INTERPRETATIONS OF, AND AMENDMENTS TO, MARPOL AND RELATED INSTRUMENTS. Management of boiler/economizer washdown water

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1 E MARINE ENVIRONMENT PROTECTION COMMITTEE 66th session Agenda item 7 MEPC 66/7/2 24 January 2014 Original: ENGLISH INTERPRETATIONS OF, AND AMENDMENTS TO, MARPOL AND RELATED INSTRUMENTS Management of boiler/economizer washdown water Submitted by Japan, Panama, the International Chamber of Shipping (ICS) and the International Association of Dry Cargo Shipowners (INTERCARGO) SUMMARY Executive summary: This document provides a draft amendment to the 2012 Guidelines for the implementation of MARPOL Annex V (resolution MEPC.219(63)), and a draft MEPC circular on best practice for management of boiler/economizer washdown water Strategic direction: 2 High-level action: Planned output: Action to be taken: Paragraph 13 Related documents: MEPC 65/7/2, MEPC 65/7/3, MEPC 65/7/8, MEPC 65/WP.12 and MEPC 65/22 Background 1 The Committee, at its sixty-fifth session, discussed matters regarding the treatment of boiler/economizer washdown water under MARPOL Annex V, and instructed a drafting group to prepare draft amendments to the 2012 Guidelines for the implementation of MARPOL Annex V, taking into account document MEPC 65/7/3, and to prepare a draft MEPC circular outlining best practice for management of boiler/economizer washdown water. 2 The Committee noted that the drafting group had prepared the draft amendments to the 2012 Guidelines for the implementation of MARPOL Annex V to define boiler/economizer washdown as ʺother similar dischargesʺ essential to the operation of a ship and a draft MEPC circular outlining best practice for management of boiler/economizer washdown water. 3 Following the discussion, the Committee did not approve the draft amendments to the 2012 Guidelines for the implementation of MARPOL Annex V to define boiler/economizer washdown water as ʺother similar dischargesʺ nor the draft MEPC circular outlining best practice for management of boiler/economizer washdown water.

2 Page 2 Investigation of properties of boiler/economizer washdown water 4 After MEPC 65, shipping industries investigated the properties of boiler/economizer washdown water. During washing operation of boiler/economizer, washdown water is temporarily collected and stored in a washwater collecting tank. For the purpose of the investigation, samples of washdown water were taken from the surface and the bottom of washwater collecting tanks on nine ships, after the economizer washing operation. It should be noted that, in the ordinary practice, alkali is put into washwater collecting tanks prior to the washing operation and that, at the time of the investigation, alkali has not been put into the washwater collecting tanks for obtaining samples without neutralization. Oil content of boiler/economizer washdown water 5 The table below shows the results of the analyses of the samples. The oil contents (extracted with normal-hexane) were 0 to 1.6 ppm. Therefore, from the viewpoint of oil content, it is not necessary to use oil filtering equipment for the washdown water while discharging, taking into account that 15 ppm is the oil content criterion referred to in MARPOL Annex I and other relevant IMO instruments. Ship type Crude Oil Carrier Container Carrier ID DWT Main engine Sampling ph Oil content [ton] power [kw] point at 25.0 C [ppm] T1 302,159 27,160 Surface T2 310,309 27,959 Surface Bottom T3 305,484 27,020 Surface Bottom T4 314,020 19,976 Surface T5 281,050 27,184 Surface T6 302,107 27,160 Mixed 3.18* 0.4 C1 103,207 87,060 Surface Bottom C2 63,096 67,179 Bottom C3 81,171 61,350 Surface Bottom Note * Sample waters taken from the surface and the bottom were mixed and used for the aquatic toxicity test. Hazardous to the aquatic environment 6 The washdown water was classified according to the criteria in MARPOL Annex III. The washdown water sample was the washwater taken from a collecting tank on the container ship specified as ʺT6ʺ in the table above, which is shown in bold font. The sample was tested according to the principles of Good Laboratory Practices (GLP) (see paragraph in the United Nations Globally Harmonized System for Classification and Labelling of Chemicals (UN GHS)). The following tests were conducted:.1 OECD Guidelines for the Testing of Chemicals 203 (1992) ʺFish, Acute Toxicity Testʺ using ʺOryzias latipesʺ;.2 OECD Guidelines for the Testing of Chemicals 202 (2004) ʺDaphnia sp. Acute Immobilisation Testʺ using ʺDaphnia magnaʺ and.3 OECD Guidelines for the Testing of Chemicals 201 (2006) ʺAlga, Growth Inhibition Testʺ using ʺPseudokirchneriella subcapitataʺ.

3 Page 3 7 In the tests the total metal content was used for the calculation/adjustment of the concentration of the sample in the water for the tests. The results of the tests were as follows:.1 96 hr LC 50 (for fish) > 100 mg/ ;.2 48 hr EC 50 (for crustacea) > 10 but 100 mg/ ; and.3 72 hr ErC 50 (for algae or other aquatic plants) > 10 but 100 mg/. 8 Based on the test results, the acute aquatic toxicity of the sample was categorized as ʺAcute 3ʺ. Furthermore, the chronic aquatic toxicity of the sample was categorized as ʺChronic 3ʺ, according to UN GHS Table Categories for substances hazardous to the aquatic environment, (b) Long-term aquatic hazard, (iii) Substances for which adequate chronic data are not available. 9 Thus, the washdown water was deemed to be not categorized as ʺharmful substancesʺ according to MARPOL Annex III or ʺenvironmentally-hazardous substancesʺ according to paragraph of the IMDG Code. Classification of boiler/economizer washdown water 10 Taking into account the above-mentioned results of the tests and the actual operation explained in the documents submitted to MEPC 65, in particular document MEPC 65/7/8, the co-sponsors propose to classify boiler/economizer washdown water as ʺother similar dischargesʺ essential to the operation of a ship and to amend the 2012 Guidelines for the implementation of MARPOL Annex V, accordingly. The draft amendment to the Guidelines prepared by the drafting group at MEPC 65 can be used for this purpose (MEPC 65/WP.12, annex 2, annex). The proposed draft amendment is as follows: ʺIn the annex, in paragraph 1.7.3, new bullet point ʹboiler/economizer washdown waterʹ is inserted after the first bullet point.ʺ Best practice for management of boiler/economizer washdown water 11 Simultaneously, the co-sponsors propose to develop a recommendation on best practice for management of boiler/economizer washdown water, as a precautionary approach. Boiler/economizer washdown water is a strong acid and the alkali is put into washwater collecting tanks prior to the washing operation in order to protect the ship s structure. Thus, the co-sponsors propose to include putting alkali in tanks for collecting washdown water and prohibition of the discharge within 12 nautical miles from shore, in the recommendation. 12 The draft MEPC circular on the best management practice for boiler/economizer washdown water is set out in the annex to this document. Action requested of the Committee 13 The Committee is invited to consider the above proposals and take action as appropriate. ***

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5 Annex, page 1 ANNEX DRAFT MEPC CIRCULAR ON BEST PRACTICE FOR THE MANAGEMENT OF BOILER/ECONOMIZER WASHDOWN WATER 1 The Marine Environment Protection Committee (the Committee), at its sixty-sixth session (31 March to 4 April 2014) adopted resolution MEPC.[ ](66) on amendments to the 2012 Guidelines for the implementation of MARPOL Annex V (resolution MEPC.219(63)), which, inter alia, recommends that boiler/economizer washdown water should be regarded as other similar discharges essential to the operation of a ship in relation to the definition of operational waste (regulation 1.12 of MARPOL Annex V). 2 The Committee also agreed that boiler/economizer washdown water, after washing the boiler/economizer gas side, should not be discharged directly overboard. The following measures on the management of boiler/economizer washdown water should be considered by shipowners and operators:.1 boiler/economizer gas side washdown water should not be discharged directly overboard;.2 corrosion of the tanks for collecting washdown water should be prevented by using alkali; and.3 the water should only be discharged into the sea not less than 12 nautical miles from the nearest land. 3 Member Governments are invited to bring the content of this circular to the attention of those interested, including port State control authorities, coastguard and maritime surveillance services, as appropriate.