40 dB (A) at night time

which is well with DM limits.

Impact Rating Noise Levels





CHAPTER 5





5.2.4 Impact on Landuse

The new installations to be constructed for station ‘M’ will be adjacent to

existing Package ‘P’ power station in eastern side. The entire location is

developed for power station and desalination plant. The proposed

desalination plant also located within existing power complex. Therefore the

proposed desalination plant will not change the existing view.

Impact Rating Landuse







5.2.5 Assessment of Works, Health and Safety

During construction work the usual Standards on workmanship and safety

regulations are applicable. Recommended construction practices will

eliminate or diminish the disturbances and irritations that construction can

cause. For road, power line and telephone crossings special arrangements

will be made such as scaffolding etc. During erection work of overhead lines

running parallel to hot lines, special provisions concerning worker health and

safety will be made such as keeping vertical and horizontal clearance

between the conductors and all parts of the new installation (cranes, trucks,

winches etc). As a protection against induced current on the new conductors

CHAPTER 5



careful earthing of these conductors will be provided.

About 1000 work men will be employed at the site during the construction

period and hence will have significant occupational health and safety issues to

be dealt with unless a proper safety management system is implemented.

5.3 Impacts during Operation Phase

Operation phase of the proposed facility mainly comprises of the following

activities:

5.3.1 Impact on Ambient Air Quality

All the pumps and equipments will be operated on the electricity. The major

portion of steam requirement shall be procured from existing Package ‘P’

power station. All the turbines in power plant and auxiliary boilers of

desalination plant shall be operated on the natural gas. There will be six

stacks in power plant and 2 stacks in desalination plant which will be the

source of gaseous emissions. The gaseous emission from these stacks shall

be the only source of gaseous emission which may contribute to increased

level of oxides of nitrogen.

The auxiliary boilers will be equipped with Low NOX burner arrangements,

which are able to reduce the NOX emissions in the flue gas from around 300

ppm without this technology to approximately 25 ppm or 51 mg/Nm3 (dry, at

25 °C, 15 % O2) during normal operation.

CO emissions of the plant will be in the same order of magnitude as the NOX

emissions. However the toxicity of CO is around 100 times lower compared to

the toxicity of NOX, which is expressed by its much higher ambient air quality

limit (23,000 for CO compared to 290 for NOX). Therefore the ambient air

CHAPTER 5



impact by CO is considered negligible and was not explicitly calculated by

dispersion calculation.

• Methodology of air Dispersion Calculation

A dispersion model provides more accurate estimates of a source’s impact

and consequently requires more detailed and precise data. In the present

case guideline model known as AIRMOD based on Industrial Source Complex

Model (ISC-3) is used. The model is the U.S. EPA approved air dispersion

model which is widely used and accepted by regulators across the world.

The increment of the ground level concentration arising from the emission of

Desalination plant ‘M’ was calculated and the background pollution level was

added. The total ground level concentrations were compared with the relevant

air quality standards of Dubai Municipality.

• Meteorological Data

As required by the model, input meteorological data of 2008 is collected from

Dubai International Airport. The metrological parameters collected were Wind

speed, Wind Direction, Temperature, Relative Humidity, Atmospheric

Pressure, Rainfall, Solar radiation.

• Receptor Network

In this case the concentrations are estimated by Cartesian receptor method. A

Cartesian network consists of north – south and east-west oriented lines

forming a rectangular grid with receptors located at each intersection point. In

most refined air quality analysis, a Cartesian grid with 50 receptors (where the

distance from the source to the farthest receptor is 5 km) is usually adequate

CHAPTER 5



to identify areas of maximum concentration.

• Emission source Data.

The proposed project will have auxiliary boilers of advanced technology. The

emissions details are given in Table 5.3.

The maximum nitrogen oxide concentration in the flue gas of the auxiliary

boilers will be 150 mg/Nm3. However, with advance low NOx burners the

concentration of NOx shall be 51 mg/Nm3.

The following table shows the source emission parameters of proposed

desalination plant.

TABLE-5.3

SOURCE DATA OF THE PROPOSED STATION ‘M’

Details Sr.

No.

Parameters Unit

Power

Station M

Power

Station L

Desalination

Plant

1 Stack height M 60 60 75

2 Number of Stacks M 6 7 2

3 Stack diameter M 7 7 3.4

4 Flue Gas velocity m/s 17.5 17.5 18

5 Exit flue gas

Temperature

°C 118.4 118.4 204

6 Volumetric flow Nm3/s 512 512 102.1

mg/Nm3 51 51 51 7 Emission rate of NOx

from each stack gm/s 26 26 5.2

CHAPTER 5



• Ground Level Incremental Concentration

The NOX ground level pollution increments were calculated for 24 hour period.

The air quality impacts have been predicted for the proposed desalination

plant on the basis that the pollution due to the existing activities has already

been covered under baseline environmental monitoring.

In the present case, model simulations have been carried out for the

monitoring period using the hourly Triple Joint frequency data viz., stability,

wind speed, mixing height and temperature. For the short term simulation, the

concentrations were estimated at around 50 receptors to obtain an optimum

description of variations in concentrations over the site in 5 km radius

covering 16 directions. For each time scale, i.e. for 24 hr (short term) the

model computes the highest concentrations observed during the period over

all the measurement points. The maximum 24 hourly short term NOX

incremental concentrations are presented in Table-5.4.

TABLE - 5.4

PREDICTED 24-HOURLY SHORT TERM

INCREMENTAL CONCENTRATIONS OF NOX

Concentration µg/m3 Pollutant

Baseline Incremental Resultant DM Standard

NOX (51mg/Nm3) 46.6 8.6 55.2 110

The maximum incremental concentrations of NOX is 8.6 µg/m3 respectively at

a receptor point about 3.1 km southeast from the stacks of the proposed

plant, which are well within the stipulated standards of Dubai Municipality.

Based on the above discussion, the overall is rated as per given below:

CHAPTER 5



Impact Rating Air Quality


Duration of impact Long term


Likelihood of occurrence Very Low

Severity of impact Low


5.3.2 Impact on Water Quality

1 Power Plant

In power plant, about 15 m3/hr of oily wastewater generated in service area

and chemical wastewater of 20 m3/hr will be generated in chemical dosing

area. These wastewaters will be collected in separate collection tanks. The

oily wastewater shall be treated in oil water separation tank. The chemical

wastewater shall be treated in a Effluent Treatment Plant (ETP) consisting of

following treatment units:

• Chemical wastewater buffer basin;

• Reaction basin and Flocculation basin;

• Sedimentation basin;

• Sludge Thickening basin;

• Hydrochloric acid dosing system;

• Alum dosing basin; and

• Polymer dosing basin.

The quantity and quality of before and after treatment is given in Table-5.5.

CHAPTER 5



TABLE-5.5

QUALITY OF WASTEWATER

Oily wastewater Chemical wastewater Sr.

No.

Parameters

Before After Before After

1 pH 6 - 8 6 - 8 2 - 12 6 – 8

2 COD (mg/l) 125 100 125 100 3 Oil & Grease (mg/l) 100 10 50 10

4 Suspended Solids (mg/l) 100 25 200 25

In addition there will be discharge from steam turbine condenser and closed

cooling water system.

The sea water will be supplied from FISIA side for condenser cooling water

(28200 ton/hr) and for auxiliary cooling water separately (1500 ton/hr) for each

block at the temperature and the water quality as supplied by FISIA (normal

condition 37°C). The above water will return (29700 ton/hr) combined-way

through seal pit of each block to FISIA side. The temperature rise in the power

plant cooling water circuits under normal operating condition is about 3.5 °C

(40.5 °C considering 37 °C inlet water from FISIA side) and maximum

temperature rise will be limited to 8 °C. The flow indicated is for Block-1 and

the similar flows are to be considered for Block-2 & Block-3 (which will return

to FISIA side separately) to ascertain the total sea water into power plant and

return from power plant.

2 Desalination Plant

In the desalination plant the main wastewater will be generated in the form of

brine, which is similar to sea water quality with high Total Dissolved Solids

concentration. The total quantity of brine generation in the plant will be about

197392 m3/hr. The brine will be discharged through outfall point in sea.

CHAPTER 5



All the above mentioned wastewater after treatment shall be collected and

mixed together will result in;

1 Dilution of the brine

2 Decrease the temperature of condense water discharge

Thus the final discharge shall have almost similar quality of the seawater.

Therefore the impact on the seawater quality and marine life will be

insignificant.

In addition to these wastewater discharges, domestic wastewater shall be

generated in rest rooms provided in power plant (75 m3/day) and desalination

plant (20 m3/day). The sewerage will be treated in Sewage Treatment Plant

and treated wastewater shall be used in landscaping. No domestic

wastewater shall be discharged into sea.

Impact Rating Water Quality




Likelihood of occurrence High



5.3.3 Impact of Brine from Desalination Plant

During the operation of the desalination plant, a variety of chemicals control

scale formation and biological growth. It is possible that the discharge to the

Gulf of seawater used in production processes and in chemical treatments

could affect the marine environment in the following ways:

CHAPTER 5



• Increase of chemical pollutants;

• Localized increase of the water temperature (thermal pollution);

• Localized increase of salinity and decrease of dissolved oxygen;

• Changes or modification in the marine biota.

Chemicals likely to be of importance include anti-scaling agent addition for

scale inhibition, bio-fouling control by chlorination, antifoam dosing to reduce

foaming and corrosion inhibition by oxygen depletion. However, the particular

additives that will be used during the plant operation have yet to be decided.

The anticipated effects on the marine environment that could be expected

during the operational phase of the complex’s outfall are analyzed below:

• Salinity.

Salt concentrations of the final effluent are above those of the receiving

waters, and will be consistently between 1 and 2.5 ppt above the existing

seawater background levels. In normal and minimal conditions, the salinity of

the effluent at the exit of the outfall (end-of-pipe) will be less than a 5%

increase above background seawater salinity. During the summer, when

seawater temperature and salinity levels are high, the increase above ambient

salinity levels could reach 5.5%. It is expected that at the edge of the mixing

zone, the Dubai Municipality (DM) Marine Standard (no more than 5% in

background concentration) would be respected at all conditions. Respecting

this DM criterion should be sufficient to avoid impacts on the marine

environment.

• Chlorine

A chlorine generating system will produce the 0.1 to 0.15% sodium

CHAPTER 5



hypochlorite solution from seawater feed. This solution will be injected into the

cooling tower and MED makeup streams on a continuous basis for a chlorine

residual of 0.5 ppm in these flows.

• Oxygen

The DEWA effluent will be aerated in a way that the dissolved oxygen (DO)

concentration at the exit of the aeration basin would be at least 3 mg/l and at

the edge of the mixing zone, the dissolved oxygen levels should be close to

the background dissolved oxygen levels. Oxygen scavengers are likely to

comprise sodium sulphite, which is oxidized to sulphate, a normal constituent

of seawater.

Carbon dioxide, oxygen, and nitrogen are the principal dissolved gases in

seawater. These atmospheric gases are dissolved in surface waters by the

movement of winds and waves at the air-sea interface. Temperature and

salinity rule the amount of gas that can be dissolved in seawater. When either

of these increases, the amount of gas that can be dissolved decreases. This

may affect the distribution and composition of communities of marine

organisms.

Hypoxia occurs when the DO level reaches a point at which organisms can no

longer survive. In marine waters, mortalities generally occur at oxygen

concentrations below 2 mg/l.

In the Gulf, the DO levels in surface waters are expected to range between

90- 103% saturation throughout the year, equivalent to 4.8-6.5 mg DO/l.

The DO concentrations in the effluent should not cause any mortality and

should not affect the marine organisms.

CHAPTER 5



• Addition of anti-scaling and antifoaming agents.

Use of anti-scaling agents may lead to formation of orthophosphates from

hydrolysis of polyphosphates. Orthophosphates are a macronutrient that may

enhance biological growth (e.g. red and green algae). Polymeric additives

based on polyacrylate or polycarboxylic acids prevent this problem, and are

biodegradable and certified non-toxic.

Similarly, antifoaming agents are also degradable and non-toxic. Therefore

anti-scaling and antifoaming agents will be selected to avoid polyphosphate

formation and their impact on the marine environment will be considered

negligible.

• Heavy Metals.

Discharged brine contains low concentrations of metal ions resulting from

corrosion, namely copper, nickel, chromium and iron. These concentrations

are profoundly increased with acid cleaning of the plants, which occurs once

or twice per year.

Bioaccumulation of heavy metals in benthic fauna around the outfall could, in

theory, occur. Nevertheless, heavy metal concentrations at the outfall would

be very low due to the cooling water dilution, and below DM regulations.

These metals are also normal constituents of the sea (even if in low

concentrations) and are not of great concern except in extreme occurrences.

If bioaccumulation would occur, it would be locally.

• Thermal Impacts

The use of seawater will result in a discharge seawater temperature will

CHAPTER 5



comply DM Standards. This small change in seawater temperature should not

be of concern for the marine environment, keeping in mind the choice of the

outfall location and design for the initial dilution.

Based on the above discussion, the overall is rated as per given below:

Impact Rating Brine from Desalination Plant






Significance of impact Minor

5.3.4 Impact on Noise Levels

Noise will be generated during operation of the plant, the main noise emitters

being the pumps, compressors, turbines etc. The entire plant will be designed

to meet the limits set by the Dubai Municipality for noise emission from

premises. Appropriate acoustics enclosures will be installed to reduce noise

levels at the project site and in the surroundings.

The designed noise levels for the pumps and compressors shall be less than

85 dB (A) at 1.0 m distance.

In order to predict the incremental noise due to the operation of the above

units, noise modeling has been carried out. The model does not take into

account the background noise levels. The predicted noise levels at the

boundary of the plant in different directions are given in Table-5.6. The

CHAPTER 5



predicted noise values calculated in the model were found to be well within

Dubai Municipality limits.

TABLE - 5.6

PREDICTED NOISE LEVELS AT PLANT BOUNDARY

Sr. No. Direction Noise Levels dB(A)

1 N 50

2 NE 52

3 E 50

4 SE 48

5 S 48

6 SW 48

7 W 50

8 NW 48

The predicted maximum incremental noise levels occur at western boundary

of the plant along the sea coast. The noise levels further falls below 46 dB(A)

at distance of 200 m from the boundary. The other three side of the plant

boundary the existing power stations are located. The impact rating is given

below;

Impact Rating Noise Level







CHAPTER 5



FIGURE-5.1

NOISE DISPERSION CONTOURS

5.3.5 Impact on Social Life

In the operational phase the Project will provide full time employment for

about 200 employees and managerial staff. This will be beneficial to the

society.

CHAPTER 5



Impact Rating Socio-Economic

Nature of impact Beneficial




Severity of impact Moderate

Significance of impact Significant

5.3.6 Impact on Cultural Heritage

Emissions of gases NOX may have adverse effects on cultural heritage due to

their corrosive nature. However, the proposed Desalination Plant ‘M’ will be

fired solely with natural gas during normal operation. NOX emissions will be

considerably reduced by means of low NOX combustion chambers. The

maximum predicted incremental concentrations of NOX are falling within 1-km

from the plant site. The noise levels will also not adversely affect area beyond

500 m from the plant site. There are no sites with cultural heritage importance

and residential townships within 1-km from the plant boundary.

Impact Rating Cultural Heritage







5.3.7 Impacts on Terrestrial Ecology

The site is barren and sandy. The terrestrial flora and fauna do not exist in the

surrounding of the project site. Therefore, the impact on the terrestrial ecology

CHAPTER 5



is not envisaged.

Impact Rating Terrestrial Ecology




Likelihood of occurrence Very Low



5.3.8 Solid Waste

In settling tank of the potable water treatment plant, dissolved and suspended

solids are settled at the bottom in the form of sludge. The sludge from the tank

is removed and dumped in the sludge drying beds located within the plant

premises. This sludge will be non-hazardous in nature and no adverse impact

is envisaged on the surrounding.

The sea water is screened at the initial stage to remove debris. This debris

will be collected in the skip and sent for disposal through authorized

transporter to disposal site of DM. Therefore, the impact on the surrounding

will be insignificant.

Impact Rating Solid Waste






Significance of impact Minor

CHAPTER 6

Proposed Mitigation Measures

6-1


6.1 Preamble

The proposed Power and Desalination Plant ‘M’ will be constructed and

operated according to high environment, health and safety (EHS) standards.

This section provides a summary of mitigation measures, as well as

environmental enhancement opportunities, for the key EHS impacts which

have been identified through the EIA.

The mitigation, monitoring and management measures proposed below, shall

be adopted by M/s Doosan and M/s Fisia and imposed as conditions of

contract on any sub-contractors employed to build or operate any part of the

proposed plant. Many of the mitigation measures presented are considered as

essential, integrated components of the construction and operation works.

6.2 Mitigation Measures during Design and Construction

6.2.1 Dust Emissions

Dust generated by construction activities could be significant locally during fill

sand hauling operations. To minimize dust nuisance, certain good site

practices will be employed as follows:

• Roads will be kept damp through use of water bowsers where applicable;

• Stockpiles of friable materials will be sited and maintained appropriately

(including the use of sheets) so as to minimize dust blow (such as

balancing of cut and fill operations);

• Drop heights for material transfer activities such as loading and unloading

of materials shall be minimized;

• The construction phase will begin with the construction of access roads;

CHAPTER 6


6-2


• Roads created during construction shall be compacted adequately;

• Regular water shall be sprinkled on the roads and at work place;

• Access into the site will be regulated;

• The vehicles carrying construction material like sand, soil, boulders,

cement etc. shall be properly covered.

In addition, to ensure that pollutant levels resulting from transport operations

are kept to a minimum during construction activities, all vehicles being used

on site will meet pollutant emission standards.

The role and responsibilities of the project proponent are given in Table 6.1

TABLE 6.1

ROLE AND RESPONSIBILITIES OF THE PROJECT PROPONENT

Personnel Key Responsibilities

HSE Manager

(Consultant)

To undertake regular site inspection and environmental

parameters to assess to assign corrective actions where

required.

To manage environmental monitoring program

To liaise with Dubai Municipality about all

environmental issues and compliance/non-compliance

with the EMP.

Environmental

Officers

(Contractors)

Provide method statements and ensure compliance with

relevant aspects of the EMP to consultant HSE Manger

Carry out daily inspection of operations

Conduct Day-to-day implementation of the EMP

specifications

Ensuring that all construction staff understand and

adhere to the EMP

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6.2.2 Noise Emissions

Specific noise mitigation measures for the construction phase reflect standard

good site management practices and include:

• Enforcement of vehicle speed limits, orderly movement of the vehicles

within the site;

• The vehicles and construction equipment will be equipped with effective

silencers;

• Activities with highest noise emissions (e.g. piling) will be undertaken only

during the daytime; and

• Personnel working at site will be provided with hearing protection.

6.2.3 Flora and Fauna

Impacts on flora and fauna during construction are not considered to be

significant since the site is devoid of vegetation.

However, species on or close to the site may be disturbed and displaced as a

result of increased noise, dust and human activity. Good site management

practices as discussed elsewhere in this section, and implementation of the

following mitigation measures, will ensure that any disturbance is reduced to a

minimum:

• Run-off from construction activities will be collected and disposed to

ensure that surrounding species/habitats are not significantly affected;

• Vehicles will be restricted to within the boundaries of the construction site,

lay down areas and hauling / access roads, arid will not be permitted to

enter surrounding land.

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6.2.4 Traffic and Transport

Construction activities will generate only limit additional traffic on local roads.

No significant volumes of heavy plant traffic and occasional abnormal loads

are foreseen, as transport of heavy and bulky items is done by boat or barge.

However, to minimize any inconvenience, hazards and damage caused to

other road users, local people and the local road network, the following

mitigation and management measures will be implemented:

• Any abnormal load movements will be confirmed with the Competent

Administrative Authority (CAA) and will adhere to prescribed routes. Their

movement will be scheduled to avoid peak hours and notices will be

published in advance to minimize disruption if required by the CAA;

• Consideration will be given to staggering construction shifts to split arrival

and departure times;

• Scheduling of traffic will be undertaken to avoid the peak hours on the

local road network wherever practicable; and

• Construction workers will be transported to the site by contract bus.

6.2.5 Socio-economic effects

The construction activities will have an overall positive impact on the local

economy. Given that the use of locally available labor will be prioritized during

construction, no mitigation measures are proposed.

6.2.6 Archaeology

No sites of archaeological or cultural heritage importance on or around the

site are expected. In any case, construction works will therefore be monitored

to ensure that in the event of remains being found construction activities will

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be stopped and the responsible authority are consulted on the appropriate

measures, which could include the following:

• Where possible, remains will be protected in-situ from construction

activities, by relocating non essential activities;

• Where identified remains cannot be protected, an excavation of the

indicated area will be undertaken prior to the commencement of

construction activities to record and remove vulnerable remains and

features

6.2.7 Solid Wastes during Construction

To ensure that impacts from solid waste generation and disposal are

successfully avoided, the following mitigation measures will be undertaken

during plant construction:

• All waste taken off site will be carried out by a licensed waste contractor

and DEWA will audit the disposal procedure;

• All solid waste will be segregated into different waste types, collected and

stored on site in designated storage facilities and areas prior to release to

off-site disposal facilities;

• All relevant consignments of waste for disposal, will be recorded,

indicating their type, destination and other relevant information, prior to

being taken off site; and

• Standards for storage area, management systems and disposal facilities

will be agreed with the relevant parties.

An engineer with responsibility for environmental aspects will be responsible

for solid waste management at the site and will ensure that all wastes are

managed to minimize any environmental risks.

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6.2.8 Occupational Health and Safety

The project owner will ensure that construction activities are undertaken in a

manner which does not present hazards to workers' health and safety. In

particular, the project company shall establish and integrate policies and

procedures on occupational health and safety into the construction of the

desalination plant. Emergency and accident response procedures shall also

be included in the safety manual of M/s Fisia

The following measures will be carried out in both the construction and

operational phases:

• Compliance with international standards for good practice;

• Adherence to local and international guidance and codes of practice on

Environment, Health and Safety (EHS) management:

• Management, supervision, monitoring and record-keeping as set out in the

plants operational manual;

• Implementation of EHS procedures as a condition of all contracts;

• Clear definition of the EHS roles and responsibilities of the companies

contracted to work on site and to all their individual staff (including the

nomination of EHS supervisors and coordinator);

• Pre-construction and operation assessment of the EHS risks and hazards

associated with construction and operation, including consideration of

local cultural attitudes, education level of workforce and local work

practices;

• Provision of appropriate training on EHS issues for all employees on site,

including initial induction and regular refresher training, taking into

account local cultural issues;

• Provision of health and safety information;

• Regular inspection, review and recording of EHS performance; and

• Maintenance of a high standard of housekeeping at all times.

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6.3 Mitigation Measures during Operation

6.3.1 Introduction

Mitigation measures introduced into the design and construction phase of the

proposed project will be carried forward into the operational phase by the

Operating Company. Many mitigation measures, as described in this report,

have already been integrated into the design of the proposed project in order

to minimize any operational impacts on the environment. Mitigation measures

such as, noise silencers and water discharge controls are for example

considered integral part to the design of the desalination plant.

The following section builds on the design criteria for the proposed project in

order to reduce to a minimal level any further potential negative impacts.

Areas where positive impacts can be introduced or maximized are also

considered.

The core responsibilities of the Environmental Department for the operational

phase are shown in Table 6.2

Table 6.2

Responsibilities of Environmental Team during Operational Phase

HSE

Department

To ensure compliance of marine discharge

To respond and report on environmental incidents

To manage environmental monitoring program.

To monitor annual environmental targets

To implement a marine spill response plan

To publish State of the Environment Report

To promote environmental awareness and clean

neighborhood policy

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6.3.2 Air Quality during operation

6.3.2.1 Emissions Guidelines

Several specific measures have been taken to reduce boiler stack emissions

from the proposed project and to comply with Dubai and World Bank

standards. The proposed plant will be fired on natural gas as its fuel which is

the least polluting fuel available. In order to reduce NOX emissions, low-NOx

burners will be installed. In addition, a stack measuring adequate hight has

been designed to allow adequate dispersion of emissions into the surrounding

atmosphere.

6.3.2.2 Air Quality Guidelines

To investigate the issue of atmospheric emissions from the desalination plant

and their impact on ambient air quality, dispersion modeling has been

undertaken and the results of the modeling were presented earlier in Section

5. The modeling clearly Shows that the predicted maximum 24 hour mean

max ground levels of NO2 concentrations, do not exceed the Dubai, World

Bank and WHO ambient air quality guidelines.

No further requirement for mitigation of the emissions to air from the

desalination plant is proposed.

6.3.3 Noise Emissions during Operation

A number of noise mitigation measures will be implemented in order to ensure

the lower noise levels well within the local and international noise standards.

Specific design mitigation measures include:

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• Air compressors are equipped with air silencers; and

• Noisy outdoor equipment will be designed to a noise limit of 85 dB(A) at

one meter a stance.

All personnel working in noisy areas will be required to wear hearing

protection.

6.3.4 Flora and Fauna during Operation

The potential impacts of the proposed development on any existing flora and

fauna will be minimized as a result of the following mitigation measures:

• Vehicles will be restricted to within the boundaries of the site and access

roads, and will not be permitted to enter surrounding land.

• Noise will be controlled during operation, and will dissipate rapidly with

distance from source. Any disturbance during operation will therefore be

localized.

6.3.5 Visual Impact during Operation

A green belt with trees around the project boundary (where technically

permissible) will assure the improved aesthetic and help in shielding the the

technical structure. This will also help to reduce the noise levels to some

extent.

6.3.6 Solid Waste Impacts during Operation

To ensure that impacts from solid waste generation and disposal are

successfully avoided, the following mitigation measures will be undertaken

during plant operation:

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• All the waste taken off site will be carried out by a licensed waste

contractor and DEWA will audit the disposal procedure;

• All solid waste will be segregated into different waste types, collected and

stored on site in designated storage facilities and areas prior to release to

off-site disposal facilities;

• All relevant consignments of waste for disposal will be recorded, indicating

their type, destination and other relevant information, prior to being taken

off site; and

• Standards for storage area, management systems and disposal facilities

will be agreed with the relevant parties.

An engineer with responsibility for environmental aspects will be responsible

for solid waste management at the site and will ensure that all wastes are

managed to minimize any environmental risks.

6.3.7 Health and Safety during Operation

The following mitigation and management measures will ensure that the

health and safety of staff and any visitors on and to the site is not jeopardized

during operation of the plant:

• Further development and implementation of an Operational Health and

Safety Plan with appropriate training;

• Provision of training in use of protection equipment and chemical handling;

• Clear marking of work site hazards and training in recognition of hazard

symbols;

• Installation of vapour detection equipment and control systems;

• Further development of site emergency response plans;

• All personnel working or standing close to noisy equipment will be required

to wear noise protectors.

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In addition, the operational health and safety measures during construction

described in Section 6.3.7 above will be carried forward into the operational

phase of the desalination plant.

6.4 Environmental Monitoring Program

The environmental monitoring is very essential during operation of the project.

This will help to assess the efficacy of the pollution control equipment. The

monitoring includes the following:

• Ambient air quality in and around the project site;

• Stack monitoring to assess the gaseous emission with respect to

concentration of the pollutants, flow, temperature etc.

• Marine water quality at intake and at final discharge point;

• Ambient noise levels around the plant boundary;

• The noise levels of the major equipment at 1- distance;

• Assessment of quality and quantity of the solid waste;

The flue gas will be monitored continuously by automatic operating monitoring

equipment. The ambient air pollutants NO2, SO2, Particulate Matter, as well as

the required reference parameters Flue gas shall be monitored.

Temperature, Oxygen Content and Pressure will be measured. The

monitoring results will be transmitted to the Main control and supervision

system of the plant (DCS) and evaluated by responsible environmental

engineers by means of computer facilities for selective evaluation of emission

data.

Additionally flue gas samples can be tapped from the stacks from special

platforms providing safe access to the tapping points.

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Analyses will be performed on regular basis by the plant's laboratory or

specialized outside laboratories.

The parameters to be monitored during construction period are given in

Table-6.3 and the parameters to be monitored during operation are given in

Table-6.4.

TABLE 6.3

ENVIRONMENTAL MONITORING DURING CONSTRUCTION PERIOD

Sr.

No.

Environmental

Attributes Locations Parameters Frequency

3 Locations NOX, SO2, CO, SPM 24 hourly twice a week 1

Ambient air

quality 2 Locations Heavy Metals, Ozone Quarterly

Industrial noise 5 locations plant

equipment Leq Once in every year

2

Ambient noise 5 locations for ambient

noise level

Leq 24 hr continuous with

hourly Leq Once in every year

3 Water quality 2 locations

Salinity, temperature, pH,

DO, BOD, suspended solids,

total nitrogen, total

phosphorous, Ammonical

nitrogen, nitrate, nitrite,

bacteria (Coliforms),

chlorophyll a.

Monthly once

4 Solid waste 1 location Physicochemical At the time of the

disposal

5 Sanitary effluent 1 Location TSS, DO and BOD At the time of the

disposal

6 Sediment quality 3 locations Organic carbon, total

phosphorous, petroleum

Quarterly during

construction phase

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Sr.

No.

Environmental


hydrocarbons and

selected metals- Al, Cr,

Mn, Fe, Co, Ni, Cu, Zn,

Cd, Pb and Hg.

7 Ecology 3 locations

• Phytoplankton biomass,

population and faunal

groups,

• Zooplankton biomass,


groups and biomass,

• Macro benthic biomass,


groups

Monthly during

construction phase

8

Occupational

Health and

Safety

Workers in potentially

hazardous workplaces Health status Once in a year

TABLE 6.4

ENVIRONMENTAL MONITORING PROGRAMME DURING OPERATION PERIOD

Sr.

No.

Environmental


1 Ambient air

quality Three Locations

NOX, SO2, CO, SPM

24 hourly Once a

week

2 Stack

emissions Each Unit

NOX

Continuous

3 Water quality 3 locations

Salinity, temperature, pH,

DO, BOD, suspended

solids, total nitrogen, total

Quarterly once

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Sr.

No.

Environmental


phosphorous, Ammonical

nitrogen, nitrate, nitrite,

bacteria (Coliforms),

chlorophyll a.

Plant effluents One Location

pH, Temperature, TSS,

TDS, Total Residual

Chlorine, Oil and Grease

At the time of the

disposal 4

Sanitary

effluent One Location TSS, DO and BOD

At the time of the

disposal

Industrial noise 6 locations plant

equipment Leq Once in six months

5

Ambient noise Four locations for

ambient noise level

Leq 24 hr continuous with

hourly Leq Once in year

6 Sediment

quality 3 locations

Organic carbon, total

phosphorous, petroleum

hydrocarbons and selected

metals- Al, Cr, Mn, Fe, Co,

Ni, Cu, Zn, Cd, Pb and Hg.

Twice in a year

7 Ecology 3 locations

• Phytoplankton biomass,


groups,

• Zooplankton biomass,


groups and biomass,

• Macro benthic biomass,


groups

Quarterly once

8

Occupational

Health and

Safety

Workers in potentially

hazardous workplaces Health status Once in a year

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6.5 Hazard Protective Measures

Any upset operation of the turbine generators, steam turbine, auxiliary boiler,

evaporators etc. will lead to an electrical trip and as a consequence to a shut

down of the natural gas supply. Therefore it will not cause a rise of emissions.

The stack emissions are continuously analyzed and monitored by automatic

equipment. Additional sample extraction points are provided.

The operation of the waste water treatment systems will be controlled and

monitored continuously.

All effluents from the several waste water treatment systems are analyzed

periodically to detect any upset operation.

Spillage of chemicals and oily liquids, possibly diluted with water, will be

collected to be treated at site or disposed according to the environmental

protection requirements of the Dubai Municipality, if a treatment at site is not

feasible.

Summary of Operating condition at main and bypass Stack

1.0 General

1.1 Operating Case STG Max.RCR

Base

NCR1

BaseNCR2 NCR3

NCRev

100

NCRo

100

MNCR

Base

STG

MCR

MIN

GT30%

MIN

GT30%

1.2 GT Load % 100 100 100Around

81%

Around

79%100 100 100 30 30

1.3 Ambient Temperature oC 50 50 32 22 10 50 50 50 50 10 50

2.0 Bypass Stack Outlet Condition

2.1 GT Exhaust gas mass flow rate kg/s 607.10 607.10 624.00 578.59 601.45 563.10 571.19 607.10 607.10 379.60 356.50

GT Outlet Gas Temp. oC 601.2 601.2 594.9 577.0 558.8 613.8 604.1 601.2 601.2 558.8 552.6

GT Exhaust gas composition *1) *1)

O2 Vol % 12.04 12.04 12.44 12.99 13.17 12.40 11.45 12.04 12.04 14.48 14.48

N2 Vol % 71.85 71.85 73.21 74.25 74.72 72.63 70.51 71.85 71.85 73.33 73.33

CO2 Vol % 3.83 3.83 3.81 3.67 3.65 3.75 5.13 3.83 3.83 2.76 2.76

SO2 Vol % 0.0002 0.0002 0.0002 0.0002 0.0002 0.0002 0.0194 0.0002 0.0002 0.0002 0.0002

H2O Vol % 11.43 11.43 9.67 8.21 7.59 10.37 12.07 11.43 11.43 8.57 8.57

Ar Vol % 0.84 0.84 0.86 0.87 0.88 0.85 0.83 0.84 0.84 0.86 0.86

GT Exhaust gas density kg/m^3 0.4001 0.4001 0.4046 0.4143 0.4239 0.3952 0.4021 0.4001 0.4001 0.4207 0.4239

GT Exhaust gas velocity at

Stack Mouthm/s 39.4 39.4 40.1 36.3 36.9 37.0 36.9 39.4 39.4 23.4 21.9

2.2 Emission

NOx ppmvd @15%O2 25 25 25 25 25 25 25 25 25 25 25

NOx mg/Nm3 @15%O2 50 50 50 50 50 50 50 50 50 50 50

CO ppmvd @15%O2 15 15 15 15 15 15 15 15 15 15 15

CO mg/Nm3 @15%O2 19 19 19 19 19 19 19 19 19 19 19

Particle mg/Nm3 @15%O2 5 5 5 5 5 5 5 5 5 5 5

Smoke Density Bacharach 1 1 1 1 1 1 1 1 1 1 1

3.0 Main Stack Outlet Condition

3.1 Duct Burner fuel type NG NG NG - - NG - NG NG NG NG

3.2 Fuel Heating Value (LHV) kJ/kg 45,300 45,300 45,300 - - 45,300 - 45,300 45,300 45,300 45,300

3.3 Duct Burner fuel mass flow kg/s 1.2310 1.3080 0.5560 - - 1.5610 - 1.3083 1.3083 3.6800 2.8100

3.5 Duct Burner Heat Input MW 55.76 59.25 25.19 - - 70.71 - 59.27 59.27 166.70 127.29

3.1 Exhaust gas mass flow rate kg/s 608.33 608.41 624.56 578.59 601.45 564.66 571.19 608.41 608.41 383.28 359.31

Exhaust gas temperature oC 110.0 121.5 122.5 125.1 126.6 120.7 149.5 123.1 112.5 120.0 120.0

Exhaust gas composition

O2 Vol % 11.35 11.31 12.14 12.99 13.17 11.46 11.45 11.31 11.31 11.35 11.58

N2 Vol % 71.54 71.52 73.02 74.25 74.72 72.22 70.51 71.52 71.52 71.54 72.27

CO2 Vol % 4.16 4.18 3.96 3.67 3.65 4.20 5.13 4.18 4.18 4.16 4.10

SO2 Vol % 0.0002 0.0002 0.0002 0.0002 0.0002 0.0002 0.0194 0.0002 0.0002 0.0002 0.0002

H2O Vol % 12.03 12.07 9.94 8.21 7.59 11.20 12.07 12.07 12.07 12.03 11.12

Appendix 2

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