Contaminated Site Assessment
Identifying, Characterising, and Managing Land Contamination to Protect Human Health and the Environment
Contaminated site assessment is the systematic process of investigating land, groundwater, and soil vapour to determine whether contamination is present, what substances are involved, the extent and severity of the contamination, and the risk it poses to human health and the environment. Workers on contaminated sites face occupational exposure to the same substances that define the site's contamination profile — volatile organic compounds, heavy metals, asbestos, PFAS, and petroleum hydrocarbons are simultaneously environmental contaminants and occupational health hazards.
The Phased Assessment Approach
Phase 1: Preliminary Site Investigation
Non-intrusive desktop study — historical records, aerial photographs, council records, planning applications, and site inspection. Produces the conceptual site model identifying potential contamination sources, contaminants of concern, migration pathways, and receptors.
Phase 2: Detailed Site Investigation
Intrusive sampling of soil, groundwater, soil vapour, and sediment. Drilling, test pits, well installation. NATA-accredited laboratory analysis for TPH, BTEX, PAHs, heavy metals, OCPs, PCBs, VOCs, PFAS, and asbestos. Results compared against NEPM HILs, HSLs, and EILs.
Phase 3: Remediation & Validation
If contamination exceeds criteria: remediation strategy development, execution (excavation, in-situ treatment, containment), and validation sampling to confirm criteria achievement. Validation report for regulatory sign-off and property settlement.
Occupational Health on Contaminated Sites
Workers conducting contaminated site assessments and remediation are exposed through inhalation of dust and vapours, dermal contact with contaminated soil and groundwater, and incidental ingestion. Real-time air monitoring during intrusive works is essential. The occupational hygiene monitoring plan for site works must specify action levels, monitoring equipment, escalation procedures, and PPE requirements for each work zone. The ERA and OHMP should be developed in parallel, drawing on the same contamination data.
Commission a Site Assessment
Whether you need a Phase 1 desktop study for a property transaction, a Phase 2 intrusive investigation for a development site, or an integrated contaminated site and occupational hygiene assessment for remediation, OHConnect connects you with verified professionals.