Measures for the Safe Removal, Collection and Disposal of Harmful Anti-fouling Systems

1. Measures for the Safe Removal, Collection and Disposal of Harmful Anti-fouling Systems Edward Kleverlaan IMO-Technical Officer

2. Introduction • Issues - general • Article 5 of the AFSC • Look at : • Removal techniques • Collection techniques • Disposal / Treatment methods • Summary

3. Shipyard facilities

4. Vessel repair and maintenance Fueling Painting Paint stripping Public access and recreation Building/grounds maintenance Chemical storage and handling Ship liquid discharges Ship breaking Cargo handling Shipyard facilities:Activities of concern

5. Underground and above ground storage tanks Chemical storage Spills and leaks Solid waste Older facilities through which seepage can occur Non-maintained facilities Shipyard facilities:potential sources of contaminants

6. Hazardous waste Anti-fouling systems Biocides Solid Waste Dry and liquid bulk Bilge Water Ballast Water Cleaning agents Nutrients Liquid waste Hydro blast streams Anti-fouling outwash Storm water discharge Fuel and hydraulic leaks Oil Sewage Particulate matter Shipyard facilities: potential discharges

7. Typesof coatings • Pesticide based: • TBT • Copper • Arsenic • Mercury • PCBs • Pesticide free • Silicone • Epoxy • Ablative • Self-polishing • Non-ablative

8. ARTICLE 5 - Waste Materials • ….a Party shall take appropriate measures in its territory to require that wastes from the application or removal of anti-fouling system controlled in Annex 1 be collected, handled, treated, and disposed of in a safe and environmentally sound manner to protect human health and the environment

9. Main AFSC Issues • Increased paint removals/overcoats by AFSC – ban of use of TBT by September 2008 • Worker Health issues: Increased (gases, dust, aerosols) • Problems with removal of fouling organisms, paint residues, paint chips, and grit increase • Handling and long term disposal of hazardous substances

10. 1.1 Bio-fouling • Biofoulants – The actual biofoulant organisms can pose a threat of pollution from: • TBT or other pesticide contamination • Increased Biological Oxygen Demand (BOD) if dumped in the sea • Non-Indigenous Species

11. 1.2 Contaminated dust and particles • Cleaning of vessel bottoms creates dust and paint particles whatever the coating • Need to contain the dust • Need to treat the wastes produced

12. 1.3 Contaminated water • Contaminated water must be contained • Sumps • Berms • Contaminated water must be treated • Treatment systems can be expensive and complex • But basic solids control is not expensive

13. Examples of poor collection and treatment • Lack of proper containment during antifouling paint removal can result in deleterious substances being released into the aquatic environment.

14. 1.4 Aerosols, dust and grit • Environmental health issues • Contact, breathing • Safety of Workers • Spray, grit

15. 2 Best Management Practice • Definition: Good Housekeeping • conduct everyday activities in a more ecologically-sound and safe manner: keeping pollutants out of surface waters and ground waters, and, recognizing that total containment and recovery is not always practical.

16. 2.1 Best Management Practices BMPs fall into two general groups: • Source-control (e.g., vessel shrouding, sweeping, covering waste piles, and bermed storage for wastes and paints) and • Collection, filtration and treatment (e.g., hull washwater settling tanks and filters)

17. 2.1 Main Techniques • Removal techniques • Scraping • Blasting • Grit • Water • Collection Techniques • Sumps • Berms

18. 2.1.1 Hull Biofoulant Removal • The primary processes for removal of hull biofoulants are scraping and pressure washing. • Hand Scraping – using large flat-bladed scrapers, generally has a slow production rate, and is only suited for working on small areas • Mechanical Scraping – Many types of mechanical scrapers have been developed that clean the hull down to the surface of the coating

19. 2.1.2 Hull Biofoulant Removal Pressure Washing • Low-Pressure (<1,000 psi) Water Washing – useful in removing “slime” and other low adhesion biofoulants • High-Pressure (1,000 – 5,000 psi) Water Washing – is very effective in removing low and high adhesion biofoulants • Pressure Washing with Chemical Additives – increases the effectiveness of biofoulant removal

20. 2.1.3 Management of Biofouling Waste • Removed fouling organisms should be collected for disposal • Sweep, vacuum , biofouling organisms and deposit in containers for disposal • Do not allow biofouling organisms to sit around the yard in containers it could cause heath problems and attract pests

21. 2.2.1 Paint Removal Dry Abrasive Blasting • Sand abrasives are generally considered to have the highest emission rates of particulate matter • Slag abrasives • Furnace Slag (possible PAH Contamination) • Smelter Slag (possible Metal Contamination) • Mineral abrasives, such as garnet, are mined and processed into abrasives • Metallic abrasives include iron and steel shot and grit • “Alternative” types of abrasives • glass abrasive • dry-ice

22. 2.2.2 Blasting Grit media choice • Some rules-of-thumb for media selection: • Choose the least aggressive media. This will result in less wear and lower equipment maintenance expense. • Use the smallest media particle size - more effective. More impacts per second will yield a faster process. • Find the lowest blast pressure. This offers the benefits of energy savings in reduced compressed air requirements, as well as less wear and lower maintenance costs.

23. 2.2.3 Blasting Types - 1 • Compressed Air Dry Abrasive Blasting –process has highest pollutant emission rates, particulate released directly to the air, and the abrasive is not reused • Slurry Blasting – uses water instead of air as the medium to accelerate the abrasive. air emissions greatly reduceddue to the “water-curtain” effect, the pollutants not eliminated, but transferred from one media (air) to another (water)

24. 2.2.3 Blasting Types - 2 • Open-Loop Dry Abrasive Blasting processes - abrasive is reused outside loop. • Depending upon type of abrasive being used and the use of an abrasive cleaning process prior to reuse, the particulate emission rates can be significantly decreased or increased. • Closed-Loop Dry Abrasive Blasting processes continuously contain both the abrasive and the particulate emissions with the blasting system. • Lowest emission rates of dry abrasive systems and prevents contamination of the dry-dock floor with spent abrasive

25. 2.2.4 Management of spent grit • Avoid spent abrasive and dust to re-suspend in the air by wind, or transport by runoff to the surface waters. • Reduce the amount of pollutants that reach the environmental media of concern by increasing the cleaning frequency to remove accumulated abrasive and dust prior to exposure to rainfall and/or other sources of runoff. • Covered Dumpsters/Bins – Covering dumpsters and bins being used to store spent abrasive prior to transport to a storage or containment area prevents the re-suspension of dust.

26. 2.2.5 Reduce and recycle – spent grit • Clean all deck surfaces of spent grit (by sweeping, brushing, shovelling and vacuuming) prior to submersion. • Clean and collect spent grit from yard areas at the end of the work shift • Filter or provide collectors around yard drains to prevent flushing of spent grit into the storm water runoff or sewer system • Recycling of spent abrasive for use as an aggregate material in the production of asphalt and cement “clinker”.

27. 2.3.1 Management of Paint Chips (TBT) • Difficult to separate grit from paint chips • Continuous cleaning of the yard surface and containment of the waste paint will help reduce contamination of the water.

28. 2.4 Waste Water • Water management is probably the largest waste stream • Recovery and reuse of water can have a significant reduction on pollution loadings • Percent recovery of liquid waste stream (volume of water used/volume of water disposed)

29. 2.4.1 Collection of Hull Waste Water • Collect hull washwater and remove all visible solids before discharging to a sewer or receiving waters. Inspect and clean all sumps, filters and/or screens regularly • Avoid any high pressure washing of hull unless prior clean-up of the dock floor, lift platform, or yard surface is completed. • Various treatment systems are available to remove the contaminants from hull washwater.

30. 2.4.2 Collection of Hull Waste Water • Option 1 - Very Low concentrations of suspended solids and/or organics (e.g. storm water), • collected wastewater can be pumped and disposed of directly into the sanitary sewer system. • Option 3- If the volume of wastewater is relatively small and contains a high concentration of solids, • the wastewater can be directly processed by a mechanical filter system.

31. 2.4.3 Collection of Hull Waste Water • Option 2 - usually applicable to ship and boat building and repair facilities with large volumes of wastewater containing high concentrations of solids. • An engineered holding settling tank system is an important component of the treatment system. The settling tank is designed to remove most of the solids. • After treatment, the clarified effluent or overflow from the holding/settling tank can be discharged into the sewer system. • The settled sludge can be further processed by dewatering through a mechanical filter and then disposed of at an approved facility.

32. Waste Water Treatment

33. Travel Lift System

34. Marine Railway System

35. Drydock

36. 2.4.3 Add On Controls for drydocks • Drydock/ground liquid barriers • impervious barrier, may be temporary or permanent, prevents contact of the waste stream with the ground or floor of the drydock, contains the waste stream until it can be removed • Filter System/Barrier • barrier that filters the waste stream as it flows from the drydock

37. 2.5 Treatment Technology • No “off-the-shelf ” technology that will reduce TBT levels in water to below safe-levels (less than 30-50 parts per trillion, ie 50ng/l) • Unproven technology such as Dissolved Air Floatation, and Activated Carbon Adsorption are the best candidates to destroy TBT in waste streams

38. 2.6 Alternates • Alternative processes include the use of oxidizers (hydrogen peroxide and ozone) and the use of UV light to degrade TBT in wastewaters • Heat agitation and organic solvents to separate TBT from water are also used.

39. 2.7 Treatment with activated sludge • TBT will attach to organic material and bind loosely. • Treats up to 20 tonnes of effluent per hour. Concentrating the TBT into a small volume of oil which can be safely incinerated or re-used. • Industrial waste streams from shipyards have measured TBT levels as high as 480,000 ng/L, which is known to be sufficient to kill the bacteria in activated sludge (Argaman et al, 1984)

40. 2.8 Floating Treatment Plant • System developed in 1999 • Waste separation and carbon treatment • TBT < 50 ng/l

41. 3.1 Summary Removal Methods • Removal of paint and fouling organisms can be performed in a number of ways • Abrasive Grit • High pressure Hydroblasting • Ultra high pressure Hydroblasting • Mechanical removal (scraping) • What is the best way? • Ultra high pressure is currently recommended

42. 3.2 Summary Treatment/Disposal • Waste treatment is possible at high cost • Treat to the level that can be achieved practically and economically • Good housekeeping is the key to waste reduction.

43. 3.3 Summary • Contamination Sources • Fouling organisms- living and dead • Paint Chips • Grit • Spraying • Reduction of waste and treatment • Use Best Management Practice for source reduction, collection and treatment

44. 4 Summary • REMEMBER • Keep it practical and safe for workers • Containment: primary step in waste management • Recycling: further step in reduction of waste and overall cost for treatment/disposal • Untreated hazardous waste TBT and other biocidal paint chips: special waste to land sites or treated by purpose built systems • THANK YOU