After Unloading Bulk Cargo: A Decision Tree for Hold Washwater

Start before the hose is opened

On October 14, 2026, the useful starting question for a bulk carrier finishing discharge is not simply whether the hold needs washing. It is what remains in the hold, what can still be recovered, and where the resulting material can go. Under MARPOL Annex V, cargo residues include remnants left on deck or in holds after loading or unloading, whether dry, wet or carried in washwater. Cargo dust left on deck after sweeping, and dust on the ship’s external surfaces, are excluded from that definition. The distinction matters because adding water does not make cargo remnants cease to be residues.

IMO guidance narrows the potential sea-discharge route further: only residues that cannot be recovered using commonly available unloading methods can be considered for it. That makes efficient unloading and collection a first step, not an optional refinement after a washing decision. The guidance also recommends limiting spillage during transfer and cleaning up spillage in port for handling as cargo. A workable handover from terminal to ship therefore identifies what has been collected, what remains to be removed, and what may be left for hold cleaning.

2017 Guidelines for the Implementation of MARPOL Annex V (resolution MEPC.295(71)) · Prevention of Pollution by Garbage from Ships

Check the declaration, including its exception

For solid bulk cargoes as defined under SOLAS, **other than grain**, the IMO guidelines specify classification against MARPOL Annex V’s harmful-to-the-marine-environment criteria and a shipper declaration stating whether the cargo is HME. For an international voyage, the guidelines say that declaration should be included with the cargo information required under the IMSBC Code. Grain is expressly excepted from this particular solid-bulk HME classification-and-declaration requirement; it should not be silently swept into a statement about ‘all bulk cargoes.’

The declaration is a decision input, not a substitute for inspecting what has entered the waste stream. IMO describes HME cargo residues as requiring reception ashore rather than sea discharge, including when those residues are in washwater. Its guidance notes that HME residues may need special handling at reception facilities. If the declared status, identity of remnants, or proposed shore-handling arrangement is unclear, resolve that uncertainty before choosing how to collect or wash the hold. A non-HME declaration likewise does not, by itself, authorize an overboard discharge.

2017 Guidelines for the Implementation of MARPOL Annex V (resolution MEPC.295(71)) · Amendments to MARPOL Annex V: HME Substances and Form of Garbage Record Book (resolution MEPC.277(70)) · Prevention of Pollution by Garbage from Ships

Treat the wash as a mixture, not just water

Hold washwater can contain cargo residues, cleaning agents or additives, or both. IMO addresses those components separately: a cleaning agent’s suitability does not change the classification of cargo entrained in the same water. Its guidelines say cleaning agents and additives in hold washwater may be discharged only if they are not harmful to the marine environment. They also recommend keeping producer evidence aboard; a dated, signed supplier statement may provide that evidence, either separately or as part of a safety data sheet.

This calls for a check before a product is used, rather than an assumption based on its trade name. Identify the cargo remaining after recovery, establish its HME status where the classification requirement applies, and check the proposed cleaning product. If the stream contains material prohibited from discharge or material subject to stricter conditions, the more stringent requirements govern the mixture. Keeping these checks separate prevents a non-HME cleaning product from being mistaken for permission to release HME cargo residues.

2017 Guidelines for the Implementation of MARPOL Annex V (resolution MEPC.295(71)) · Amendments to MARPOL Annex V: HME Substances and Form of Garbage Record Book (resolution MEPC.277(70))

Match any proposed discharge to the waters

Outside MARPOL Annex V special areas and Arctic waters, the IMO guidance summarizes a possible route for **non-HME, unrecoverable** cargo residues: the ship must be en route, as far as practicable from the nearest land, and more than 12 nautical miles away. These are conditions to check, not a standing instruction to wash overboard. Dry residues and residues in washwater also need to be distinguished when the voyage enters a special area: the special-area route described for cargo residues concerns hold washwater and carries additional conditions.

Within a special area, the IMO training material sets out those conditions together: the residues and any cleaning agents in the hold washwater must not be HME; the departure and next destination ports must both be inside the area, with no transit outside it; and adequate reception facilities must be unavailable at those ports. Only when the applicable conditions are met does the distance-and-en-route test for hold-washwater discharge come into play. The practical alternative is to plan retention and reception ashore. Do not transfer an outside-area rule to a special-area passage merely because both mention 12 nautical miles.

2017 Guidelines for the Implementation of MARPOL Annex V (resolution MEPC.295(71)) · MARPOL Annex V Training Package

Close the disposal trail

The Garbage Record Book separates cargo residues from other garbage. Its Part II identifies category **J** for non-HME cargo residues and **K** for HME cargo residues. The prescribed entries distinguish amounts discharged into the sea from amounts transferred to a reception facility or another ship. For a permitted sea discharge of cargo residues, the record includes the ship’s start and stop positions as well as the other required particulars. An intended route for washwater is therefore incomplete until the actual route and quantity are known.

A concise operational closeout links the shipper’s cargo information, the remaining material after unloading, the cleaning product evidence, the chosen reception or discharge route, and the resulting record entry. That sequence is more useful than treating hold washing as a single housekeeping task. It makes the key distinction visible throughout: recovering cargo comes first; deciding whether any remaining residue may be discharged comes later; and the final record should describe what happened, not merely what had been planned.