You are invited to ACLCA Victoria's membership presentation on Tuesday 28 May 2013 at 5.30pm to be held at GHD, Level 8, 180 Lonsdale Street, Melbourne. The session will be presented by Joe Duran and Dr Matt Edwards from BlueSphere Environmental on "Terrestrial Groundwater Discharge to Marine Environments".
In order to assess the potential impacts of contaminants from terrestrial aquifers to tidally influenced surface water bodies, it is necessary to understand the basic interaction and mechanisms between the groundwater derived from a terrestrial aquifer with the marine environment. The broad dynamics of groundwater discharge to a marine environment have been well understood for a considerable period of time (over 100 years) and is often simplistically conceptualised by the Ghyben-Herzberg principal, where groundwater in a coastal system discharges to the marine system via a freshwater/saltwater interface. This conceptual model does not discretely characterise the discharge zone, treating the interface as a fixed sharp line in time and space (static model). In reality, the mechanisms of groundwater discharge to a marine environment are more complex and dynamic and are influenced by a number of factors. Numerous local and international studies have demonstrated that the terrestrial component of the pore water which discharges through intertidal zone is typically less than 20%. Due to the complex hydrodynamics which occur within the intertidal zone, the use of terrestrial groundwater concentrations to evaluate potential impacts to a marine environment may be highly misleading, since in terms of the regulatory framework, Maintenance of Ecosystems beneficial use guidelines apply to terrestrial groundwater immediately prior to the point of discharge (i.e. within the intertidal zone). Two separate case studies will be presented which includes the former Pivot site located adjacent to the Maribyrnong River in the Whitehall St Precinct in Yarraville, and the other is a site located adjacent to Port Phillip Bay. The case studies will outline the hydrodynamics within the intertidal zone and the characterisation methods used for quantification of the terrestrial groundwater component in the pore water discharge and how this information can be used for the derivation of site specific trigger levels in accordance with ANZECC (2000).
Joe Duran is a Senior Principal Hydrogeologist at BlueSphere Environmental and has over twenty five years experience as a consultant in the waste and contaminated land industries in Australia and the USA. Joe has completed the groundwater characterisation and remediation of numerous large-scale contaminated sites including the Orica Botany complex (formerly ICI). It was during this project (15 years duration) that he first started to develop specialisation in the characterisation and assessment of the impacts of terrestrial groundwater contamination on marine environments including intertidal pore water, sediments and surface water. Since that time, he has completed studies at an additional nine reference sites in Victoria, NSW and South Australia.
Matt Edwards is an Associate Hydrogeologist at BlueSphere Environmental with ten years experience in the research and consulting sectors, with exposure to the contaminated land, mining and natural resource industries. Matt has been extensively involved over the past five years in assessing tidal influences on groundwater discharges and related contaminant discharges to marine and estuarine systems throughout south eastern Australia. This work has resulted in quantification of both contaminant concentrations and mass loads and, in some cases, a rationalisation of compliance targets, with this work used to inform statutory audits, numerical models and risk assessments.
This seminar is open to ACLCA members and registration prior to Monday 27 May is essential.
Please note that entry will not be permitted after 6pm.
CLICK HERE TO REGISTER
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