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Regulation & FAQ

Regulation & FAQ


Ballast water management legislation

Invasive aquatic species are one of the four greatest threats to the world’s oceans and can cause extremely severe environmental, economic and public health impacts. 

Shipping has been identified as a major pathway for introducing species to new environments. The problem increased as trade and traffic volume expanded over the last few decades, and in particular with the introduction of steel hulls, allowing vessels to use water instead of solid materials as ballast.

For tackling this challenge, the International Maritime Organization (IMO) introduced in 2004 the International Convention for the Control and Management of Ship’s Ballast Water and Sediments or just Ballast Water Malmanagement Convention (BWMC). This finally came into force in September 2017, while USCG has introduced the Final Rule in June 2013.

1. IMO

With 174 member states, IMO is the general rule maker for shipping. As such, vessels trading internationally should comply with its regulations. When it comes to Ballast Water, new build vessels built from September 2017 onwards, and existing vessels with drydocking from the same date onwards, should comply with the BWMC. 

For complying, vessels should follow an approved flag or classification society Ballast Water Management Plan. These mainly include the installation of a Type Approved Ballast Water Treatment System (BWTS). Until October 28, BWTS should follow MEPC 174(58), known as G8 guidelines. From October 28, onwards those should follow MEPC 300(72) or the BWMS Code. 


Those vessels calling at US-based ports for de-ballasting ballast water should comply with the Final Rule. This rule has the same discharge standards as with IMO BWMC, but follows a different implementation plan and affects vessels built from December 1, 2013. This rule also differentiates from BWMC as the Ballast Water Treatment Systems follow a different certification procedure for obtaining a UCSG Type Approval Certificate. 

3. Why do we install a BWTS?

This is a question every shipowner, manager or operator should always have in mind. 

The answer is simple, they install a BWTS in order to comply with the current regulations which eventually is the ticket to trade. 

Installing an IMO and/ or USCG Type Approval Certificate is the first step to comply but it is not the only one. Installation design, operation and maintenance of the BWTS is of similar importance as the Type Approval. Bear in mind that the Type Approval is just the evidence of a BWTS meeting the D-2 discharge standards. This efficacy has been proved against prescriptive guidelines (BWMS Code and USCG Final Rule) which the BWTS maker has followed during its certification process.

The vessels should at least be able to prove that: 

  1. The BWTS is well maintained and functional 
  2. The crew is trained to operate and maintain the installed BWTS 
  3. The BWTS has a valid Type Approval Certificate 
  4. The process and control instrumentation of the BWTS is calibrated
  5. Water sampling and analysis at commissioning was in accordance to D-2 discharge standards
4. Why ERMA FIRST is your compliance partner?

Compliance has been ERMA FIRST’s focus from the design of its BWTS to its daily operation. Working around the clock from various global locations, ERMA FIRST offers all the required services and consultation for a vessel to be compliant. These can be summarized but not limited to the following: 

  1. Sampling and analysis of treated water at commissioning (BWM.2/Circ.70 REV1) 
  2. Vessels General Permit (VGP) sampling and analysis (EPA, VGP 2013)
  3. Maintenance and calibration services
  4. Crew training 
  5. Remote BWTS health check*

* This applies to those ERMA FIRST BWTS equipped with METIS and have this service activated

5. Further Regulation reading
    1. IMO 
      1. BWMC
      2. MEPC.300(72) (Note: Please log in the IMO WEB ACCOUNTS to get access)
      3. BWM.2/Circ.70, Rev.1 (Note: Please log in the IMO WEB ACCOUNTS to get access)
    1. USCG 
      1. Final Rule
      2. UCSG Certified BWTS 
    2. Classes 
      1. ABS
      2. DNV
      3. LR 
      4. NK
    3. Other Interesting reading 
      1. ABS BWTS Insights
      2. Invaders From the Sea, A BBC Worldwide- IMO Production






1. What type of disinfection method is it used?

The water disinfection is done through Electrolysis. An electrolytic cell is able to produce free active chlorine (TRO), used for the disinfection of ballast water, by electrolysis of seawater. A TRO concentration of 4-6mg/L as Cl2 is produced for the sufficient disinfection of ballast water.

2. Can the system components be installed at different locations and what are the requirements/limitations?

They can be installed at different locations.

For main ballast tanks in Hazardous Zone, the limitations are:

  • The T/R and control panels are installed in Safe Zones.
  • Filter, E/C, Flow Meter, TRO sensors and valves are installed in Hazardous Zones, such as P/R.

3. Does the system require other services (i.e. addition of air, ballast/fresh water etc.) to operate?  

Compressed air: 6-10 bars. In our BWTS diaphragm pump (DAP) is applied for TRO sampling.  Our standard BWTS feature, is to use 1 DAP per TRO sensor.  According to the standard feature, air consumption of the BWTS is indicated below:

  • DAP: average is 3.5m3/h and can be up to 8.6m3/h each
  • Flow control valve (FCV): 4lt/h
  • Rest of the valves: 17lt per full operation (ballast/de-ballast) Cooling Water for T/R: Tmin= 20 Celsius, Tmax= 45 Celsius, Quality: Fresh Water.

4. What is the average and maximum time to complete the treatment operations and what is the required time interval to effectively neutralize containing bacteria and organisms?

Offered BWTS are chosen according to the ballast pumps capacity of each vessel. As long as bacteria & organisms contact chlorine produced by Electrolysis, their disinfection starts instantly. As a result, the incoming water to B.T. is already treated. The remaining chlorine in B.T. ensures that no organisms’ colony will form. For eliminating any non-compliance risks we recommend minimum holding time 3-4hrs.

5. What the control system of said system consists of? What alarms are available?

Automation is based on Programmable Logic controller (PLC)

Alarms are divided into: Attention & Critical.

In case BWTS Attention Alarm is triggered the system still remains in operation but corrective action or adjustment is required by the BWTS operator.

In case BWTS Critical Alarm is triggered the system is set to OFF and the alarm is activated. The operator should check the critical alarms data log, identify the cause and perform corrective action if needed. Then by setting the main switch to OFF the alarm is reset and BWTS can be set again to ballast operation.