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Offshore Support Journal

Ballast Water Treatment Technology

MEPC approves revised G8 Guidelines

Tue 01 Nov 2016 by Paul Gunton

MEPC approves revised G8 Guidelines
MEPC agreed new guidelines on how to test BWMSs (credit: Sunrui)

IMO’s Marine Environment Protection Committee’s 70th meeting (MEPC 70) last week approved a set of substantial revisions to the G8 Guidelines on equipment testing, which had been prepared by an Intersessional Working Group, which had met the week before.

The committee also agreed the guidelines will be reviewed and revised into a mandatory code at a subsequent session of the committee.

In a summary of the meeting’s outcomes issued yesterday (31 October), class society ABS listed the main changes introduced by the revisions:

  • Testing facilities: Testing is to be carried out by an independent facility accepted by the administration. Facilities should implement a rigorous quality control/quality assurance programme that addresses appropriate challenge water, sample collection, sample analysis and method detection limits.
  • Salinity and temperature: Testing is to be carried out across a full range of salinities (fresh, brackish and marine) and through a temperature range of 0°C to 40°C (2°C to 40°C for fresh waters). A ballast water management system (BWMS) that is unable to demonstrate successful performance across these salinity and/or temperature ranges will be assigned Limiting Operating Conditions on its type-approval certificate.
  • Consecutive testing: Land-based testing is to consist of five consecutive valid test cycles that show D-2 compliance. Shipboard testing is to reflect actual ballast operations and consist of at least three consecutive valid tests, which show D-2 compliance spanning a period of not less than six months.
  • System Design Limitations: An important development is the concept of documenting the critical parameters known as System Design Limitations (SDLs). These parameters impact the operation of BWMSs (for example, minimum and maximum flow rates, time between ballast uptake and discharge) and design limits (for example, water quality expressed by oxidant demand and ultraviolet transmittance). SDLs are to be identified by the manufacturer, validated during testing and indicated on the type-approval certificate.
  • Bypass arrangements: BWMS bypass or override arrangements, provided to protect the safety of the ship and personnel in the event of an emergency, should activate an alarm and be recorded by the control equipment.
  • Self-monitoring: BWMSs are to be provided with a system that monitors, records and stores sufficient data/parameters to verify correct operation for the past 24 months. Alerts are to indicate when the system is shutdown or when an operational parameter exceeds the approved specification.
  • Scaling effects: Mathematical modelling and/or calculations should demonstrate that any scaling of the BWMS will not affect the functioning and effectiveness on board the ship. Shipboard testing is intended to further validate the scaling and should, preferably, be carried out at the upper limit of the rated capacity of the BWMS.
  • Report of test results: Reports for land-based and shipboard testing, submitted to the administration, should include information regarding the test design, methods of analysis and the results of these analyses for each test cycle, including invalid test cycles, BWMS maintenance logs and any observed effects of the BWMS on the ballast system. Shipboard test reports should include information on the total and continuous operating time of the BWMS.
  • Installation survey and commissioning procedures: Prior to issuance of the International Ballast Water Management Certificate, installation of the BWMS is to be carried out in accordance with the technical installation specification, relevant type-approval certificate and the manufacturer's equipment specification. The workmanship of the installed system, including completion of all agreed commissioning procedures is to be satisfactorily demonstrated.

Source: ABS

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