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

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

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

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Shipyard facilities
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Shipyard facilitiesActivities of concern

• 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

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Shipyard facilitiespotential sources of
contaminants

• Underground and above ground storage tanks
• Chemical storage
• Spills and leaks
• Solid waste

• Older facilities through which seepage can occur
• Non-maintained facilities

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Shipyard facilities potential discharges

• 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

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Types of coatings

• Pesticide based
• TBT
• Copper
• Arsenic
• Mercury
• PCBs
• Pesticide free
• Silicone
• Epoxy
• Ablative
• Self-polishing
• Non-ablative

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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

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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

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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

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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

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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

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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.

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1.4 Aerosols, dust and grit

• Environmental health issues
• Contact, breathing
• Safety of Workers
• Spray, grit

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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.

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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)

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2.1 Main Techniques

• Removal techniques
• Scraping
• Blasting
• Grit
• Water
• Collection Techniques
• Sumps
• Berms

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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

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2.1.2 Hull Biofoulant Removal Pressure Washing

• Low-Pressure (lt1,000 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

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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

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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

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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.

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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 reduced due to the
  water-curtain effect, the pollutants not
  eliminated, but transferred from one media (air)
  to another (water)

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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

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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.

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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.

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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.

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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)

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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.

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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.

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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.

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Waste Water Treatment
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Travel Lift System
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Marine Railway System
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Drydock
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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

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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

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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.

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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)

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2.8 Floating Treatment Plant

• System developed in 1999
• Waste separation and carbon treatment
• TBT lt 50 ng/l

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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

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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.

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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

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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