Ballast Water Management

BWM retrofit

BWMS installations and retrofit

Compliance with emerging regulations regarding ballast water management (BWM) will be one of the biggest challenges for the shipping industry in the near future. Eventually, all relevant vessels shall have installed a ballast water treatment system (BWTS) to inactivate invasive species and prevent the spread of non-native aquatic species in lakes, rivers and coastal waters. The IMO implementation schedule for BWTS implies that the installation must take place during the “first IOPP renewal survey after the entry into force of the convention” at the latest.

In order to facilitate the retrofit installations of BWMS, DNV GL has developed a guide for retrofit installations of BWMS. The guide includes all the documents which need to be prepared and are required to be submitted for approval when a BWMS is to be installed on board a ship classified by DNV GL. The document approval will be followed by an initial survey of the BWMS installation and certification. The rules applicable for BWMS installations can be found online in DNV GL Rules for SHIP Pt. 6 Ch.7 Sec.1. The rules have to be followed to ensure safe installation and operation of the BWMS, but the rules shall also be followed to be in compliance with the BWM Convention. The current rules also incorporate the Unified Requirements for Installations of BWMS published by IACS (M74). 

Once the retrofit process has started, we will assign a project manager for the document approval to ensure a good communication line throughout the project. Approval engineers in all relevant disciplines will be involved in the evaluation of the installation. Normally, the following disciplines are involved during a retrofit project: environmental, piping, electrical and control systems. Updated drawings may also be required for fire safety and stability, and structure if this is modified.  

We will issue a reminder to ship owners: a Statutory Retroactive Requirement (SRR) note in the ship’s profile in DNV GL Exchange. It details the date the ship must comply with the exchange method of the BWM Convention. We will also issue another SRR note with the date the ship is required to be in compliance with the D-2 standard (i.e. installation and utilization of a BWTS).

DNV GL has gained a lot of knowledge about treatment system technologies through the type approval of BWTS for IMO and USCG, and we utilize this knowledge during installation and retrofit projects.

Related downloads and links

DNV GL rules for BWM

Additional class notation - Environmental protection and pollution control (PDF)

Guide to approval of retrofit ballast water management system installations

Download the PDF

BWM plan template

Download the template as word file

Biofouling Management Plan template

Download the template as word file

IACS M74 Installation of BWMS

Visit the IACS website

BWM insights - Regulatory status, applicable treatment technologies and compliance solution

Request your 20-page copy


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