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Our People

Contact our Senior Staff Members for more information on the wide range of geotechnical and environmental consultancy services we can offer.

JK Geotechnics

Linton Speechley

Director / Principal Geotechnical Engineer

Specialising in slope stability, shoring and retention system analysis, landslide risk assessments.  Linton has wide-ranging experience on a variety of technically challenging projects in NSW and interstate and was part of the JKG peer review team for the Port Botany expansion.

Andrew Jackaman

Director / Principal Geotechnical Engineer

Specialising in dam and levee investigations and assessments, deep basement excavations, earthworks, landslide and river bank stabilisation. Andrew’s experience extends throughout NSW and interstate. He has distinguished himself as the geotechnical lead in multi-disciplinary design teams focusing on smart, practical and cost effective solutions.

Peter Wright

Director / Principal Geotechnical Engineer

Peter specialises in pavement design, analysis of shoring and retention systems, with a particular interest in landslide risk assessment for residential projects and council roads.  Peter’s extensive experience consistently enables him to develop cost effective solutions for sites and projects with complex geotechnical issues.

Paul Stubbs

Senior Consultant / Geotechnical Engineer

Paul continues to be involved in more complex and/or sensitive projects, forensic analysis of damaged structures and slope failures, projects with a high component of engineering geology, and providing expert reports.

Rolf Rohleder

Principal Geotechnical Engineer

Rolf has over 25 years’ experience in the consulting engineering industry, both in Australia and abroad. He is a Chartered Engineering Geologist / Geotechnical Engineer and has developed expertise in most areas of geotechnical engineering, including project management of multi-discipline projects from feasibility design to construction.  He has an interest in site investigations, ground modelling, slope stability, and ground improvement.

Woodie Theunissen

Principal Geotechnical Engineer

Woodie has worked on a wide range of infrastructure, industrial, commercial and residential developments. This has included the management of investigations, preparation of interpretive reports, completion of both 2D and 3D numerical analysis and the provision of advice during the construction period. Woodie has extensive experience in working collaboratively in multidisciplinary teams to assist in developing solutions that meet both the client’s and infrastructure owner’s requirements.

Paul Roberts

Principal Engineering Geologist (QLD office)

Specialising in landslide risk assessments, slope stability analyses, coastal and river bank erosion assessments, as well as providing geotechnical advice for residential, industrial and commercial developments and expert witness services. Paul manages JK Geotechnics operations in Queensland. Paul can be contacted for all your projects’ geotechnical and engineering geological requirements in Queensland.

Adrian Hulskamp

Principal Associate Geotechnical Engineer

Adrian has a wide range of experience throughout the Sydney area and beyond, meeting the needs of a broad range of public and private sector clients. Adrian has extensive experience assessing the geotechnical stability of sites for projects in the Snowy Mountains region of NSW, in accordance with the requirements of the Kosciuszko Alpine Resorts Geotechnical Policy.

Nicholas Smith

Principal Associate Geotechnical Engineer

Specialising in developments near road and rail corridors.  Nick has a comprehensive understanding of the geotechnical challenges associated with developing above and adjacent to rail and road corridors in the Sydney metropolitan area. He has also been involved in a number of technically challenging land-based and foreshore developments.

Ali Parsa

Associate Geotechnical Engineer

Ali has a PhD in Geotechnical Engineering and is our primary geotechnical analysis engineer specialising in 2D and 3D FE analysis of all manner of technically challenging developments with a complex range of geotechnical issues.

Matthew Pearce

Associate Geotechnical Engineer

Matt has been involved in the construction stages of a number of large projects including the UTS ITE Building. He was also JKG’s project manager for the viaduct section of the Metro North West Line. Matt provides geotechnical advice for all types of projects from design development through to construction.

Owen Fraser

Associate Geotechnical Engineer

Owen have over 12 years’ experience in geotechnical engineering projects throughout NSW. He has primarily specialized in planning and implementing site investigations across various sectors, including residential and commercial developments. He has regularly also undertaken analysis for slope stability, retention systems, and groundwater seepage using established software.

David Schwarzer

Associate Geotechnical Engineer

David has experience spanning a wide range of critical areas in the construction industry. David has extensive knowledge of landslide risk assessment, analysis and stabilisation works, excavation and rock face stabilisation, hydrogeological modelling and analysis. David has worked on a variety of infrastructure, industrial, commercial and residential projects.

Arthur Billingham

Associate Geotechnical Engineer

Arthur has been with JK Geotechnics since 2015 and has acquired experience on a broad range of projects across various sectors, including key infrastructure, residential, commercial and industrial developments. He is experienced in overseeing and planning site investigations, including specialised field testing and monitoring. Arthur is a fully accredited risk assessor having completed the TfNSW Slope Risk Assessment training course.

Michael Egan

Associate Geotechnical Engineer

Michael has over ten years of professional experience with areas of interest including deep basement excavations, slope stability assessments, coastal infrastructure works, and damage cause assessments. Michael was jointly awarded the Australian Geomechanics Society (Sydney Chapter) Young Geomechanics Professional of the Year in 2023 and is committed to providing on-time delivery of projects with best practice and cost-effective solutions.

Thomas Clent

Associate Engineering Geologist

Tom is an Engineering Geologist with over 10 years’ consulting experience in Australia, New Zealand and the UK. Tom has worked on a broad range of projects across the commercial, residential and infrastructure sectors. Key areas of interest include landslide risk assessments, slope stability and coastal engineering.

Bruce Walker

Senior Consultant

Bruce is a highly respected senior member of the Sydney geotechnical community. Bruce was the Convenor of the Working Group which prepared the AGS Landslide Risk Management Guidelines first published in March 2000. Bruce now acts as an independent geotechnical consultant primarily involved in peer review and expert reports.

Agi Zenon

Senior Consultant

Agi now acts as a specialist geotechnical consultant primarily involved in select projects and expert reports associated with insurance claims and court related matters.

JK Environments

Brendan Page

Director / Principal Environmental Scientist

Brendan has worked as an environmental consultant since 2006 and is currently the Principal Environmental Scientist and the team manager for JK Environments (JKE). Brendan is a Certified Environmental Partitioner, Site Contamination Specialist (CEnvP SC) under the EIANZ scheme and he has extensive experience designing and implementing site investigations, managing projects and providing technical review of reports. Brendan also provides expert support for contaminated land matters subject to proceedings in the Land and Environment Court of NSW.

Vittal Boggaram

Principal Associate Environmental Scientist / Environmental Engineer

Vittal has over 20 years’ experience in environmental consulting both in Australia and India. He specialises in contaminated land investigations, hydrology, remote sensing and climate resilience. He has worked with various clients, including government organisations, on complex environmental issues to achieve sustainable solutions. His expertise range from providing expert witness in court proceedings, systems management of JK Group, project management of multi-discipline projects, training and management of JK Environments (JKE) staff.

Todd Hore

Senior Associate Environmental Scientist

Todd has over 20 years’ experience as an Environmental Engineer, specialising in providing site contamination, waste and remediation consulting services across projects ranging from small scale residential developments to large commercial/ industrial and infrastructure developments. Todd has managed multiple large, state significant developments under independent environmental site audits.

Mitchell Delaney

Senior Associate Environmental Scientist (QLD office)

Mitch has over 15 years’ experience in environmental consulting and is a Certified Environmental Practitioner, Site Contamination Specialist (CEnvP SC) under the EIANZ scheme. Mitch has worked with various clients, ranging from state and local government agencies to private developers, on complex environmental issues associated with landfills, slipways, schools and hospital development sites. His expertise includes landfill gas and soil vapour assessment. Mitch manages JK Environments (JKE) operations in Queensland.

Katrina Taylor

Associate Environmental Scientist

Katrina has over 13 years’ experience in environmental consulting in Australia and over 5 years remediation contracting experience in the UK. She specialises in contaminated land investigations and hazardous building materials surveys and is a NSW Licenced Asbestos Assessor (LAA). Her expertise range from portfolio management of large government contracts for schools and emergency services, to assisting with training and management of junior staff.

Craig Ridley

Associate Environmental Scientist

Craig has a wide range of experience in contaminated land consulting throughout Sydney and regional NSW. Craig has extensive experience in designing, implementing and reporting on contaminated land investigations for large sites including hospitals, residential care facilities and state significant developments.

Harry Leonard

Associate Environmental Scientist

Harry has a wide range of experience in hazardous materials and contaminated land consulting throughout Sydney and NSW. Harry has extensive experience in undertaking hazardous building material surveys and contaminated land investigations for large sites including hospitals, school and industrial developments. Harry is a NSW Licensed Asbestos Assessor (LAA).

Other Technical Staff

Duncan McDermott

JK Drilling Operations Manager

Manager of JK Drilling and is responsible for the overall management and ongoing quality and development of the JKD team, works completions and fleet of drilling, CPT and specialised rigs.

Duncan holds an MBA from Macquarie University and has over 30 years’ experience in the Drilling industry.

David Treweek

STS Laboratory Manager

David heads our in-house, NATA-accredited soil and rock testing laboratory Soil Test Services (STS), and is a former Director of the JK Group of companies. Dave has over 45 years’ industry experience in all aspects of laboratory testing, including overseeing adherence to testing standards and equipment certification and maintenance.

Tom Finnegan

STS Assistant Laboratory Manager

Tom leads our earthworks team within Soil Test Services (STS). With over 25 years’ experience in earth works Toms extensive knowledge of earthworks practices are invaluable to both our clients and our team.

Contact us today to see how we can help you.