Transcript CASE STUDY. PORT SUSTAINABILITY: DREDGED MATERIAL MANAGEMENT Contact: T.ANGEL DEL VALLS University of Cádiz UNESCO/UNITWIN7WiCop. Marine and Environmental Sciences Faculty Av.

CASE STUDY. PORT
SUSTAINABILITY: DREDGED
MATERIAL MANAGEMENT
Contact:
T.ANGEL DEL VALLS
University of Cádiz
UNESCO/UNITWIN7WiCop.
Marine and Environmental Sciences Faculty Av. República
Saharaui, s/n
11510-Puerto Real (Cádiz) SPAIN
Phone: +34 956 01 6794
Fax: +34 956 01 6040
e-mail: [email protected]
Outline I

General description of the areas

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

Port of Cadiz; Huelva, Santos
Problem description
Solutions / measures
Effects and lessons learnt
Description of the areas

Cadiz bay
Description of the areas

Cadiz bay
 Economy
has been principally based on
maritime commerce, fishing and ship
construction as it hosts an important shipyard.
 It is entry and exit door for merchant traffic
from the European Union to the Magreb
countries and also connects the Iberian
penynsula with Canary Islands.
Description of the areas

Huelva
Description of the areas

Huelva
 Important
mining and metallurgical activities
dating back three thousand years and based
on pyrite (FeS2) and other sulphuric minerals.
 Important industrial and fishing port with
several dockyards and quays.
Description of the areas

Santos
Description of the areas

Santos
 Biggest
Brazilian industrial complex while
major Latin American port.
 Environmental importance: São Vicente
Estuarine System surrounded by mangroves
(43% of total mangrove area of São Paulo).
Problem description

Dredging is an essential activity for maritime
navigation:


Deepening navigable waterways
Maintenance dredging
 sand and mud deposited by water currents
 estuarine areas –high deposition of riverine
sediments.
Problem description
Pose the sediments any risk to the
environment?
International framework of recommendations
for dredged material characterisation and
management.
 London Convention
 OSPAR
 etc.
Solutions and measures

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

Step 1: Project planning, including the nature
and the scope of the activities, the potential
dredged material placement options and the
regulatory requirements.
Step 2: Initial evaluation, where available data is
examined. It may lead to the conclusion that no
further pre-dredging evaluations are needed. If
needed, one proceeds to Step 3.
Step 3: Physical, chemical and biological
characterizations of dredged material.
Step 4: Interpretation of results of the data
assembled and evaluated.
Solutions and measures

Traditional physico-chemical characterisation
 Grain
size/TOM
 Metallic compounds –As, Cd, Cr, Cu, Hg, Ni, Pb, Zn
 Organic compounds –Σ7PCBs
 Not always required- Σ12PAHs

Comparison with limit values in use National Action
Levels, i.e. Spain
 Other empirically derived SQGs, i.e. TEL/PEL;
ERL/ERM; etc.
Solutions and measures
Action Level Approach
AL1
No risk
AL2
?
8XAL2
Evident risk
Solutions and measures

Management requirements in Spain according
to dredged material characterisation
Category Concentrations Aquatic disposal
Type of license
I
C< AL1
Free aquatic
Normal
disposal
authorization
II
AL1< C< AL2
Dumping under
controlled
conditions
Special
authorization
III
C> AL2
Dumping under
adequate
management
techniques
Special
authorization
Requirements
-Sedimentological
studies and biological
effects
(physical/mechanic).
-Controlled dumping
and justification.
-Impact hypothesis.
-Environmental control
management.
-Corrective measures.
-Contaminants sources
study and source
control measures
-Isolation techniques
and justification.
-Impact hypothesis.
-Environmental control
program.
-Corrective measures.
Solutions and measures

Ecotoxicological characterisation of sediment
samples from Huelva, Cadiz and Santos
Bioassay
Exposure
route
Duration
Type of tests
Endpoints
Adult amphipod
Whole
sediment
10 days
Acute
Mortality
Informs on the
potential toxic effects
of sediments on
benthic infauna.
Solutions and measures

Ecotoxicological characterisation of sediment
samples from Huelva and Cadiz
Bioassay
Exposure route
Duration Type of tests
Sea urchin
embryos
Elutriates
48 hours Acute/chronic Arrested or abnormal
development
Informs on the
potential toxic effects
of aqueous extracts
on pelagic organisms
during
dredging/disposal.
Normal
Endpoints
Abnormal
Solutions and measures

Bioaccumulation potential of metals in
commercial clams -Huelva and CadizBioassay
Exposure route
Duration Endpoint
Juvenile
clams
Whole
sediment
28 days
Informs on the potential
bioaccumulation of
compounds in commercial
organisms/possible human
health risks.
Tissue concentrations
of key compounds
Solutions and measures

Dredged sediments from Port of Cadiz
Sample
Category
CA1
I
No
Sand
Beach nourishment
CA2
III
-Whole sediment
-Elutriates
Mud
Confined disposal, isolation
depending on Toxicity
Identification Evaluations
Mud
Further assessment
on environmental windows
CA3
CA4
II
Toxicity?
-Elutriates
-Bioaccumulation
potential of Hg
Comments
Management option
Solutions and measures

Dredged sediments from Port of Huelva
Sample
Category Toxicity?
Comments
Management option
H1
I
-Whole sediment
Mud
Confined disposal, soft isolation
H2
III
-Whole sediment
-Elutriates
Mud
Confined disposal, hard isolation
H3
III
-Whole sediment
Mud/sand
Separation (sand/mud)
Confined disposal, hard isolation
H4
I
No
Coarse
Land reclamation
Construction
Solutions and measures

Dredged sediments from Port of Santos
Sample
Category
Toxicity?
Comments
Management option
SSV1
I
No
Fines <10%
Beneficial uses
SSV2
II
Yes
Fines <10%
Not suitable for sea disposal
SSV3
II
Yes
Fines <10%
Not suitable for sea disposal
SSV4
I
Yes
Fines <10%
Not suitable for sea disposal
SSV5
I
Yes
Fines <10%
Not suitable for sea disposal
SSV6
I
Yes
Fines <10%
Not suitable for sea disposal
Further information on potential toxicity would allow to identify
least detrimental management option.
Integrated approach for dredged material management
(CHEMICAL+ECOTOXICOLOGICAL):
-
+
Costs of characterisation:
Only for not-completely
characterised sediments categoría II-.
Management costs:
For intermediate
contaminated sediments
causing toxicity.
Environmental benefits:
Risk-based decisions.
Economic benefits:
Re-use of
contaminated but not
toxic sediments