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Ballast Water Treatment: IMO & USA Requirements  


1. Ballast Water and Sediment Management Requirements

Ballast is an important issue for the safety of a ship as explain in ship's stability section. The issue is known over 90 years ago However recent IMO actions lead to regulation since the increase in global shipping traffic, increases in vessel size and capacity has lead to contamination of in 84% of the world's 232 marine eco-region. For the seaman with limited environmental awareness should be noted that this ballast issue is eventually threating people's health in many countries. 


The transfer of pathogen organisms through ballast water has been proven to be a major threat to local ecosystems and public health. The microorganisms transferred through water have been shown resistance to long voyages on ships ballast tanks. The definition ballast tank means any tank or holds on a vessel used for carrying ballast water, including dedicated tanks or strengthened cargo holds.

As a reaction to the threat, the IMO introduced the Guidelines for the Control and Management of Ships' Ballast Water to Minimise the Transfer of Harmful Aquatic Organisms and Pathogens (IMO Resolution A.868 (20), adopted November 1997). The scope of this convention is to minimise the global distribution of microorganisms through ballast transfer.

The BWM Convention requires all ships of 400 gross tonnes (gt) and above to comply as follows.

  • to have on board an approved Ballast Water Management Plan (approved by class or flag as appropriate) and
  • to have on board a Ballast Water Record Book,
  • to be surveyed and issued with an International Ballast Water Management Certificate.

(For ships whose flag administration has not ratified the BWM Convention a certificate or statement of compliance can be issued.)

The ballast discharges are currently allowed as per regulation D-1 or D-2, i.e., that ballast is exchanged or treated: this obligation applies to ballast discharges both at sea and in port. Exchange means to replace the water in a ballast tank using one of the following methods:

  • Flow-through by pumping out ballast water in mid-ocean and continuously overflowing the tank from the top until three full volumes of water has been changed. This is usually carried before entering EEZ (Exclusive Economic Zone is the area which extends from the baseline of the territorial sea of a state up to 200 nautical miles)
  • Empty/refill a ballast tank and then refilling it with mid-ocean water.

2. Ballast Water Treatment Systems


The risks of blast water exchange are significant when considering stability, strength abilities of a ship. Furthermore, in al long distance from ashore, a damaged ship will be a great risk for seamen lives and marine environment.  Consequently, Ballast Water Treatment Systems are a promising solution.


Ballast water treatment standards should be approved as per Regulation D-2 of the BWM Convention. Each system should have a type approval certificate according to Resolution MEPC. 174(58), which updated Resolution MEPC.125(53). The same standards apply to USCG.


2.1 Certification Timeline as per MEPC 71 (2017)

For existing ships, i.e., ships constructed before 8 September 2017, the date for compliance with the D-2 standard is linked with the renewal survey of the ship associated with the International Oil Pollution Prevention Certificate under MARPOL Annex I. For existing ships this would be the first or second five-year renewal survey after 8 September 2017:

  • By the first renewal survey: this applies when that the first renewal survey of the ship takes place on or after 8 September 2019 or a renewal survey has been completed on or after 8 September 2014 but prior to 8 September 2017.
  • By the second renewal survey: this applies if the first renewal survey after 8 September 2017 takes place before 8 September 2019. In this case, compliance must be by the second renewal survey (provided that the previous renewal survey has not been completed in the period between 8 September 2014 and 8 September 2017).


2.2 USA requirements (CFR, Title33, Vol2, Sec151-2036)

Existing vessels (for the USA) with ballast capacity greater than 5,000m3

  • First scheduled dry-docking after 1 January, 2016

An extension letter for the above deadline may be provided by the USCG and EPA for 2 years, case by case. Subject to the following:

  • Extension requests must be submitted to the Coast Guard no later than 12 months before the scheduled implementation date.
  • The United States means the States, the District of Columbia, the Commonwealth of Puerto Rico, Guam, American Samoa, the Virgin Islands, and the Trust Territory of the Pacific Islands including the navigable waters of the United States. For this regulation, the navigable waters include the territorial sea as extended to 12 nautical miles from the baseline (as this is marked in nautical charts)
  • USA requirements apply to all vessels, US and foreign, equipped with ballast tanks, that operate in the waters of the United States and are bound for ports or places in the United States. Voyage means any transit by a vessel destined for any United States port or place in which a vessel is anchored or moored.
  • Captain of the Port (COTP) means the Coast Guard officer designated as the COTP, or a person designated by that officer, for the COTP zone covering the US port of destination. These COTP zones are listed in 33 CFR part 3.


3. BWTS Options


There are two generic types of process technology used in ballast water treatment; Solid-liquid separation is the separation of suspended solid material, including the larger suspended microorganisms, from the ballast water, (usually by filtration). The process produces a waste stream containing the suspended solids which require appropriate management where during ballasting they can be discharged at the same time. On deballasting, the solid-liquid separation operation is inactive.

A primary physical method includes filtration:


  1. Limited space and power, time limitations during short voyages, and ship motions prevent the use on ships of some of the most common and effective processes used to treat water on land
  2. However, in the case of a system with filtration, screens or strainers are used as filter media which are much less efficient at removing microbes (most bacteria are 61.5 lm in diameter)



  1. The screens or strainers that are used as filter media which are not very efficient at removing microbes (most bacteria are 61.5 lm in diameter)
  2. The limitations of filtration require to be combined with the other disinfection technologies making their operation complicated.


Another physical method is the use of hydro-cyclones:

  • High-velocity centrifugal rotation of water is used to separate the particles/ organisms
  • Hydro-cyclones are less effective than filters in terms of their removal efficiency



Apart from physical solid-liquid separation another method of treating ballast water is disinfection chemical treatment. Disinfection removes and/or inactivates microorganisms using one or more chemical treatment (chemical inactivation, oxidising biocides, non-oxidizing biocides, UV light, heat or cavitation, asphyxiation).

These involve:

  • treatments with chlorine to sterile water
  • addition of CO2 to electro-chlorination to improve the efficiency
  • water deoxygenation which however is time consuming process and may cause delays to short voyages in warm climates
  • the radiation of ballast water treatment with ultraviolet (UV) lamps with some serious challenges such as the high cost and the lack of accurate monitoring of the lamp output


3. Critics of the BWT systems

 However, so far there are approval concerns about such systems since there is limited consideration of hazards such as energy consumption, air pollution or waste generation. The installation of BTWS onboard ships is also raising training, safety concerns, maintenance and repair challenges, and operation by ships' personnel. In general, the following criticisms exist:


  • In several cases, the reduction of microbes after ballast water treatment of certified systems could have been achieved without treatment.
  • There are cases that bacterial communities rebounded after a few days
  • The efficiency of water disinfection depends on water quality factors such as salinity, alkalinity, and organic compounds in water
  • With respect to environmental condition temperature and sea ice concentration determine habitat suitability for 61% of species

 Another category of criticisms is related to ship structural concerns. The majority of BWT systems, nearly 51, use UV or Chlorine as a disinfection method which causes corrosion of ballast tanks due to strong oxidising ability. It is also argued that continuous disinfection could damage the original tank biofilm structure.


There also concerns about environmental damage from active substance chemical by-products released at sea. It is believed that the uncontrolled release of chemicals will harm aquatic organisms. The problem is believed to be higher in geographical areas with restricted circulation of water in harbours and bays, especially in colder regions. There are cases that some active substances used as disinfectants are neutralised by a reducing agent such as sodium thiosulfate. However, the most significant concern is that there are not any data to validate or reject these arguments. Monitoring of marine environments should be established as a permanent procedure by state in order to measure results of BWM Convention effectiveness. It is believed that coastal zones and rivers are particularly vulnerable to the above side effects


The installation of BTWS onboard ships is also raising concerns about

  • Training
  • Crew safety
  • Maintenance
  • Repair challenges
  • Operation by ships' personnel with limited experience


It has been found that ballast water treatment methods with continuous disinfection could damage the original tank biofilm structure. The (IMO) has set standards for approval of a ballast water management system, regarding the aquatic toxicity of the active substance and relevant by-products used.

 However, for the majority of ballast water treatment systems using oxidative compounds, the formation of chemical by-products (CBPs) is an issue and could cause adverse effects on aquatic organisms.


3.1 Criteria to choose a ballast system


  • Manufacturer Longevity Cost, Maintenance
  • Power (KW) Cost, Environmental Issues
  • Treatment Time Cost, Ease of use, Physical and performance characteristics
  • System Capacity Maintenance, Physical and performance characteristics
  • Installation dimensions (m2) footprint Physical and performance characteristics
  • Installation Dimensions Height Physical and performance characteristics
  • Safety/ Use of Chemicals Maintenance, Safety factors








3.2 VGP related requirements

In addition to maintenance of a ballast water management plan, the following VGP requirements should be followed in the USA:

  1. Avoid the discharge or uptake of ballast water in areas within or that may directly affect marine sanctuaries, marine preserves, marine parks, or coral reefs.
  2. Minimise or avoid uptake of ballast water in the following areas and situations:
    1. Areas known to have infestations or populations of harmful organisms and pathogens (e.g., toxic algal blooms).
    2. Areas near sewage outfalls.
    3. Areas near dredging operations.
    4. Areas where tidal flushing is known to be poor or times when a tidal stream is known to be more turbid.
    5. In darkness when bottom-dwelling organisms may rise up in the water column.
    6. Where propellers may stir up the sediment.
    7. Areas with pods of whales, convergence zones, and boundaries of major currents.


  1. Discharge only the minimal amount of ballast water essential for vessel operations while in the waters of the United States.
  2. Rinse anchors and anchor chains when you retrieve the anchor to remove organisms and sediments at their place of origin.
  3. Remove fouling organisms from hull, piping, and tanks on a regular basis and dispose of any removed substances in accordance with local, State and Federal regulations.


3.3 Ballast Water Treatment in the USA

“If the vessel carries ballast water that was taken on in areas less than 200 nautical miles from any shore into the waters of the US after operating beyond the Exclusive Economic Zone, the ship must employ at least one of the following ballast water management practices:

  1.  Perform complete ballast water exchange in an area no less than 200 nautical miles from any shore prior to discharging ballast water in US waters;

(A vessel will not be required to deviate from its voyage, or delay the voyage, in order to conduct a ballast water exchange.)

  1. Retain ballast water onboard the vessel; or
  2. Prior to the vessel entering US waters, use an alternative environmentally sound method of ballast water management that has been approved by the Coast Guard.”


4.      The Maintenance of The Installed Ballast Water Management System

Maintenance of equipment should include as apart of ISM Code:

  • Inspection of ballast tanks for structure and coating failures
  • Ballast pumps overhauling and testing















4.1  Exemptions of Operations in Adverse Weather


Section 15 CFR 754.2(j)(1)(iii) requires a mandatory program of deep water ballast exchange unless doing so would endanger the safety of the vessel or crew.

The master, operator, or person in- charge of a vessel is not required to conduct a ballast water management practice (including exchange), if the master decides that the practice would threaten the safety of the vessel, its crew, or its passengers because of:

  • adverse weather,
  • vessel design limitations equipment failure, or
  • any other extraordinary conditions.

"The vessel will not be prohibited from the discharge of ballast water in areas other than the Great Lakes and the Hudson River"

A vessel that cannot practicably meet the requirements of § 151.2035(b)(3) because its alternative environmentally sound ballast water management method is inoperable must notify port captain.

The discharge of oil or noxious liquid substances (NLS) in a manner is prohibited by the United States or international laws or regulations. Ballast water carried in any tank containing a residue of oil, NLS, or any other pollutant must be discharged in accordance with applicable regulations.


5.      The Safety & Human Health of Seafarers


Some BW treatments systems may require disinfection of water with the application of chemicals. Relevant Materials Safety Data Sheet for these chemicals should be onboard to provide information for:

  • handling and storage
  • crew safety
  • emergency procedures in the event of a spill, fire or explosion
  • first aid measures (when contact with the skin or being inhaled)
  • Storage of PPE (e.g. full-body protection, eyewash drops etc.)


5.1  Precautions for Entering Tanks for Sediment Removal


Emphasis should be given that prior entering ballast tanks an enclosed space work permit should be issued and signed. It is also essential a thorough risk assessment to be carried out before any task regarding tank entrance and sediment removal.


5.2  Handle, Package and Store Sediment


Ballast tanks should be cleaned regularly to remove sediments. Clean the tanks in mid-ocean or under controlled arrangements in port, or at dry dock.

Disposal of sediments in accordance with local, State, and Federal regulations. In USA the biofouling requirements (Resolution MEPC.207(62)) should be followed as well.







6.      Local Disposal Facilities and Regulations

The BWM Convention empowers PSC officers to inspect ships (Resolution MEPC.252(67) in the following areas:

  • verifying certification
  • inspecting the ballast water record book
  • sampling ballast water in accordance with the IMO's guidelines

Additionally, the IMO guideline describes sampling actions in order to verify that the ballast water has been treated or exchanged with ocean water (regulations D-1 and D-2 of the BWM Convention, G2 Guidelines).


6.1  PSC Sampling


Statistical ‘‘representativeness'' of the sample is an issue related to the heterogeneity of the distribution of organisms in ballast water and show compliance.

Factors affect the accuracy of obtaining representative samples that represent the total ballast water onboard a vessel such as large volume of ballast water, the shape, size and number of ballast tanks and the heterogeneous distribution of organisms within tanks


6.2  USA requirements


The COTP may take samples of ballast water and sediment, examine documents, and make other appropriate inquiries to assess the compliance of any vessel subject to this subpart.

USA penalties:


(a)            A person who violates this subpart is liable for a civil penalty not to exceed $ 27,500. Each day of a continuing violation constitutes a separate violation. A vessel operated in violation of the regulations is liable in rem for any civil penalty assessed under this subpart for that violation.

(b)            A person who knowingly violates the regulations of this subpart is guilty of a class C felony.


7.      Record Keeping

The recordkeeping is showing compliance with international and local regulations. The records should be maintained by the ship's Ballast Water Management Officer, as identified in the BWM plan. Ballast Water Record Book, which is part of a ship-specific Ballast Water Management Plan, should provide evidence of the following requirements:

  • Ship efforts to minimise the risk of the transfer of harmful aquatic organisms and pathogens in ships' ballast water and associated sediments
  • Evidence to port authorities and PSC officers
  • Evidence of crew training on BWM operational practices

What are the mandatory recordkeeping requirements for vessels equipped with ballast tanks that are bound for a port or place in the United States?

Exemption: A foreign vessel merely traversing the territorial sea of the US (i.e., not entering or departing a US port, or not navigating the internal waters of the US) is exempt from the Ballast requirements.

The master, owner, operator, or person in charge of a vessel bound for a port or place in the United States, must keep records that include the following information:

(1)   Vessel information.

  • Name;
  • International Maritime Organization (IMO) Number (official number if IMO number not issued);
  • Vessel type;
  • Owner or operator;
  • Gross tonnage;
  • Call sign; and
  • Port of Registry (Flag).

(2)   Voyage information. Include the date and port of arrival, vessel agent, last port and country of call, and next port and country of call.

(3)   Total ballast water information (ballast water capacity, volume number of tanks in ballast).

(4)   Ballast Water Management Plan. (Total number of ballast tanks/holds that are to be discharged into the waters of the United States or to a reception facility, alternative methods if any). IMO guidelines on board.

(5)   Information on ballast water tanks that are to be discharged into the waters of the United States or to a reception facility. Include the following:

(i)                 The origin of ballast water. (date(s), location(s), volume(s) and temperature(s) (If a tank has been exchanged, list the loading port of the ballast water that was discharged during the exchange.).

(ii)               The date(s), location(s), volume( s), method, thoroughness (percentage exchanged if exchange conducted), sea height at time of exchange if exchange conducted, of any ballast water exchanged or otherwise managed.

(iii)             The expected date, location, volume, and salinity of any ballast water to be discharged into the waters of the United States or a reception facility.

(6)   Discharge of sediment (if any).

(7)   The master, owner, operator, person in charge, or responsible officer's printed name, title, and signature attesting to the accuracy of the information provided and certifying compliance with the USA requirements.

The ‘‘Ballast Water Reporting Form'' contained in the

 IMO Guidelines meet the requirements of this section.

USA mandatory ballast water reporting requirements:

  • Location
  • Person in Charge When
  • United States regardless of whether a vessel operated outside of the EEZ (which includes the equivalent zone of Canada) The master, owner, operator, agent, or person-in-charge of a vessel 24 hours
  • If your voyage is less than 24 hours, you must report before departing your port or place of departure. If your voyage exceeds 24 hours, you must report at least 24 hours before arrival at your port or place of destination.
  • All required information is to be sent to the National Ballast Information Clearinghouse (NBIC). The NBIC will compile the data obtained from the submitted reports. This data will be used, in conjunction with existing databases on the number of vessel arrivals, to assess vessel reporting rates.


8.      Bibliography

CFR Title 40. Protection of Environment Chapter I. Environmental Protection Agency Subchapter D. Water Programs Part 122. EPA Administered Permit Programs: The National Pollutant Discharge Elimination System Part 122—EPA Administered Permit Programs: The National Pollutant Discharge Elimination System

CFR § 151.2036 If My Voyage Does Not Take Me Into Waters 200 Nautical Miles Or Greater From Any Shore, Must I Divert To Conduct A Ballast Water Exchange?

CFR 151.2037 If My Vessel Cannot Conduct Ballast Water Management Practices Because Of Its Voyage And/Or Safety Concerns, Will I Be Prohibited

CFR Title 33. Navigation and Navigable Waters Chapter I. Coast Guard, Department Of Homeland Security Subchapter O. Pollution Part 151. Vessels Carrying Oil, Noxious Liquid Substances, Garbage, Municipal Or Commercial Waste, And Ballast Water Penalties For Non-Submission Of Ballast Water Management Reports

CFR Title 33. Navigation And Navigable Waters Chapter I. Coast Guard, Department Of Homeland Security Subchapter O. Pollution Part 151. Vessels Carrying Oil, Noxious Liquid Substances, Garbage, Municipal Or Commercial Waste, And Ballast Water Subpart D. Ballast Water Management For Control Of Nonindigenous Species In Waters Of The United States Section 151.2036. Extension Of Compliance Date.

Comdtpub P16700.4 Nvic 01-04 02 January 2004 Navigation And Vessel Inspection Circular No. 01-04 Subj: Shipboard Technology Evaluation Program (Step): Experimental Ballast Water Treatment Systems

Karahalios, H. (2017). The Application Of The Ahp-Topsis For Evaluating Ballast Water Treatment Systems By Ship Operators. Transportation Research Part D: Transport And Environment52, 172-184.

Lloyd’s Register Group Limited. 2015. Understanding Ballast Water Management – Guidance For Shipowners And Operators

Marine Environment Protection Committee (Mepc), 71st Session 3-7 July 2017

Mohammadkhanloo, Kianoosh, And Hassan Ghassemi. "Critical Review Of The Imo On Ballast Water Convention And Its Impact On Shipping." International Journal Of Multidisciplinary Sciences And Engineering, Vol. 8, No. 2, March 2017

Title 33 - Navigation and Navigable Waters Chapter I - Coast Guard, Department Of Homeland Security (Continued)Subchapter O – Pollution Part 151 - Vessels Carrying Oil, Noxious Liquid Substances, Garbage, Municipal Or Commercial Waste, And Ballast Water Subpart D - Ballast Water Management For Control Of Nonindigenous Species In Waters Of The United States

UK P&I (2013). Ballast Water Management Convention 2004 – An Update.