Shipyard Waste Management during Dry Dock
Hull blasting generates a specific hazardous waste: anti-fouling paint residue that, if poorly managed, simply shifts pollution from the sea to the shipyard.
Operational Explanation
Dry dock operations generate specific waste types, distinct from normal onboard MARPOL waste management: sandblast waste containing anti-fouling paint particles, often with organotin compounds, hull washdown water, waste oils from machinery interventions, and scrap materials from structural work.
Blasting residue is the most environmentally critical waste: its main components are spent sand/abrasive particles and anti-fouling paint fragments, which can contain persistent toxic substances if the ship has not yet undergone complete remediation from old antifouling systems. Recommended practices include closed-loop recycling of washdown water (with oil/water separation and recovery of waste oils) and alternative old-paint removal methods (high-pressure water, wet grit, plastic particles or wheat starch) to reduce airborne dust generation.
Regulatory Reference
National/local shipyard environmental regulations applicable to hazardous waste management; industry guidelines (e.g. EBRD Environmental and Social Guidelines for Shipbuilding) for best practices in managing blasting residue, washdown water and scrap materials.
Scope of Application
Every dry dock operation involving hull blasting, washing, anti-fouling paint removal or interventions generating special/hazardous waste.
Procedure / How to Complete It
- Verify in advance with the shipyard the procedures for managing blasting waste and the availability of closed-loop treatment plants for washdown water.
- Request the separation and recovery of waste oils generated from hull washdown water before discharge or disposal.
- For ships with old antifouling systems containing organotins, verify the application of specific containment and disposal procedures for blasting residue.
- Prioritize, where available, paint removal methods with lower dust dispersion (high-pressure water, wet grit) over traditional dry blasting.
- Verify that the shipyard uses certified disposal services for the transport and final treatment of hazardous waste generated during docking.
Practical Example
Example of management: during hull blasting of a ship with a previous organotin-based antifouling system, the shipyard applies a closed-loop containment system for the blasting residue, separating it as specific hazardous waste and delivering it to a certified disposal service, distinct from generic shipyard waste.
Real Cases
Common Mistakes Mistake Library
| Mistake | Consequence | How to avoid it |
|---|---|---|
| No preliminary verification of the shipyard's waste management procedures before dry dock entry | Late discovery of non-compliant disposal practices | Verify the shipyard's waste management procedures as part of dry dock entry planning |
| Blasting residue with organotin compounds treated as generic shipyard waste | Risk of environmental contamination at the shipyard site | Always require specific containment procedures for blasting residue from old antifouling systems |
| Hull washdown water discharged without oil/water separation | Release of waste oils into the shipyard environment | Always require closed-loop treatment with separation and recovery of waste oils |
PSC Observations
Operational Tips
- Verify the shipyard's waste management procedures as part of dry dock entry planning, not once docking has already begun.
- Always require specific containment procedures for blasting residue from old organotin antifouling systems.
- Favour shipyards offering closed-loop treatment of washdown water with waste oil recovery.
Checklist
- Shipyard waste management procedures verified during dry dock planning
- Specific containment required for blasting residue from old antifouling systems
- Closed-loop washdown water treatment with oil/water separation verified
- Lower-dust paint removal methods prioritized where available
- Certified disposal services verified for transport and final treatment of waste