1. London Convention Guidelines for Assessment of Dredged Material
PIANC-Dredged Material
Management Guidance Documents

2. Specific Guidelines for Assessment of Dredged Material
Introduction
Dredging is essential to maintain navigation in ports, harbours, marinas and inland waterways; for the development of port facilities; for flooding mitigation; and for removal of sediments from structures, basins and water intakes. Dredged material worldwide is, by nature, similar to undisturbed sediments in inland and coastal waters. A smaller proportion of dredged material, however, is contaminated by human activity.

3. Evaluation of Need for Dredging and Disposal
CAPITAL DREDGING - for navigation, to enlarge or deepen existing channel and port areas or to create new ones
MAINTENANCE DREDGING - to ensure that channels, berths or construction works, etc., are maintained at their designed dimensions; and
CLEAN UP DREDGING - deliberate removal of contaminated material for human health and environmental protection purposes.

4. The schematic provides a clear indication of the stages in the application of this guidance where important decisions should be made.
Components are:
1. Dredged material characterization
2. Waste prevention audit and evaluation of disposal options
3. Is material acceptable
4. Identify and characterize dump-site
5. Determine potential impacts and prepare impact hypothesis(es)
6. Issue permit
7. Implement project and monitor compliance
8. Field monitoring and assessment (monitoring)

5. Dredged Material Assessment Framework
SOURCE
CONTROL
OTHER NO
YES
CAN MATERIAL
ACCEPTABLE?
BE MADE NO NO
Representation of the Jurisdictional Boundary of the Convention
Dredged Material Assessment Framework NO
YES
YES
IMPLEMENT PROJECT &
MONITOR COMPLIANCE
NEED FOR DREDGING
DREDGED MATERIAL
CHARACTERIZATION
IDENTIFY AND CHARACTERIZE
DISPOSAL SITE
IS MATERIAL
ACCEPTABLE?
DETERMINE POTENTIAL
IMPACTS AND PREPARE
IMPACT HYPOTHES(I/E)S
BENEFICIAL USE
POSSIBLE?
ISSUE PERMIT?
FIELD MONITORING
& ASSESSMENT
YES
BENEFICIAL
USE

6. NEED FOR DREDGING
DREDGED MATERIAL
CHARACTERIZATION
SOURCE
CONTROL

7. CAN MATERIAL IS MATERIAL OTHER BENEFICIAL USE BE MADE ACCEPTABLE?NO NO
OTHER
YES
YES
YES
BENEFICIAL USE
POSSIBLE?
BENEFICIAL
USE NO

8. IDENTIFY AND CHARACTERIZE DISPOSAL SITENO
IDENTIFY AND CHARACTERIZE DISPOSAL SITE
DETERMINE POTENTIAL IMPACTS AND PREPARE IMPACT HYPOTHES(UE)S

9. ISSUE
PERMIT? NO
YES

10. IMPLEMENT PROJECT & MONITOR COMPLIANCE
YES
IMPLEMENT PROJECT & MONITOR COMPLIANCE
FIELD MONITORING & ASSESSMENT

11. Waste Prevention Audit
For dredged material, the goal of waste management should be to identify and control the sources of contamination.
SOURCE CONTROL STRATEGY
1. The continuing need for dredging;
2. The hazards posed by contaminants and the relative contributions of the individual sources to these hazards;
3. Existing source control programmes and other regulations or legal requirements;
4. Technical and economic feasibility;
5. The evaluation of the effectiveness of measures taken; and
6. Consequences of not implementing contaminant reduction.

12. Management Options
Reduce or control impacts to a level that will not constitute unacceptable risks
Treatment
Disposal management techniques
Methods of containing dredged material in a stable manner
The practical availability of other means of disposal should be considered in the light of a comparative risk assessment involving both dumping and the alternatives

13. Dredged Material Characterization
Physical characterization
The basic physical characteristics required are the amount of material
Exemptions from detailed characterization
Dredged material is excavated from a site away from existing and historical sources of appreciable pollution, so as to provide reasonable assurance that the
dredged material has not been contaminated, or
dredged material is composed predominantly of sand, gravel and/or rock, or
dredged material is composed of previously undisturbed geological materials.

14. Chemical Characterization
Available information
Geochemical characteristic
Contaminant routes /sources

15. Biological Characterization
Biological tests should incorporate:
Acute toxicity
Chronic toxicity and sub-lethal effects
The potential for bioaccumulation
The potential for tainting
at and in the vicinity of the disposal site.

16. Action List Chemical and/or biological screening resulting in:
- Wastes containing specified substances, or causing biological responses, exceeding the relevant upper level shall not be dumped, unless made acceptable.
- Wastes which contain specified substances, or which cause biological responses, below the relevant lower levels should be considered to be of little environmental concern.
- Wastes, which contain specified substances, or which cause biological responses, below the upper level but above the lower level require more detailed assessment before their suitability for dumping can be determined.

17. Dump-Site Selection Site Selection Considerations:
Physical, chemical and biological characteristics of the water-column and the seabed
Location of amenities, values and other uses of the sea in the area under consideration
Assessment of the constituent fluxes associated with dumping in relation to existing fluxes of substances in the marine environment
Economic and operational feasibility

18. Important Amenities, Biological Features and Uses of the Sea
The shoreline and bathing beaches
Areas of beauty or significant cultural or historical importance
Areas of special scientific or biological importance, such as sanctuaries
Fishing areas
Spawning, nursery and recruitment areas
Migration routes
Seasonal and critical habitats
Shipping lanes
Military exclusion zones
Engineering uses of the seafloor

19. Site Selection Consideration
Size of the dump-site
Site capacity
Evaluation of potential impacts
Contaminant mobility

20. Assessment of Potential Effects
Impact hypothesis
Integrate waste characteristics / site information
Comprehensive assessment
Emphasis on biological effects / habitat modification
Cumulative impacts

21. Monitoring Compliance monitoring, Field monitoring
Modify or terminate the field-monitoring programme
Modify or revoke the permit
Redefine or close the dump-site
Modify the assessment basis

22. Permit and Permit Conditions
The types, amounts and sources of materials to be dumped
The location of the dump-site(s)
The method of dumping
Monitoring and reporting requirements

23. International Navigation Association PIANC
Dredged Material Management Guide
(Supplement to Bulletin no. 96, 1987
Assessment framework (LC)
Material characterization
Sustainable relocation

24. Contamination source control Management strategy
Management options
Contamination source control
Management strategy
Relevant background literature

25. Disposal Land-based confined disposal - Contaminant release mechanisms
Aquatic (LC guides)
Land-based confined disposal
- Contaminant release mechanisms
- Processes
- Pathways
- Isolation
- Surplus water treatment

26. Confined Disposal Site
Management
Implementation guidelines
Monitoring (physical and environmental)
Evaluation
Optimization

27. Treatment
Pretreatment
Biological
Chemical
Thermal
Immobilization

28. Impact Assessment Long- or short-term Direct or indirect
Beneficial or adverse
Long- or short-term
Direct or indirect
Reversible or irreversible
Local or strategic
Independent or cumulative

29. Monitoring Port operational monitoring
Specification of baseline conditions
Port operational monitoring

30. International Navigation Disposal of Dredged Material
Association
PIANC
Management of Aquatic
Disposal of Dredged Material
(Working Group )

31. Outline 2. Management framework
1. Introduction
2. Management framework
3. Dredged material and site characterization
Survey and sampling methods
Dredged material characterization
- Physical
- Chemical
- Ecotoxicological
- Biological

32. Outline (cont.) Characterization of disposal site - Physical
- Chemical
- Biological
- Functional uses of receiving area

33. Outline (cont.) Effects of disposal - Physical processes
- Physical effects on ecology
- Chemical and ecotoxicological
- Functional uses / amenities

34. Outline (cont.)
International, regional and National environmental controls
- General approaches
- Marine and estuarine disposal
- Inland waterways disposal

35. Planning and engineering for aquatic disposal
- Regulatory decision framework
- Technical decision framework
- Project decision framework

36. Operational aspects of aquatic disposal
- Operations plan
- Monitoring requirements

37. - Description of physical properties of dredged material
References
Annexes
- Description of physical properties of dredged material
- Metals in sediments
- List of international agreements, protocols and guidelines
- Beneficial uses of dredged material in the aquatic environment
- Mitigation measures
- Consideration in design of monitoring plans

38. Managing Contaminated
Dredged Material
Defining CDM
Risks
Chemical characteristics and sources

39. Identifying, Assessing, and
Selecting Options
Planning CDM projects
State-of-the-art technologies
PIANC technical position
Documenting results with case studies

40. The Environmental Facts Where to Find What You Need to Know
Dredging:
The Environmental Facts
Where to Find What You Need to Know
Dredging a vital process
Dredging for sustainable development
Dredging must be safe and sound

41. Sources of Information
CEDA
IADC
WODA
PIANC
IAPH
WEDA
EDA

42. CEDA
IAPH
WEDA
EDA