Stephen is the Principal Director of Diomides & Associates Pty Ltd. He is an environmental scientist with over 35 years experience in environmental management and pollution control including 16 years of professional EPA experience in Victoria, and extensive experience and expertise as an environmental specialist in the assessment and clean up of contaminated land. He is a certified Lead Environmental Auditor for environmental compliance and contaminated site audits – Registration No. 14079 on the RABQSA Register of Certified Auditors. This certification has national and international standing.

As Principal Director, Mr Diomides has executive responsibility for all projects undertaken by Diomides & Associates, and his role in the company is in the planning and management of contamination assessment, site remediation, and environmental audit projects throughout Australia. He is engaged as project manager and consultant for contamination assessment and clean-up projects of all types involving current and former industrial sites including oil storage sites, gasworks, chemical works and electroplating workshops. He is also engaged in liaising and negotiating with EPA and other Government agencies, and the provision of expert evidence for VCAT hearings and various court cases.

Academic Qualifications

  • Diploma of Applied Science majoring in Chemistry (1973).
  • Bachelor of Applied Science majoring in Chemistry (1978).
  • Graduate Diploma in Water Science (1979).
  • Member & Chartered Chemist, Royal Australian Chemical Institute.
  • Lead Environmental Auditor (Site Contamination), Certificate No 14079, Register of Certified Auditors of RABQSA International (Since 1996).

Professional Experience Summary


In 1993 as Principal Director he established and subsequently developed the environmental consultancy – Diomides & Associates Pty Ltd.


In 1991, as Director, he established and subsequently developed the Environmental Division, Beveridge Williams & Co Pty Ltd, Victoria. Director responsible for contamination assessment, remediation and waste disposal projects throughout Victoria.


Senior Environmental Scientist, Golder Associates Pty. Ltd, Melbourne. Engaged in the planning and management of waste disposal and contaminant assessment projects throughout Australia.


Regional Control Officer. Environment Protection Authority, Geelong. Responsible for the assessment of complex works approval and licence applications and the supervision of staff engaged in pollution control activities within the south-west region of Victoria.


Executive Officer and Assistant Director, Rural Water Commission of Victoria. Responsible for direction of the Pollution Control Section and the Water Quality Management Section. Provided management for a wide range of monitoring projects and policies for the protection of surface water and groundwater resources.


Water Quality Officer, Senior Water Quality Officer and Principal Water Quality Officer, Rural Water Commission, Pollution Control Section. Responsible for direction of staff engaged in Pollution Control Activities under EPA delegation.



Costa Diomides is a director and a senior environmental scientist with Diomides & Associates Pty Ltd. He has gained many years of professional experience as an environmental scientist and has extensive experience in the environmental consulting field since joining the company in 2001. He is an environmental specialist in contaminated site assessments, site groundwater investigations, site remediation management projects and has been involved in numerous EPA environmental audit projects.

Costa has also been involved in numerous site remediation and site cleanup projects which in many cases have also been part of the EPA statutory environmental audit process. As a Director and Senior Environmental Scientist, Costa’s role is in the planning and management of contamination assessment, site remediation, and environmental audit projects throughout Victoria involving numerous current and former industrial sites including manufacturing sites, oil industry sites, gasworks, transport depots, warehouses, dry cleaning plants, plant nurseries and school sites.

Academic Qualifications

  • Bachelor of Science majoring in Chemistry and Environmental Science at the University of Melbourne (1999).
  • Master of Science in Environmental Management at Victoria University (2001); and,
  • Doctor of Philosophy in Environmental Management at Victoria University. His PhD was awarded in 2006. His PhD topic was to investigate inorganic background soil constituents in Victorian soils, with a focus on arsenic speciation. A database was developed for the storage and convenient analysis of inorganic background soil constituent data including concentrations, within specific Victorian geological groups.