Heavy Metals

Summary

Heavy metals such as lead, arsenic, cadmium, mercury and chromium are common environmental contaminants in Australian soil, sediment and groundwater. Identifying and managing heavy-metal contamination is crucial for land redevelopment, remediation, and environmental compliance.

Definition

Heavy metals are naturally occurring metallic elements (e.g., lead, arsenic, mercury, cadmium, chromium, nickel and zinc) that become environmental contaminants when present at concentrations harmful to human health or ecosystems. These substances persist in soils and groundwater and can bioaccumulate in plants and animals.

Why It Matters

Heavy metals are among the most significant contamination issues addressed in Australian environmental consulting and land remediation.

Environmental & human-health impacts

• Toxicity: Many heavy metals are toxic even at low concentrations, affecting neurological, renal and reproductive health in humans and wildlife.
  
  
• Persistence: Unlike organic contaminants, heavy metals do not degrade over time. They accumulate in soil and groundwater, creating long-term liability.
  
  
• Mobility: Acidic or disturbed soils (such as those affected by Acid Sulfate Soils or leachate from hazardous waste) can mobilise metals, increasing groundwater and off-site risk.
  
  
• Bioaccumulation: Metals such as mercury and cadmium enter the food chain through plants and aquatic life, leading to cumulative ecosystem impacts.
  
  

Regulatory & compliance relevance

• Heavy-metal contamination triggers assessment under the National Environment Protection (Assessment of Site Contamination) Measure (NEPM, 2013), which sets health investigation levels (HILs) and ecological investigation levels (EILs) for soil and groundwater. (nepc.gov.au)
  
  
• Regulators such as the NSW EPA, EPA Victoria, and DWER WA require compliance with NEPM criteria and specific sampling, analytical, and reporting standards.
  
  
• Many state planning and development frameworks (e.g., NSW Environmental Planning and Assessment Act 1979) mandate investigation and remediation when heavy metals exceed acceptable thresholds for proposed land use.
  
  

Common Sources of Contamination

• Industrial sites (smelters, foundries, metal-plating or battery facilities)
  
  
• Former fuel depots and mechanical workshops
  
  
• Landfills or fill sites containing construction/demolition waste
  
  
• Agricultural areas impacted by pesticides, fertilisers or biosolids
  
  
• Acid Sulfate Soils releasing metals under acidic drainage conditions
  
  
• Historic paint, solder and fuel residues (e.g., lead-based paint, tetraethyl lead in petrol)
  
  

Understanding heavy-metal contamination is fundamental to environmental due diligence, soil classification and remediation planning. Proper investigation and management of heavy metals protect human health, groundwater, ecosystems and project viability.

When It’s Required

Common triggers

• Environmental Site Assessment (ESA): Phase 1 or 2 assessments where potential contamination from industrial use, fill or construction activity is suspected.
  
  
• Soil & Waste Classification: Excavated soils or stockpiles must be tested for metals to determine if they are General Solid, Restricted Solid or Hazardous Waste under EPA classifications.
  
  
• Remediation Action Plans (RAP): Heavy metals are typically assessed to design appropriate containment, removal or immobilisation measures.
  
  
• Groundwater Monitoring Wells: Installed to detect dissolved metals migration (e.g., arsenic, nickel, chromium VI) and assess plume behaviour.
  
  
• Regulatory approvals: Development consents or environmental licences may require investigation and ongoing monitoring when metal concentrations exceed background levels.
  
  

Key regulatory references

• National Environment Protection (Assessment of Site Contamination) Measure (NEPM 2013) – establishes national soil and groundwater investigation levels.
  
  
• Australian Drinking Water Guidelines – specify limits for heavy metals in potable water. (nhmrc.gov.au)

• State EPA guidelines – detail sampling, analysis, reporting and remediation processes for heavy-metal-impacted land and groundwater.

How We Can Help

At Nova Group Pacific, our environmental consulting and remediation specialists help developers, consultants and regulators manage heavy-metal risks efficiently and compliantly. Our services include:

• Soil and groundwater testing for key heavy metals in accordance with NEPM 2013 and EPA analytical requirements.
  
  
• Site assessments (ESA/DSI) – identifying sources, pathways and receptors for metal contamination.
  
  
• Remediation Action Plans – designing and implementing treatment, containment or validation programs tailored to metal-impacted sites.
  
  
• Waste classification & management – integrating results into EPA-compliant disposal, reuse or containment strategies.
  
  

Whether you are planning redevelopment, remediation or due diligence investigations, Nova Group Pacific can help ensure accurate assessment, compliant documentation and effective management of heavy-metal risks. Contact us today.

Related Terms and Concepts

• Soil & Waste Classification – Determines contaminant levels, including heavy metals, to assign disposal or reuse categories.
  
  
• Environmental Site Assessment (ESA) – The first step in identifying heavy-metal contamination and its extent.
  
  
• Groundwater Monitoring Wells – Used to track dissolved metals migration and assess remediation performance.
  
  
• Remediation Action Plan (RAP) – Outlines site-specific remediation of metals through removal, stabilisation or capping.
  
  
• Hazardous Waste – Waste streams with metal concentrations above hazardous thresholds requiring regulated handling.
  
  
• Acid Sulfate Soils – A condition that can mobilise heavy metals into groundwater, often co-investigated in contaminated-site assessments.