Marine transportation drives global trade. Unfortunately for years, shipping companies and ports have operated with limited environmental oversight. But accidental oil spills, coastal pollution and seabird mortality triggered the need for regulations to prevent marine pollution by ships. A running ship has endless ongoing operations. Water is indispensable for those onboard a ship. On the other hand, a lot of waste water generated as a result of ongoing operations on a ship can potentially harm those in the surroundings of the ship (i.e. the marine organisms). Human Health and Environmental Health go hand in hand. Increasing environmental awareness has attracted attention from the international community for treatment of marine oily wastewater.

POTABLE WATER

QUALITY WATER=QUALITY LIFE

Health is Wealth. A golden rule for healthier living is to drink more of clean water. Protecting the health of the seafarers should always be a priority. And this can be best done by providing good quality water.

POTABLE WATER SIMPLIFIED

Access to safe-drinking water is a basic human right and essential to good-health. Potable water as defined by the WHO Guidelines is drinking-water that does not represent any significant health risk over a lifetime of consumption. In other words, it is fresh water that is intended for human consumption and usage such as drinking, washing, bathing, brushing, cooking etc.

NEED FOR MAINTAINENCE OF HIGH-QUALITY STANDARDS OF POTABLE WATER

Contaminated or inappropriately managed water is the most common cause for infectious disease transmission on ships. In a review of more than 100 outbreaks associated with ships, undertaken by Rooney et al (2004), one fifth was attributed to a waterborne route. The quality of potable water on board a ship may appear to be a small factor in the overall picture of the functioning of a ship but is in fact a very crucial one. The slightest of negligence can lead to a potentially dangerous health scare for the crew and passengers and ultimately result in possible detention for non-compliance. Water loaded via a port or produced on board should comply with the standards of the WHO Guidelines for Drinking-Water Quality (GDWQ).

WHO STANDARDS FOR POTABLE WATER

The World Health Organization (WHO) provides comprehensive guidelines covering drinking and potable water quality on ships and other marine vessels. World Health Organisation (WHO) Guide to Ship Sanitation (2011) and Guidelines for Drinking Water Quality (2008) recommend monitoring alongside the Physiochemical (colour, taste, appearance) and Microbial (E.coli, Legionella, Pseudomonas etc) arameters. WHO recommends testing for bacteria, pH, hardness, free chlorine, total chlorine, metals, in order to determine the quality of drinking water.

POTABLE WATER TESTING

Maritime Labour Convention guidelines ensure that everybody onboard a ship has access to good quality potable water. Potable water testing is done in order to comply with the quality standards of water used for drinking and recreational purposes on board a ship. To avoid any long-term harm and mishaps, ship owners and operators should maintain high water-quality standards.

BALLAST WATER

What is Ballast Water?

Ballast Water is fresh or salt water held in the ballast tanks and cargo holds of a ship. It provides stability to a ship in the middle of rough seas and when the ship is carrying less or no cargo at all. This water is pumped-in and pumped-out of ballast tanks at the port as and when the ships deliver and receive cargo.

BALLAST WATER BEING PROBLEMATIC AND HOW?

A ship that receives and delivers cargo at multiple ports will have a mix of waters from all ports and is likely to contain a mixture of organisms from different ecosystems. The release of ballast water is likely to introduce alien species at the port of discharge. The problem here occurs when this alien species becomes invasive and reproduces an uncontrollable number of its population. This not only damages the native marine community but also creates an ecological imbalance.

For eg: The Amazon estuary is port of entry and exit of ships from the Maritime Trade International (CMI). This mode of transport is capable of introducing invasive species and export in oceans and coastal areas around the planet. This bio invasion represents considerable threat to ecosystems and necessitates the need for legal instruments for management of ballast water.

IMO GUIDELINES FOR BALLAST WATER

The IMO has established guidelines relating to the discharge of ballast water and adopted the 2004 BWM Convention. In accordance with this convention, physical, chemical or combination treatment methods of ballast water management have been employed across the world.

BALLAST WATER TESTING

In 2019, the IMO established a Code for approval of BWMS (Ballast Water Management Systems). All BWMS need to be tested in accordance with this code. Standard D-2 is a set of strict rules for different organisms that can be safely and legally released in certain volumes of water. On being installed and before being used, a BWMS should be checked for compliance with Standard D-2 testing rules. Regulation D-3 is a code that require any BWMS that makes use of active substances needs to prove that these substances are safe for the environment.

BILGE WATER

BILGE WATER-MEANING AND COMPONENTS

Wastewater that collects and stagnates in the bilge of the ship is referred to as Bilge Water. This water is generated as a result of various activities that are required to keep a ship running. It also contains fluids from machinery spaces, internal drainage systems, sludge tanks etc. It has a characteristic foul smell owing to its components.

MARPOL REGULATIONS FOR BILGE WATER

The MARPOL Convention adopted on 2nd November 1973 at IMO is the main international convention that prohibits the discharge of oil or oily mixtures from the ships into the sea. It is aimed at preventing pollution of marine environment by ships from operational or accidental causes. The IMO MARPOL tandard measures oil in water content in ppm (parts per million) and describes the concentration level of oil within the water. One ppm is therefore equivalent to 1 millilitre of oil per 1000 litres of water, 0.001%.The IMO states that no bilge water is to be discharged into the sea that has an oil content that exceeds 15ppm.

IMPACT OF BILGE WATER ON THE MARINE ENVIRONMENT

Marine environment is highly susceptible to pollution by oil from accidents, spillages and deliberate discharges of bilge waters. Thicker layers are responsible for biological damage by creating toxic action and inhibiting lifecycles. The end result always is long-term environmental problems for birds and other marine organisms. The MARPOL Convention aims at controlling this ecological damage caused bilge water.

BILGE WATER TESTING IS IMPERATIVE

In order to comply with MARPOL’s Annex I, the oil content in the Oily Water Separator Effluent must be tested. This can be accomplished using any one of the two methods namely Solvent Extraction and Gas Chromatography Method or the EPA method. Bilge Water Testing is extremely essential for businesses to achieve environmental compliance and to save ship owners from million dollar fines and imprisonment associated with bilge water spills.

SEWAGE TREATMENT PLANTS (STPs)

WASTE MANAGEMENT ON THE SHIPS

Sewage on ships comprises of waste produced from toilets and urinals. This sewage cannot be stored on the ship for a long time and needs to be discarded. Shipping companies have to be really cautious while discarding this sewage. Moreover, it cannot be directly discharged into the sea. But has to be properly treated in line with the regulations related to discharge of sewage

MARPOL REGULATION ANNEX IV FOR SEWAGE ON BOARD A SHIP

According to this regulation, every ship of 400GT and above, carrying minimum 15 persons onboard should have a sewage holding tank of appropriate capacity or an approved sewage treatment plant (STP) or both.
The sewage discharge from a ship with an approved STP is allowed at a distance of 4 nautical miles away from the nearest land. Untreated sewage from foreign cargo ships is allowed to be discharged at a distance of 12 nautical miles away from the nearest land, provided it has no visible floating solids and does not cause discoloration of the surrounding water.
The rate of discharge of the sewage should be limited to 1/200,000 of swept volume.

SEWAGE TREATMENT PLANTS (STPs)-COMPONENTS AND TYPES

All sea-bound vessels have special arrangements made for holding and treatment of sewage. Specially designed sewage tanks are meant for holding of sewage. Whereas, STPs are built-in for treatment of sewage before it is discarded.
STPs are used to treat the sewage and make it less harmful for the sea. The components of a STP namely the screen filter, primary chamber, aeration chamber, demisters, blowers, settlement and chlorination chambers function to treat the waste to comply with ANNEX IV of MARPOL regulation. The most common STPs use biological or aerobic digestion based system.

STP WATER ANALYSIS

STP water is usually checked for the following parameters: Appearance, Odour, Total Dissolved Solids, Suspended Solids, pH value, Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Nitrogen, Free Ammonia etc. This is to ensure the suitability of sewage to be disposed in the environment.

GREYWATER

What is Grey Water?

The International Maritime Organisation defines greywater as the drainage from dishwasher, galley sink, shower, laundry, bath and washbasin drains. Greywater is generated as a normal part of a ship’s operations. It is different from black water (i.e. drainage from toilets and urinals). Considering the nature of activities through which greywater is generated, it may not seem as harmful as black water. However, if untreated greywater can turn out to be potentially dangerous

Dangers Related to Release of Untreated Grey Water

The first thought that crosses our mind when we think about sewage is that it is filthy and gross. But do we even realise how dreadful untreated greywater can turn out to be. Greywater although different from sewage water is likely to possess similar characteristics to that of sewage if left untreated. In certain cases, greywater is found to have higher concentrations of certain components compared to sewage water. For example, faecal coliform concentrations in untreated vessel greywater are one to three times higher than untreated domestic wastewater. It also contains harmful pathogens, bacteria, metals, food waste and problematic ingredients.
Passenger vessels are the major contributors of greywater since the number of people are directly proportional to the quantity of sewage and grey water. Discharge of untreated grey water into the marine environment can lead to oxygen depletion, spread of pathogenic bacteria and viruses and increased nutrient levels in the surrounding ecosystem. It is likely to disturb and damage existing food chains. Moreover, humans that consume aquatic food are more likely to contract a wide range of illnesses from the contaminated waters.

MARPOL regulation on greywater

Although there are existing international regulations with respect to sewage, practically there is no existent law to regulate grey water. However the IMO’s MARPOL Annex IV is being revised and chances are high that it may finally bring into existence the long awaited greywater regulation. Some states however regulate the discharge of greywater from large passenger vessels. Large cruise ships are required to use advanced wastewater systems to treat both greywater and sewage. They should also meet the sampling, reporting and monitoring requirements to ensure compliance with laws.
The Code Of Practice For Vessel and Facility Management is linked to the Environment Protection (Water Quality) Policy, 2015. This code mentions certain requirements for operators to assess their vessel and undertake the most reasonable and practical measures outlined to manage greywater.

REGULATING GREY WATER WITH THE HELP OF TESTING

The need of the hour is to understand the horrible outcomes of untreated greywater. Once we understand this, there are a number of chemical and microbiological testing options. This will further help in regulating greywater.

EXHAUST GAS CLEANING SYSTEM (SCRUBBER)

What is a Scrubber or EGCS?

An Exhaust Gas Cleaning System or Scrubber is a device installed onboard marine vessels that quite literally “scrubs” harmful sulphur oxides from exhaust gases.

How do scrubbers help in reducing pollution?

As an engine on a ship operates, it creates exhaust. Prior to the use of scrubbers the exhaust would directly go up into the atmosphere. With a scrubber, sulphur oxide is removed as the exhaust moves through a scrubber tower. The scrubber wash water removes and converts sulphur oxides from the exhaust gases and discharges them as harmless sulphate.
Marine scrubbers can be classified as wet scrubbers and dry scrubbers. They are further categorised into Open-loop EGS, Closed-loop EGS and Hybrid EGS.

Compliance of Ships with IMO 2020 with regards to SO2 and CO2 emissions

“IMO 2020” limits the sulphur in the fuel oil used onboard ships operating outside designated emission control areas to 0.50% m/m. In order to comply with the MARPOL regulations, ships can limit the air pollutants by installing scrubbers. Scrubbers enable ships to use less expensive and a higher sulphur fuel while maintaining the emission standards set by IMO 2020. A ship’s machinery with an EGCS will help in reducing sulphur content from 3.5% to 0.5%

Compliance with the IMO 2020 rules with regards to sulphur emission could prevent 1,50,000 premature deaths and millions of childhood asthma cases every year.

Scrubber Washwater Testing

Scrubbers remove sulphur from ship exhaust by spraying a buffer solution, usually seawater, over it and then discharging the washwater overboard, often without treatment. The washwater is more acidic than the surrounding seawater and contains polycyclic aromatic hydrocarbons, particulate matter, nitrates, nitrites, and heavy metals including nickel, lead, copper, and mercury. Scrubber washwater is toxic to some marine organisms, harms others, and can worsen water quality

Any vessel discharging exhaust gas washwater is required to collect samples and get them tested by an accredited testing facility. In the first 12 months, samples have to be collected and analysed twice. After the first 12 months, samples may be can be submitted once a year for testing and analysis.

Quality of water is crucial for the survival of all living organisms on earth. It is an integral part of many ecosystems. It is time that we humans take necessary steps and procedures to restore the quality of water. Let us all keep in mind,

WATER IS LIFE AND THERE IS LIFE IN WATER!