Pollution in ports
Mr. Prashant Kokil, Chief Sustainability Officer, Mumbai Operations, The Tata Power Company Ltd., Mumbai
M. Sc. Inorganic Chemistry with specialization in Control and Analysis of Pollutants
Diploma in Administrative Management (DAM)
Advance Diploma in Industrial Safety
Functional Responsibilities:
Compliance to national and international Environmental Laws for all Tata Power locations.
Obtaining Environmental Clearances and Consents/ Permits for all the new and expansion projects.
Ports are major focal points of activity and a separate category of industry in itself. They are the hubs of transport related activities connecting waterways to mainland for various goods. A healthy port connectivity system is indicator of progress of a region and augers all round development. Like any other industry, ports also have its own contribution to environmental impacts and if not addressed can cause considerable environmental damage. Since this industry is operating in both terrestrial as well as marine ecosystem the likely environmental impacts on both need to be considered together. While the terrestrial ecosystem related impacts are well documented, studied and addressed, the marine ecosystem related impacts are relatively less stressed upon. This paper is an effort to converge and documents the likely impacts on both the ecosystem for coordinated efforts to minimize the negative impact of this industry.
KEYWORDS: Pollution; Ports; Ecosystem; Marine impacts; Landward Impacts.
1. INTRODUCTION
Port construction and operation involves various environmental impacts. They are segregated and listed in phase-wise manner below:
2. CONSTRUCTION PHASE IMPACTS:
During construction phase, the impacts are on landward side as well as on waterfront side.
Construction related impacts for port facilities (Onshore)
These mainly consist of following elements: Increase in Vehicular movement, use of construction equipment and high level of primary as well as secondary dust suspension are highly likely to cause adverse impact on Air Quality.
There can be severe impact on flora and fauna in the area due to cutting off of the project area which used to be available for unhindered movement of various animal species, Loss of habitat due to cutting of trees and clearing vegetation. Land use may change due to levelling and construction. Indirect impacts like storage of material, disposal of wastes etc. Wastes generated during construction may get disposed in nearby areas if there is no control or its disposal in the nearby coastal waters is also possible.
Waterfront side impacts:
Dredging/blasting is required to be done for construction of approach channels. Disposal of silt/dredged material at appropriate place is a must for avoiding adverse marine impact.
Marine Ecological impacts are highly likely due to dredging/offshore activities. This involves temporary loss to ecosystem due to dredging as well as offshore construction activities, where there is possibility of construction material getting deposited or dumped in adjacent areas of construction. Accidental spillages of construction material also pose a big threat to the marine environment.
Port construction may involve Construction of breakwaters, toe bunds, barriers, berthing jetties/facilities, Cargo Handling and storage area constructions etc. This results in changes in ecosystem already existing in the area. This may result in damage to the rare and endangered species which may exist in the area.
3. OPERATION PHASE IMPACTS:
There are likely impacts on land as well as waterfront side during operation phase. They are classified and listed as water side impacts and Other impacts and covered in detail below:
Water side impacts:
Due to operational facilities on shore there will be waste water generation and discharge related to port operations like, cleaning liquid waste cargo spillages etc. Also there will be domestic waste water generated as there will be number of people working in the port area. This if not properly collected, treated and reused/discharged will cause perpetual damage to water quality.
Discharge of untreated sewage/sullage water in to the water body next door is considered as an easy option for disposal and causes great damage to ecosystem.
Ballast water discharge: Ships operating from the ports have their own system of Ballast Water Operations. This water is taken from water body to balance out the ships’ cargo holds so that the ship remains stable during the loading/unloading and travel. Upon completion of loading/unloading the ballast water is emptied out. Ballast water from different areas may be carried and discharged into the local environment causing large scale impact and massive loss of biodiversity due to invasive species being transported through the ballast water.
Oil discharge from the ships as well as from foreshore facilities may cause damage to marine ecology. Waste dumping in the sea is an easy option. This may result in high concentration of heavy metals in the sea water leading to bioaccumulation in the fish and other marine aquatic species. If it enters the food chain, it may adversely impact the entire ecosystem and humans as well. Metals/ oils spills during maintenance of ships also have the same risk of contamination causing damage to the marine ecosystem.
Water discharge during pigging of discharge lines: The discharge lines are cleaned of the material using water. This water contains sizable quantum of material in the pipeline. When such water is discharged into the water body, it may result in large scale pollution of water body.
Spillage of cargo material into water: Loading and unloading operations may result in spillage of the cargo into the water. This may be in smaller quantities in carefully planned operations or in large quantities when operations are not neat and tidy or in case of accidental discharges during operations. Such accidental spillages are more likely in rough weather operations. Such spillages can have large scale cumulative adverse impact during operation phase.
Other Impacts:
Air Pollution: Various sources of Air pollution in port operations are Flue gases from I/C engines of ships, small boats, tugs resulting in emissions of SO2, NOx and PM. Fumes/VOC coming from storage both on board the ships as well as on shore.
Fugitive emissions during handling of cargo Noise pollution due to operation of heavy machinery Use of DG sets and emissions during maintenance activities involving welding/gas cutting etc.
4. MITIGATIONS MEASURES:
There are many systems which are used and are proven to be effective in abatement and control of pollution in the ports. They are:
Pipe conveyors: These are best in preventing fugitive emissions during loading and unloading of cargo.
Enclosed conveyors: This also prevents secondary dust emissions due to wind in the port area.
Pile spray system: Wetting of the material results in lesser fugitive emissions. However this can be used in certain materials only.
Dry fogging system: Uses less amount of water but has limitation for use.
Covered storage: This is an option available for cargo which is easy to handle. However this is a very costly option.
Curtains while unloading: Use of curtains prevents accidental discharge in to the water. Material can be recovered and used.
Mechanized handling systems: This involves using screw type unloaders this results in much less spillage and loss of material as compared to bucket unloaders. Mechanized systems can also use pre-packed containers for ease and pollution free loading unloading. Diligent use of various systems can keep the pollution due to ports at minimum level.