CASE STUDY. PORT SUSTAINABILITY: DREDGED MATERIAL MANAGEMENT

Contact:T.ANGEL DEL VALLSUniversity of CádizUNESCO/UNITWIN7WiCop.Marine and Environmental Sciences Faculty Av. República Saharaui, s/n11510-Puerto Real (Cádiz) SPAINPhone: +34 956 01 6794Fax: +34 956 01 6040e-mail: angel.valls@uca.es

Outline I

General description of the areas Port of Cadiz; Huelva, Santos

Problem description Solutions / measures Effects and lessons learnt

Description of the areas

Cadiz bay

Description of the areas

Cadiz bayEconomy 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

SantosBiggest 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).

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

Problem description

International framework of recommendations for dredged material characterisation and management. London Convention OSPAR etc.

Pose the sediments any risk to the environment?

Solutions and measures 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 Step 3: Physical, chemical and biological characterizations of dredged material.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 ApproachAction Level Approach

AL1 AL2 8XAL2

No risk Evident risk

?

Solutions and measures Management requirements in Spain according

to dredged material characterisationCategory Concentrations Aquatic disposal Type of license Requirements I C< AL1 Free aquatic

disposal Normal authorization

-Sedimentological studies and biological effects (physical/mechanic).

I I AL1< C< AL2 Dumping under controlled conditions

Special authorization

-Controlled dumping and justification. -Impact hypothesis. -Environmental control management. -Corrective measures.

I I I C> AL2 Dumping under adequate management techniques

Special authorization

-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 Endpoints

Sea urchin embryos

Elutriates 48 hours Acute/chronic Arrested or abnormal development

Normal AbnormalInforms on the potential toxic effects of aqueous extracts on pelagic organisms during dredging/disposal.

Solutions and measures Bioaccumulation potential of metals in

commercial clams -Huelva and Cadiz-

Bioassay Exposure route Duration Endpoint

Juvenile clams

Whole sediment

28 days Tissue concentrations of key compounds

Informs on the potential bioaccumulation of compounds in commercial organisms/possible human health risks.

Solutions and measures Dredged sediments from Port of Cadiz

Sample Category Toxicity? Comments Management option

CA1 I No Sand Beach nourishment

CA2 III -Whole sediment

-Elutriates

Mud Confined disposal, isolation depending on Toxicity Identification Evaluations

CA3

II

-Elutriates

-Bioaccumulation potential of Hg

Mud Further assessment

on environmental windowsCA4

Solutions and measures

Dredged sediments from Port of HuelvaSample 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.

Environmental benefits:

Risk-based decisions.

Environmental benefits:

Risk-based decisions.

Integrated approach for dredged material management (CHEMICAL+ECOTOXICOLOGICAL):

Integrated approach for dredged material management (CHEMICAL+ECOTOXICOLOGICAL):

Economic benefits:

Re-use of contaminated but not toxic sediments

Economic benefits:

Re-use of contaminated but not toxic sediments

Costs of characterisation:

Only for not-completely characterised sediments -categoría II-.

Management costs:

For intermediate contaminated sediments causing toxicity.

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