Contaminated Land Management


Expertise and Experience

OHMS Environment has the expertise and experience in the assessment and management of contaminated sites in Western Australia within the legislative framework provided within the amendment of the National Environment Protection (Assessment of Site Contamination) Measure 1999 (NEPM) in May 2013 and the Western Australian epartment of Water and Environmental Regulation (DWER) Contaminated sites guidelines.

Contaminated sites services provided by OHMS Environment include but are not limited to the following:

  • preliminary site investigations (PSI);
    development of conceptual site models (CSM);
  • sampling and analysis quality plans (SAQP);
    detailed site investigations (DSI);
  • human and ecological health risk assessment;
    remediation action plans (RAP); and
  • site-remediation and validation (SRV).

Contaminated Site Services

Preliminary Site Investigation (PSI)
A PSI is a desktop assessment and site walk-over that consolidates relevant current and historical information to assist in the development of a preliminary CSM. A PSI summarises the key areas and chemicals of concern and provides the platform for the development of a Sampling and Analysis Quality Plans (SAQP) for implementation as part of a detailed site investigation (DSI), if deemed necessary.

Conceptual Site Models (CSM)
A CSM summarises a site’s environmental setting, potential areas/contaminants of concern, human/ecological receptors and contaminant migration and exposure pathways. CSMs are typically produced in diagrammatic and tabulated formats for inclusion in reports.


Contaminated Site Services

Detailed Site Investigation (DSI)
A DSI generally involves intrusive investigation(s), to characterise the site and the nature and extent of any contamination. The data obtained are then used to update the CSM and assess risk to human and ecological health. A DSI can provide recommendations for further risk assessment or remedial works necessary to meet site management objectives.

Remediation Action Plans (RAP)
RAPs detail the type and extent of remediation required to ensure that the site is suitable for ongoing or future use, while considering risk to the sites surrounds. A RAP specifies remediation methods, clean-up objectives and criteria for assessing the effectiveness of the programme.

Site Remediation and Validation (SRV)
SRV is the implementation of the chosen clean-up approach as specified in a RAP. The validation being the process of evaluating the effectiveness of the remediation works in meeting the clean-up objectives.


Where Science Meets Sustainability

OHMS Environment provides focused & risk-based environmental solutions to support all industries to best manage risks to human and ecological health. In achieving this, we are committed to upholding strong environmental values and the provision of high-quality science within a regulatory framework.