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Environmental
Impact Assessment for
Proposed Sethusamudram Ship Channel Project
by
National
Environmental Engineering Research Institute
Nehru
Marg, Nagpur - 440 020
August
2004
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Detailed Version
Executive
Summary
Top
Introduction
India
does not have, within her own territorial waters, a continuous
navigable route around the peninsula due to the presence of a
shallow (1.5 to 3.5 m depth) ridge called ‘Adam’s Bridge’
between Pamban island on south-eastern coast of India and
Talaimannar of Sri Lanka. While Rameshwaram is a major pilgrim
centre on Pamban island, the tip of the island is marked by
Arimunai. Consequently, the ships calling at ports on the east
coast of India have to go around Sri Lanka entailing an additional
distance of about 254-424 nautical miles and about 21-36 hours of
ship time.
The
Sethusamudram Ship Channel Project under the consideration of the
Ministry of Shipping, Government of India, envisages creation of a
ship navigation channel to suit different draughts (9.15 m, 10.7 m
and 12.8m) through dredging/excavation in Adam’s Bridge, parts
of Palk Bay and Palk Strait. The navigation route will originate
from the Tuticorin new harbour in the Gulf of Mannar (GOM) using
available navigation depths (> 20 m) up to south east of Pamban
Island, pass through a channel created in Adams Bridge within the
International boundary and proceed parallel to the International
Medial Line for fishing rights as the Bengal Channel. In Palk Bay
area availability of depths in middle channel, capital dredging
across Adams Bridge and in Palk Strait and continuous maintenance
dredging along the proposed transit are the critical project
related issues.
The
routes selected through earlier studies particularly in Gulf of
Mannar area have been rejected, keeping in view sensitivity along
the coastal stretch of GOM harbouring marine national park.
Instead a navigation route keeping a minimum 6-8 km distance from
Van Tiu near Tuticorin and more than 20 km from Shingle in Adams
Bridge approach area has been suggested.
Tuticorin
Port Trust (TPT), the nodal agency identified by Ministry of
Shipping, Govt. of India for the implementation of the project in
pursuance of its decision to incorporate environmental
considerations in the design phase of the project, retained, in
March 2002, National Environmental Engineering Research Institute
(NEERI) to conduct the Environmental Impact Assessment (EIA) study
for the project.
This
report presents briefly the project setting, describes the
baseline environmental status of the project area, identifies
environmental issues, predicts and evaluates impacts due to the
proposed project and delineates environmental management plan to
mitigate potential adverse impacts.
The
EIA study has primarily drawn upon the available information on
the proposed project, the hydrography, marine water quality and
ecological resources in the project area, and the primary data
generated during the course of study. This environmental impact
assessment study with intensive data collection has resulted into
fuller description and appreciation of the natural processes
occurring in the study area, and delineates the environmental
consequences including the ecological risk associated with the
proposed project with or without proper environmental management
plan.
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Project
The
proposed Sethusamudram ship channel will have two legs, one near
the Point Calimere called the Bay of Bengal Channel and the other
across the Adams Bridge. The Bay of Bengal Channel traverses the
Palk Bay wherein the sea-bed is mostly soft to hard clayey-sand in
nature. Some hard strata has been reported beneth the soft sand
during recent survey by the National Hydrographic Office, Dehradun.
The area adjoining Adma’s Bridge, Dhanushkody Peninsula on the
North and the South is reported to be sandy by National Ship
Design Research Centre (NSDRC), Visakhapatnam during their survey
in connection with this project.
While
navigational depths will be used in Gulf of Mannar from Tuticorin
Port to Adam’s Bridge area, a 20 km long, 300 m wide channel
with 10.7 m draught with two way controlled traffic is proposed to
be created as ultimate phase by dredging shallow area of Adam’s
Bridge upto 12 m depth. Similar excavation will be done in Palk
Strait and adjoining parts of Palk Bay to achieve the required
depth over a stretch of around 36 km and 18 km respectively. A
control station, administrative building and Vessel Traffic
Management System (VTMS) is proposed to be located at Rameswaram
island between Dhanushkodi and Koil Nagar village to control
navigation, besides other infrastructure including administrative
requirements.
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Environmental
Regulations
At
the National level, the environmental clearance to the project is
subject to compliance with the stipulated safeguards under the
provisions of Environment (Protection) Act, 1986; Forest
(Conservation) Act, 1980; The Water (Prevention and Control of
Pollution) Act, 1974; The Water (Prevention and Control of
Pollution) Rules, 1975; The Water (Prevention and Control
Pollution) Cess Act, 1977. The Water (Prevention and Control of
Pollution) Act, 1981; and other rules and regulations in force.
Land use on the coastline will be subject to regulation as per the
Coastal Regulation Zone (CRZ) Notification issued by the Ministry
of Environment and Forests (MoEF), Government of India in 1991 and
subsequent amendments under the Environmental Protection Act. This
notification is administered by the State Department of
Environment and Forests.
The
Wildlife (Protection) Act of India (1972) provides legal
protection to many marine animals including reef associated
organisms. Chapter IV of this Act dealing with Sanctuaries,
National Parks etc. is equally applicable to marine reserves,
marine national parks and biosphere reserves.
The
Gulf of Mannar Marine Biosphere Reserve (GOMMBR) has been notified
in 1989 through an executive communication from the Secretary to
the Government of India, Ministry of Environment and Forests to
the Chief Secretary, Government of Tamil Nadu.
During
the operational phase of the project, the most important
instrument to be complied relates to the International Convention
for the Prevention of Pollution from Ships 1973 as modified by the
Protocol of 1978 (MARPOL 73/78) for which India is a signatory.
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Key
Findings
Environmental
Status
Marine
Environment
The
Palk Bay and the Gulf of Mannar covering an area of 10,500 sq. km
in which the proposed ship channel is to be created are
biologically rich and rated among the highly productive seas of
the world. Its diversity is considered globally significant. In
the Gulf of Mannar, between the coast line and the proposed
alignment, there are 21 islands which have been declared as
National Marine Parks by the Tamil Nadu Forest Department and the
MoEF, Government of India. While the proposed channel alignment in
the Tuticorin Port area shall be about 6 km from Van Tiu the
nearest island, in Adam’s Bridge area it will be about 20 km
from Shingle Island which is a part of National Marine Park.
The
data on physico-chemical characteristics and marine biological
resources was collected from various sampling stations in Gulf of
Mannar and Palk Bay. Primary data on physico-chemical
characteristics of marine water shows no significant variation in
alkalinity (102-106 mg/l) and pH (8.0-8.2) along the proposed
channel alignment. The DO values varied from 3.2 to 5.7 mg/l and
the silicates from 0.003 mg/l to 0.017 mg/l. No significant
variation in salinity is observed between surface and bottom
samples. An inverse relationship between salinity and silicates
has been observed. The nitrate concentrations vary from 0.78 mg/l
to 1.1 mg/l. Data from secondary sources in coastal areas of Palk
Bay near Palk strait shows pH ~ 8.2, D.O. 5.8-6.5 mg/l and Total
nitrogen content of 0.4 mg/l.
Sediment
samples collected along the proposed channel alignment show the
presence of organic carbon, total nitrogen, total phosphorous and
sulphates in concentrations adequate for biological growth. Almost
all the sediment samples show presence of oil & grease. The
concentrations of heavy metals are high in some of the sediments
in the Palk Bay as compared to other locations.
Biological
Resources
The
gross primary productivity along the proposed channel alignment
vary from 142 to 472 mgC/m3/day indicating that the
Gulf of Mannar and the Palk Bay are biologically productive
regions. The zooplankton are dominated by copepod. Macrobenthos
represented by 78 varieties exhibit fairly good diversity. The
meiofauna comprised larval polychaetes, nematodes and worms.
The
corals along the proposed channel alignment in Adam’s Bridge do
not exist though major groups of biological resources like sea
fan, sponges, pearl oysters, chanks and holothuroids at various
sampling points have been recorded. In general, the density of
economically/ecologically important species along the proposed
alignment is not significant.
All
the three groups of prochordata organisms, considered as the
connecting link between invertebrates and vertebrates, viz.,
hemichordata, cephalochordata and urochordata comprising 1, 6 and
59 species respectively have been recorded around the islands of
the Gulf of Mannar.
There
are 87 fish landing stations between the south of Point Calimere
and Pumban in the Palk Bay, and 40 stations in the Gulf of Mannar
between Pamban and Tuticorin. Out of over 600 varieties of fishes
recorded in this area, 200 are commercially important. During
1992-1996, the fish production has increased gradually from 55,325
tonnes in 1992 to 2,05,700 tonnes in 2001.
Biodiversity
Non-conventional
fishing in the region is represented by pearl, chank, sea weeds,
ornamental shells and holothurians. There has been a declining
trend in the production of these organisms as evidenced by the
revenue received by MPEDA.
Rare
and endangered species of sea turtle, dolphin, sea cow and whale
are recorded in the Gulf of Mannar and the Palk Bay. The sea cow
inhabitates the shallow shore regions where grasses occur, while
other endangered animals mostly prefer deep sea.
Several
species of green algae (32), brown algae (35), red algae (59),
blue green algae (3) and sea grasses are recorded in the Gulf of
Mannar and the Palk Bay. A few of the 21 islands are reported to
possess patches of mangroves predominated by Avicennia sp.
And Rhizophora sp.
Most
of the habitats of the sensitive biota, viz., corals, pearl
oysters, chanks, sea cow, holothuroids and marine algae are along
the coast and around the 21 islands, and mostly away from the
proposed canal alignment.
Point
calimore wild life sanctuary sprawling over 17.26 sq. km. Area
comprising tidal swamp, dry evergreen forests and mangroves is
located in coastal areas of Palk strait in Nagapattinam District.
The sanctuary is bestowed with population of varied wildlife such
as Chital, Wild Bear, Bannet, Macaque, Black Buck, Flamingoes,
Teals, Gulls Tems, Plovers and Stilts, Dolphins and Turtles are
seen close to shore area.
Land
Environment
Based
on an analysis and interpretation of IRS IC LISS-III satellite
data, merged with PAN data, degraded area in Pamban island has
been delineated for anticipated disposal of dredged material to
the extent possible with prior approval under CRZ regulations. A
large stretch about 753 hectare, of such land between Rameshwaram
and Dhanushkody is available.
There
are no archaeologically significant structures along the proposed
channel alignment. However, there are apprehensions of
encountering cultural/ archaeological artifacts during the
excavation of the channel though borehole data generated by the
National Ship Design Research Centre (NSDRC) does not support such
a situation.
Socio-economic Environment
Along
the coast in the Gulf of Mannar and the Palk Bay there are 138
villages and towns belonging to 5 districts. The socio-economic
profile of the fishermen in the villages of Gulf of Mannar coast is low, and more
than 40% of families are in debt. The local people are of concern
that the creation of channel would result in the reduction of
their income due to fishery.
Oceanographic
Status
The
hydrodynamic studies of the seabed in Adam’s Bridge and its
adjoining area have been carried out in May 2003 and February 2004
by retaining the services of National Ship Design Research Centre
(NSRDC), Vishakhapatnam. The hydrographic charts bearing nos.
1584, 1586, 1587, 2069, 2197 and 96 have been referred while
conducting the surveys.
There
are two circulations of water masses observed in the Bay of
Bengal, the clockwise circulation in south-west monsoon and the
counter clockwise circulation in the north-east monsoon. The tidal
variations are between 0.05 to 0.7 m. The current velocities in
the Palk Bay and the Gulf of Mannar are as mild as 0.2 - 0.4 m/s
except on few days during south-west monsoon when it rises upto
0.7 m/s. Water currents follow the directions of predominant
winds. The analysis of current data shows no potential threats to
siltation of channel. It is observed that during southwest monsoon
the sediments move from Gulf of Mannar to Palk Bay and during fair
weather the direction reverses. In annual cycle, a net exchange of
6000 m3 of sediment is found to move from Palk Bay to
Gulf of Mannar through Pamban pass and 25000 m3 of
sediment moves from Gulf of Mannar to Palk Bay through Arimunai.
Geological
strata in Adam’s Bridge area shows soft and hard sand upto 12 m
with particle size varying from 65 to 600 mm.
The bathymetry varies from 0.6 to 6.3 m. Depth in Palk strait
averages to about 8 m.
The
hydrographic survey of Palk Bay and Palk strait area has been
carried out during Jan. 25 - Feb. 18, 2004 by the Naval
Hydrographic Department of National Hydrographic Office (NHO).
According to the findings of NHO, the seabed in this region
comprises of sand and mud with few broken shells. The depth
contours in the sea are in agreement with those depicted on the
existing navigational chart no. 358. While navigable depth (more
than 12 m) will be used in about 78 km stretch in Palk Bay, a
sizable stretch (about 54 km) will require to be dredged in Palk
Strait and adjoining area. Sub bottom profile studies indicate that
though the upper layer of sediment is made up of mud and sand,
there is some hard strata under the soft sediment. This hard
strata if discovered to be rock, if would require blasting at the
time of dredging to achieve the desired draught.
The
tides in the area are not similar. Both semi-diurnal and diurnal
tides are observed at the tidal station set up. The range of
spring tides vary between 0.4 to 0.7 m. The current in the area is
N-S direction with speeds varying from 0.08 to 0.8 m/s and may
reach 1.8 m/s (4 kt) in spring. No wrecks and obstruction have
been observed during the survey.
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Impacts
due to the Project
Impacts
on Landbased Facilities
The
project envisages construction of shore facilities to cater the
needs of channel in Adam’s Bridge area, viz. service jetties,
slipways, buoy yard, repair workshop as also staff and
administration buildings for facilitating regulated traffic in the
vicinity of Adam’s bridge area. The locations of land-based
structures, and the extent of area required for their construction
is required to be identified on Pamban island in consultation with
local authorities. Most of the land east of Rameshwaram is barren
and covered by sand and scant vegetation. There are few hamlets at
Arimunai and Dhanushkodi who are engaged
in fishing. These fisherman will be displaced in the event the
land based facilities are planned in this area. Temporary
displacement of these fisherman is envisaged. A BSF check post
will also be temporarily affected. Land
on Pamban island has also been identified for disposal of dredged
material (silt / clay / sand). The land cover, landuse as also the
ownership of sites required for the project related activities
will be firmed up once the modus-operendi of traffic regulation in
channel is finalized. Hence, the extent of land acquisition, the
need for resettlement and rehabilitation of affected population,
if any, can not be assessed at this juncture. However, given the
fact that channel will cut across the Adam’s Bridge area, the
impacts on land based facilities would be negligible in comparison
to that envisaged in earlier studies where land locked canal
cutting through Pamban Island was proposed.
During
the construction of the ship channel, it is anticipated that
considerable sea-borne activity in the form of logistic and
support services would take place. This would have significant
adverse impact on the traditional fishing activities by the
licensed fisher folk and consequently on their income levels.
Impacts
on Productivity and Ecology in GOM/Palk Bay
As
the proposed alignment in Gulf of Mannar is more than 20 km away
from the existing 21 islands in National Marine Parks in the Gulf
of Mannar, the marine biological resources around these islands
will not be affected to any significant level.
The
existing level of primary productivity in the project area will
remain practically unaltered during the construction and operation
phases of the channel. There would not be any significant change
in water quality including turbidity due to the proposed
deployment of cutter suction/trailor suction hopper dredgers for
capital and maintenance dredging.
Due
to dredging the bottom flora and fauna on an area about 6 sq. km
along the channel alignment in Adams Bridge and about 16-17 sq.km
in Palk Bay/Palk Strait area will be lost permanently. This loss,
however, will be very insignificant compared to the total area of
10,500 sq. km of the Gulf of Mannar Marine Biosphere Reserve.
In
Adam’s Bridge area about 38 million m3 of dredge
spoil comprising about 7-8 million m3 clay silt will be
generated for achieving 12 m depth for 300 m wide channel
including allowances for slope and tolerance. It is proposed that
spoil containing a mixture of clay and sand will be disposed on
degraded areas of Pamban island for reclaiming the land subject to
approval of Forest and Environment Department (TN) for use of area
falling under CRZ as dumping of wastes in CRZ area is not
permissible activity. Balance 30 million m3 spoil
containing mainly sand (particle size 125 mm
to 600 mm)
will be discharged in sea 25 km away from the dredging area
keeping safe distance from medial line at depths varying from
30-40 m to minimise the impact. In the event of restricting the
channel to 10 m depth to suit vessels with 9.15 m draught, the
quantity of dredged spoil will reduce by 13.5 million m3
and material required to be disposed in sea will be 16-17 million
m3 instead of 30 million m3 as envisaged for
12 m depth. This would further minimize impacts on sea bed due to
disposal of dredged spoil.
In
Palk Bay area, about 44 million m3 of dredged spoil
will be generated due to excavation activity in Palk strait and
Palk Bay to achieve 12 m depth for 300 m channel including
allowances for slope and tolerance. The NHO data indicate hard
strata beneth soft sand hence spoil may contain silt, sand and
hard material. The dredging may also require blasting if hard
strata is encountered. In the event of blasting, adverse impact on
sea bottom fauna is envisaged. The spoil is proposed to be
discharged in Bay of Bengal at suitable depth (25-40 m) to
minimize impacts on coastal areas of Palk Bay. An option of using
silt/clay for beach nourishment is also recommended. In the event
of restricting the channel depth to 10 m the requirement of
dredging in Palk Bay/Palk strait will drastically reduce to about
14.8 million m3 as against 44 million m3
envisaged for 12 m depth. This would minimize environmental
impacts as well cost of dredging and disposal.
It
would be ideal to explore the possibility of dredging the channel
to 10 m depth in first phase to cater to vessels of 9.15 m draught
and monitor environmental status during construction and operation
phases. The proposal of 12.0 m depth can subsequently be taken up
in second phase provided adverse impacts on environment are not
observed.
Hydrodynamic
modelling studies using Depth Integrated Velocity and Solute
Transport (DIVAST) model have shown that, even for the highest
spring tidal water conditions, there will be no significant change
in the magnitude and direction of current velocities along the
proposed alignment due to the construction of the channel in
Adam’s bridge area.
During
the construction and operation phases of the channel, the
potential sources of marine pollution are spillage of oil and
grease, marine litter, jetsam and floatsam including plastic bags,
discarded articles of human use from the sea-borne vessels which
will have to be controlled.
The
channel may facilitate the movement of fishes and other biota from
the Bay of Bengal to the Indian Ocean and vice versa. By this way,
the entry of
oceanic and alien species into the Palk Bay and the Gulf of Mannar,
as also the dispersal of endemic species outside the Palk Bay and
the Gulf of Mannar could occur.
Socio-economic
Impact
The
channel will establish a continuous navigable sea route around
peninsular coast within the Indian territorial waters, reduce
shipping distance by about 254-424 nautical miles and voyage time
of about 21-36 hrs as also the attendant operating costs. The
channel will become a valuable asset from national defence and
security point of view enabling easier and quicker access between
the coasts.
Due
to the construction of infrastructure in the island, the land
access, now available to the local fisher folk to Dhanushkody area
for traditional fishing will be hindered unless alternative
arrangements are made. The dredging and shipping operations will
have to be so regulated as to cause minimum disturbance to the
normal fishing activities.
The
project will provide employment opportunities and avenues of
additional income through establishment of small ancillary
industries. The project will also trigger development of coastal
trade between the ports south and north of Rameswaram
consequently reducing the load and congestion on railways and
roadways.
The
project will help in saving considerable foreign exchange through
reduction in oil import bill and generate revenue income from dues
levied on ships transiting the channel which will add to the
national economy.
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Environmental
Management Plan
Construction
Phase
-
No dredging will be done in Gulf of Mannar except in Adam’s
Bridge area
-
Alignment of navigation route at Adam’s Bridge in Gulf of
Mannar will be minimum 20 km away from marine national park
-
Land
acquired for mobilization and monitoring of activity will be
returned to users after completion of dredging activity
-
A proper rehabilitation plan for the fisherman at Dhanushkody
will be drawn during construction phase
-
Dredged spoil comprising clay and sand upto 2 m of dredging
depth will be used for reclaiming degraded land in
Pamban island subject to approval of FED for CRZ. Balance
dredged spoil will be disposed in sea at a depth 30-40 m,
20-25 km away from islands in National Marine Park in Gulf of
Mannar. Dredged spoil generated in Palk Strait / Palk Bay area
will be disposed in open sea in Bay of Bengal at
25-40 m depth, 30-60 km away from dredging area
-
Safe distance (about 4 km) from international medial line will
be maintained
-
During
dredging activities, the equipments, vessels, barges required
for dredging and transportation of dredged spoil will be
maintained in secured area and spillage of oil or any toxic
material including paints, anticorrosive agents etc. will not
be allowed to spill in sea/coastal waters
-
Movement
of barges for transporting dredged spoil to land area will not
interfere with movement of fishing boats in both Gulf of
Mannar and Palk Bay region adjoining the Adam’s Bridge
-
It
is also recommended that existing jetties at Rameswaram which
only cater to fishing activities presently should be augmented
to cater to the requirement of handling dredging activities in
Adam Bridge and Palk Bay area
-
Transportation
of heavy machinery and construction material in the vicinity
of Adam's Bridge will be by sea route using the available
navigational depths
-
During
transportation of heavy equipments and machinery by road, care
will be taken to avoid traffic hazard, traffic congestion and
if required roads will be augmented to meet the conditions of
hazard free transportation.
Operational
Phase
-
All
the ships originating from Tutitcorin Port will comply to
International Maritime Standards and follow MARPOL convention
(MARPOL 73/78)
-
Discharge
of bilge, ballast, treated sewage, solid wastes, oily wastes
and spillage of cargo will not be allowed in the Gulf of
Mannar and Palk Bay area
-
The
traffic of crude oil tankers will be allowed in this route
with strict vigilance so as to avoid any possibilities of
spillage in this region
-
It
will be ensured that ships navigating in this region should
not use such paints and anticorrosive agents on ship bottom
which can cause damage to marine organisms
-
A
pilot should be trained or environmental watcher will board
the ship to watch marine animals viz. turtle, dolphins, sea
cow etc. in the region and navigate the ship safely avoiding
any damage to this fauna.
-
It
will be ensured that all the ships berthing at TPT as well as
all those using the route without touching TPT will have
proper treatment facilities for sewage however discharge of
treated sewage will not be permitted in GOM and Palk Bay /
Palk strait area
-
Ships
bypassing TPT and transiting the channel will be inspected for
its navigational safety measures before it is allowed to enter
proposed navigation route
-
An
oil spill contingency plan will be drawn by Tuticorin Port
Trust with preparedness to prevent spread of spillage in Gulf
of Mannar and Palk Bay area and its immediate recovery by
deploying equipments and ships
-
To
benefit large fishing communities in the coastal area of
Ramnathpuram and Rameshwaram, a corridor both in terms of
space and time be provided to fisherman to use the channel in
Adam’s Bridge area for moving across Palk Bay to GOM and
vice versa for fishing activity
-
The
jetties at Rameswaram are in dilapidated conditions. A
programme to construct a few Jetties at Pamban island to
augment fishing activity in the region be supported by TPT
-
The
traffic of ships carrying crude oil will be handled with
strict vigilance so as to avoid possibility of spillage
-
The
oil spill contingency plan in operation at TPT will be
extended to navigation activities in new channel
-
A
pilot will board the vessel either from Rameswaram or
appropriate place to navigate ship through GOM area up to
Bengal Channel in Palk Bay
-
The
channel will be properly marked by navigational light buoys
-
Accidents
by collision of ships with fishing boats will be totally
prevented by slowing down the cruise speed and also alerting
the fisherman by cautionary measures. During implementation
and operational phases of the project, TPT will take action to
avoid the collisions of ships with fishing boats or damage to
fishing nets with cooperation from fishing communities, Navy,
Coast Guards and other Govt. authorities
-
Suitable
timings apart from ship transit will be given for fishermen to
continue with their fishing activities
-
Maintenance
dredging of about 0.55 million m3 per year is
envisaged in the channel based on data available for sediment
transport across Palk Bay and Gulf of Mannar
-
The
dredged material will be mostly silt and clay and will not be
disposed in sea. Instead it will be used to reclaim degraded
areas on Pamban island, Ramnad and Mandapam coastal stretches
-
To cater to increase in trade envisaged due to this project
and to transfer benefit to local fisherman, a minor port
facility can be created at Rameswaram in consultation with
state authorities
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