environmental assessment of assessment of beach man hole...

Environmental Assessment of Assessment of Beach Man Hole at Santhome Beach, Chennai (Tamil Nadu)

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CHENNAI-ANDAMAN NICOBAR ISLANDS SUBMARINE CABLE SYSTEM

(CABLE LANDING AND CONSTRUCTION OF BEACH MANHOLE AT SANTHOME BEACH,

CHENNAI, TAMIL NADU)

ENVIRONMENTAL IMPACT

ASSESSMENT REPORT JULY 2018

Submitted For: Submitted By:

Universal Service Obligation Fund, Department of Telecommunication

EQMS India Pvt. Ltd.

20, Sanchar Bhawan, Ashoka Road, 304 and 305, 3RD Floor, Plot No. 16

New Delhi, Delhi-110001 Rishabh Towers, Community Center

Phone: 011-23739191 Karkarduma, Delhi-110 092

Phone – 011-3000-3200-3216


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Table of Contents 1. Introduction ......................................................................................................... 1-1 1.1. The Project ................................................................................................... 1-1 1.2. Project Background ...................................................................................... 1-2 1.3. Need for the Project ...................................................................................... 1-3

1.3.1. Need Based Assessment .......................................................................... 1-4 1.3.2. Alternative Sites Analysis .......................................................................... 1-4

1.4. Objective and Scope of EIA Study ................................................................ 1-5 1.5. Legal framework ........................................................................................... 1-6 1.6. Methodology of EIA Study ............................................................................ 1-8

1.6.1. Documents Review ................................................................................... 1-8 1.6.2. Data Collection ......................................................................................... 1-8 1.6.3. Impact Assessment .................................................................................. 1-9 1.6.4. Environmental Management Plan ............................................................. 1-9

1.7. Structure of the EIA Report ........................................................................... 1-9 2. Description of the Project .................................................................................. 2-1 2.1. Prelude ......................................................................................................... 2-1 2.2. Location of the Project .................................................................................. 2-2

2.2.1. Cable Route Alignment ............................................................................. 2-2 2.2.2. Landing Site at Chennai ............................................................................ 2-3 2.2.3. Terrestrial Route and Scope of this Study ................................................. 2-1 2.2.4. Existing Utilities in Project Area ................................................................ 2-1 2.2.5. Potential Risks to Submarine Cable Laying Operations and laid Submarine

Cable ........................................................................................................ 2-2 2.3. Category of the Project ................................................................................. 2-5 2.4. Submarine Cable .......................................................................................... 2-5

2.4.1. Submarine Cable – General Design Considerations ................................. 2-5 2.4.2. Submarine Cable Specifications ............................................................... 2-6 2.4.3. Submarine Cable - Toxicity ....................................................................... 2-9 2.4.4. Cable Joint and Repair ........................................................................... 2-10 2.4.5. Cable Repeaters ..................................................................................... 2-10 2.4.6. Branching Units, Housing and Seal ......................................................... 2-10 2.4.7. Cable Markers ........................................................................................ 2-11 2.4.8. Cable Termination .................................................................................. 2-11 2.4.9. Cable End Seal ....................................................................................... 2-11

2.5. Pre-Commissioning Activities ..................................................................... 2-11 2.6. Marine Installation Operations .................................................................... 2-11

2.6.1. Cable Route Survey ................................................................................ 2-13 2.6.2. Route clearance...................................................................................... 2-14 2.6.3. Pre Lay Grapnel Run (PLGR) ................................................................. 2-15 2.6.4. Main Cable Lay ....................................................................................... 2-15 2.6.5. Plough Operation .................................................................................... 2-16 2.6.6. Crossings Engineering ............................................................................ 2-17 2.6.7. Post Lay Inspection and Burial (PLIB) ..................................................... 2-18 2.6.8. Shore End Installation ............................................................................. 2-19 2.6.9. Pre-Lay Shore End ................................................................................. 2-20 2.6.10. Direct Landing ........................................................................................ 2-20 2.6.11. Near shore operations during landings ................................................... 2-20 2.6.12. Navigation and as-laid position ............................................................... 2-21

2.7. Timeframe of the Cable Lay Installation ...................................................... 2-23 2.8. Maintenance/Repair.................................................................................... 2-23


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2.9. Lifecycle Analysis ....................................................................................... 2-23 2.10. Effects of Marine Installation ....................................................................... 2-23

2.10.1. Toxicity ................................................................................................... 2-23 2.10.2. Sonar in cable route survey .................................................................... 2-24 2.10.3. Marine Pollution ...................................................................................... 2-24 2.10.4. Large marine animals – Whales, Cetaceans, Turtles .............................. 2-24 2.10.5. Disturbance to Living Organisms ............................................................ 2-25

2.11. Quality Assurance, Health and Safety ........................................................ 2-26 2.11.1 Health and Safety ................................................................................... 2-26

3. Baseline Environment ........................................................................................ 3-1 3.1. Background (Study area, Methodology, References, etc.) ............................ 3-1 3.2. Site Description and Its Environmental Salient Features ............................... 3-3 3.3. State of Environment .................................................................................... 3-6

3.3.1. Climate and Winds .................................................................................... 3-6 3.3.2. Oceanography: ....................................................................................... 3-11 3.3.3. Geology .................................................................................................. 3-12 3.3.4. Continental Shelf and Slope, Chennai .................................................... 3-16 3.3.5. Seismicity: .............................................................................................. 3-16 3.3.6. Surface Temperature and Salinity ........................................................... 3-16 3.3.7. Sub surface Temperature and Salinity .................................................... 3-17 3.3.8. Coastal Regulation Zone (CRZ) Mapping Survey ................................... 3-18 3.3.9. Noise Environment ................................................................................. 3-18 3.3.10. Air Quality ............................................................................................... 3-18 3.3.11. Biological Environment ........................................................................... 3-19 3.3.12. Marine Ecology Within 12 Nauticle Miles of Marien Water from Chennai Landfall

............................................................................................................... 3-27 3.3.13. Fishing Activities near the Cable Route .................................................. 3-28 3.3.14. Hydrocarbon Exploration and Production ................................................ 3-29 3.3.15. Dumping and Dredging Activities ............................................................ 3-30 3.3.16. Military Activities and Manoeuvre Areas ................................................. 3-30 3.3.17. Marine Protected Areas: ......................................................................... 3-31

4. Anticipated Environmental Impacts and mitigation measures ........................ 4-1 4.1. Prelude ......................................................................................................... 4-1 4.2. Anticipated Impacts and Associated Activities .............................................. 4-1

4.2.2. Construction Phase .................................................................................. 4-2 4.2.3. Operational Stage ..................................................................................... 4-8

4.3. Impact Assessment and Proposed Mitigation ............................................... 4-8 4.4. Conclusion .................................................................................................. 4-13 5. environment management plan ......................................................................... 5-1 5.1. Prelude ......................................................................................................... 5-1 5.2. The EMP ...................................................................................................... 5-1

5.2.1. Oil Pollution Management Plan ................................................................. 5-2 5.2.2. Garbage Management Plan ...................................................................... 5-2 5.2.3. Sewage Management Plan ....................................................................... 5-2 5.2.4. Air Emissions Management Plan .............................................................. 5-2 5.2.5. Noise Management Plan ........................................................................... 5-2 5.2.6. Bio-Diversity Management Plan ................................................................ 5-3

5.3. Occupational Health and Safety Management Plan ...................................... 5-3 5.4. Emergency Preparedness Plan .................................................................... 5-4 5.5. Institutional Framework: ................................................................................ 5-5 6. Summary and Conclusion .................................................................................. 6-1 6.1. Summary ...................................................................................................... 6-1

6.1.1. Beach Installation ..................................................................................... 6-1 6.1.2. Marine Installation ..................................................................................... 6-1


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6.1.3. Associated Risks ...................................................................................... 6-1 6.1.4. Conclusion ................................................................................................ 6-1


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List of Tables TABLE 1.1 : NEED BASED ASSESSMENT FOR THE PROJECT - COMPARATIVE ANALYSIS ...................................... 1-4 TABLE 1.2 : FEATURES OF SUGGESTED BMH SITES .............................................................................................. 1-5 TABLE 1.3 LEGISLATIONS APPLICABILITY – CANI SUBMARINE CABLE SYSTEM .................................................... 1-6 TABLE 2.1 : SALIENT FEATURES OF THE PROJECT ................................................................................................ 2-3 TABLE 2.2 ENVIRONMENTAL AND SOCIAL RISK ANALYSIS ASSOCIATED WITH CABLE ROUTES WITHIN 12

NAUTICLE MILE FROM CHENNAI COASTLINE AND BMH LOCATIONS ......................................................... 2-3 TABLE 2.3 SUMMARY OF THE CHARACTERISTICS OF LW/LWP/SA/DA SUBMARINE CABLES .............................. 2-8 LOGISTICS OF EFFORTS REQUIRED DURING NEAR SHORE OPERATIONS DURING LANDING ............................ 2-21 TABLE 2.4 ........................................................................................................................................................... 2-21 TABLE 3.1 METEOROLOGICAL DATA OF CHENNAI (1981-2010) ........................................................................ 3-10 TABLE 3.2 : FIVE YEARS MONTHLY RAINFALL OF DISTRICT CHENNAI ................................................................ 3-10 TABLE 3.3 : TIDAL INFORMATION FOR THE CHENNAI PORT .............................................................................. 3-12 TABLE 3.4 AMBIENT AIR QUALITY STATUS (2016) ............................................................................................. 3-19 TABLE 3.5 FAUNAL SPECIES IN BUFFER AREA .................................................................................................... 3-20 TABLE 3.6 PLANKTONS IN ADYAR CREEK ........................................................................................................... 3-21 TABLE 3.7 LIST OF PHYTOPLANKTON PRESENT IN WATER OF SANTHOME BEACH ........................................... 3-23 TABLE 3.8 : LIST OF ZOOPLANKTONS PRESENT IN WATER OF SANTHOME BEACH ........................................... 3-23 TABLE 3.9 :LIST OF PELAGIC FISHERY IN COASTAL WATERS OF TAMIL NADU ................................................... 3-24 TABLE 3.10 :LIST OF DEMERSAL FISHERY IN COASTAL WATERS OF TAMIL NADU ............................................. 3-25 TABLE 4.1 : POTENTIAL SOURCES OF ENVIRONMENTAL IMPACTS ...................................................................... 4-1 TABLE 4.2 : WASTE GENERATED DURING CABLE LAYING OPERATION ................................................................ 4-3 TABLE 4.3 IMPACT ASSESSMENT OF THE PROJECT WITH PROPOSED MITIGATIONS .......................................... 4-9


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List of Figures

FIGURE 2.1 : LOCATION OF BMH AT SANTHOME BEACH, CHENNAI ................................................................... 2-1 FIGURE 2.2 : MAP SHOWING CABLE ROUTE WITHIN 12 NAUTICLE MILES (INDIAN TERRITORIAL WATERS) ...... 2-2 FIGURE 2.3 : LOCATION OF BMH AT SANTHOME BEACH, CHENNAI ................................................................... 2-4 VIEW OF CLS STATION FROM BMH LOCATION ................................................................................................... 2-1 FIGURE 2.4 ...................................................................................................... ERROR! BOOKMARK NOT DEFINED. FIGURE 2.5 PROPOSED AND EXISTING BMHS AT CHENNAI ................................................................................. 2-2 FIGURE 2.6 : MAIN SHIPPING LANE ACROSS BAY OF BENGAL ............................................................................. 2-4 FIGURE 2.7 : A TYPICAL LW TYPE SUBMARINE CABLE – OCC-SC530.................................................................... 2-6 FIGURE 2.8 : A TYPICAL LWS TYPE SUBMARINE CABLE – OCC-SC530 .................................................................. 2-7 FIGURE 2.9 : A TYPICAL SA TYPE SUBMARINE CABLE – OCC-SC530 ..................................................................... 2-7 FIGURE 2.10 : A TYPICAL DAS TYPE SUBMARINE CABLE – OCC-SC530 ................................................................ 2-8 FIGURE 2.11 : PLGR OPERATIONS ...................................................................................................................... 2-15 FIGURE 2.12 : PLOUGHING OPERATIONS .......................................................................................................... 2-17 FIGURE 2.13 : PLOUGHING MECHANISM .......................................................................................................... 2-17 FIGURE 2.14 : POST LAY INSPECTION AND BURIAL OPERATIONS ...................................................................... 2-19 FIGURE 2.15 : SHORE END OPERATIONS ........................................................................................................... 2-20 FIGURE 2.16 : SCHEMATIC DIAGRAM BEACH MAN HOLE ................................................................................. 2-23 FIGURE 3.1 : VIEW OF AREA WITHIN 500M OF BMH LOCATION ........................................................................ 3-2 FIGURE 3.2 : SITE PHOTOGRAPHS ........................................................................................................................ 3-6 FIGURE 3.3 : MEAN SURFACE WIND DIRECTION DURING SOUTH-WEST MONSOON (LEFT) AND NORTH-EAST

MONSOON (LEFT) ....................................................................................................................................... 3-7 FIGURE 3.4 TROPICAL STORM TRACKS FOR THE STUDY AREA FROM 1985 TO 2005 .......................................... 3-9 FIGURE 3.5 SURFACE CIRCULATION DURING THE SOUTHWEST (LEFT PANEL) AND NORTHEAST (RIGHT PANEL)

MONSOONS. ............................................................................................................................................. 3-12 FIGURE 3.6 : BOTTOM TOPOGRAPHY CONTOURS OF THE BAY OF BENGAL ..................................................... 3-14 FIGURE 3.7 : SCHEMATIC DIAGRAM OF THE CONTINENTAL SHELF SHOWING BOTTOM PROFILE AND ZONES OF

SEDIMENTS ............................................................................................................................................... 3-15 FIGURE 3.8 : SUB SURFACE TEMPERATURE PROFILE ACROSS BAY OF BENGAL ................................................ 3-17 FIGURE 3.9 : SALINITY PROFILE ACROSS BAY OF BENGAL ................................................................................. 3-17 FIGURE 3.10 : PERCENTAGE OF LANDINGS OF PELAGIC FISHERIES IN COASTAL WATERS OF TAMIL NADU ..... 3-25 FIGURE 3.11 : PERCENTAGE OF LANDINGS OF DEMERSAL FISHERIES IN COASTAL WATERS OF TAMIL NADU . 3-27 FIGURE 3.12 TYPICAL SMALL FISHING VESSEL, CHENNAI .................................................................................. 3-29 FIGURE 3.13 TYPICAL LARGE FISHING VESSEL, CHENNAI .................................................................................. 3-29 FIGURE 3.14 FIRING PRACTICE AREAS (IN RED) IN VICINITY OF CHENNAI ......................................................... 3-31 FIGURE 3.15 : MARINE PROTECTED AREA, TAMIL NADU .................................................................................. 3-32


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List of Annexure

Annexure I – CRZ Map and Report

Annexure II – List of Algae and Sea Grass present in Coastal Waters of Tamil Nadu

Annexure III – Excepts from ZSI Report for Similar Project at Similar Location

Annexure IV- Disaster Management Plan

Annexure V – Oil Spill Emergency Plan


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ABBREVIATIONS

USOF Universal Service Obligation Fund

CANI Chennai Andaman and Nicobar Island

ANI Andaman and Nicobar Island

BMH Beach Man Hole

BU Branching Unit

CBL Cable Breaking Load

CMFRI Central Marine Fisheries Resources Institute

CLS Cable Landing Station

cm Centimetre

CPCB Central Pollution Control Board

CRZ Coastal Regulation Zone

DAS Cable Double Armoured Cable

DC Direct Current

DoT Department of Telecommunication

DG Diesel Generator

EHS Environment Health and Safety

EIA Environmental Impact Assessment

EMP Environmental Management Plan

EQMS EQMS India Pvt. Ltd

FADs Fish aggregating Devises

FSI Fisheries Survey of India

Gbps Gigabit per second

GPS Global Positioning System

GSM Global System for Mobile communications

IMD Indian Meteorological Department

IMO International Maritime Organization

INCOIS Indian National Centre for Ocean Information Services

ISO International Standards Organisation

kmph Kilometre per hour

m meter

MARPOL International Convention for the Prevention of Pollution from Ships, 1973

MCC Municipal Corporation Chennai

MEPC Marine Environment Protection Committee

MoEF&CC Ministry of Environment and Forests and Climate Change

MOP Methods of Procedures

MPA Marine Protected Area

NAAQS National Ambient Air Quality Standards

NOx Oxides of Nitrogen

NPTS Nominal Permanent Tensile Strength

NOTS Nominal Operating Tensile Strength

NTTS Nominal Transient Tensile Strength

OOS Out Of Service

PLB Post Lay Burial

PLGR Pre-Lay Grapnel Run

PLIB Post-Lay Burial and Inspection

PLSE Pre-Lay Shore End

SOLAS Safety of Life at Sea

SWBT Shallow Water Burial Tool

QA Quality Assurance

ROV Remote Operated Vehicle

ROW Right-of-Way


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RPL Route Position List

SO2 Sulphur Dioxide

SPCB State Pollution Control Board

TNCZMA Tamil Nadu Coastal Zone Management Authority

VoIP Voice over Internet Protocol

WD Water Depth

ZSI Zoological Survey of India


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1. INTRODUCTION

1.1. The Project

1. Universal Service Obligation Fund (USOF), Department of Telecommunication (DoT) has planned to connect the Andaman and Nicobar (ANI) group of islands (eight nos. of islands) with India mainland at Chennai through submarine optic fiber cable system: Chennai Andaman and Nicobar Island (CANI) cable system. CANI cable system will have speed of 100 (Gbps) Gigabit per second. Eight islands to be connected with Chennai includes Port Blair, Little Andaman (Hut bay), Car Nicobar, Kamorta, Great Nicobar (Campbell bay), Havelock, Long and Rangat Islands. CANI Submarine Cable System will help in augmenting the existing capacity to likely high capacity demand for communication and internet applications. USOF, DOT has appointed Telecommunication Consultants India Ltd as technical consultant for the project.

2. The cable system has initial traffic capacity consisting of eight segments with one being repeatered from Chennai to Port Blair and six unrepeatered segments from Port Blair to 7 different islands as defined above. Cable will comprise of four pair of optic fibres, i.e. eight fibre cables. Total route length is estimated to be approx. 2199.66 km. CANI cable system will provide secure, reliable, robust, and affordable telecom facilities in these islands.

3. Desktop study for the proposed cable route has been carried out by

consortium of three, companies, i.e. Ocean Science & Surveying Pvt. Ltd, Atlantis Consultancy and Saltwater Cables for all areas except for Rangat and Long Islands. The desktop study for Rangat and Long Island is carried out by the consortium of Eqms India Pvt. Ltd, Ocean Science & Surveying Pvt. Ltd, and Atlantis Consultancy. NEC Corporation, a Japanese company has been assigned the responsibility for the deployment of submarine cable system by DoT. NEC shall be responsible for installing cable and repeaters and will also be responsible for project management, system design and commissioning and marine operations.

4. Project involves providing submarine cable connectivity between Indian

mainland at Chennai and eight islands of A& N islands. Submarine cable will be laid in Bay of Bengal to connect Chennai and eight islands. Cable in Chennai will land at Santhome beach opposite to Faith Fullgospel church, Chennai, Tamil Nadu. A beach man hole (BMH) measuring 3 m X 4 m X 4 m will be developed for housing the cable. There are 4 existing similar BMH close to the proposed BMH site. No other major infrastructure will be developed in coastal area other than BMH. Cable from BMH will be connected to the cable landing station which is existing BSNL is building located in R. K. Nagar, Chennai.

5. Cable landing points at sea edge, BMH and cable route from landing point to

BMH and from BMH towards cable landing station till 500 m from HTL will fall

This chapter provides introduction to the cable system, project proponent, brief of Cable system, Need of Project, Alternative analysis to BMH locations, Need of the EIA Study, Legislative Requirements, EIA methodology and Structure of the report. .


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under CRZ area as defined under the CRZ Notification, 2011 as amended. As per study conducted by Anna University, beach man falls under CRZ II area and cable from landfall to the BMH falls in CRZ I b area. Thus according to CRZ Notification, 2011, it is required to obtain CRZ clearance from TNCZMA and MoEF&CC prior development on the basis of the application form and the rapid EIA study. EQMS India Pvt. Ltd. (EQMS) has been contracted by TCIL as environmental consultant to conduct the environment impact assessment study for the proposed project. This EIA report covers the impact due to the submarine cable laying and BMH construction at Santhome Beach in Chennai. Map showing location of BMH is given below in Figure 1.1.

Figure 1.1Location Map: BMH location at Santhome Beach, Chennai

1.2. Project Background

6. The fiber optic option is the most cost-effective one and the one that is most compatible with the rest of the global network of transmission infrastructure. Without fiber optic connections to the rest of the world, internet services development and integration into the global information economy are achievable only with unnecessarily high cost, greater difficulty and more risk


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than need be the case given the choice of technology available.

7. In 2013, the European Investment Bank estimated that the international transmission capacity of submarine fiber optic cable is being 7 – 10 times cheaper than current prices for satellite-based links.

8. An alternative to marine routing of the system is a terrestrial route. However, in practice the installation costs of a land-based system would be far higher than the marine option. Moreover for terrestrial systems permitting is complex and time consuming and cable faults are more frequent. In addition to these practical and security issues, there are clearly complicated potential environmental and social impacts to be expected from terrestrial cable burial for a system with a length of several thousand km.

9. Most carriers today therefore will prefer submarine fiber optic systems for long haul transmission. This is confirmed by the continued successful existence of several precedents for the development of such systems to serve India’s telecommunications needs.

1.3. Need for the Project

10. The proposed CANI Cable System will enhance the telecommunications connectivity, providing additional capacity, speed for traffic, secure, reliable, robust and affordable telecom system from Chennai to eight Islands of Andaman & Nicobar Islands which are of immense strategic significance to India. It is a key infrastructural improvement that will assist the Andaman & Nicobar islands and Chennai both economically and socially. It will enhance communications security, by diversifying the communications networks to improve the likelihood of continued connectivity during natural disasters or failures of other systems.

11. Currently the only medium of providing telecom connectivity between Mainland and Andaman & Nicobar Islands is though satellites, but the bandwidth available is limited to 1 Gbps. Satellite bandwidth is very costly and its availability is limited due to which future bandwidth requirement cannot be met solely through it. There is an issue of redundancy, that is, no alternate media is available in case of any emergency. Lack of bandwidth and telecom connectivity is also hampering socio-economic development of the islands. Hence it is essential to have submarine OFC connectivity between the mainland India and Andaman & Nicobar Islands, being the only option for catering to projected future bandwidth requirements

12. Many advantages have been acknowledged for high-speed, high-volume international and domestic connectivity including:

• Overcoming geographical and financial barriers to a wide range of educational, cultural and recreational opportunities and resources,

• Enabling provision of medical care to un-served and underserved populations through remote diagnosis, treatment, monitoring and consultations with specialists,

• Promoting economic development and re-vitalisation through e-commerce,

• Enabling electronic government to help streamline people’s interaction


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with government agencies and provide information about government policies, procedures, benefits and programs,

• Providing access to new telecommunications technologies such as Voice over Internet Protocol (VoIP).

• Extending and enhancing opportunities for business process outsourcing, international online collaborations, meetings through videoconferencing, digital media recordings and transmissions.

1.3.1. Need Based Assessment

13. A comparative analysis has been carried out for the project taking into account certain important factors – environmental, technical and socio-economic, to assess the importance of the project. Table 1.1 presents the summary of the attributes impacted by the project.

Table 1.1 : Need Based Assessment for the Project - Comparative Analysis

Factors Considered

Without Project With Project

Environment All the biological and physical parameters of the environment remain unaffected.

Short term impacts of negligible significance may occur on marine environment during the project implementation. Impact assessment study for the project has been carried out to assess the impacts and accordingly mitigation measures and an Environmental Management Plan (EMP) is proposed.

Society/People Data transferability, security and storage, hurdles in the field of advancement, will persist.

There is a need of bringing in advanced and quicker communication technologies to strengthen the existing telecommunication services in Country.

The project will enhance telecommunications connectivity, providing additional capacity and speed for traffic of India.

A key infrastructural improvement that will assist the State and India, both economically and socially.

Will enhance communications security, by diversifying the communications networks to improve the likelihood of continued connectivity during natural disasters or failures of other systems.

1.3.2. Alternative Sites Analysis

14. The site for Submarine cable system and BMH location was selected taking into Environmental, Social, and Engineering feasibility and earlier precedence of CRZ clearance of other cables in near future. The cable alignment landing was considered based on location of Cable landing station and clear approach to the Santhome beach. Two BMH locations at Santhome beach were considered for construction of BMH. The coordinates of these two BMH locations are given at Table 1.2. Following points are considered while selecting BMH site

i. Distance from eco-sensitive zone, residential and recreational areas


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ii. Minimal disturbance to existing fishing activities, shipping and future development

iii. Minimal disturbance to recreational/ tourism activity

iv. Minimal disturbance to ecology

v. Absence of Mangroves (within 500 m stretch)

vi. Accessibility

vii. Impact of overall cable route

viii. Possibility of direct landing of cable (nearness to deep waters)

ix. Minimum distance of BMH to the finalized cable landing station (CLS)

15. Proposed & optional landing site considered and the rational for selection of the site is tabulated in Table 1.2.

Table 1.2 : Features of Suggested BMH sites

Proposed BMH Location

Optional BMH Location

Rational for Selection of Proposed BMH site

13° 1.475’ N 80° 16.722’ E Located at Santhome Beach near Srinivaspuram

13° 1.268’ N 80° 16.690’ E Located at Santhome beach opposite Foreshore Estate

Proposed BMH location is considered for development of BMH as distance of this BMH site is only 1.9 km from proposed cable landing station at R.K. Nagar. Proposed BMH site is at 4 km south of the in service TIISCS landfall and as such will require an offshore crossing of the latter cable and would also provide a landfall within the established Cable Protection Corridor (CPZ).

1.4. Objective and Scope of EIA Study

16. The purpose of this EIA is to document the assessment of the environmental consequences arising from the installation of CANI Submarine Cable System, in Chennai, India. This EIA is structured in accordance with the recently developed environmental assessment guidelines by MoEF&CC that comply with Indian legislations and MoEF&CC safeguard policies being adopted for preserving the environment.

17. The EIA for the proposed submarine cable landing has been conducted to identify and minimise the adverse environmental impacts, if any, associated with construction, installation, and operation of the submarine fibre optic cable network. The four basic objectives of the EIA are the following:

• Provide information about the general environment near the cable route and cable landing site as baseline data;

• Determine the magnitude of potential environmental concerns to ensure that appropriate consideration is given to the environmental


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parameters when laying or installing the cable;

• Identify potentially required mitigation measures, if any; and

• Develop an Environmental Management Plan (EMP).

18. To meet the above objectives of this EIA , the EIA was carried out with a

suitable methodology focused on the following:

• Review of applicable laws and guidelines;

• Collection of environmental data from primary and secondary sources;

• Interaction with key stakeholders;

• Interaction with other members of the Project Team, and;

• Project details provided by the Team.

1.5. Legal framework

19. Table 1.3 lists the legislations applicable to the CANI Submarine Cable System.

Table 1.3 Legislations Applicability – CANI Submarine Cable System

Legislation Key Requirement Applicability Reason and Stage of Applicability or non-applicability

Granting Agency, if applicable

Type of permit and Indicative time frame for grant of permission, if applicable

Responsibility And Stage of Applicability if applicable

A. APPLICABLE LEGISLATION

I. Coastal Zone Management Legislation

Coastal Regulation Zone ( CRZ), 2011, under Environment ( Protection) Act, 1986 Amendment, 2018

Defines the area where development activities are regulated.

Applicable BMH and Cable laying operation activity will happen with this regulated zone and falls within permissible activity as per CRZ regulation.

District CRZ Committee, followed State CRZ Authority followed by MoEF&CC (Ministry of Environment and Forests), Government of India

Clearance from CRZ Authority

Project Owner and prior to commencement of BMH construction and cable laying activity.

II. Environmental Protection Legislation

Air (prevention and control of pollution) Act, 1981 and rules there under

An Act to prevent and control of Air Pollution

Limited applicability (Applicable only for ambient air quality perspective)

Since no air polluting plant is proposed to be installed, the applicability will be limited to construction stage only and for maintaining air quality of the area as per National Ambient air quality standards

Not Applicable

Not Required since no hot mix or air polluting plant is proposed to be set up

Contractor ( Cable laying company -NEC in this case)


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Noise Pollution (Regulation And Control) Act, 2000 Amendment Rules, 2010

To comply with Ambient Noise Standards for different area/zone

Applicable for the duration of construction due to generation of construction noise

Primarily Applicable during construction Stage

Not Applicable

No specific permission is required. To ensure compliance to the Ambient Noise standard for residential areas.

Contractor

Construction & Demolition Waste Rules, 2016

To manage the waste generated due to construction and demolition works

Applicable but only very small quantity of waste man generate due to construction of BMH and Cable landing stations

Primarily Applicable during construction stage

Not Applicable

No specific permission is required. To ensure compliance of rules for waste disposal

Contractor

B. NOT APPLICABLE LEGISLATION

I. Environmental Protection Legislation

Environmental (Protection) Act, 1986 and rules there under including EIA Notification, 2006.amended 2009

Requires prior environmental clearance for specified project.

Not Applicable

BMH construction or cable laying are not included in the list of project requiring environmental clearance appended to this EIA notification.

Not Applicable

Not Applicable

Not Applicable

Water (prevention and control of pollution) Act, 1974 and rules there under

An Act to Prevent and Control of Water Pollution

Not Applicable

No liquid waste is likely to be generated from the project activities.

Not Applicable

Not Applicable

Not Applicable

Hazardous Wastes (Management, Handling and Trans Boundary Movement,) Rules, 2008

Protection to the general public against improper handling, storage and disposal of hazardous wastes

Not Applicable

No Hazardous wastes are likely to be generated during construction or operation stage

Not Applicable

Not Applicable

Not Applicable

The Bio Medical Waste (Management and Handling rules) 1998

To control storage, transportation and disposal of Bio Medical Waste.

Not Applicable

Very short duration activities. No medical waste is likely to be generated.

Not Applicable

Not Applicable

Not Applicable

II. Forests Conservation and Wild Life Protection Legislation

Forest (conservation) Act, 1980 and rules there

Restriction on the de-reservation of forests or use of forest land for non-forest purpose

Not Applicable

No Diversion of Forest Land is involved

Not Applicable

Not Applicable

Not Applicable


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1.6. Methodology of EIA Study

20. The EIA study carried out following the standard practice of data collection, Identification of Environmental Impact due to project activities, developing mitigation measures to eliminate or minimise the impacts Assessment, and evolving the environmental management plan to implement the identified mitigation measures. The broad step followed is given below:

1.6.1. Documents Review

21. Technical reports, project information (including the project plan), execution schedules, and associated details were provided by TCIL, Desk Top Study Reports (prepared by Ocean Science & Surveying Pvt. Ltd, Atlantis Consultancy and EQMS India Pvt. Ltd.), Saltwater Cables and NEC Corporation. These reports were reviewed to identify the potential environmental aspects and impacts associated with project activities. The project’s environmental issues were studied to characterise and quantify the various environmental releases and waste streams that would be generated from the project during its life cycle.

22. Technical consultations and information exchange were made with project authorities and NEC ( the project execution contractor) throughout the review process to better understand project activities. EIA studies conducted for similar projects were also reviewed. In addition, the rationale for the selection of all critical project processes and technologies were reviewed. The control and management schemes proposed for marine discharge, air emissions, wastewaters, solid wastes, and noise were also reviewed.

1.6.2. Data Collection

23. The majority of the environmental baseline information on climate, meteorology, oceanography, and marine ecology was sourced from the published documents from government departments, non-government institutions, and previous studies in this region. Other relevant information also was gathered from Internet searches.

24. Site specific field assessments were also carried out to augment / validate the available baseline data at the cable landing site.

25. CRZ mapping on the scale of 1:4000 scale was also undertaken with the

under

Wildlife (protection) Act, 1972 and rules there under

No person shall destroy, exploit or remove any wild life including forest produce from a sanctuary/National park or destroy or damage or divert the habitat of any wild animal by any act whatsoever or divert, stop or enhance the flow of water into or outside the sanctuary, except under and in accordance with a permit granted by the Chief Wild Life Warden

Not Applicable

No Such area is located in and around the project area.

Not Applicable

Not Applicable

Not Applicable


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help of Anna University. Ann University report was also used in the study.

26. EQMS India Pvt Ltd has has undertaken a zoological study through ZSI (Zoological Survey of India) for BBG cable system having BMH landing at Santhome beach itself. The same zoological study is also referred for this study.

1.6.3. Impact Assessment

27. The significant environmental aspects were reviewed with respect to project activities. The qualitative assessment technique was used to determine the nature and magnitude of these impacts. The anticipated impacts on the environment were then rated accordingly in terms of no impact, minor to moderate impact, and significant impact.

1.6.4. Environmental Management Plan

28. The EMP has been developed to eliminate or minimise and mitigate all significant and minor to moderate impacts to acceptable levels. The EMP discusses all phases of the project (i.e., construction, and operation). An environmental monitoring program has been developed to ensure proper implementation of the EMP.

1.7. Structure of the EIA Report

29. The EIA report contains project features, baseline environmental conditions, assessment of environmental impacts, the formulation of mitigation measures and an EMP. The report has six chapters. The structure of the EIA Report, with necessary tables, drawings, and annexure is as follows: Chapter 1: Introduction

30. This Chapter provides background information on the project need, reasons for conducting the EIA, and overview of the project. EIA methodology adopted in the preparation of the EIA report is also described in this chapter. It discusses the identification of the project and the project proponent; a brief description of the nature, size, and location of the project; and its importance to the country and region. Chapter 2: Project Description

31. This Chapter deals with the project details of The Chennai Andaman and Nicobar Island (CANI) Submarine Cable System including location, route identification, submarine cable specification, marine installation operations, quality assurance and health and safety. Chapter 3: Description of the Environment

32. This Chapter describes the baseline environmental conditions around the project site for various environmental attributes, within 500 meters of radial zone, which is termed as the study area. Topography, soil, water, meteorology, air, noise, and land constitute the physical environment, whereas flora and fauna constitute the biological environment. Baseline environmental conditions are based on the field studies carried out during study period around the project site. Chapter 4: Anticipated Environmental Impacts and Mitigation Measures


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33. This Chapter describes the overall impacts of the proposed project activities

and underscores the areas of concern for which mitigation measures should be implemented. Chapter 5: Environmental Management Plan

34. This Chapter details out the management plan formulated for ensuring the environmental health and safety protection during and after commissioning of project. Chapter 6: Summary and Conclusion

35. This Chapter provides the summary and conclusions of the EIA study for the proposed project, with overall justification for project implementation and a description of how adverse effects will be mitigated.


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2. DESCRIPTION OF THE PROJECT

2.1. Prelude

1. Proposed Chennai Andaman and Nicobar Island (CANI) cable system, a 100 (Gbps) Gigabit per second will connect Chennai (Indian Mainland) with eight islands at Andaman and Nicobar ( namely Port Blair, Little Andaman also called Hut bay, Car Nicobar, Kamorta, Great Nicobar also called Campbell bay, Havelock, Long and Rangat). CANI cable system will provide secure, reliable, robust, and affordable telecom facilities in these islands. Cable at Chennai will land at Santhome beach and will terminate in the proposed BMH proposed to be constructed at Santhome beach at approx 35 m from sea edge. Cable from BMH will then be taken to cable landing station for distribution. This EIA covers laying of submarine cable in Indian territorial water (upto 12 nm), cable landfall at Santhome Beach, BMH construction, and connecting the cable from BMH to Cable Landing Station (CLS) upto CRZ area limits. Overview of the CANI cable laying systems is given in Figure 2.1.

Source: BMH coordinates provided by DTS Survey and superimposed on Google Earth Imagery by EQMS

Figure 2.1 : Location of BMH at Santhome Beach, Chennai

This chapter deals with the project details of The Chennai Andaman and Nicobar Island (CANI) Submarine Cable System including location, route identification, submarine cable specification, marine installation operations, quality assurance and health and safety.


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2.2. Location of the Project

2.2.1. Cable Route Alignment

2. There are total eight segments of submarine cable which will be laid in Bay of Bengal under the project “CANI Cable Laying System”. Total length of the cable and route is 2245.96 km and 2199.66 km respectively. Submarine cable route to be laid within the territorial waters (12 nauticle miles) is considered under the study. The cable within territorial waters of India Main land crosses the route of two major existing cable systems, i.e. TIISCS & SMW4 Seg1-07 cable systems and Firing Practice Area. The proposed cable route does not traverse or impact any known sites of environmental importance such as coral reef, seagrass, marine protected areas such as mangroves, important fish breeding grounds, etc within territorial waters of Chennai. The majority of the cable route in Indian waters is within India’s Economic Zone Cable route map from Chennai BMH upto 12 nauticle miles in Bay of Bengal is shown in Figure 2.2.

Source: Google Earth Imagery

Figure 2.2 : Map Showing Cable Route Within 12 Nauticle Miles (Indian Territorial Waters)


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2.2.2. Landing Site at Chennai

Cable in Chennai will land at Santhome Beach and will be housed in beach man hole proposed to be located opposite to Faith Fullgospel church. Geographical coordinates of the BMH site is 1301.475N and 800 16.722 E. There is an access road to the beach at this location; the back-beach area is covered by low-cost housing. No eco-sensitive zones like national park, wildlife sanctuary etc is present within 500 m from proposed BMH site. As per CRZ mapping study carried out by Anna University, BMH site and cable landfall falls under CRZ II and CRZ I b area respectively. Map showing location of BMh site is given in Figure 2.3. Salient features of the BMH site are given in Table 2.1. Cable on beach will be buried to depth of approx. 1-2 m and then the excavated area for cable laying will be filled back with sand. Cable marker will be placed at the BMH for identifying the cable.

Table 2.1 : Salient Features of the Project

Particulars Description Landing Site BMH proposed to be located at Santhome

Beach, opposite to Faith Fullgospel church

Longitude and Latitude 13° 01.475’ N

80° 16.722’ E

Land status Beach – Recreational Area

Nearby Residential area Foreshore Estate (140.0 meters, W)

Nambikkai Nagar, Mullima Nagar (30.0 meters, W)

Nearest Road Shrinivasa Beach Road ( 5.0 meters, W)

Nearest Railway Station Mandaiveli MRTS (2.0 km, NW)

West Mambalam Railway Station (6.0 km, WNW)

Nearest Airport Chennai International Airport (10 km, SW)

Location of Eco-sensitive Areas within 10 km radius of the project site

Tholkappiar Ecological Park (0.62 km WSW)

Adyar Creek (370 meters, W)

Guindy National Park (5.0 km, SW)


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Source: BMH coordinates provided by DTS Survey and superimposed on Google Earth Imagery by EQMS

Figure 2.3 : Location of BMH at Santhome Beach, Chennai

13° 1.475’N 80° 16.722’E


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2.2.3. Terrestrial Route and Scope of this Study

3. Distance of BMH site to the cable landing station at R.K. Nagar is 1.9 km from BMH site. Cable will be laid along the roads till cable landing station. Map showing location of BMH and cable landing station is given in Figure 2.4. The scope of the present EIA study is limited upto the cable laying within CRZ area and BMH construction. The terrestrial route from the BMH to the Cable Landing Station (Non CRZ Area) is not covered under any environmental regulation that requires an environmental study so is not covered under this EIA report.

Source: Google Earth Imagery

2.2.4. View of CLS Station from BMH locationExisting Utilities in Project Area

4. BMH site is located on Santhome Beach. That beach area is not used majorly by visitors. Some fishing activity is reported on the beach. Low cost housing and fishermen houses are present in the back beach area. There are 4 similar existing beach man hole sites at Santhome beach. Map showing location of the proposed and existing BMH sites is given in Figure 2.5:

Name of BMH Latitude Longitude

Reliance Jio - 1 13° 01.333’N 80°16.688’E

Reliance Jio – 2 13° 01.267’N 80°16.677’E

Airtel 13° 01.318'N 80°16.683'E

SMW4 13° 01.468'N 80°16.720'E


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Source: DTS report

Figure 2.4 Proposed and existing BMHs at Chennai

2.2.5. Potential Risks to Submarine Cable Laying Operations and laid Submarine Cable

5. Risks associated with the cable laying operations can be physiographical, geological and environmental. Physiographical and geological risks include cyclones, high waves, heavy surface currents and volcanoes. Risks due to cyclone, high waves and heavy surface currents can be minimize by scheduling the cable laying operations during non monsoon period, i.e. Dec to April and taking additional care during installation. CANI cable system does not cross any area of significant volcanic activity.

6. Environmental and social risks generally associated with submarine cable laying are due to shipping, anchoring, trawling, Tuna long lining, FADs (Fish aggregating Devises)/traps, hydrocarbon concessions, mineral/sand excavation, pipelines, dumping or dredging or land reclamation, existing submarine cables, military activity areas (especially areas with buried UXO), wrecks, sea grass, coral reefs, sea turtle nesting sites and presence of mammals like Cetaceans and Dolphins. However in this project, risks associated with cable laying within 12 nauticle mile distance from Chennai coast are shipping, fishing, military activity areas (especially areas with buried UXO) and existing submarine cables. Environmental and social risk analysis is given in Table 2.3.


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Table 2.2 Environmental and Social Risk Analysis Associated with Cable Routes Within 12 Nauticle Mile from Chennai Coastline and BMH Locations

Environmental/Social Parameters

Presence Remarks

Shipping √ Cable route is designed to avoid these risks as much as possible. Some minimal shipping activity is observed near the Chennai landing site and proposed cable route. Map showing proposed cable route and high shipping traffic zones is given in Figure 2.6.

Fishing, Trawling, Tuna Long lining, FAD

√ The number of active large fishing vessels in the CANI landfall areas is generally low, but numerous smaller artisanal vessels are likely to be encountered in the inshore areas, particularly off Chennai. Larger vessels are engaged in trawling in addition to longlining and purse seining. Fishing stakes have not been identified as a threat to this system. Assistance of fishing department is required for liasoning with fishermen prior taking up cable laying operations. No FAD exist near Chennai landfall or within 12 nauticle mile distance from landfall.

Anchoring X Anchorage can pose threat to the cable especially in shallow water (1000 m depth) so to minimize the risk cable is proposed to be buried to 1 m depth. However cable could be affected by large commercial and fishing vessels anchoring in the shallow water areas (generally around 5 to 100m) on the continental shelf in the case of emergency anchoring, or if anchors drag due to severe weather and seas. But, majority of the cable route lies in water too deep for vessels to consider anchoring except in an emergency. As a safety measure, deep burial of cable is proposed for cable near the shores especially where ships are liable to anchor for commercial or weather related reason. After laying the cable, cable should be registered in the charts immediately to prevent risk from anchors

Hydrocarbon Concession X No concession blocks exists within 12 nauticle miles from Chennai landfall

Mineral/sand excavation X No mined or previously mined areas have been identified near the proposed CANI routes. There is no charted offshore mineral extraction or sand mining activity along the proposed CANI routes.

Pipelines X There are no known petroleum or water pipelines in the identified route.

Dumping or dredging or land reclamation

X There are no reports of dredging activity off Chennai and none of the other landfalls are close to Port facilities. There are therefore no spoil grounds or charted dump sites near the proposed route

Existing submarine cables and cable faults

√ There are various existing and planned cable in Bay of Bengal especially near Chennai. No power cable exists along the route. Cable faults are reported in the proposed cable laying area and cable faults are reported due to anchoring, cable industry, seismic activity, fishing etc.

Military activity areas like firing practise area

(especially areas with buried UXO)

√ Two military exercise area lies along or close to the route, i.e. Firing practise area off the Chennai landfall and Firing practice area east of Great Andaman Island. Proposed cable route crosses Chennai Firing Practise area whereas Great Andaman island area is avoided. There are no charted prohibited or


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restricted areas along the CANI cable route.

Wrecks X Wrecks are common in Bay of Bengal, but are avoided along the proposed cable route

Marine protected Areas X No marine protected area is crossed by proposed cable route. In Chennai, Guindy National Park is located at 5.0 km from proposed BMH in SW direction.

Ramsar Site X No Ramsar site exists in proposed landfalls/BMH/Cable Route

Coral reefs X Cable will not cross any coral reaf in the coastal waters of Chennai upto 12 nauticle miles

Sea turtle nesting sites √ As per new CZMP map of Chennai, Santhome Beach is turtle nesting area. But cable laying activity will not eb carried out during turtle nesting period (Sep to Jan, 2018)

Seagrass √ Seagrass is likely to be encountered in shallow waters near landfalls. Route can be diverted to minimize the seagrass bed during laying with help of divers. Impact can be minimized further on sea grass bed by carrying out burial by jetting in place of plough burial.

Important Bird Areas √ No important bird areas observed in Chennai BMh site and surrounding area.

Presence of mammals like Cetaceans and

Dolphins (high noise and collisions)

√ Cable laying operations are done through slow shipping methods where speed of ship may not exceed 10 knots (18.6 kmph) thus risks of encountering or collision with mammals is minimal. Level of noise emitted by survey and installation vessels is indistinguishable from that emitted by other sea-going vessels. Anecdotal evidence indicates that both whales and dolphins occasionally approach operational survey vessels and come close alongside, without any visible signs of discomfort. However survey and installation operations will be stopped if whales are observed within 1 km area.

Source: DTS Survey Report Note: Intense traffic is shown in red, less predominant lanes in green and the low traffic areas in blue

Figure 2.5 : Main Shipping Lane Across Bay of Bengal


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2.3. Category of the Project

7. The proposed project does not require environmental clearance with reference to the “List of projects or activities requiring prior environmental clearance” mentioned in the Schedule 1 of EIA Notification, 2006, by the Ministry of Environment and Forests and Climate Change (MoEF&CC). However, beach man hole and the cable from landfall point to BMH falls under CRZ II and CRZ I b zone as defines in Coastal Zone Regulation, 2011 and thus Coastal Regulation Zone (CRZ) Notification is applicable. Environmental impact assessment study is conducted in accordance with CRZ Notification, 2011 and further amendments. CRZ mapping done as per the new CZMP map of Chennai approved in 2018

2.4. Submarine Cable

2.4.1. Submarine Cable – General Design Considerations

8. In a fiber optic cable, data is transmitted via beams of laser-generated light that travel along glass optical fibers housed within the core of the cable. The main design function of a cable is to protect the optical fiber transmission path over the entire service life of the system, including laying, burial, and recovery operations.

9. A secondary function is that its metallic elements are used either to feed an electric current to the repeaters or to monitor on a permanent basis the status of the transmission system and to localise cable breaks.

10. Cable to be laid is OCC-SC530 optic fibre cable. This cable can house 8 pairs of optic fibre (16 fibres). Four types of optical submarine cables to be used are LW cable, LWS cable, SA cable and DAS cable. Cable is designed such that it protects the optical fibres from external forces such as high water pressure, tensile load, lateral load, bending and water ingress. Fibre. Optical fibres are surrounded by the gel to prevent water ingress and three layer of the steel segments which act as armour. Detail structure & layers of all the 4 cables is given in sections below. 8. For shallow water applications, external layers of steel armour wires will be added to provide additional protection as per the requirement of site and hazard anticipated in the area. The cable design ensures that negligible strain and ultra low pressure are applied to the fibers in normal operation. Even in the most adverse conditions such as cable recovery, cables are dimensioned so that stress applied to the fibres never reach critical levels. The combination of loose structure and fibre proof-test prevents any fibre break that will be caused by ageing stress during the design life of the system. Even if the cable breaks, high strain on the fibers and sea-water ingress are limited to a short length, so that the bulk of the cable remains serviceable. The cable will have insulation resistance of more than 2X1011 Ώ-km after application of 0.5kV between the copper tube and earth for 5 minutes or more, DC resistance value of less than 1.2 Ώ/km at 30C. Cable can withstand +/-45kV DC applied between the copper tube and earth for 5 minutes and will have capacitance of 198nF/km. Cable is designed to inhibit the water and gas ingress into its internal structure under


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normal operating conditions. In the event of cable damage, it has been confirmed experimentally and theoretically that the maximum length of cable to be replaced from the point of damage is 250m in shallow water (less than 1,000 m) and 1km in deep water (down to 5,500 m). The cable core structure inhibits the ingress of gases up to the fibers. Therefore no effects are caused on the optical fibre attenuation by corrosion of installed armoured cables. All cables, joint boxes and cable terminations are designed to be capable of being operated in the temperature range from -100C to +400Cwhile meeting the overall system performance requirement.

2.4.2. Submarine Cable Specifications

2.4.2.1 Light Weight (LW) Cable

11. Optic fibres are provided with the three layers, i.e. steel pipe, tension member & copper tube and insulating layer. Steel pipe: In this cable three divided steel segments are assembled longitudinally over the optical fibres to form pressure resistant steel pipe. The space between the fibre and the pipe's inner walls is filled with water blocking compound (thixotropic gel) continuously to prevent water ingress into the cable. The nominal outer diameter of the steel pipe is 5.3mm. Tension member & copper tube: The tension member consists of 14 high tensile steel wires, has a nominal diameter of 1.5mm, and is left hand stranded around the steel pipe. The water blocking compound is filled up around the tension member at regular intervals to prevent longitudinal water ingress into the cable. The copper tape is applied longitudinally over the stranded wires and both edges of it are seam welded to form a tube. The oversized tube is then swaged down tightly on the tension member. The nominal outer diameter of the finished composite copper tube is 8.9mm. Insulating Sheath: Medium density polyethylene is extruded over the copper tube to insulate the power feed conductor and protect it against external abrasion. The nominal outer diameter of the insulating Sheath is 17.0mm. Cross section of typical LW submarine cable is given in Figure 2.7. This cable can be laid in deep sea.

Source: OCC-SC530 by OCC Corporation

Figure 2.6 : A Typical LW Type Submarine Cable – OCC-SC530

2.4.2.2 Light Weight Screened (LWS) Cable


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12. The above defined LW cable structure is protected by an additional coated steel tape formed longitudinally over the cable core for a protection from fish bite, external abrasion and so on followed by sheath of High density polyethylene. This cable has outer diameter of 23.5 mm. This cable should be used in lesser deeper waters where damage to cable is expected due to anchoring or fish bites. Typical section of the LWS cable is given in Figure 2.8.


Figure 2.7 : A Typical LWS Type Submarine Cable – OCC-SC530

2.4.2.3 Single Armoured Cable (SA)

13. SA cable is armoured cable and is suitable for shallow waters and areas where cable is at risk due to various activities like fishing, trawling, anchoring etc. In this armour is provided over the LW cable for additional protection. Armouring consist of 20 galvanized steel wires of 3.0mm nominal diameter. These wires are coated with bitumen compound and helically applied over the cable core with left hand lay. This is then covered with outer serving consisting of polypropylene yarn helically applied over the armour wires followed by bitumen. The finished cable is coated with chalk and outer diameter of the SA cable is 28 mm. Typical section of the SA cable is given in Figure 2.9.


Figure 2.8 : A Typical SA Type Submarine Cable – OCC-SC530

2.4.2.4 Double Armoured Smart Cable (DAS Cable)


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14. DAS cables are further protected cables. In DAS cable typical LW cables are provided with four additional layers so as finished diameter of cable is 38 mm. In this LW cable is covered with inner armour comprising of 20 galvanized steel wires of 3.0mm nominal diameter which are coated with bitumen compound and helically applied over the cable core with left hand lay. This inner armour is followed by intermediate serving comprising of polypropylene yarn helically applied over the inner armoring wires which is then covered with Bitumen. Intermediate serving is followed by outer armour comprising of 28 galvanized steel wires of 3.2mm nominal diameter coated with bitumen compound and helically applied over the intermediate serving with left hand lay. Outer armouring is followed by outer serving. Outer serving consists of polypropylene yarn helically applied over the outer armor wires covered with bitumen followed by chalk. Typical section of the DAS cable is given in Figure 2.10.


Figure 2.9 : A Typical DAS Type Submarine Cable – OCC-SC530

15. The standard tension characteristics of the LW, LWP, SA and DA OALC-4 cables are summarised in Table 2.3

Table 2.3 Summary of the Characteristics of LW/LWP/SA/DA Submarine Cables

Characteristics Unit LW LWS SA DAS

Cable Outer diameter mm 17 23.5 28 38

1st layer steel pipe outer dia mm 5.3 5.3 5.3 5.3

2nd Layer tension membrane and copper tube outer dia

- 8.9 8.9 8.9 8.9

3rd Layer Insulating sheath outer dia mm 17 17 17 17

Steel Tape and HDPE sheath outer dia mm - 23.5 - -

Armouring galvanized steel wires outer dia

mm - - 20 20

Intermediate Serving outer dia mm - - - 27

Double Armouring outer dia mm - - - 30

Outer Serving outer dia mm - - 28 38

Weight in air kN/km 5.7 8.3 18.3 37.9

Weight in water kN/km 3.5 4.0 13.2 28.5


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Performances

NPTS kN 22 22 80 140

NOTS kN 48 48 130 260

NTTS kN 60 60 200 350

CBL kN >/77 >/77 >/250 >/500

Crushing Load kN/10 cm 10 10 15 30

Impact Energy kgX1 m 2 2 4 8

Hydrodynamic constant deg.knots 44 38 61 77

• The Nominal Permanent Tensile Strength (NPTS) is the maximum tension that the cable can withstand during the system lifetime without any impairment of fibers or degradation of the overall cable performance.

• The Nominal Operating Tensile Strength (NOTS) is the maximum tension that can be applied to the cable during the time necessary to make cable joints, without significant reduction of NPTS.

• The Nominal Transient Tensile Strength (NTTS) is the maximum tension that can be applied to the cable during a cumulative period of one hour, without significant reduction of NPTS/NOTS.

• CBL: Cable Breaking Load

2.4.3. Submarine Cable - Toxicity

16. Submarine cables are made of a mixture of materials including the following from the inside to the outside:

• Optical fibre: Silica glass and Epoxy/Acrylic resins

• Water blocking thixotropic gel: Amorphous silica in a mineral oil base

• Stainless Steel

• High Carbon Steel

• Oxygen free high purity copper

• Medium Density Polyethylene

• Medium Carbon Steel

• Zinc in the form of Galvanizing of the steel

• Blown Asphalt

• Polypropylene yarn

17. The construction is designed for a minimum 25-year operational life and this requires stable construction materials. There are only three materials that can be exposed to the sea water in an operational system: zinc (in the form of galvanizing of the steel), blown asphalt and polypropylene yarn.

18. All submarine cables use Polyethylene as an insulator. Polyethylene insulation is very stable and hydrophobic. It is commonly used in the transportation of water for human consumption, in construction and domestic installations. It has no components that leach.


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19. The outer layers of the cable, designed to prevent ingress of sea water, consist of several layers of polypropylene yarn impregnated with a proprietary compound of blown asphalt.

20. Polypropylene, like polyethylene is a very common material used for the storage of potable water and similarly does not leach any material. The yarn is similar to that used in agricultural binding twine and some fishing netting.

21. Blown asphalt is a petroleum-based product. Asphalts are well known for their low erosion rates and suitability for a wet environment. The material on the cable is the base asphalt without the mineral content added. Asphalt is an inert material, and not soluble or harmful in a water environment, e.g. asphalt paving materials are used to line the surfaces of fish hatcheries and drinking water reservoirs. Asphalt cement has also been used to line water pipes that supply potable water to humans.

22. Steel armour wires are carbon steel with a zinc coating to minimize corrosion. Minimal chemical dissolution of the zinc can be expected at a very slow rate when exposed to the sea (as might happen if the external coating were abraded, or through limited sea water ingress). In this case the zinc surface quickly becomes coated with insoluble carbonates.

2.4.4. Cable Joint and Repair

23. Cable joints are required for connecting two cables accommodating different type fibres each other for the transmission compensation, restoring a cable by joint in case of an unexpected accident during the process.

2.4.5. Cable Repeaters

24. Transoceanic Repeaters are key elements in submarine networks where periodic amplification of the optical transmission signal is required to overcome the loss of the optical fibers within the undersea cables. Repeater Unit is composed of the Surge Protection Circuit and Sub-System Units, consisting of Optical Amplifier Circuits for "UP" and "DOWN" directions. Each Sub-System Unit is electrically connected in series. The input electrical surge to the Repeater is by-passed by Gas Tube Arrester for both directions. Both Gas Tube Arrester and Zener diodes protect the Repeater electronics from excessive voltage. Repeaters are design so as heat generated is easily dissipated.

25. Repeaters are designed to function continuously without maintenance for a minimum system life of 25 years, however the design allows laying, operation, recovery and re-laying of optical repeaters in deep waters also with no degradation in mechanical, electrical and optical performance. Each repeater has individual identification marking which is not altered during the life of the system. There is no noise emitted from the Repeater, as its internal construction does not use any intentional noise generating components. High efficiency erbium-doped fibre and low loss gain flattening filter enables wide band amplification. 980nm pump lasers are used for low noise amplification

2.4.6. Branching Units, Housing and Seal


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26. Branching Unit (BU) is designed for repeatered applications in submarine cable networks. It provides fibre branching capabilities and a simple robust scheme for reconfiguring the power feed paths, enabling flexible and economical solutions. Branching units are housed in branching units housings. The housing comprises a monobloc sea-case of high tensile steel, a three cable entry system and provision to connect a Sea Earth.

27. Branching unit & housing assembly seals the housing providing full protection to the internal unit against water and gas ingress, both directly from the surrounding sea and from axial cable leakage should a cable be broken close to the BU.

2.4.7. Cable Markers

28. Cable section markers, as per the SLD/RPL, are applied at both ends of each cable piece, which is separated from the next one by repeater or JB. For spare cables, tape code indicating the fiber type is applied in addition to the above described marking method.

29. Length markers are applied at 2 km intervals according to the laying direction. The cable length marker position accuracy is ±0.5% of the cable span length. Warning markers are applied at 1 km and 2 km away from repeater or JB according to the laying direction.

2.4.8. Cable Termination

30. Cable terminations are assembled to connect the ends of the cable with repeater or branching units mechanically, optically and electrically.

2.4.9. Cable End Seal

31. Cable end seal will be performed with the metal cap for buoying off during laying operation or repair operation

2.5. Pre-Commissioning Activities

32. The pre-commissioning activities for a submarine cable system include the following tasks:

• Route study and desktop review;

• Identification of feasible ROW for the cable system;

• Marine route survey; and

• Project permitting.

• Installation

33. A project-specific cable laying operation plan will be followed when the CANI

Submarine Cable Systemis installed.

2.6. Marine Installation Operations

34. The installation process will be done by especially designed vessels for cable laying. The vessel to be used will have an obligation (as per any other competent marine provider) to comply with all International Maritime Organization (IMO) requirements on not only the marine environment (i.e.


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Marine Pollution - MARPOL1 etc) but Safety (i.e. Safety of Life at Sea - SOLAS) and maritime security as well.

35. In water deeper than 1,000 meters, the cable will be laid on the surface of the sea-bed. There is no mechanical contact with the seabed during the operation. The cable is laid out from the stern of the vessel, descends through the water column by gravity and finally comes to rest upon the surface of the seabed, in an alignment corresponding to the route developed from the by the survey and route engineering process.

36. The vessel does not require the use of anchors to assist in any of the cable

installation operations – cable laying, ploughing and shore end landings are all performed using dynamic positioning mode. The installation vessels can produce a high bollard pull for ploughing, which is essential for achievement of target burial depths for submarine cable systems. The vessel is entirely self-sufficient throughout all cable installation operations.

37. The cable laying vessel does not deploy high powered or low frequency seismic or sonar survey technology, and noise will be limited to that associated with engines and thrusters. In areas that are well-used by shipping, there will not be a significant addition to the level of background noise in the water column.

38. The marine installation comprises of the following constituent operations:

• Cable Route Survey

• Route Clearance (RC)

• Pre-Lay Grapnel Run (PLGR)

• Shore end Installation

• Main cable laying and Burial

• Post-Lay Inspection and Burial (PLIB)

1MARPOL is the International Convention for the Prevention of Pollution From Ships, 1973 as modified by the Protocol of 1978. It was designed to minimize pollution of the seas, including dumping, oil and exhaust pollution. Its stated object is to preserve the marine environment through the complete elimination of pollution by oil and other harmful substances and the minimization of accidental discharge of such substances. All ships flagged under countries that are signatories to MARPOL are subject to its requirements, regardless of where they sail and member nations are responsible for vessels registered under their respective nationalities. There are six Annexures: Annex I: Regulations for the Prevention of Pollution by Oil (October 1983). Annex II: Regulations for the Control of Pollution by Noxious Liquid Substances in Bulk (April 1987). Annex III: Regulations for the Prevention of Pollution by Harmful Substances Carried at Sea in Packaged Form (July 1992). Annex IV: Regulations for the Prevention of Pollution by Sewage from Ships (September 2003). Annex V: Regulations for the Control of Pollution by Garbage from Ships (December 1998). Annex VI: Regulations for the Prevention of Air Pollution from Ships (May 2005).


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2.6.1. Cable Route Survey

39. Cable route surveys are conducted to define a cable routing that will maximize cable survivability for the life of the cable system. The route that will be eventually selected will determine cable length and cable design (factors that the cable manufacturer must understand), and establish the methods to be followed for cable installation. The survey also generates a reference record that supports subsequent maintenance and repair of the cable. Route selected is such that it avoids presence of geographical, physiographic and environmental risk parameters.

40. In water of depths less than 1,000 meters, swath bathymetry, side scan sonar, seismic profiling and a geotechnical survey will be performed. In water of depths greater than 1,000 meters, only multi-beam bathymetry will be performed. The nominal corridor to be surveyed is usually 500 meters wide. This corridor allows adjustment of the cable location to an optimal position. The final installed cable will lie within the survey corridor.

41. It is a common practice to bury the cable to a depth of about 1 meter in the sea bed in shallow water sections (i.e. between 1,000 meters and 15 meter of water depth), to protect it from hazards such as fishing trawls. This is only done where conditions will allow, e.g. in sandy and muddy sediments. Cable is buried to 3 m depth in areas of shallow waters where the risks of trawling or anchoring are high.

42. Cable route survey also involves “burial assessment”, which tests the mechanical properties of the seabed along sections of the proposed route where it is expected that the cable will be buried. The sediments are investigated by hydro-acoustic means (side scan sonar and sub-bottom profiler), and by intermittent physical samples (grab samples or penetrometer tests).

43. Inshore cable route survey (0-15 meter water depth) is conducted using small boats and divers to perform visual checks of the seabed and map the ideal route for the cable as it will approach the shore. The inshore survey is normally conducted along a corridor of about 200 meters wide, in order to provide flexibility to adjust the cable routing to avoid hazards and minimize threats to marine habitats.

44. If necessary, the inshore survey can also incorporate video footage or mapping of important ecological zones, habitats and features on the approach to shore, to ensure that they will not be damaged, or to support planning of mitigating and compensating measures for unavoidable impacts.

45. The studies (desktop studies) and route surveys that precede cable installation are mainly intended to determine a stable and benign route for cable installation; e.g. one in which the plough can be operated most effectively for burial if needed; and one in which there can be the highest possible confidence that the cable will not be affected by seabed disturbances of various kinds. A cable route designed in this way will tend to be directed away from structurally diverse seabed terrain, seamounts, volcanoes, canyons, vents, seeps, deepwater reefs, carbonate mounds and other such features. These kinds of seabed features are


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often associated with above average ecological importance and relatively high biological values.

46. Cable route study and route engineering ensures that statutorily protected sites

are avoided as far as possible.

47. Complementary local site visits and local consultations are part of the process and these obtain further information on sites that may be important habitats or feeding grounds, nesting sites and migratory routes for marine wildlife; or places that are important for other marine users or which have heritage value. The existence of such sites in the vicinity of the proposed route is recorded and an aim of the route engineering process is to ensure they are avoided to the greatest extent possible. All these areas not only pose problems for plough deployment but which are also often associated with above-average biodiversity values.

48. The overall effect of the observance of these principle in cable route survey and cable route engineering is that the final cable route will be on an “ecologically optimal” alignment compared with what might be expected had the cable been routed in a in a random and insensitive fashion though the same area.

2.6.2. Route clearance

49. The purpose of Route Clearance (RC) is to clear the cable path of obstacles such as old cables identified during the cable route survey, as these can be hazardous to both the Vessel’s installation equipment and the cable itself. The RC is only carried out in areas where plough burial is deemed necessary.

50. The Desktop Study and Marine Route Survey will establish positions of any redundant (i.e. Out Of Service, OOS) cables that may need to be removed from the proposed routes.

51. Vessel position itself perpendicular and close to the OOS cable. Then an adequate sized grappling device shall be towed along the cable route. The vessel will then move towards the cable, allowing the fluke of the DTG to penetrate the seabed and unbury the cable. The vessel will then continue to move until the cable is broken, leaving the two ends on the seabed. The vessel will then do the grapnel runs to retrieve each end individually. Once back on the deck, a section will be cut from the cable. Clump weights are attached to the cut cable ends. The Vessel will return the ends to the seabed, leaving a space of 1 km though which the new cable will be installed. The OOS cables in the ploughing section would need to be recovered so as to clear a corridor from the center line of the route. Any recovered cable would be landed for proper disposal at locations that are convenient to the operations. It is assumed that recovery operations will only proceed following the obtainment of necessary approvals for recovery of the crossed OOS cables by the System Owners. OOS cable sections are normally removed so as to clear a 500 meters corridor on either side of the centerline of the route. The cable ends will be left on the seabed.

52. RC operation will exclude all works associated with ordnance, radio-active, or other hazardous materials.


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2.6.3. Pre Lay Grapnel Run (PLGR)

53. Prior to the Main Lay operations, at each location a pre-lay grapnel run may be carried out along the cable route where ploughing is required. The intention is to attempt clearance of any seabed debris, for example wires or hawsers, fishing equipment, etc. which may have been deposited along the route. Any debris recovered during these operations would be discharged ashore on completion of the operations.

54. One or an array of grapnels will be towed along the length of the route to be ploughed. The vessel will move at a speed that will ensure that the grapnel(s) stay in continuous contact with the seabed.

55. PLGR operations will normally be carried out by a specially mobilized and fitted out vessel capable of sustaining good slow speed positional control, and with high strength bollard pull capability. The vessel will have sufficient deck space to mount a simple winch, simple guides and a stern roller to deploy the grapnel(s) and stow any recovered debris. Alternatively, depending on operational logistics and on the information obtained from the surveys, the PLGR operation may be performed by the main lay vessel. Depth of penetration of the seabed by the grapnel is up to 40-80 cm.

56. The route followed by the PLGR is maintained as close as practicable to the selected ploughing route and is always maintained within the swathe of the route surveyed during route selection.

57. PLGR operation will exclude all works associated with ordnance, radio-active, or

other hazardous materials. Figure showing the PLGR operations is given in Figure 2.11.

Source: Information provided by NEC Corporation

Figure 2.10 : PLGR Operations

2.6.4. Main Cable Lay

58. In order to install the cable system, a suitable cable ships will be used. Cable installation vessels will meet the Purchaser’s requirements, which can generally stow the submersible plant safely to lay and repair the cable in emergency

PLGR Vessel

ChainGrapnel AnchorPlanned Cable Route


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cases. It is noted that actual ship arrangements are subject to the ship’s availability at the time of project implementation.

59. Precise route tracking and slack control shall be applied to lay the cable on the sea-bottom topographies. State of art navigation such as Differential GPS system and a detail cable laying monitoring system is equipped to assist the precise cable installation.

60. The cable installation vessel is designed to stow the submersible plants in a

good condition. Cables are horizontally coiled in the cable tanks. Submersible housings are stacked in appropriate condition. The cable bights shall be correctly arranged between repeater stack and cable tank via cable recess of the tank slot. Cable trough is laid out towards cable engine without excessive bending and with smooth face finish to prevent chafing to the cable.

2.6.5. Plough Operation

61. From the shore end approach limit down the continental slopes, the cable installation vessels (Main lay vessel) use their reasonable endeavors to plough the cable to the target burial depth of 1.0m by simultaneous lay and bury operation. The actual limit of cable burial operation shall be designed reflecting the results of the Marine Route Survey and capability of the burial machine. The main cable installation is planned to carry out in favorable sea conditions.

62. The amount of burial required to provide adequate protection is greatly influenced by the type of seabed material. Soft materials that are easily penetrated require deeper cable burial to protect the cable from external aggression. Harder seabed’s, that are difficult to penetrate, will provide adequate protection with less burial depth.Also deep burials are required in area prone to risk of fishing/trawling and anchoring.

63. During cable laying operation, support vessels may assist the cable vessel for

plough launch/recovery and guarding against the fishery vessel working in vicinity of the cable routes. Ploughing operations are depicted in Figure 2.12.

64. In water of depths of less than 1,000 meters where the seabed conditions allow, the cable will be buried using a cable plough. An industry-standard cable plough weighs approximately 12 tonnes in water. It will be deployed from the stern of the installation vessel and towed behind the ship, burying the cable into the seabed, usually to a depth of 1 meter, as it will progress along the route.

65. As the plough will be towed across the seabed, its share blade and inclined

cutting disk will lift a wedge of substrate. As the plough will progress forward, this sediment will be dropped back into the trench, emplacing the cable at the bottom of a relatively undisturbed sediment wedge.

66. A combination of specialist cable lay software and a differential GPS will allow close control of the position of the ship and the plough to achieve accurate cable positioning. The ship will maintain station using thrusters and propellers and there will be no need for anchors.


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67. The plough will not be deployed in areas where steep or side slopes prevent it, or where the route crosses an in-service cable or pipeline. After the plough will have passed, a 4 meters wide strip footprint will be evident for a period depending on the nature of the substrate and local seabed hydrodynamics and sedimentation regimes. The cable route will be selected and planned so that the plough can be utilised effectively wherever burial is required. Figure 2.13 shows the typical plough burial mechanism.


Figure 2.11 : Ploughing Operations

Source: The Schamatic diagram drawn from similar cable laying system for view prospective purposes.

Figure 2.12 : Ploughing Mechanism

2.6.6. Crossings Engineering

68. It is not possible to plough without interruption through areas where the route of the cable will cross in-service cables, oil and gas pipelines or other seabed

Cable Ship

Plough

Umbilical cable

Towing wire

CableTargetBurialDepth

Cable Ship


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installations. However in this project, cable is crossing the existing cables but no oil/gas pipe line or any oil concession blocks.

69. Buried in-service cables can be located by use of tone detection equipment. If necessary, this may be followed by careful excavation with diver’s jetting/Remotely Operated Vehicle (ROV) tools to allow verification and identification.

70. The plough is raised and lowered either side of the intersection, thereby creating a “plough skip” or interruption in the ploughed alignment. This may be done 100-500 meters on either side of the intersection, the margin of safety depending on factors like crossing angles, complexity of the seabed installation, etc.

71. Alternative means must be used to achieve cable burial at and around crossing points to avoid any risk of damage to in-situ infrastructure while ensuring that the new cable is also protected. Divers or ROV then perform the cable burial precisely around the intersection using jetting or other tools.

72. Pipeline crossings may be protected by use of concrete mattressing, “uraduct” (a plastic sleeving on the cable to reduce friction with pipe casing) or, rarely, by rock dumping. However there are no pipelines being crossed by cable on proposed route

2.6.7. Post Lay Inspection and Burial (PLIB)

73. As a result of the cable installation, due to restriction of operational circumstances, several section of cable might be left unburied on the seabed. In order to bury these temporary surface-laid-cables to the specified target burial depth, a Post Lay Burial (PLB) work by means of water jetting by Remotely Operational Vehicles (ROV) shall be carried out. Figure showing post lay inspection and burial operation is given in Figure 2.14. The following areas are the major possible sections for PLB operations.

1) Shore end / Main Cable Interface in cable burial section

2) Final/Interim Splice Bight in burial section, if any

3) Plough Share Change, if any

4) Cable/Pipeline Crossing Section.

5) Section where Plough Operation was limited due to seabed condition


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Figure 2.13 : Post Lay inspection and Burial Operations

2.6.8. Shore End Installation

74. Shore End installation methods are categorized into two methods. One is the Direct Landing which is directly installed from the main cable vessel and the other is Pre-Lay Shore End Lay which is installed by a small vessel or specially rigged barge to access shallow water depth.

75. Selection of above two shore end installation method is dependent on site conditions and approach limit of the main cable vessel to the shore. The actual method to be adopted shall be determined after detail analysis of the result of marine route survey. Figure showing the cable laying operation direct and through pre lay shore methodology is given in Figure 2.15.

Mother Vessel

Cable

Umbilical cable

Mother Vessel

Umbilical cable

“PLI” “PLB”

BMH

Landing Approach <2km

Direct Landing by Main Lay vessel

BMH

PLSE by Barge

Landing Approach <2km Main Lay continues

WD = 15m

WD = 3m

Maximum 2km

PLSE Barge Main Lay Vessel


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Figure 2.14 : Shore End Operations

2.6.9. Pre-Lay Shore End

76. Pre-Lay Shore End (PLSE) installation methods are adopted if main lay vessel’s approach limit is typically more than 2km from BMH. In such case, a small vessel approaches to BMH less than 2km and lay the shore end cable prior to commencement of Main Lay.

77. After PLSE completion, main lay vessel comes and pick up the cable end, joint to main cable, and start main lay from that point.

2.6.10. Direct Landing

78. Where possible, cable will be brought to shore directly from the main-lay cable ship (where this is not possible, a “separate” shore end will be required). Such shore-end operations are usually completed within one day, although some preparations are often made the previous day.

79. Prior to the cable landing operation, divers will place a marker buoy at the inner limit of the cable to be laid by the Cable Vessel. This will mark the start position of the proposed shore end route. Divers will identify gullies / slopes along the route centre line, through which the cable can be routed, and will again mark their position(s) using marker buoys.

80. During the shore end landing operation, the Cable Vessel will position itself as

close as reasonably practicable to the first marker buoy. The cable will be floated off the stern of the vessel and pulled into the Beach using a winch or similar device. This will enable the cable to be initially aligned as close as possible to the target route selected by the divers. During the pull-in operation, additional slack cable (approx 10-15 meters) will be pulled inshore of the anchor points, installed by the divers.

81. On completion of the pull-in operation, the cable will be stoppered off to ensure that the slack cable is secured, prior to cutting off the cable floats and laying the cable down onto the seabed. By maneuvering the vessel and controlling the tension of the cable during the lay down operation, the cable can be laid down as close as possible to the optimum route.

82. Following completion of cable testing, the vessel will depart and the divers will release the slack cable from inshore and where necessary move the cable manually, using the slack cable available, to finalize the position of the cable on the seabed. This process will exploit natural features on the seabed, such as channels and gullies, to protect the cable and minimize “suspensions”.

83. With planned preparation prior to each of the shore ends, controlled lay down

during the shore end landings and post lay utilization of slack cable, shore ends can be laid close to the required final position in good conformity with sea bed topography.

2.6.11. Near shore operations during landings

84. The near shore operation includes the diving team and small workboats required to support the cable landing operation, cable sinking and positioning on seabed


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out to around 15 meters of water and may do any post burial activities, if required.

85. All work will normally be done in daylight hours only and will be subject to tide wind, current and waves. Table 2.5 presents the summary of the logistics of the efforts required, in terms of manpower and equipment, for the near shore operations during landing.

Table 2.4 Logistics of Efforts Required during Near Shore Operations during Landing

Diving Team normally includes Min. 2 small local work boats One diving supervisor One diving team of 3-6 men

Other resources

One NEC Representative One USOF (DoT) Representative Work boat from main lay vessel

If post burial is required

Airlifts and compressors Water jetting burial tools and water pumps Small workboat(s)

If clamping of articulated pipe is required

Clamps and bolts, as required/agreed Special underwater drills plus engine driven power pack and hoses/cables Chemical resin and guns to extrude resin into drilled holes Small local work boat or zodiac

86. It is not possible at this point in time to specify precisely which local vessels will be used and will be available for this activity. The Beach contractor and the diving team, when selected, will ensure to highlight this as required, when they will apply for local permits to do the specific work. Furthermore, local notification to relevant authorities and parties will be made as agreed/required.

2.6.12. Navigation and as-laid position

87. All cable ships/vessels will have state of the art navigational systems and software that will allow precise surface positioning and prediction where cable will be installed on seabed.

88. In ploughing mode acoustic positioning, together with water depth and tow wire length deployed, will determine precisely where the cable will be ploughed into the seabed. In surface lay mode, the precise horizontal position of the vessel, and advanced cable lay software will predict where the cable will be on the seabed.

89. Available softwares may also use current vector data to improve prediction of as-laid accuracy within certain depth ranges. The planned route position list will indicate the target route to follow. The as-laid route position list will be available after installation. However, additional alter course (A/C) points may be included to give accurate track of cable on seabed based on actual vessel and plough movements during installation.

2.6.12.1 Shore-end cable protection and fixing – burial methods


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90. Plough burial operations are not normally possible where water is shallower than 15 meters depth, due to the size of the plough and the draught of the cable vessel. Consequently, where such areas have suitable sea-bed characteristics, the cable can be buried by other means.

91. Various kinds of Shallow Water Burial Tool (SWBT) will be used to accomplish the burial. The SWBT is a system that employs water jetting to cut trenches of depths of 0.5-1.0 meters in the sea bed, in water up to 20 metres water depth, under the manual control of divers. There is no instrumentation on the burial tool. The SWBT is usually connected to a pump on a barge or pontoon which provides high pressure pumped water.

92. Using the high pressure water directed as jets through nozzles on a jetting “sword”, the SWBT cuts into the seabed a channel no wider than the sword itself. Sediment will be generated and dispersed to varying degree depending on the seabed substrate characteristics.

2.6.12.2 Shore-end cable protection and fixing – non-burial methods

93. Cables laid across rocky seabed will be protected by the installation of articulated pipe, which will be fitted by divers after the cable is landed. Articulated pipe is commonly used to protect the cable in the near-shore area where burial is impracticable for environmental or engineering/technical reasons.

94. Articulated pipe can be installed with minimal impact to existing marine environmental conditions. The pipe is readily colonized by marine flora and fauna. Like the cable, iron pipe is non-toxic and inert in the marine environment, though in certain situations it may be oxidized by sulphur reducing bacteria.

95. The cable will be buried across the Beach, both for system security and environmental and public safety reasons. The cable trench is usually dug with hydraulic digging machinery and the Beach will be reinstated at the end of burial.

2.6.12.3 Beach Manhole (BMH)

96. The BMH is the transition between the submarine cable and the land cable. The Beach joint will be made here and if required, the OGB connected to the earth cable. The BMH is a concrete chamber situated below ground, above the high-water level, in the coastal area. On the Beach, the cable is typically installed in articulated pipe with outside diameter on the order of 20 cm, in a trench 4 meters deep dug previously by equipment such as backhoe. The installation will be achieved by the cable vessel stationed offshore near its minimum working depth – a messenger line will be passed ashore and a winch located near the BMH will pull the cable through the trench and into the manhole. There may be some localized, short term, disruption to recreational activities but after installation, Beachgoers are typically unaware of the cable and it will have no effect on their activities. Figure 2.16 shows the layout of a typical BMH.


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Figure 2.15 : Schematic Diagram Beach Man Hole

2.7. Timeframe of the Cable Lay Installation

97. The timeline expected for the cable lay installation at Santhome Beach, Chennai, is between 15-20 days.

2.8. Maintenance/Repair

98. The cable is to be regularly serviced during a standard 25 year design life. If the marine cable is damaged or broken, it may be necessary to retrieve and remove damaged sections and replace them with new cable, which is spliced into the system. Cable recovery involves grapnel operations similar to those used in route clearance.

2.9. Lifecycle Analysis 99. Donavan (2009) estimated that over a 25 year operational lifetime (manufacture-

to-decommissioning)2, the main environmental impacts of a submarine fiber optic cable system are the carbon emissions associated with:

• power use at the terminal stations

• Vessel transits to and from site of cable maintenance and repair work.

2.10. Effects of Marine Installation

2.10.1. Toxicity

100. In an installed system, normally the only three materials exposed to sea water and ocean floor are: Polyethylene, Blown Asphalt and Polypropylene yarn.

2 Donavan, 2009. “Twenty thousand leagues under the sea: A life cycle assessment of fiber optic submarine cable systems”.


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101. The external protection of the cable comprises naturally occurring bitumen (asphalt) as a compound to adhere the outer polypropylene roving to the armour wires on the armoured shallow water cables. No form of additive to prevent bio-degradation or anti-fouling is used in the cable's outermost layers. The other cable components in contact with the sea are the galvanized steel armour wires and the polyethylene sheath, which also contain no additives harmful to marine life.

2.10.2. Sonar in cable route survey

102. The acoustic systems used in cable route surveys are very much less powerful than those deployed for oil industry seismic operations or military exercises. High-energy oil industry seismic surveys and military applications also generate most sound within the frequency range of normal hearing of marine animals, while route survey sonar propagates sound at higher frequencies.

103. Reports of effects on cetaceans of marine acoustic systems have been associated with oil industry seismic operations and military operations, and there have been few, if any literature reports or direct observations of adverse impacts of route survey sonar.

2.10.3. Marine Pollution

104. The vessel conforms to IMO/MARPOL standards in relation to waste management and ballast water management. This includes general requirements over the control of waste oil, engine oil discharges and grey and black waste water discharges; prevention of pollution by garbage from ships and prevention of air pollution; and operating procedures for dealing with incidents such as oil and waste spillages that potentially may threaten the marine environment. Under normal circumstances the vessel therefore represents no risk as a source of marine pollution.

105. The vessel is entirely self-sufficient throughout all cable installation operations. The vessel’s dynamic positioning capability enables it to manoeuvre and hold station without the use of anchors; therefore there will be no anchoring impacts on the seafloor.

2.10.4. Large marine animals – Whales, Cetaceans, Turtles

106. Any kind of shipping can impact large marine animals, e.g., by:

• collisions with ships

• underwater noise pollution

• disposal at sea of wastes from vessels

107. Collisions with ships are known to injure or kill cetaceans and certain species

may be at particular risk because they make little effort to avoid large ships.

108. It is believed that the main collision hazard to whales is posed by large fast-moving vessels (e.g. high speed ferries, which may operate at speeds of more than 20 knots). The cable-laying vessel is a large vessel but for cable laying operations, speed is normally restricted to 10 knots. The cable ship thus poses a lower collision risk to cetaceans than conventional fast shipping.


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109. In areas where there is a risk of conflict with whales, smaller cetaceans, turtles

and other large sea animals, the following general precautions will be observed:

• Use accumulated knowledge from survey and other projects to define sensitivity zones and to identify critical periods in which operations must be conducted with extreme caution to avoid conflict with whales and related species.

• During cable laying, nominate competent crew member to perform marine species observation during the operation.

• Maintain records of sightings and on conclusion of operations, provide the data to relevant local competent biological records authority in order to support research, monitoring and conservation programs that may be underway.

• Reduce vessel speeds (not more than 10 knots) and avoid sudden changes of direction (by its nature, cable laying cannot involve sudden course changes: the vessel is connected to the seabed by the cable)

• Report details of injury/death of any whales, or other large marine animals to the competent local authority.

• Level of noise emitted by survey and installation vessels is indistinguishable from that emitted by other sea-going vessels. Anecdotal evidence indicates that both whales and dolphins occasionally approach operational survey vessels and come close alongside, without any visible signs of discomfort. However survey and installation operations will be stopped if whales are observed within 1 km area

• Burial will be carried out through jetting in areas where seagrasses are present.

110. The cable laying vessel does not deploy high powered or low frequency seismic or sonar survey technology, and noise will be limited to that associated with engines and thrusters.

111. The vessel is MARPOL-compliant and the usual standards and precautions are observed to minimise the possibility of pollution arising from discharge of shipboard wastes into the marine environment.

112. Modern methods of cable deployment allow the cable to be surface-laid on the sea-bed with good conformity with the seafloor topography. This together with the resistance of modern cables to coiling reduces the probability of formation of “suspensions” and loops that might pose an entanglement threat to large marine animals (no such incidents have been reported since the 1950s).

113. Cable laid in deeper water (eg in excess of 3,000 meters), is believed to be beyond the normal diving range of the deepest diving whales such as sperm whales (Physeter macrocephalus), which typically range through depths of 300 - 1,000 meters and only very exceptionally reach 3,000 meters.

2.10.5. Disturbance to Living Organisms


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114. Optical fiber cables carry a constant dc current of 1.6 Amps to feed power to the underwater repeaters. This current is fed along the copper clad steel inner conductor and depending on the length of the cable span it may require several thousands of volts to maintain it. In very approximate terms, the cable resistance is about 1 Ohm per kilometre and the repeaters, spaced at 50 km, drop about 30 volts each. Thus, a cable spanning 2,245.96 km will have about 45 repeaters and require a power feed voltage of about 3649.7 volts. It is a normal practice to apply half this voltage at positive polarity to one end of the system and half the voltage at negative polarity to the other end to establish a zero voltage point midway along the cable span. This reduces the level of voltage stress on the cable and repeaters.

115. There will be no external electric field associated with the power on the inner conductor. The ratio of the conductivity of the polyethylene insulation to that of seawater means that the electric field remains only within the cable insulation. However, the dc current in the inner conductor does set up a stationary magnetic field in the form of concentric rings emanating from the cable.

116. The magnetizing force produced by this field diminishes with increasing radius from the cable. It is two orders of magnitude lower than the earth's natural magnetic field, meaning that marine life forms will need to approach to within less than half an inch of the cable to detect its magnetic field above that of the earth.

117. Audible sound lies in the range 15 to 40,000 Hertz and neither coaxial nor optical cables emit this range, or any other frequencies, during their normal operation. During the laying of the cable, it does vibrate as a result of regular vortex shedding as it descends the water column. This is a low frequency phenomenon, at approximately 10 Hertz, and ceases when the cable comes to rest on the bottom.

2.11. Quality Assurance, Health and Safety

118. The purpose of the Quality Plan is to define the Quality, Health and Safety and Environmental management practices and procedures in place that are to be employed during the implementation of the project.

119. Responsibility for the implementation of the Environmental, Health and Safety (EHS) Policy rests with the USOF & Cable installation agency, each Function and Location and requires the active participation of each employee. The prime driver behind the implementation of the Policy and the establishment of the EHS Management System is the belief that all accidents can be prevented and that there can be continual improvement of the environmental performance so as to minimise any detrimental elements of any activities.

2.11.1 Health and Safety

120. Cable will be installed by NEC Corporation, Tokyo. NEC will be thus responsible to maintain the health and safety of its employee involved in cable installation process. NEC is committed to sustainable and safe operations that protect the health, safety and environment (HSE) of employees, contractors, customers, and the communities. It is their belief that all accidents and losses can be


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prevented. Meeting this commitment is a primary management objective and the individual and collective responsibility of all employees.

121. NEC has established procedures for the assessment of risks across its office, factory and field installation and maintenance activities and these are customised to reflect the specific activity concerned.

122. The responsibility for planning and defining the nature and extent of the risk

assessment rests with the line manager or senior supervisor of NEC for the field installation and maintenance location. The risk assessment findings are recorded and all assessed risks are addressed to minimise impacts before activities commence. Standard assessment criteria for typical locations and activities are available, but it is also necessary to identify special local conditions or regulations and potential emergency situations relevant to the intended activity. A written record of actions required and carried is maintained and copied to the relevant functions within NEC.

123. NEC activities are reviewed to identify the associated aspects that have a

potential environmental impact. These aspects are evaluated to determine those, which have or can have a significant impact on the environment.

124. Any aspect that potentially has a significant environmental impact are recorded

in a Significant Aspects Register. This Significant Aspects Register is reviewed by the nominated site representative at least annually to ensure that the established control mechanisms and measures are still appropriate and effective.

125. NEC shall do the needful, wherever applicable:

• Comply with applicable HSE laws, regulations, directives, commitments with customers, company requirements, and with other requirements.

• Provide employees and those who visit or work at NEC locations or work sites with safe and monitored working conditions, and with the necessary resources, equipment and training.

• Assess and continually improve HSE performance in a responsible manner by implementing management systems, setting goals and meeting objectives.

• Strive to efficiently and effectively prevent pollution, optimize energy and resource consumption, and increase recycling to minimize impacts from our current and future activities, services and products.

• Regularly assess potential risks to employees and near misses in the activities with the intention of preventing accidents and losses.

• Appropriately train, communicate, motivate and consult with employees to help them perform their activities in a safe and environmentally responsible manner.

• Promote the adoption of similar principles by contractors and suppliers.


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3. BASELINE ENVIRONMENT

3.1. Background (Study area, Methodology, References, etc.)

126. Generation of environmental baseline of a project area is an important phase of environmental assessment process. Baseline data provide vital information on the existing environmental quality in which a development is planned. It is also useful for delineating environmental sensitive areas and for preparing an environmental sensitivity map for contingency planning. This will help to predict potential environmental impacts during the construction and operation phases. In this study, the environmental description of the project area will be established through site visits, expert’s consultation, extensive literature search, stakeholder consultation and data interpretation.

127. The environmental status proximal to the proposed project site is determined for physical and biological settings within 500 m of either side along cable route to the BMH location at Santhome Beach, Chennai. It is determined through the collation of existing data gathered from secondary sources. Since interface of project activities is minimal with valued environmental components, extent of baseline data collection has been limited to secondary data only. Baseline data were gathered through literature and are described in the sections of the chapter.

128. The cable laying and BMH construction does not generate any emission, liquid effluent, or solid waste. Hence focus of baseline status has been on climatic, oceanographic, geological, seismic, marine and ecological resources. For baseline assessment the project activity area is considered as core zone and 500 m area around the project site is considered as buffer zone. Study area map is shown in Figure 3.1.

This chapter describes the baseline environmental conditions around the project site i.e. BMH cable landing location for various environmental attributes, within 500 meters of radial zone, which is termed as the study area. Topography, soil, water, meteorology, air, noise, and land constitute the physical environment, whereas flora and fauna constitute the biological environment. Baseline environmental conditions are based on the field studies carried out during July, 2018 around the project site.


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Figure 3.1 : View of area within 500m of BMH location


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3.2. Site Description and Its Environmental Salient Features

129. As discussed in Chapter 2, project involves laying of communication cable and construction of BMH. Cable will be laid on sea bed and will terminate in BMH at beach. Cable will traverse a distance of approximately 35 m from sea edge/landfall point to reach BMH on Santhome Beach. As per the land revenue records, BMH and cable route alignment on Beach falls in survey no. 4592. As per the CRZ mapping survey conducted by Anna University and new CZMP map of Chennai, BMH falls under the CRZ II area and cable from landfall to BMH point falls under CRZ I B zone. Srinivasa Beach Road runs parallel to the beach and BMH is accessible through this road. The location map of the surrounding area of the BMH location is shown in Figure 3.1.

130. Project activity will not affect any environmental and social component or any structure. There are few fishermen hutments located in the southern direction from BMH location. BMH is located on beach just opposite to Faith Full Gospel Church. Photographs of the BMH site and its surroundings are given in Figure 3.2.

131. Santhome Beach is naturally formed and world’s second longest urban Beach, spread between Latitude 1303’50.4”N- Longitude 80017’9.6”E and Latitude 1303’34.7”N – Longitude 80017’2.4”E. The Beach is relatively flat from the entrance (i.e. access road) to the high water mark. The gradual slope appears to continue out to sea for some distance. The Beach is developed mainly due to deposition of two rivers Kuvam and Adyar. Adyar creek is 370 m in west direction from BMH location. The geo-morphological classification category for the Beach is sandy. Santhome Beach stretches to 13 km long and 0.6 km at its widest traverse. The width of Beach traverse at BMH location is approx. 85 m.


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Location of BMH

Residential colony opposite to BMH location

Children Activity Centre Faith Fullgospel Church


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Sea side view from project site Land side view from project site

Fishermen Hutments along BMH2 location

Srinivasa Beach Road


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Cable Landing Station, BSNL Exchange, R.K Nagar

Figure 3.2 : Site Photographs

3.3. State of Environment

3.3.1. Climate and Winds

132. Climate of Chennai is tropical with mean annual temperature of 23.30C to 39.60C. Temperature is usually in range of 210C to 410C. Mean relative humidity varies from 56% to 88% at 08:30 hrs and 57% to 81% at 17:30 hrs. Sea breeze in the evening hours helps to combat high temperature and humidity during summer months.

133. The Beach area enjoys a semi-arid climate with an annual average temperature of 320C and annual average precipitation of 1300 mm. Temperature ranges from 420C in May and 180C in January. Dominant wind direction is found to be from South with average wind speed 8.4 km/hr (1982-2011)3. Since the study area is microtidal coast, sea level oscillates between 1 and 2 m4.

134. Seasonally reversing monsoon winds affect the Bay of Bengal circulation

significantly. Due to above characteristics of Bay of Bengal and its proximity to equator together with immense quantity of fresh water influx from the rivers contribute to formation of a highly complex circulation system. Mean Surface Wind Direction during South-West Monsoon and North-East Monsoon is given in Figure 3.3.

135. The wind pattern over the Bay of Bengal is south-westerly during the northern summer which switches to north easterly during the northern winters. During the northern winters, the dry north easterly winds are coupled with the cooling and evaporation. During the summer, the southwesterly winds are coupled with heating, precipitation, with an increased freshwater run-off into the northern bay.

3 https://www.weatheronline.in/weather/maps/city?WMO=43279&CONT=inin&LAND=II&ART=WST&LEVEL=162&MOD=tab 4“Aesthetic Blight of Beach: Chennai Marina in Focus” by D. Ruby, J. Kishore Ananthand Dr. V. Radhakrishnan, 2013, Department of

Marine Science, Bharthidasan University, Tiruchirappali


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During the northern winters, the winds blow from high pressure region over the Asian continent into the Bay of Bengal in a southwesterly direction which is strongest in December with an average speed of 5 m/s attaining a maximum speed of 6 m/s over the central western Bay. The highest wind velocities prevail during January while winds are week during March to April. During this period, an anti-cyclonic wind field is developed over the Bay with westerlies along the equator and easterlies. In May, the winds are predominately southwesterly, over the entire Bay of Bengal. This wind pattern intensifies by July attaining maximum velocities of 10 m/s over the central Bay. Generally, the SW monsoon lasts for four months from June to September. Following the summer monsoon, the winds during SW-NE inter-monsoon (October – November) are weak and variable. During the inter-monsoon, strong (>1m/s) eastward flowing equatorial jets, also popularly known as Wyrtki jets, develop along the equator during April-May and October-November. These equatorial jets transport both heat and salt from the western basin to the eastern basin in the equatorial Indian Ocean5.

Source: National Institute of Oceanography

Figure 3.3 : Mean Surface Wind Direction during South-West Monsoon (Left) and North-East Monsoon (left)

5Seasonal variation of the flux of living coccolithophore communities in the Bay of Bengal and their implication on hydrography by

Mergulhao, L.P., National Institute of Oceanography


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3.3.1.2 Cyclones:

136. Geographical setting of Tamil Nadu makes the state vulnerable to natural disasters such as cyclones, floods and earthquake induced Tsunami. About 8% of state is affected by 5-6 cyclones every year, of which two or three are severe.6The districts mostly affected along the Tamil Nadu coasts are Pudukkottai, Cuddalore, Kanchipuram, Tiruvarur, Nagappattinam, Chennai, Ramanathapuram, Toothukudi and Tirunelveli.7

137. The north Indian Ocean accounts for 7% of global tropical cyclones; on average,

5 to 6 tropical cyclones form over this area every year. Activity is concentrated in two cyclone seasons; a pre-monsoon season from March to May and post-monsoon season in October to December. A cyclone in November 1970 in the Ganges River delta resulted loss of enormous lives and material. A storm of comparable magnitude occurred in 1991 and devastated the eastern shore of Bangladesh. Another cyclone took place in 1999, devastated the Orissa. Water sputs out frequently in the bay during the summer months. The bay is also subject to occasional Tsunamis, one such event, caused by an undersea earthquake near the Indonesian island of Sumatra in December, 2004. Devastated extensive coastal areas of the bay, particularly in Sri Lanka and The Andaman and Nicobar Islands. Major cyclones and Tsunami which have occurred along Chennai coast are given below8: 1. December, 2016: Cyclone Vardah made landfall close to Chennai leading

to damaging the infrastructure and affecting transportation service 2. Dec, 1976: Unprecedented torrential rain lashed the city and Chengalpattu

district 3. Nov, 1975: Caused continuous heavy rains in Chennai city and

neighbourhood for 3 to 4 affected City life. Many thousands of hut dwellers rendered homeless and huts damaged

4. Nov, 1966: Heavy rains occurred leading to loss of property andlife June, 1941: Earthquake of magnitude 8.1 in Andaman affected East coast of Chennai

5. August, 1883: Eruption of Karkatoa volcano (Sunda Strait) Indonesia affected East coast of India and 2 m Tsunami was reported at Chennai

6. December, 1881: Earthquake of magnitude 7.8 beneath Car Nicobar affected East coast of India including Andaman and Nicobar Island

138. Since 1800, 7 individual runups have been recorded at Chennai. These were

due to just 3 tsunami sources. The maximum runup in Chennai was 5.56m, due to the December 2004 tsunami.

139. In December, 2004 tsunami, occurred at 00:58:53 UTC on 26 December with the epicentre off the west coast of Sumatra, Indonesia. The worst affected area

6Disaster in Tamil Nadu, India: Use of Media to Create Health Epidemic Awareness, S. Kuppuswamyand Dr S. Rajarathnam, Anna

University, Chennaiandhttp://www.britannica.com/EBchecked/topic/60740/Bay-of-Bengal 7Cyclone Hazard Proneness of Districts of India, Regional Specialised Meteorological Centre India Meteorological DepartmentLodhi Road,

New Delhi 8Addressing the Risk of Tsunami in the Indian Ocean by Shailesh Nayak and T. Srinivasa Kumar, 2008


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in Tamil Nadu was Nagapattinam district and 13 km (8.1 miles) Marina Beach in Chennai. 9 Cyclone Vardah in 2016 also caused destruction in Chennai.

Chennai Landfall in January 2001

Chennai Landfall in September 2014

140. Although smaller structures visible before the tsunami appear to have gone,

larger structures appear unaffected and the coastline did not suffer a significant retreat. However seasonal monsoon changes will affect the beach profile and the risk from tsunami continues.

141. As per IMD, Chennai, no cyclone have crossed Tamil Nadu and Puducherry coast during the year 2018.

142. Figure 3.4 below shows tropical storm tracks for the study area over a 20 year period from 1985 to 2005. (http://commons.wikimedia.org/wiki/User:Nilfanion). In general terms it can be seen that the risk from tropical storms is high in the Bay of Bengal.

Figure 3.4 Tropical storm tracks for the study area from 1985 to 2005

9Effects of the December 2004 Indian Ocean Tsunami on the Indian Mainland, Alpa Sheth, Snigdha Sanyal, Arvind Jaiswal, and Prathibha

Gandhid, 2006

http://commons.wikimedia.org/wiki/User:Nilfanion


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3.3.1.3 Relative Humidity and Temperature

143. Temperature and humidity data for Chennai from year 1981 to 2010 is given in Table 3.1 below. Temperature varies from 21.20C to 37.10C. Relative humidity varies from 63-82%. Meteorological data for the period of 1981 to 2010 is mentioned in Table 3.1.

Table 3.1 Meteorological Data of Chennai (1981-2010)

Month

Mean Temperature(oC)

Mean Total

Rainfall

(mm)

Mean Number of

Rainy Days

Mean Number of days with Relative Humidity*

(%)

Daily Minimu

m

Daily Maximu

m

HAIL

Thunder

FOG

SQUALL

Am Pm

Jan 21.2 29.3 25.9 1.4 0 0 0.1 0 80 67

Feb 22.2 30.9 3.4 0.8 0 0.1 0.1 0 80 67

Mar 24.2 32.9 3.5 0.3 0 0.4 0.1 0 78 69

Apr 26.6 34.5 14.4 0.8 0 0.8 0 0 74 72

May 28.0 37.1 34.2 1.8 0 2.1 0 0.1 66 68

Jun 27.5 37.0 55.8 4.0 0 3.5 0 0.3 63 63

Jul 26.4 35.3 103.8 6.5 0 3.8 0 0.2 71 66

Aug 25.9 34.7 126.8 7.7 0 4.6 0 0.2 75 68

Sep 25.6 34.2 147.7 7.3 0 6.2 0 0.1 78 73

Oct 24.6 32.1 315.6 10.9 0 7.3 0 0 82 76

Nov 23.1 29.9 374.4 11.5 0 3.1 0 0 82 75

Dec 21.9 28.9 177.4 5.8 0 0.6 0 0 81 73

Annual

24.8 33.1 1382.9 58.8 0 32.5 0.4 0.8 75.83

69.75

* Relative humidity data represents the 30 year Climatological normal data (1981-2010) for Nungambakkam station, Chennai. Source: IMD Chennai

3.3.1.4 Visibility

144. Visibility along Chennai coast is usually good throughout the year and poor visibility is commonly associated with precipitation in autumn. Some fog and haze form locally at Chennai in winter.

3.3.1.5 Rainfall

145. Average annual rainfall of Chennai district is 1382.9 mm as per IMD Chennai. Most of the rainfall is received during months of October and November due to North-East Monsoon. Precipitation occurs in the form of one or two cyclones caused due to depression in Bay of Bengal. Monthly rainfall data of the district is given in Table 3.2 below.

Table 3.2 : Monthly rainfall of District Chennai

Month/Year 2013 2014 2016 2017

January 0.0 0.0 0.5 4.5

February 16.9 7.1 0.0 0.0

March 25.1 0.0 0.0 0.0

April 1.9 0.0 0.0 0.0


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May 1.8 30.5 198.1 1.8

June 40.3 141.6 109.3 58.5

July 154.7 47.3 59.6 86.6

August 194.8 210.2 51.7 233.4

September 210.2 129.6 275.3 71.2

October 195.4 386 28.8 269.8

November 174.4 182.4 66.1 583.8

December 93.7 151.2 247.2 84.2 Source: IMD

3.3.2. Oceanography:

3.3.2.1 Currents:

146. Currents vary during the four seasons in Bay of Bengal. During NE monsoon (December-February), an equator-ward surface current is well developed along the east coast of India under the influence of north-easterlies. A cyclonic circulation cell develops in the interior of Bay of Bengal. During NE-SW inter-monsoon (March to May), two anti-cyclonic gyres forms which merges to form a large anti-cyclonic circulation cell. During SW Monsoon (June to September) A cyclonic circulation cell develops in the south eastern Bay of Bengal. During SW-NE monsoon (October to November) a basin wide cyclonic circulation develops west of the arc of the Andaman Island.10Surface circulation during the southwest and northeast monsoons is given in Figure 3.5 below.

3.3.2.2 Waves:

147. Waves and wind climate in the Bay of Bengal during May to September is primarily controlled by the SW monsoon activity over the tropical Indian Ocean. During July and August, the south-westerly winds sweep the south central Bay of Bengal and the wind speed reaches up to 9 to 15 m/s in July which is the peak of the south-west monsoon. The mean wave height in the central Bay during July and August reaches up to 2.5 and 2.0 m respectively. In addition to water level changes resulting from waves and tides, average sea level varies throughout the year. Rainfall and riverine input exceeds evaporation, the bay exhibits a net water gain annually11.

10Seasonal variation of the flux of living coccolithophore communities in the Bay of Bengal and their implication on hydrography by

Mergulhao, L.P., National Institute of Oceanography 11Observation of wind and waves in the central Bay of Bengal during BOMBEX-99 and their effect on mixed layer depth variability due to

forced mixing


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Source: National Institute of Oceanography

Figure 3.5 Surface circulation during the southwest (left panel) and northeast (right panel) monsoons.

3.3.2.3 Tidal Information:

148. The tides in the port area are semi-diurnal in nature. The spring tides are up to 1.2 m. The mean tidal range varies from 0.914 m to 1.219 m at spring and from 0.805 m to 0.610 m at neap tides.

149. The change in water levels combined due to astronomical tide, wind setup, wave setup, barometric pressure, seiches and global sea level rise are estimated as 1.57 m, 1.68 m and 1.8 m at 15 m, 10 m and 5 m depth contours, respectively. Waves ranging from 0.4 m to 2.0 m in the deep water around Chennai harbor have been experienced with the predominant being 0.4 m to 1.2 m with wave periods predominantly in the order of 4 to 10 seconds. During cyclone season, waves of height exceeding 2.5 m are common. The predominant wave directions during southwest and northeast monsoons are 145° from north and 65° from north, respectively. The following are the particulars of tidal levels of Chennai port are given in Table 3.3.

Table 3.3 : Tidal information for the Chennai Port

LOCATION TIDE TYPE MHWS MLWS RANGE

(M)

MHWN MLWN RANGE

(M)

MSL ABOVE CD (M)

ADMIRALTY LOCATION NUMBER

Chennai, Tamil Nadu

Semi diurnal 1.0m 0.4m +0.65m 4452

(Admiralty Tide Tables 2015)

150. There are seasonal changes due to monsoon effects, with MSL varying by up to 0.2m from the mean at Chennai.

3.3.3. Geology

151. Chennai is vast coastal plain characterized by several strandlines, lagoon, mangroves, salt marsh, estuaries, creek, barred dunes, spits, Beach terraces etc. Geographical formations are Beach sand at quaternary and recent period.

http://en.wikipedia.org/wiki/Wave_setup


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Cuddalore sandstones of MioPliocene age, shoals and sand stone of upper Gondwanas and Chornockites of Archaean era also occur. Tamil Nadu has coastline measuring 1,076 km with 13 coastal districts and continental shelf area measuring 44,412 sq m. Offshore area of state is 2.2 X 105 hectares12.

152. Centre part of Bay of Bengal has very simple sea floor topography. “The head of

the Bay off the Ganges Delta is flat and shallow, cut only by the Ganges Submarine Canyon, or Swatch of No Ground. Below 100 fathoms the slope steepens, then decreases again very gradually, resulting in a smooth southward sloping plain with a gradient of about one fathom per mile”. Southern Bay of Bengal however is extremely smooth except for occasional trough-shaped depressions. These depressions are bilaterally symmetrical and the sides of these are levied like bank of river. Sea floor of Bay of Bengal has a gentle sloping topography cut by network of Channel like depression running north to south13. Bottom topography contours of Bay of Bengal are given in Figure 3.6. Schematic Diagram of the Continental Shelf showing bottom profile and zones of sediments is given in Figure 3.7.

12

FIMSUL Work Package 5 Report-WP5AR2, Marine Fish Production in Tamil Nadu andPuducherry, A report based on a detailed analysis

of Central Marine Fisheries Research Institute Data, 2011 andhttp://www.annauniv.edu/iom/iomour/Chennai.htm

13

Oceanographic studies in the Bay of Bengal by E.C. LAFOND, communicated by Sir C. V. Raman, 1957

andhttp://www.bpedia.org/B_0361.php

http://www.bpedia.org/B_0361.php


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Source: Hydrography and circulation in the western Bay of Bengal during the North-East Monsoon, Journal of Geophysical Research

Figure 3.6 : Bottom topography Contours of the Bay of Bengal


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Source: Oceanographic studies in the Bay of Bengal by E.C. LAFOND, communicated by Sir C. V. Rama, 1957

Figure 3.7 : Schematic Diagram of the Continental Shelf showing bottom profile and zones of sediments


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3.3.4. Continental Shelf and Slope, Chennai

153. The continental shelf and slope off Chennai have been subjected to eustatic variations, which are linked to deltaic inputs to the area. The continental shelf is 43 km wide, with gentle inclines of around 0.5 % out to the shelf break at 200 m water depth. Beyond the 200 m water depth contour the continental slope is steeper, with inclines of up to 12.5 %. The abyssal plain starts at around 3000 m water depth (Murthy et al., 2012). The continental slope off Chennai is largely covered by fine grained terrigenous sediments except close inshore, where the combination of biological activity and a higher energy environment has produced deposits of calcareous sands and silts.

3.3.5. Seismicity:

154. Site falls under seismic zone III, which indicates moderate risk of earthquake occurrence. History of Earthquakes in Chennai area of Tamil Nadu14

1. 10 December 1807: Maximum Observed Intensity is VI, i.e. strong earthquake

2. 16 September 1816: Maximum Observed Intensity is VI, i.e. strong earthquake

3. 12 August 1889: Maximum Observed Intensity is VI, i.e. strong earthquake 155. Seismic activity onshore is low in Chennai and within the Bay of Bengal

3.3.6. Surface Temperature and Salinity

156. The Bay of Bengal receives enormous quantity of fresh water and sediment input from some of the world’s largest river and surface run-off. This enormous discharge of fresh water in the Bay of Bengal causes changes in salinity over a wide range of values both seasonally and geographically. The oceanic precipitation results in salinity gradient in the upper layers.

157. Salinity in open part of the Bay of Bengal oscillates from 32% to 34.5% and in coastal regions varies from 10% to 25%. At rivers mouths salinity decreases upto 5% or even less. Salinity in waters of Bay of Bengal off Chennai show cyclic changes. For the Gulf of Mannar, mean annual range of salinity is 7-4%. High value of salinity is observed in the period of May-October (SW Monsoon), while lower values are found between November and April (NE Monsoon). Seasonal distribution of salinity in these waters is governed by the monsoon driven currents. During period of SW monsoon, the direction of the current is from south to North in this region, which brings in large amount of oceanic water from the Indian Ocean and also from the southern part of the Arabian Sea. Due to higher salinity of these waters (34.5 to 35%), rise in salinity is observed. Also high winds and temperature leads to evaporation of water which further increases the salinity of water.

158. With onset of NE monsoon, direction of the current is reversed and water of lower salinity (24 to 27%) from north enters these waters reducing the salinity. Vertical salinity gradient is not significant. Vertical gradient is observed mainly during the calm months. Nutrient salts, i.e. phosphates, nitrates and silicates are present in these waters. Phosphate content is low and do not show much variation. Nitrates show wider variation due to activity of denitrifying bacteria. Silicates concentration varies with the salinity of water.

14asc-india.org/seismi/seis-tamil-nadu.htm,


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159. Mean annual temperature of the surface water is 280C. Maximum temperature is observed in May (300C) and the minimum (250C) in January-February. Annual variation in surface temperature over Bay of Bengal ranges between 4 and 60C. Vertical temperature structure of water is largely determined by the physical processes going on in the sea. Increase in temperature below surface is result of cooling at surface. Vertical temperature structures are usually formed due to upwelling and sinking15.

3.3.7. Sub surface Temperature and Salinity

160. Temperature profiles for the Bay of Bengal are presented in Figure 3.8. Equivalent profiles for salinity are presented in Figures 3.9

Source: http://www.ewoce.org/gallery/eWOCE_tables.html

Figure 3.8 : Sub surface Temperature profile across Bay of Bengal

Source: http://www.ewoce.org/gallery/eWOCE_tables.html

Figure 3.9 : Salinity Profile across Bay of Bengal

15

Seasonal Variations in Salinity, Dissolved Oxygen and Nutrient Salts in the Inshore Waters of the Gulf of Mannar and Palk Bay Near

Mandapam (S. India) by R. Jayaraman, 1954

Oceanographic studies in the Bay of Bengal by E.C. LAFOND, communicated by Sir C. V. Raman, 1957

Hydrography and circulation in the western Bay of Bengal during the North-East Monsoon, Journal of Geophysical Research

http://eprints.cmfri.org.in/1636/1/Article_16.pdf


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161. Figure 3.8 indicate that the Potential Temperature drops from around 25°C at the surface to around 2.5°C at 2000m water depth and 1.5°C at 3000m water depth, reaching between 1°C and 1.3°C at the seabed in the deep Bay of Bengal basin.

162. Bottom temperatures are warmer than can be explained by simple adiabatic heating (R Burns 1964) and it is inferred that the increased temperatures in the basin are due to geothermal heat flows.

163. Figure 3.9 indicates that the Salinity rises from about 34 psu at the surface to a value around 35 psu between 200 and 600m WD before decreasing again to 34.8 psu at 1800m WD in the Bay of Bengal. Beyond this depth the Salinity stays at <34.8 psu in the Bay of Bengal.

3.3.8. Coastal Regulation Zone (CRZ) Mapping Survey

164. Institute of Remote Sensing, Anna University, Chennai, was approached to conduct a survey to work on the demarcation of High Tide Line (HTL) and Low Tide Line (LTL) at Santhome Beach, Chennai, and accordingly a CRZ map was also prepared. The survey was conducted in the July, 2018. The tide level observations for the last 19 years were also studied for Ennore Point (near to the site) from the Tide Tables available from Tamil Nadu Maritime Board.

165. The satellite imagery of the coastal zone and Geomorphology were also

studied. Based on the geomorphic units, the high tide line has been identified in the field and traced by field survey.

166. Dual Frequency GPS (Model: Trimble 5700) instruments were used for HTL/LTL demarcation, image control points observation and delineation of the project boundary. There were two teams involved in the field survey. During the field survey, one team took GPS points for entire project boundary, control points for satellite imagery and block map (cadastral map) for the corresponding area and another team took HTL points along the coast and creek falling on the project site.

167. The observed GPS data was downloaded and processed in the Trimble Geomatics Office software. The processed GPS image coordinates were fed into ArcGIS 9.2 software for Geo- referencing. The processed HTL points were plotted using the same software on the Cadastral map at the scale of 1:4,000. The complete survey report is attached as Annexure I.

3.3.9. Noise Environment

168. BMH site is located at Santhome Beach. Srinivaspuram beach road runs parallel to beach and the housings are located on other side of the road. Beach is not used by visitors majorly however some fishing activity and fishermen hutments were observed during visit. Major source of noise at the site is vehicular movement on beach road and some fisher man activity. No major activity is observed at site after 8:00 PM. Noise levels are not anticipated to be higher on the BMH site

3.3.10. Air Quality

169. Ail quality monitoring was performed by CPCB for Chennai the year 2016 nearby to proposed BMH location as mentioned in Table 3.4


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Table 3.4 Ambient Air Quality Status (2016)

Location No. of monitoring days

Minimum SO2

Concentration (µg/cum)

Maximum SO2


SO2 Annual Average Concentration (µg/cum)

Adyar (3.48 km from BMH location)

70 8 13 10

Kilpauk (~7 km from BMH location)

87 10 32 12


Minimum NO2


Maximum NO2 Concentration (µg/cum)

NO2 Annual Average Concentration (µg/cum)


70 5 18 14


87 13 27 19


Minimum PM10


Maximum PM10 Concentration (µg/cum)

PM10 Annual Average Concentration (µg/cum)


70 11 96 48


88 35 212 96

24 hour air quality monitoring results indicates that SO2, NO2 and PM10 were within the standards as per National Ambient Air Quality Standard (NAAQS, 2009) except at Kilpauk where maximum concentration observed is 212 µg/cum.

3.3.11. Biological Environment

170. A detailed biological impact assessment study has been carried out to determine Impact of the project (BMH construction and cable laying) to assess if there are any sensitive species in project area that could be impacted by cable laying operation. Data on existing marine species has been taken from available literature/authentic sources like Central Marine Fisheries Resources Institute (CMFRI), Indian National Centre for Ocean Information Services (INCOIS), FSI (Fisheries Survey of India)etc. A site visit was conducted to collect information about the area from various concerned agencies, discussions with local people and fishermen etc. Also a report of ZSI has been referred for collection of marine ecology available in coastal waters of Chennai. The report is prepared by ZSI for a similar project.16

16 Study carried out by ZSI for BBG Submarine Cable Project. EQMS India Pvt Ltd has contracted ZSI to carry out the job and reference of the study is taken here as BMH location of BG cable system project is within 500 m distance from proposed BMH location.


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171. Purpose for the biological study is to identify the sensitive marine species,

determine its probability of getting impacted and extent of the impact. Additionally study has also helped out to propose the mitigation measures that should be taken to ensure environmentally sound practices to be followed and measures taken during deployment.

3.3.11.1 Terrestrial Ecology:

172. The study area is divided into core and buffer zones. In this, (BMH) and cable traversing area from sea edge to BMH is considered as core zone. Area within 500 m radius from the core zone is considered as buffer area.

173. Santhome beach is sandy and does not support any terrestrial vegetation or any wild fauna. The area has no eco-sensitive zones like turtle breeding ground on the Beach and this stretch is also not used for any recreational and fishing purpose. No eco-sensitive zones like national park, wildlife sanctuary etc is present within 500 m from proposed BMH site. Adyar Creek is at a distance of 370 m in west direction from location of BMH. Tholkappiar Ecological park is at distance of 0.62 km in W direction from location of BMH. Guindy National Park is located at 5.0 km from proposed BMH in SW direction. Birds were seen at the Beach and they are Wilson Storm Petrel, Sea gulls, White cranes, Median egret and Red Wattled Lapwing.

174. Adyar Creek and Foreshore Estate falls in 500 m buffer area around the core zone. Adyar creek is at a distance of 370 m from project site and Foreshore terminus is at distance of 330 m in SW direction from BMH location. No mangrove species were reported during site visit in the buffer area. Floral species reported within 500 m buffer area are Prosopis juliflora, Crotons sparciflorous, Ipomea biloba, Thespesia populnea, Cassia occidentalis, Cephalandra coccinia, Pongamia glabra, Abrus precatorius, Lantana camara, Zizyphus jujube, Azadirachta indica, Morinda species, Antigonon species, Hyptis species and Acacia sp.

175. Project activity is confined to the core zone and the least impact is anticipated in buffer zone due to project activity. Data on terrestrial and aquatic flora near Adyar Creek is collected from secondary available sources. Faunal species present in and around Adyar Creek region are listed in Table 3.8 and 3.9.

Table 3.5 Faunal Species in Buffer Area

S. No. Fauna Species Scientific Names

1. Avifauna Black Bittern Cinnamon Bittern Black Winged Kite White Bellied Sea Eagle Pied Kingfisher Yellow Wagtails Little Egret Chestnut Winged Cuckoo Black Winged Stilt Painted Storks Cattle Herons India Jungle Crow

Ixobrychus flavicollis Ixobrychus cinnamomeus Elanus caeruleus Haliaeetus leucogaster Ceryle rudis Motacilla flava Egretta garzetta Clamator coromandus Himantopus himantopus Mycteria leucocephala Bulbulcus ibis Corvus culminates


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Mynahs Blue Rock Pigeon Water Paddybirds Eaglet Yellow Billed little Egret

Acridotheres tristis Columba livia Ardeola grayii Haliaeetus leucocephalus Egretta garzetta

2. Reptiles Common Indian Bronzeback Saw scaled viper Turtles

Dendrelaphis tristis Echis carinatus Olive Ridley

3. Butterflies: Painted lady Black Rajah Blue tail Green Darnor Dragon Fly

Vanessa cardui Charaxes solon Anax guttatus

4. Amphibians

Flapshell turtle Indian Pained frogs Skipper frog Common Indian Toad Green frog Soft shelled turtle

Lissemys punctata Kaloula taprobanica Euphlyctis cyanophlyctis Duttaphrynus melanostictus Lithobates clamitans Nilssonia gangetica

5. Mammals:

Grey Mongoose Indian Flying Fox

Herpestes edwardsii Pteropus giganteus

6. Fishes: Indian shortfin eel Spotted snakehead Flathead mullet

Anguilla bicolor pacifica Channa aurantimaculata Mugil cephalus

Table 3.6 Planktons in Adyar Creek

S. No. Group Name of Organism

1. Cladocera Daphnia

Calanoida

2. Copepoda Diaptomus

Eucalanus

Epischura

Eurytemora

Naupli

Oithona

Cyclopoida

Cyclops

Eucyclops

Halicyclops

Heterocyclops

Mesocyclops

Paracyclops

Harpacticoida

Bryocamptus

Mesochra

Paradactylopodia

Stenocaris

3. Ostracoda Cypris

Candona

Limnocythere

4. Rotifera Brachionus

Filinia


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Keratella

Lecane

Monostyla

Nothoica

Platyias

Trichocera

176. A study carried out by NEC shows that there are no eco-sensitive zones or

marine protected areas on the cable route from Chennai landfall to 12 nauticle miles. The secondary data from reputed organizations like CMFRI, FSI, ZSI etc shows that good biological marine resources in coastal waters of Tamil Nadu which are listed above. Also disturbance caused by cable laying operation would be temporary in nature. Activities which may lead to impact the marine life are bed burial and descending of cable. These activities will cause a temporary shock to the marine life but for a very short duration. Thus it seems that impact anticipated on marine life is not significant. Also all mitigation measures are proposed to be taken during cable laying operation to minimize the disturbance to marine habitat. These are discussed in Chapter 4 in detail.

177. As per the new CZMP Map of Chennai as approved in 2018, Santhome beach is marked as Turtle Nesting Site Area. Thus as preventive measure cable laying activity will not be undertaken during turtles nesting season (Sep to Jan, 2018)

3.3.11.2 Marine Ecology:

178. Study area considered for marine biological study is coastal waters within 500 m radius from BMH site at Santhome Beach at Chennai in Tamil Nadu towards sea.

179. Cable route is designed in a way so as to avoid eco-sensitive zones like coral reefs, sea weed/grass bed, volcanoes, sea mounts, seeps etc. Proposed cable route does not overlap any marine eco-sensitive zone (NEC).

180. Marine biodiversity includes large variety of organisms including sessile forms, crawling forms, swimmers and floaters. Species composition varies with the depth in the sea. Abundance of species decreases with increase in depth. As cable is to be laid on sea bed, most effected life-forms will be bottom dwellers (sessile and crawlers). Demersal or benthic fisheries will be most impacted followed by pelagic life forms. Least impact is anticipated on floating species. Biological species present in various zones (as per depth) is given below:

3.3.11.2.1 Planktons

181. Coastal waters of Tamil Nadu support luxuriant growth of Sea Weeds. As per CMFRI17, some of commercially important sea weeds that grow in these waters are Ulva, Enteromorpha, Caulerpa, Codium, Sargassum, Hydroclanthrus, Laminaria, Undaria Porphyra, Gracilaria Eucheuma, Laurencia, Acathophora etc. of the sea weeds also exhibit epiphytic and epizootic associations, e.g. Polysiphonia sp. growing on Sargassum wightii, Gracilaria corticata, C. fergusonii, Laurencia flagelliformis, Cheilosoporum spectabile and Hypnea, Ulva lactuca growing on Cheilosporumspectabile,

17SeaWeed Potential and its Exploration in India, CMFRI, 1997


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Sargassum wightii, Amphiroa anceps and Amphiroa sp. attach to shell surface of Astraea stellaretc. List of chlorophyta, Pheaophtya, Rhodophyta, Cyanophyta and Sea grass present in coastal waters of Tamil Nadu is given in Annexure II.

182. No sea grass bed is observed on the proposed cable route (NEC), thus cable laying operation will not have any impact on sea weeds. Phytoplankton and Zooplanktons found in waters of Santhome Beach area are given in Table 3.8 and 3.9.

Table 3.7 List of Phytoplankton Present in Water of Santhome Beach

S. No. Genus

1. Ceratium

2. Navicula

3. Biddulphia

4. Nitzschia

5. Gyrosigma

6. Chaetocera

7. Coscinodiscus

8. Pleurosigma

9. Chlordla

10. Aulca

11. Thelasiro Source: Water Quality Analysis by CMFRI, 2008

Table 3.8 : List of Zooplanktons Present in Water of Santhome Beach

S. No. Zooplanktons

1. Hydrozoa

2. Siphonophora

3. Ctenophora

4. Polychaeta

5. Pteropoda

6. Heteropoda

7. Cladocera

8. Gastropods

9. Ostropoda

10. Copepod

11. Mysid

12. Lucifer

13. Stomatopods

14. Chategnaths

15. Copelata

16. Salps

17. Doliolum Source: Water Quality Analysis by CMFRI, 2008

3.3.11.2.2 Fisheries Resources

183. Survey carried out by CMFRI18, listed out the following pelagic and Demersal fisheries resources in coastal waters of Tamil Nadu. Details of fisheries are

18

An approval of the Marine Fisheries of Tamil Nadu and Pondicherry, 1987, CMFRI

Present Status of Marine Fisheries of Tamil Nadu and Pondicherry, 1994, CMFRI


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given along with the percentage of their occurrence against total landings annually in Table 3.10 and 3.11. Figures 3.10 and 3.11 present the percentage of landings of pelagic and demersal fisheries, respectively, in coastal waters of Tamil Nadu.

Table 3.9 :List of Pelagic Fishery in Coastal Waters of Tamil Nadu

S. No Group %age of total

marine

landings

Main species

1. Sardines 12.2 Sardinelladayi, S. culpeoides, S. fimbriata, S.

gibbosa, S. sirm, S. longiceps, S. sirdensis

2. Anchovies 7 Coiliadussumieris, C. neglecta, Setipinnataty,

Stolephorusbataviensis, S. buccaneeri, S.

commersonii, S. devisi, S.heterolobus, S.indicus,

S.macrops, S. waltei, Thrissinabaclama, T.

dussumieri, T. hamllionil, T.kammalensis,

T.malabarica, T.mystax, T.purava and T.setirostris

3. Ribbon Fishes 5.6 Eupleurogtammus intermedius, E. muticus,

Lepturacanthussavala, Trichiuruslepturus

4. Carangids 4.2 Jack Mackerel, runners, scads, jacks and

Pompanos: Few species are Alectis indicus,

Alepes mate, A. para, Carangoidesarmatus,

Caranx carangus, C. ignobilis, C. melampygus, C.

sexfasciatus, Decapterusdayi, D. russelli, Elagalis

bipinnulatus, Gnathanodon speciosus, Megalaspis

cordyta, Scomberoides commersonianus, S. lysan,

S. tala, S. tol, Selarcrumenophthclmus, Selaroides

leptolepis, Seriolanigro fasciata, Tranchinotus

baillonii and T. blochii

5. Perches: 38 Epinephelus, Aprion, Lurjanus, Pristipomoides,

Lethrinus, Nemipterus, Acanthurus, Ambasis,

Apogon, Callyodon, Dipleprion, Drepane,

Ephippus, Gateria, Gerres, Holocentrus, kurtus,

Lates, lebotes, Acanthophagus, Pempheris,

Pentaprion, Plectorhyneus, Pomadasys,

Pricanthus, Peamonoperca, Scatophagus,

Scolopsis, Siganus, Sillago and Therapon

6. Others

:

33 Seer fishes Scomberomorus commerson, S.

guttatus, S. lineolatus, King seer, spotted seer,

Wahoo

Tunnies Auxis rochei, A. thazard,

Katsuwonuspelamys, Euthynnusaffinis,

Sardaorientalis

Fisheries Management and Ecology, “Fisheries and trade of sea horses, Hippocampus spp. In Southern India”, 2005 Diversity of Molluscan Fauna along the Chennai Coast, Zoological Survey of India, 2012 Marine Fish Production in Tamil Nadu andPuducherry, 2011, FIMSUL


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marine

landings

Main species

Cuttleass Fish (Trichiurids): Lepturacanthus

savala, Trichiurus lepturus

White baits: Stolephorus bataviensis, S.

andhraensis, S. buccaneeri, S. devisi, S.

coomersoi, S. indicusand S. macrops

Sea Horses: Hippocampus borboniensis, H.

spinosissimus Weber, H. kudaBleeker, H. Fuscus

Ruppell, H. trimaculatus Leach

File fishes: Odonus, Sufflamen

Halfbeaks and Full beaks: Hemirhamphus

Garfishes: Belone

Turtle : Olive Ridley

Bill fishes, Barracudas, Mullets, Loligo,

Unicorn Cod, Squids, Sail fish, Oil Sardines and

others like Coryphaena, Lactarius, Mugil, ,

Pseudobalistes, andphyraena etc.

Source: CMFRI, 1987, 1994, Fisheries Management and Ecology, 2005, ZSI, 2012 and FIMSUL, 2011

05

10152025303540

Pe

rce

nta

ge o

f la

nd

ing

Groups of Fisheries

Pelagic Fisheries in Coastal Waters of Tamil Nadu (2001-2010)

Percentage of Landing (2001-2010)

Figure 3.10 : Percentage of landings of pelagic fisheries in coastal waters of Tamil Nadu

Table 3.10 :List of Demersal Fishery in Coastal Waters of Tamil Nadu


marine

landings

Main species

1. Silverbellies

(Pony fishes)

16.6 Leiognathus berbis, L. bindus, L. blochii, L.

brevirostris, L. daura, L. dussmieri, L. equalus, L.

fascilatus, L. joneri, L. leuciscus, L. lineolatus, L.

splendens, Gazzaachlamys, G. minuta, Secutor

insidiator, and S. ruconius

2. Elasmobranchs 6.9 Sharks: Chiloscyllium, Rhiniodon, Stegostoma,


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marine

landings

Main species

Alopias, Carcharinus, Galeocerdo, Scoliodon and

Sphyrna

Skates: Rhina, Rhinobatus, Rhynchobatus, Pristis

and Roja

Rays: Dasyatis, Gymmura, Himantura,

Urogymnus, Aetobatus, Aetobatus, Aetomyldeus,

Rhinoptera, Manta, Mobula and Nercine

3. Croakers 6.4 Johnius opsaneus, J. sina, J. vogleri, Johnius

belengeril, J. carutta, J. dussumieri,

Kathalaaxillaris, Otolithuscuvieri, O. ruber and

Protonibea diacanthus

4. Penaeid

prawns

5.1 Metapenaeopsis, Metapenaeus, Parapenaeopsis,

Parapenaeus, Penaeopsis and Penaeus

5. Crabs 4.4 Syllaserrata, Portumuspelagicus and Portunuss

anguinolentus, hermit crab, spider crab etc

6. Others 60.6 Shrimps: Paraconchoecia elegens,

Paraconchoecia procera, Paraconchoecia

decipiens, Conchoecettagies brechti,

Microconchoecia curta, Metaconchoecia

rotundata, Orthoconchoecia atlantica,

Platyconchoecia prosadena, Spinoecia porrecta,

Spinoecia parthenoda, Conchoecia magna,

Conchoecissa imbricate etc.

Gastropods:Ficus subintermidus, Cypraea,

Turritella attenuate, Babylonia spirata,

Cantharustranquebaricus, Conusbetulinus,

Conusfigulinus, Conusloroissi, Pleuroploca

trapezium, Pugilinaconchlidium,

Chicoreusvirgineus, Murex trapa,

Ropanarapiformis, Bulliavittata,

Nassariusalbescens, Nassariusluridus, Olivia

vidua etc.

Bivalves:Arca symmetrica, Arcatortusa,

Trisodostortusa, Pectentranque baricus, Cardita

bicolor, Lucina vesiculata, Lucina ovum, Cardium

flavum, Cardium setosum, Sunettamero, Sunetta

scripta, Mactra turgid, Donax cuneatus, Donax

scortum, Tellinaala, Tellinaangulata, Laternula

anatine, Crucibulumex tinctorium, Callistanivea,

Semelec renulata

Pomfrets: Black pomfrets, Silver pomfretsand

Chinese pomfrets

Lobsters: Spiny lobster and Sand lobster

Lizard fishes


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marine

landings

Main species

Goat Fishes

Big jawed jumpers

Flat fishes: Halibut, Flounders, Soles

Non- Penaeid Prawns

Chanks: sacred chanks, other chanks.

Mussel:PernavirdisMussel

Eel

Cat fishes

Source: CMFRI, 1987, 1994, Fisheries Management and Ecology, 2005, ZSI, 2012 and FIMSUL, 2011

020406080

Pe

rce

nta

ge o

f la

nd

ing

Groups of Fisheries

Demersal Fisheries in Coastal Waters of Tamil Nadu (2001-2010)

Percentage of Landing (2001-2010)

Figure 3.11 : Percentage of landings of demersal fisheries in coastal waters of Tamil Nadu

184. As per the annual studies carried out by CMFRI, species which occurs in coastal waters around Santhome Beach are Oil Sardines, Mackerel, Squids, Port. San, Cuttle Fish, Pernavirdis, Ribbon Fish, Crasistoristoliferous, White bait, Penaeid shrimps, Non penaeid shrimps, Nemipteris, Loligo, Silver bellies, Crabs, Turtle and Humpback dolphins

185. As per DTS study, the main catch in the region includes Sharks, Eels, Catfish, Chinocentras, Sardines, Flying Fish, Perch, Red Mullet, Silver Bellies, Pomfrets, Mackerel, Seer, Mugil, Crabs, Lobsters, Prawns and Turtle.

3.3.12. Marine Ecology Within 12 Nauticle Miles of Marien Water from Chennai Landfall

186. Specific data on the marine ecology within 12 nauticle milles from the proposed Chennai landfall can be referred from the ZSI report as mentioned above. Excerpt from the ZSI report are attached as Annexure III


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3.3.13. Fishing Activities near the Cable Route

187. Many small fishing communities exist along the Beaches of Chennai. There is no commercial fishing around the landing areas but soem fishing boats were observed at the beach site. Trawling does take place offshore, reportedly to about 100m WD. Due to the sensitive nature of cable landings in the vicinity of potential fishing areas, no discussions were held with local fishermen during the visit.

188. Tamil Nadu has a coastal length of 1076 km (13% of the country’s coast line) and a continental shelf of area about 41,412 sq. km, is one of the leading states in marine fish production. Exclusive economic Zone of the state measures 0.19 million sq.km of EEZ (9.4% of the India’s EEZ), i.e. the area in which marine resources can be exploited19.

189. Fishing is developed over the entire continental shelf area and even beyond in waters off the Tamil Nadu coast. The State has fishermen population of 1.05 million of which 0.20 million fishermen are actively engaged in fishing from 591 marine fishing villages scattered along the 13 coastal districts. In the inshore waters the fishery potential is exploited by 45,000 traditional crafts and 6000 mechanized boats. The infrastructure facilities include 3 major fishing harbors, 3 medium fishing harbors and 363 fish landing centers. The marine fishing potential of Tamil Nadu is estimated at 0.72 million tonnes out of which 0.37 million tonnes comes from less than 50 m depth and 0.35 million tonnes from beyond 50 m depth. Coastal fishery has declined due to increased competition for fishing. Mechanized sector takes a large share of fish catch (70%) compared to small scale sector (30%). There are total 591 fishing villages in the state. Out of 2500 species of fishes occurring globally, 1570 are found to be in Tamil Nadu.

190. There is no fisheries protection zone around Chennai, and accordingly no formal permission is required from Fisheries Department to lay a cable. Also a letter has been submitted to Director of Fisheries for their concurrence to carry out the operation and to obtain their assistance in liaising with fishermen in the event that the cable laying operation may impact on their fishing activities.

191. As per fishing harbor north of the Chennai Port Trust, it was advised that the larger fishing vessels operated to around 50km offshore in water up to approximately 100m in depth. Most if not all of these vessels were involved in trawling, but it was confirmed that the trawlers do not fish to the seabed. Closer to shore, it was suggested that the smaller fishing vessels operate using gill nets only. Figures 3.12 and 3.13 depict the typical small and large fishing vessels used in Chennai respectively.

19

Final Report Vol. I., Key Findings and Future Recommendations, Dec, 2011)

FIMSUL Work Package 5 Report-WP5AR2, Marine Fish Production in Tamil Nadu andPuducherry, A report based on a detailed

analysis of Central Marine Fisheries Research Institute Data, 2011)

Fisheries Policy in tamil Nadu andPuducherry, Word Package 2 Report –R 8C, 2011)


3-29

Source: Information provided by DTS Report, CANI

Figure 3.12 Typical Small Fishing Vessel, Chennai

Source: Information provided by DTS Report, CANI

Figure 3.13 Typical Large Fishing Vessel, Chennai

3.3.14. Hydrocarbon Exploration and Production

192. Cable within 12 nauticle mile distance does not traverses through any oil concession block or crosses any oil or gas pipeline. Concession blocks are present beyond the 12 nauticle miles but these are not currently productive but exploration activity during cable laying may obstruct survey and installation but there are no such likely chances.


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3.3.15. Dumping and Dredging Activities

193. The nearest shipping channel is for Chennai Port which is at 6 km distance in north direction from location of BMH and planned cable route. The approach channel to the Chennai port has two sections- the entrance channel within the protection of outer arm and the outer channel beyond the protection of outer arm. The draught in the navigational channel is maintained by dredging approximately 1 million cubic meters annually20. No specific dredging is observed/reported in cable route area

3.3.16. Military Activities and Manoeuvre Areas

194. Proposed cable route crosses a firing practice area off the Chennai landing site. These firing and exercise areas have been taken from old Indian Notices to Mariners, and the current status of the areas is, however,

unknown. Figure 3.14 shows the firing practice area in the vicinity of Chennai.

20 Waste Land Allocation and Waste Assimilation Capacity Studies for Ennore Creek and Northern Chennai Coastal Waters, National

Institute of Ocean Technology


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Source: DTS Report

Figure 3.14 Firing practice Areas (in red) in vicinity of Chennai

3.3.17. Marine Protected Areas:

195. There are 31 marine protected areas (MPA) sites all over India. Out of these Gulf of Mannar Marine NP, Point Calimere Wildlife and Bird sanctuary and Pulicat Lake (bird) Sanctuary lies in Tamil Nadu21. All of these MPA are at a considerable distance (>50 km) from landing site and also cable route will not pass through any of these areas. Map showing MPA in Tamil Nadu is given in Figure 3.15.

196. One of these MPA sites, Point Calimere Wildlife and Bird sanctuary located in Nagapattinam district of Tamil Nadu, is also covered under Ramsar Sites. This is approximately 300 km from the landing site in south direction.

21 Marine Protected Areas in India, H.S.Singh, 2003, Office of conservator of Forest, Gujrat, Indian Journal of Marine Sciences


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Figure 3.15 : Marine Protected Area, Tamil Nadu


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4. ANTICIPATED ENVIRONMENTAL IMPACTS AND MITIGATION MEASURES

4.1. Prelude

197. This chapter focuses on the probable impacts of the CANI Submarine Cable System on individuals and surrounding environment. Impact can be defined as “any effect of the service”. Definition of impact makes it clear that an impact can be either positive or negative. The essential element of an impact is change.

198. Environmental Impact Assessment study is done to assess the magnitude and significance of the change which may impact the society and the surrounding environment. The study is carried out to judge environmental feasibility of the project. Impact assessment study is the key requirement for framing an Environment Management Plan (EMP) for any project. Depending on the magnitude and significance of the impact, suitable mitigation measures can be proposed in the EMP.

199. A qualitative and quantitative assessment has been carried out for this project to identify each impact and assess the degree of the change that it can cause.

4.2. Anticipated Impacts and Associated Activities

200. Impacts anticipated due to the project development in construction and operation phase are listed in Table 4.1.

Table 4.1 : Potential Sources of Environmental Impacts

Source No.

Types of Likely Environmental Issues Construction

Phase Operation

Phase

1. Gaseous emissions

2. Dust

3. Odor

4. Noisy operations

5. Night-time operations

6. Traffic generation

7. Liquid effluent generation, discharges, or contaminated run-off

8. Generation of waste or by-products

9. Storage, handling, transport or disposal of hazardous materials or waste

10. Risk of accidents that would result in pollution or hazard

11. Disposal of material, including potentially contaminated material

12. Disruption of water movement or bottom sediment

13. Unsightly visual appearance

This Chapter deals with the impact assessment study associated with the project. It helps to identify and assess the impacts prior to project development so that proper measures can be taken to reduce or mitigate the negative impacts of the project and enhance the project benefits.


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Source No.

Types of Likely Environmental Issues Construction

Phase Operation

Phase

14. Ecological impacts (marine)

15. Socio-economic

16. Health and safety

17. Fishing

18. Recreation and tourism

Note: Potential to cause concernUnlikely to cause any concern

4.2.2. Construction Phase

201. The environmental consequences during the construction phase of the proposed CANI submarine system cable landing at Santhome Beach are anticipated to be short-term, temporary, and minor. Onshore construction procedures include excavation of a trench using standard construction equipment. The land and sediment grade will return to pre-existing conditions within a relatively short timeframe following installation. All environmental conditions onshore and offshore that exist prior to construction are anticipated to return to pre-installation conditions with only minor, temporary impacts. Key environmental issues are described in the following sections;

4.2.2.1 Gaseous Emission and Odor

202. The sources of air emissions during the construction phase include emissions from the engine driven construction machinery and vehicular emissions, DG sets, earthworks (excavation, compacting activities, etc.), trenching, and mechanical / electrical installations. It is to be noted that construction of BMH and cable laying process on the Beach will take only 3 weeks. Nowhere there will be odor associated with the construction of BMH and cable laying process. As discussed in Chapter 3, the ambient air quality near the project site is well within the NAAQS, 2009 except level of PM110 at Kilpauk which is approx. 7 km away from site. There will be a slight change in the air quality due to the construction activity.

203. Sources of air pollution from ship include exhaust fumes from combustion of engines and the equipment used for the cable laying operation. All such ships and vessels are subjected to the national and international regulations on controlling emissions. As of now, there are no Indian regulations for emissions from the mobile sources; however International standards like MARPOL and IMO, and Marine Environment Protection Committee (MEPC) will be followed. The Protocol of 1997 (MARPOL Annex VI) sets the limits on Sulphur Oxide and Nitrogen Oxide emissions from the ship exhaust.

204. Since there is no major construction work involved and the whole process of BMH construction and the cable laying will take only 3 weeks, the impact related to gaseous emissions and odor is therefore considered to be “Low” and “Insignificant”.

4.2.2.2 Dust

205. Construction of the BMH and the cable laying process at Santhome Beach will generate dust. However, the construction will be small scale and no significant dust impacts will result. The dust control measures stipulated in


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the EMP will be applied during the construction phase to mitigate any impact due to dust. The impact due to dust is therefore considered to be “Low”.

4.2.2.3 Noise

206. During the construction of the BMH and cable laying process, noise will be generated because of the use of excavators. The construction work will be carried out during day time hours only. The excavators have a noise range of 75-85 dB(A). There is no significant noise source in the project area

207. Noise generated from the cable laying vessels and cable laying equipment during the submarine cable installation will be minimal, and therefore, no unacceptable noise impacts upon the nearby residential and commercial areas will result from this project. The noise impact associated with the project is considered to be “Medium”.

4.2.2.4 Liquid Effluent

208. The onshore construction activities will not generate any liquid effluent. However, there will be only sanitary wastewater generation from the ship used for cable laying operations.

209. The sanitary wastewater on the ship is generally from toilets, washrooms, galleys etc. The volume and quantity of such wastewater varies with the number of persons onboard. Sanitary wastewater will be treated and disposed off as per MARPOL guidelines within the ship and will not be discharged on beach or in coastal waters within 12 nauticle miles. Discharge of waste water will strictly be as per MARPOL guidelines only. Therefore, the anticipated impact will be “Negligible”.

4.2.2.5 Solid Waste

210. Solid wastes will include excavated soil, packaging material, scrap metal, vehicle/ equipment maintenance waste, etc. While soil will be re-utilized for the BMH (trench) construction, other waste will be segregated and stored at the site and will be recycled to the extent possible. There will be no impacts on the environment due to any waste material associated with the project.

211. Wastes generated from the ships are normally divided into two categories, i.e. non-hazardous waste and hazardous waste. The waste expected to be generated during the route survey and cable laying operations are given in Table 4.2.

Table 4.2 : Waste Generated during Cable Laying Operation

Waste Type Source of Generation Nature of Release

Non-hazardous Waste Domestic waste and general waste

Onboard general activities Intermittent; Non-recyclable biodegradable

Empty plastic containers of non-hazardous material etc.

Packaging material recyclable biodegradable

Paper, packing material, cables, steel, etc.

Packaging material Intermittent; recyclable biodegradable

Empty metal containers of non-hazardous material

Packaging material Intermittent; recyclable biodegradable

Hazardous Waste Clinical waste Medical treatment Intermittent; small quantity

Waste oil and sludge Fuel oil storage Intermittent;

Special waste (batteries and used filters)

Machinery Intermittent


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212. The non-hazardous waste will be segregated and collected in a designated

area within the ship or barge and will be disposed off as MARPOL guidelines. Any non-recyclable or re-usable non-hazardous waste will be transported to municipal landfills. Appropriate facilities will be provided in the ships and barge for storage and handling of hazardous waste generated during the construction phase. The hazardous waste will be disposed off as per the MARPOL guidelines. The impact associated with the project is therefore considered to be “low”

4.2.2.6 Geology and Sediments

213. The environmental impacts of constructing the cable network on the geology or sedimentary characteristics of the Bay of Bengal and along the proposed submarine corridor will be temporary and have no anticipated significant impact over the lifetime of the project. The cable material is composed of inert materials that will not alter the geological or physical properties of the seafloor. Displacement of sediments within the route is only temporary, and sediments will settle immediately following installation.

214. No permanent or long-term impacts associated with the project are anticipated that will affect the quality of sediments, including texture or other chemical characteristics. For the excavation of the underwater trench near the seashore, a seawater jetting system will be adopted. The seabed materials are moved to form the trench during the jetting operation, which naturally will re-form and “backfill” the trench after the burial has passed. Therefore, there is no material excavated and be removed from the site.

215. During the plough burial, the seabed sediments will be disturbed and a small percentage will be lost to suspension in the lower part of the water column in the immediate vicinity of the plough.

216. During cable laying, the seabed sediment will be released at the bottom of the water column, resulting in a highly localized suspended sediment concentration and high settling velocities. At high concentrations and within a localized area, suspended sediment tends to form large aggregations of sediment particles (i.e., flocculation) that have a higher settling velocity than the individual sediment particles. It is expected that the suspended sediments will remain within 1 m of the seabed, which is independent of water depth. The current velocities at the seabed are lower than those near the water surface due to effects such as bottom friction.

217. Therefore, impact on the geology and sediments due to the project is

considered to be “Low” and “Negligible.”

4.2.2.7 Water Quality

218. The impacts to the quality of the water resources within the Bay of Bengal should be minimal and temporary. No long-term, permanent, or significant impacts on chemical or physical characteristics or the quantity of available water resource within the project area are anticipated.

219. During the ploughing of the submarine section of the cable, impacts to water quality from ploughing of submarine section of cable will be in the form of seabed sediments suspended in the water column, which will form a dense cloud in the immediate vicinity of the cable laying operations and, due to the


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high concentrations and the close proximity of the release to the seabed, would settle back onto the seabed rapidly. For this project, the surrounding seawater will be used for the jetting system.

220. Other sources of water quality impacts during the land-based activities primarily relate to surface water run-off and discharge of pumped water, if any. The following measures will be incorporated to prevent any adverse impacts:

• Surface run-off from the construction site will be directed into storm drains via adequately designed sand/silt removal facilities;

• Any water pumped from the excavated trenches will pass through silt-removal facilities prior to discharge to storm drains;

• Silt removal facilities, channels, and manholes will be maintained regularly at the onset of and after each rainstorm; and

• Stockpiles of material will be covered with tarpaulin or a similar fabric.

221. Based on the discussion above, impacts on water quality during the onshore

construction phase are therefore rated as “Low” and “Negligible.”

4.2.2.8 Marine Ecology

222. It is not expected that the proposed site construction will cause any significant impacts on marine ecology. The potential impact on marine ecology from cable installation are as follows:

• Direct physical damage to flora and fauna from grappling, ploughing, cable movement, anchoring and seabed disturbance by vessels;

• Excessive turbidity leading to depletion of dissolved oxygen levels; and

• Asphyxiation of organisms with displaced sediment.

223. Direct impacts on marine ecology include damage to coral reefs, sea grasses and associated marine life. However, there are no sensitive coral reefs and other sensitive receptors along the planned cable RoW in 12 nauticle mile from beach edge. The turbidity effects during project installation phase are also short-lived. Furthermore, native species in near shore environments are capable of adapting such short period elevated high turbidity. The baseline cable route survey did not encounter any sensitive species.

224. In general, the project works are likely to cause a few potential adverse effects which persist for a short duration. The impacts are rated to be “Negligible” to “Low” since there are no sensitive habitats along the cable route.

4.2.2.9 Terrestrial Ecology

225. No endangered and threatened species have been identified in the study area.

4.2.2.10 Fishing Activities

226. Fishing and cables can potentially interact during the installation phase and sometimes after the cable is deployed. During the cable installation, there is a risk of mutual obstruction both by vessels and by towed equipment, consisting of nets trawls and lines deployed by fishermen and survey equipment grapnels or cables by cable installers. Fishing activities of one


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sort or another will be most intense on the Continental Shelf. There may be trawlers operating throughout the area. Fishing with drift nets can be expected.

227. Since the cable laying operations are carried out for relatively shorter periods, the impacts are considered to be “Negligible”.

4.2.2.11 Anchoring Activities

At Chennai the existing anchorages are well north of the proposed landfall did not indicate that anchoring takes place near the route, thus impacts are considered to be “Negligible”.

4.2.2.12 Shipping Activities

228. Both cable route survey and cable installation can cause temporary disruptions to shipping traffic flow. However, these operations are of short duration and can generally be accommodated without significant disturbance to normal shipping activities.

229. Generally, all marine activities should be notified to the nearest port in the area, so that vessels can be warned in advance of the ongoing operations. When operating within Port limits or close to navigational channels, “Notices to Mariners” will be issued in coordination with concerned agencies. Historic data on subject did not reveal and indicate any adverse impact on shipping due to cable installation and maintenance operations. Hence, the impact on shipping can be classified as “Negligible”.

4.2.2.13 Recreation and Tourism

230. The cable will terminate at Santhome Beach. The Beach is not used much for recreational activities and is mainly used by the local people. Hence, there will be “No” direct impacts on recreational use and tourism activities.

4.2.2.14 Cultural and Heritage Sites

231. There is Devi Karumari Amman Temple and another Temple which is under construction located approximately 200 meters from the BMH location. However, the proposed cable laying and construction will not cause any impact on these two Temples as they on other side of the road. Therefore, there will be “No” impacts to the cultural and heritage sites due to the project.

4.2.2.15 Oil and Gas Activity and Pipelines

232. No petroleum, water or gas pipeline is present within the entire cable route. However oil concession blocks are existing along the cable route but beyond 12 nauticle miles distance. These blocks are currently not productive and no major infrastructure for exploration is visible.

4.2.2.16 Existing Cables and Cable Faults

233. There are existing cables along the routes. Cables to be encountered within 12 nauticle miles distance includes SMW4 Seg1-07 and TIISCS. Cable faults are also reported in the project area due to various reasons like anchoring, cable industry, seismic activity, fishing etc.

234. Maps of recorded cable faults near the proposed CANI routes are presented in Figure 4.2 below. The seismic and morphological faults are typically chafe faults, caused by sediment movements caused by earthquakes or by cable strum in areas of irregular seabed and strong bottom currents.


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Figure 4.2 Detail of Cable faults in vicinity of Chennai landfall

235. Historic data on subject did not reveal and indicate any adverse impact on shipping due to cable installation and maintenance operations. Also, as per DTS report, proposed landfall did not indicate that anchoring takes place near the route. So, impact on proposed cable installation is not significant.

4.2.2.17 Military Exercise Areas

236. Firing Practise area exists off the Chennai landfall. There is a probability of presence of buried UXO in these areas which may be encountered during the cable laying process. Thus it is essential permission should be taken from such military exercise areas prior cable laying

4.2.2.18 Electro-magnetic Fields

237. Electromagnetic fields are generated by operational transmission cables. Electric fields increase in strength as voltage increases. In addition, induced electric fields are generated by the interaction between the magnetic field around a submarine cable and the ambient saltwater. Magnetic fields are generated by the flow of current and increase in strength as current increases. During AC electroding the intensity of the magnetic field in the near vicinity of cable has been reported as approximately 0.1µT which varies inversely with distance from the cable. This magnetic field is well below the background magnetic field produced by the earth. Additionally, scientific literature suggests that the electro sensory resolution ability of marine organisms able to detect alternating current induced fields appear to be limited to slowly alternating fields below 10Hz. Therefore marine organisms are not expected to be affected by the AC induced magnetic fields used for electroding (≈ 25Hz).


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4.2.2.19 Socio-economics

238. The construction and installation activities related to this project will cause temporary increase in income and employment in the surrounding area. There is no likelihood of any adverse impacts on community services, schools, housing, or other local services and facilities. Once completed, the proposed submarine cable could potentially create a small number of additional jobs.

4.2.3. Operational Stage

239. In an installed submarine cable system, normally the only three materials exposed to sea water and ocean floor are: Polyethylene, Blown Asphalt and Polypropylene yarn. The external protection of the cable comprises naturally occurring bitumen (asphalt) which adheres to the outer polypropylene roving to the armour wires. No form of additive to prevent bio-degradation or anti-fouling is used in the cable's outermost layers. The other cable components in contact with the sea are the galvanized steel armour wires and the polyethylene sheath, which also contain no additives harmful to marine life. These components when exposed to the sea environment will not cause any adverse impact.

240. Any repair or recovery work will be done with utmost care, not to disturb the seabed. The impacts above are found to be either “Negligible” or “Low” for the operational phase.

4.3. Impact Assessment and Proposed Mitigation

241. Detailed assessment of the anticipated impact was made to assess the significance of these impacts on environment. Suitable mitigation measures have been proposed accordingly and the significance of these impacts was re-analyzed after the proposed mitigation measures. The impact assessment of the project along with the proposed mitigation measures are tabulated in Table 4.3.


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Table 4.3 Impact Assessment of the Project with proposed Mitigations

S. No. Environmental Issues Receptors Significance without

mitigation measures

Mitigation Measures Significance with

mitigation measures

1. Gas Emissions and Odour (SO2, NOX, CO, PM10, PM2.5)

Human, Flora and Fauna

Low and

Insignificant

Onshore Activities

• Comply with National Ambient Air Quality Standards for residential, rural and other areas.

Offshore Activities

• Procure standard construction equipment and vehicles.

• Plan periodic maintenance schedules including engine tuning, filter cleaning, etc. for construction equipment and vehicle.

• Minimize idling time of fuel run heavy equipments by adequate planning of construction activity.

• Plan periodic maintenance schedules including engine tuning, filter cleaning etc for vessels.

• Comply with international standards.

• Cable laying vessel conforms to IMO/MARPOL standards in relation to prevention of air pollution (among others). Thus, under normal circumstances the vessel represents no risk as a source of air pollution.

Insignificant

2. Dust Human, Flora and Fauna

Low

Onshore Activities

• Stockpiles of excavated soil and loose construction material shall be less than 2 m height with a gradient of 2:1 to minimize the dust generation due to wind; and,

• Implementation of dust suppression methods (e.g. water spraying etc.) at dust prone areas;

Nil

3. Noise

Human and marine

Medium

Onshore Activities

• Comply with Ambient Air Quality Standards with respect to noise, 2009.

• Avoid night time operation on the Beach.

Low


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mitigation measures


mitigation measures

fauna • Use only well maintained equipment. Install suitable enclosures for high noise equipments, wherever required and feasible.

• Provide personal protection equipment (ear plugs or ear muffs) to all

workers operating in the vicinity of high noise generating machines.

• Monitor noise levels regularly to check compliance with the standards.

• The acoustic systems used in cable route survey sonar use very high

frequencies which do not affect the cetaceans.

Offshore Activities

• The cable laying vessel does not deploy high powered or low frequency seismic or sonar survey technology, and noise will be limited to that associated with engines and thrusters. However, there will be no significant addition to the level of background noise in the water column.

• Reducing the time for equipment use.

4. Liquid Effluents Marine Flora and Fauna

Negligible Offshore Activities

• Sanitary wastewater shall be managed as per MARPOL guidelines.

Nil

5. Solid Waste Human, Flora and Fauna

Low Onshore Activities

• The excavated soil generated during the construction of BMH and cable laying process will be reused for reinstatement.

• Construction debris generated during the BMH construction will be disposed off as per Municipal Corporation of Chennai (MCC) guidelines.

Offshore Activities

• The non-hazardous waste will be segregated and collected in a designated area within the ship and disposed off as per MARPOL guidelines.

• Any non-recyclable or re-usable non-hazardous waste will be transported to municipal landfills.

• Appropriate facilities will be provided in the ships and barge for storage

Nil


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mitigation measures


mitigation measures

and handling of hazardous waste generated during the construction phase which will be managed as per MARPOL guidelines.

6. Geology and Sediments

Marine flora and fauna

Low and

Negligible

Onshore Activities

• Sediments removed from sea bed (> 15 m) deep by plough burial will be in form of wedges that will be placed back as plough burial moves forward. Sediments dispersed will settle back due to the heavy ocean currents.

• Vessel dynamic positioning ability will enable vessel to hold station without use of anchors therefore no anchoring impacts on sea bed will occur due to vessel.

Low

7. Water Quality Marine flora and Fauna

Low and

Negligible

Onshore Activities

• Vessels operating during route survey and cable laying operation shall be equipped with spill response kit and comply with international maritime laws such as MARPOL.

• Discharge of waste or accidental discharge from the vessels will be prevented.

• Avoid burial operation in strong current water to minimize sediment disturbance.

• Debris retrieved during prelay grapnel run will be collected in vessel and will be disposed offshore as per prescribed standards.

Low

8. Marine Ecology Marine flora and fauna

Low and

Negligible

Onshore Activities

• Cable should not be laid on beach during turtle nesting period (Sep to Jan, 2018)

• Avoidance of ecologically important and sensitive areas during selection of final cable route. No such area however exists along the proposed cable route

• Haulting vessels in case any whale, shark or dolphins are sighted

• Monitoring will be undertaken to ensure marine ecology is not disturbed during cable laying process.

• Avoid burial operations in strong current water to minimize sediment

Low


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mitigation measures


mitigation measures

disturbance. • Cable laying vessel will comply with MARPOL guidelines.

• Speed of cable laying vessel will be restricted to a maximum of 6 knots. Thus there will be low collision risks to cetaceans as compared to fast moving large vessels.

• Cable to be used is resistant to coiling and thus low risks of marine animals to get entangled within cable.

• Competent and experienced crew members will be nominated so that they can observe marine species while performing the task. Also they can use their experience and review available literature to avoid sensitive zones and whale encounter zones.

• If any injury to whale or any other organism happen to occur, incident will be reported to competent authority

9. Fishing Activities Humans Negligible Offshore Activities

• The presence of fishing fixed nets will be investigated during the cable lay process near the landing site.

• Cable burial shall be carried out at most of the places to prevent any interference with fishing activity.

Nil

10. Shipping Activities Humans Negligible Offshore Activities

• All marine activities shall be notified to the nearest ports in the area, so that vessels can be warned in advance of the ongoing operations.

• When operating within Port limits or close to navigational channels, “Notice to Mariners” shall be issued in coordination with concerned agencies.

Nil


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4.4. Conclusion

1. A detailed impact analysis has been carried out to identify the impacts associated with the CANI Submarine Cable System and its effects on receptors. Accordingly, mitigation measures have been proposed to minimize the adverse impacts of the Project. As can be seen from the Tables and discussion above, the Project will not cause any adverse impact on the environment.


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5. ENVIRONMENT MANAGEMENT PLAN

5.1. Prelude

2. M/s Universal Service Obligation Fund (USOF) is implementing the CANI Submarine Cable System landing at Santhome Beach in Chennai (Tamil Nadu) through NEC, who has been contracted for the deployment of the undersea communication cable system. NEC shall be responsible for installing cable and repeaters and will also be responsible for project management, system design, commissioning and marine operations. NEC will also be responsible to ensure compliance of the EMP as applicable to them.

3. A properly prepared Environment Management Plan (EMP) helps in planning and monitoring of various environmental parameters in and around the project area and helps in identifying critical parameters for timely corrective actions. The aim of the EMP is to ensure that the various adverse impacts associated with the Project are properly mitigated; either by preventing the impacts or by mitigating those to reduce the effect to an acceptable level by adopting the most suitable techno-economic option. The EMP also ensures that the positive impacts associated with the Project are conserved and enhanced.

5.2. The EMP

4. An EMP consists of a set of mitigation, monitoring and institutional measures applicable to design, construction and operation (Post construction) stages. The major components of EMP are:

• Implementation of mitigation measures for mitigation of potentially adverse impacts

• Monitoring during project implementation and operation

• Integration of EMP with project planning and implementation framework

• Implementation schedule

5. The EMP has been designed considering regulatory and other requirements to ensure minimal disturbance to the baseline environmental conditions in the project area.

6. EMP for both construction and operation phase of the project is defined with respect to activities which may have an impact on the environment and society. The mitigation measures, as propos ed in Table 4.3, will be implemented by NEC EHS personnel and other technical staff and will be supervised by the implementation agency and USOF, DOT.

7. Additional best practices and management plan for various concern areas for onshore and offshore activities are defined in the Sections below.

This Chapter details out the management plan developed for ensuring the effective implementation of proposed mitigation measures and protection of environment during and after project implementation.


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5.2.1. Oil Pollution Management Plan

8. There may be incidents in the operation of a vessel whereby oil or oil and water mixtures can enter the sea and cause pollution. Oil leakage prevention will be ensured as per the MARPOL guidelines. No waste oil generation is anticipated during onshore activities.

5.2.2. Garbage Management Plan

9. Garbage management is the most important component of the EMP as it can impact air, water and soil environment and degrading the quality. Garbage management plan for both onboard and offshore (beach) has been addressed in the report. Onboard Garbage will be managed as per MARPOL guidelines.

10. Garbage Management Plan on Beach: Sand will be excavated for cable laying and BMH construction. However this sand will be filled back and remaining will be spread on the beach area. Small quantity of domestic waste may be generated as 8-10 personnel will be appointed for the Beach operations. Any domestic waste generated, however small quantity, will be properly collected and disposed off in the dustbin provided by Municipal Corporation Chennai, near Santhome Beach, Chennai. Most of the excavated sand will be re-filled and the remaining will be spread over the Beach. Any construction debris will be disposed off as per MC Chennai guidelines. Any cable cutting and packaging material remains will be disposed off as per Municipal Solid Waste (Management & Handling) Rules, 2000.

5.2.3. Sewage Management Plan

11. Sewage expected to be generated onboard will be managed as per MARPOL guidelines as the cable laying vessel to be used will comply with MARPOL.

5.2.4. Air Emissions Management Plan

12. Cable laying vessel will comply with MARPOL guidelines. Emissions expected to be generated from cable laying vessels will be within the specified limits as per MARPOL. Small quantity of dust and exhaust gases are expected to be generated from excavators. Excavators and jackhammers that will be used at the Project Site will carry PUC certificates and will only use low sulphur diesel as the fuel. The construction of BMH and the cable laying process will take approximately 3 weeks and thus the effect, if any, will be temporary and insignificant. Water will be sprinkled over excavated sand to suppress dust generation.

5.2.5. Noise Management Plan

13. During the marine operations, noise will be generated by engines, thrusters etc. Noise generated by these is negligible as compared to background noise of water column. Sonar technology is used for cable route survey using high frequency sound waves (above normal hearing range of marine animal), which will have no impact on marine organisms.

14. During the construction of BMH and cable laying process, noise will be generated by the operation of excavators. Excavators have a noise range of 75-85 dB(A). Excavators will be operated only for 1-2 days for construction of BMH (4 x 3 x 4 m). Ear plugs will be given to men at work. Offshore activities will be carried out during day time only.


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5.2.6. Bio-Diversity Management Plan

15. Undersea cable laying operation will have minimal and temporary impact on marine ecology. However, management plan for bio-diversity protection has been prepared. The details of which are listed below.

• The burial activity will take place away from areas with higher conservation value.

• There will be no discharge of liquid effluents and solid waste in marine waters.

• Speed of cable laying vessel will be restricted to a maximum of 10 knots which is very less as compared to large moving vessels. This low speed ensures low collision risks to cetaceans as compared to fast moving large vessels.

• Cable that will be used for the Project is resistant to coiling. This will ensure low risks of marine animals getting entangled within cable.

• Competent and experienced crew members will be nominated so that they can observe marine species while performing the task. Also, they can use their experience and review available literature to avoid sensitive zones and whale encounter zones.

• Standard speed and specific route will only be followed during the cable laying process.

• Burial depth at sea bed will not exceed 1 meter except at some locations having risks of fishing and anchoring. Sediments will be removed as wedges by plough burial causing minimum disturbance to habitat of micro flora dwelling within seabed. These wedges will be placed back as soon as the plough burial moves forward. This will lower the chances of disturbance to habitat of benthos and bottom dwellers.

• There is no external electric field associated with the cable. Polyethylene is the outer covering of the cable and it serves as an excellent insulator. Concentric rings of very low magnetic field are set up around the cable, due to presence of internal conductor, but its strength diminishes with the distance. This can be experienced within less than half inch of distance from cable.

16. Due to sandy nature of Beach, no vegetation is found on the Beach. Excavation of sand may disturb the inhabiting micro flora and fauna residing in sand on Beach. Sand will be excavated, with utmost care to ensure zero mortality of any species. Sand removed will be filled back immediately after cable laying and termination operation. Floral and faunal life will be restored back very shortly as the cable laying process on Beach will take only 3 weeks.

5.3. Occupational Health and Safety Management Plan

17. Health and Safety Management Plan has been drafted for both the employees and visitors at the Project Site. Health and safety plan defines the roles and responsibilities of the participants of EHS cell.

18. Roles and Responsibility of Departmental Manager (Marine): The Departmental Manager (Marine) is responsible for establishment of safe working practices are established and compliance with the health and safety legislation for the Marine off-site operations. During Marine operations, the


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shipboard Project Manager will be responsible for ensuring the health and safety of the NEC team on board, that the procedures and instructions on the vessel are followed and that all appropriate vessel, equipment and health and safety documentation is on-board and is most current.

19. Roles and Responsibilities of Site Directors are: The roles and responsibilities of the Site Directors are listed below:

1. For maintaining the site in safe condition by implementing following controls

• Safe systems of Work: Maintenance of plant permit to work systems

• Statutory Testing of all the construction machinery and equipment

• Fire Precaution: Examination/testing of all equipment

• Environmental Controls: Temperature, dust, lightning, noise, ventilation, pollution and cleanliness

• Machine Guarding: To comply with legislation

• Electricity: Safe installation and usage

• Safety of Visitors: Warning signs, risk area identification and display

2. Ensuring no health and safety risk are introduced onto the site through their activities and all of their contractors’ activities are covered by risk assessment and method statement.

3. Providing Competent Authorized persons for all relevant pieces of legislation.

4. Ensuring that all personnel are formally informed, trained and accept their Health and Safety responsibilities.

5. Ensuring that safe methods of working and risk assessments are established and maintained.

6. Providing sufficient competent resources to establish and maintain an effective EHS management system and ensure its continual improvement.

7. Implementing the EHS policy. 8. Providing EHS representatives and committees.

20. Roles and Responsibility of Employee and Sub Contractors :All

employee and temporary workers/contactors are responsible for: 1. Working safely and efficiently, by using protective equipment provided

and by meeting statutory requirements. 2. Adhering to health and safety procedure and rules for securing a safe

work place. 3. Raising EHS issue to their supervisor or to an appointed

representative. 4. Co-operating in the investigation of accidents to aid prevention of a

recurrence

5.4. Emergency Preparedness Plan

21. Project involves deployment of cable on the seabed and construction of BMH on the Beach. Both the operations have certain risks involved, which can be either natural such as cyclone, tsunami, earthquake, shark attack etc or man-made disasters such as failure of construction machinery or equipment, slip and fall etc.

22. First aid process is implemented by NEC as a statutory requirement covering provision of trained personnel and first aid facilities. An on-site emergency


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plan has been prepared which defines plans and processes for responding to and recovering from emergency situations (major incidents or minor localised incidents). On-site emergency preparedness plan for the project is attached as Annexure IV.

5.5. Institutional Framework:

23. Roles and Responsibilities: The EMP will be implemented by the Universal Service Obligation Fund (USOF) with technical manpower and best EHS practice support from NEC. One official will be designated from Universal Service Obligation Fund (USOF) to ensure effective implementation of EMP and maintain. NEC will also depute trained EHS professionals to ensure effective implementation of the proposed mitigation measures during the construction phase of the project

24. Time Frame: The construction of BMH and the complete cable laying process will take approximately three weeks of time.

25. Environmental Monitoring: During the construction phase, monitoring will be carried out for noise and air emissions, as required. In addition to that, NEC designated officer will monitor and ensure adherence to NEC operation procedures and proposed management plans. No environmental monitoring is proposed during operation (post construction stage). Monitoring reports will be submitted as per regulatory requirements and internal procedures of the Universal Service Obligation Fund (USOF) and NEC.

26. Environmental Budget: No separate capital investment is required since all mitigation measures are related either to the design and constructions stage or monitoring during various stages of its implementation. Required money for ensuring implementation of mitigation measures and adherence to EMP will be part of construction budget and thus requisite money will be available for implementation of the EMP.

27. Grievance Redress Mechanism: Any complaint or suggestion received from the interested parties will be analyzed by designated EHS site officer of NEC. He will intimate the Project Proponent for the corrective and preventive action required to be taken, if any.


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6. SUMMARY AND CONCLUSION

6.1. Summary

6.1.1. Beach Installation

28. The BMH is located at Santhome Beach, Chennai opposite to Faith Fullgospel church. This stretch of Beach is not used for recreation. Beach operation including construction of BMH and cable route and termination of cable will take 3 weeks. After installation, Beach will be restored to its original state. Impacts due to air pollution, liquid effluent and solid waste generation are low and insignificant. Also, there is no significant impact anticipated on terrestrial ecology, water quality and socio-economic conditions. The only medium impact associated with the project will be there due to noise generation.

6.1.2. Marine Installation

29. The disturbance caused by cable laying operation can be assessed in two ways: 1) very short duration (i.e., hours to 1 day) in which sediment settles and fishes return and 2) longer duration (i.e., months to years) in which the benthos re-colonizes the cable path. The impacts associated with the construction and installation of the fiber optic cable are site-specific and of a short duration (i.e., hours to a days). The predicted impacts are, therefore, low and not significant. On the whole, the impacts would not substantially affect the maintenance and enhancement of long-term biological productivity or pose long-term risks to health or safety of the area.

30. Impacts due to air pollution, odor, liquid effluent and solid waste generation are low and can be easily mitigated by the mitigation measures suggested in EMP. Also, there is medium impact anticipated on marine ecology, water quality, fishing and shipping activities, which are reversible in nature and can be mitigated easily by the mitigation measures as suggested in EMP.

6.1.3. Associated Risks

31. Risk is minimal to the populace over the life of the system. The cable itself is protected through varying means along the length of the route onshore and offshore. If standard safety and construction techniques are followed in the vicinity of the cable, such as notification prior to operations and marking of the cable route, risk of damage to the cable and electrocution is mitigated. Based on the lack of electrical field and the minimal magnetic field, there is little to no known effect on the marine population.

6.1.4. Conclusion

32. The impact assessment has demonstrated that the impacts likely to be generated in the cable-laying operation in deep offshore water will be minimal. No impacts are expected on fisheries or shipping activities provided normal international marine activity procedures are followed.

33. Based on the EIA, it is clear that the CANI submarine cable system has low and insignificant impacts on the environment. The activities of installation also are of short duration. During the operation phase, there is no adverse impact associated with the cable laid. Thus, it can be concluded that the project will not significantly impact the environment. The mitigation measures mentioned in the report need to be taken to tackle any associated impact during the installation phase of the cable to prevent any environmental damage.