3041
Geo-environmental challenges of a major coal terminal development in Australia
Défis géo-environnementaux du développement d'un terminal majeur de charbon en Australie
Jones S.R.
Douglas Partners Pty Ltd
ABSTRACT: This paper describes the integration of geotechnical, environmental and groundwater investigations for the Terminal 4
Project in Newcastle, Australia, aimed at identifying appropriate remediation measures to protect human health and environmental
values. The site presented a series of complex challenges due to its geological setting, previous uses for waste disposal and adjacent
environmentally sensitive areas. Past industrial wastes have caused contamination of soil and groundwater. The site and adjoining
wetlands form habitats for protected flora and fauna species. Without mitigation measures, the proposed coal terminal development
would have the potential to increase the mobilisation and flow of contaminants off site into the wetlands and other environmental
receptors. Geotechnical and groundwater modelling was undertaken, resulting in a series of remediation and mitigation measures for
specific identified risks. The implementation of the proposed remediation and mitigation measures for the project will protect
environmental values, and is expected to improve the long-term environmental condition of the project area and immediate surrounds.
RÉSUMÉ : Ce document décrit l'intégration des études géotechniques, environnementales et de sondages des eaux souterraines du
Projet Terminal 4, afin que des mesures d'assainissement appropriées puissent être mises en œuvre pour protéger la santé humaine et
l’environnement. Le site présente plusieurs défis complexes en raison de son contexte géologique, de son utilisation historique pour
déposer des déchets et de sa proximité avec des zones à caractère environnemental sensible. Les déchets industriels ont entraîné la
contamination des sols et des nappes souterraines. Le site forme avec les marécages adjacents des habitats pour des espèces protégées
de la flore et de la faune. Le développement proposé du terminal de charbon a le potentiel d’accroître la mobilisation et la circulation
des contaminants hors du site, et par là-même de contaminer les marécages adjacents ainsi que d'autres récepteurs de l'environnement.
Les résultats des modélisations géotechniques et d'écoulement des eaux souterraines ont entraînés une série de mesures d'atténuation
des risques identifiés. La mise en œuvre du projet d'assainissement et des mesures d'atténuation pour le projet protégera les valeurs
environnementales, et devrait permettre d'améliorer sur le long terme l'état de l'environnement.
KEYWORDS: coal export, landfill, soil and water contamination, barrier wall, permeable reactive barrier, multi-phase extraction.
1 INTRODUCTION
Kooragang Coal Terminal on Kooragang island near Newcastle,
Australia is the world’s largest coal export facility with an
export capacity of 120 Mtpa. It is planned to substantially
increase the size of the facility by construction of a new
adjoining terminal, known as Terminal 4. The location of the
site is shown in Figure 1.
The site has a total area of 246 ha and comprises reclaimed
land over soft alluvial soils. For 40 years the site was used for
dumping of various industrial wastes, leading to significant soil
and groundwater contamination.
Industrial landfill cells were constructed in the 1970s and
80s by pushing out slag bund walls and filling in between; no
base or side liners were installed. It is proposed to fill and level
the site by dredging approximately 5 million m
3
of sand from
the nearby Hunter River. The development will impose
significant loads to the ground and the sand will also be used as
surcharge material for ground improvement purposes.
The groundwater system comprises dual aquifers connected
to the adjacent Hunter Estuary Wetlands that support
endangered flora and fauna. These sensitive wetlands are a
national park and listed by the Ramsar Convention as having
international importance. The wetlands and two arms of the
nearby Hunter River represent the environmental receptors
requiring protection.
The complex conditions presented many geotechnical and
environmental challenges to the project. The project is unique to
Australia, and relatively unusual worldwide, whereby multiple
remediation technologies will be implemented on a large scale.
Some of the proposed remediation measures have had only
limited previous application in Australia.
The work included extensive field investigations, laboratory
testing, water level monitoring, groundwater flow modelling
and contaminant transport modelling.
Figure 1. Location of Kooragang Island, near Newcastle, Australia.
