Wilhelmsen insights

Ballast Water Management Enters into Force: Are you well prepared?

2017 is the year when ship owners are pressed to make a decision on their BWMS. Still, ship owners are unwilling to decide on ballast water treatment systems until the standards are finalized.

Wilhelmsen insights |

Before that, we need to look into some history and the concern that started it all.

For over 120 years, water is used by steel-hulled vessels to stabilize vessels at sea. Water is pumped into and out of ballast tanks while discharging and loading cargo.

Commercial vessels threatening the marine life by releasing alien species into local waters.

The act of discharging waters into destination ports has lead to the introduction of different marine species in local waters that could hurt the ecosystem.

The ballast and de-ballast activity can be explained in the simple illustration below: 

Ballast Deballast Infographic

At any one time, up to 5 billion tonnes of ballast water is being carried in ships’ ballast tanks. 

While most of the live organisms may die due to harsh and dark conditions, and lack of oxygen, hardy organisms can survive and become invaders in foreign waters when discharged with ballast. 

These invaders thrive in absence of natural predators and if left unchecked, they can pose serious economic and health problems to the population. 

Mapping out your needs before installation

It is challenging for owners to navigate through a slew of suppliers with broad ranges of technology mixes in treatment systems. In addition, different vessels require different solutions and there is no straightforward retrofitting of systems that can be done with little planning.

Our New Building and Technical Services team invested a lot of time with BWMS manufacturers through site visits to conduct research, view designs and understand the technologies behind those systems. 

During these surveys, we are able to establish guidelines and assist owners from the planning, measuring and selection processes to the actual retrofitting.

We have summarized a few key considerations as you plan for your installation:

Trading waters and IMO compliance

Installation of systems must follow the revised G8 guidelines to operate in compliance with IMO. If you trade in US waters, you may trade with only the USCG type-approved BWMS.

Vessel requirements

Vessel Type
  • High ballast/low ballast dependent vessels
  • Full ballasting/deballasting/partial
  • Time limitations for ballasting/deballasting
  • Frequency
  • Residual life
Trading Pattern /
Water Quality
  • Turbid water vs clean water
  • Sea water/brackish water/fresh water
  • Organic compounds in water
  • Water temparature
Capacity of Unit Required
  • Dependent  on ballast pattern and vessel type
  • Review capacity for one or two pumps
Space Considerations
  • Modular system
  • Components can be assembled separately
  • Matching footprint with available space
  • 3-D scanning and mapping required
Availability of Surplus Power for
Operation of BWMS 
  • Amount of surplus power during loading / discharging
  • Review of load diagram
  • Sufficient power to operate the system

BWMS selection

The most common question for the BWMS retrofit is “How much will it cost?”. A budget for retrofitting a BWMS can be worked out at different stages once the water treatment system is selected.

Financial consideration - CAPEX & OPEX

  • Cost of unit
  • Cost of installation
  • Operating cost – Power & chemical requirements
  • Maintenance requirements
  • Cost of training included in cost

Crew Training

Crew training is an important requirement by the regulations. Crew must be knowledgeable to handle various technologies.

It is important to select the timing and correct BWMS after careful consideration of the vessel trading and ballasting pattern, residual age, applicable regulations, vendor profile, health and safety considerations, and cost assessment

Sanjiv Rastogi, Head of New Building and Technical Services, Wilhelmsen Ship Management

We recommend some very important criteria before selection: 


  • Suitability for vessel requirements
  • Technology / Combination of systems
  • Simple & Robust for ease of operation and maintenance
  • Ease of installation

Vendor Track Record

  • Number of units sold
  • Company reputation and financial viability
  • Worldwide support network
  • Redundancy – availability of spare parts
  • Health and Safety

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