Groundwater Monitoring in the Era of PFAS & Emerging Contaminants

Introduction

In today’s environmental and construction landscape, the need for robust groundwater monitoring has never been greater. The presence of Per‑ and Polyfluoroalkyl Substances (PFAS) in groundwater is reshaping how we understand contamination pathways, design monitoring networks and meet Environment Protection Authority (EPA) standards. At Nova Group Pacific we support property developers, construction companies, industrial operators and government bodies to navigate this evolving terrain confidently.

In this article we will:

• Explore PFAS migration and its implications for groundwater monitoring
  
• Discuss how to design efficient monitoring networks tailored for PFAS and emerging contaminants
  
• Outline what EPA reporting expectations mean for your project in Australia
  

Understanding PFAS Migration in Groundwater

Why PFAS matter for groundwater

PFAS, often referred to as "forever chemicals", are synthetic compounds that resist degradation and can migrate through soil into groundwater. They are found in a variety of legacy uses: fire-fighting foams at airports and defence sites, manufacturing processes, chemical spills and landfills. The national guidance, the PFAS National Environmental Management Plan 3.0 (PFAS NEMP 3.0), provides a consistent frame for managing PFAS in the environment.

Key migration behaviours include:

• Subsurface flow of PFAS dissolved or sorbed in groundwater and in soil pore-water
  
• Vertical migration, particularly where preferential pathways (e.g., boreholes, cracked aquitards) exist
  
• Lateral spreading from point sources, but also diffuse migration from broader urban/industrial catchments
  
• Long-term persistence and “tailing” behaviour — even where source control is applied, concentrations diminish slowly
  

A recent Australian groundwater study highlighted the challenge of legacy PFAS migration from landfill and industrial sites, showing detectable concentrations and complex hydrochemical interactions.

Key implications for our industry

For property developers, construction companies, industrial operators and local councils, the migration behaviour of PFAS demands a re-thinking of groundwater monitoring. Traditional contaminant models (heavy metals, hydrocarbons) may not fully address PFAS behaviour. Practical implications include:

• Monitoring wells must consider deeper/smaller contaminant plumes and longer-term persistence
  
• Risk assessments must incorporate aquifer connectivity, potential off-site migration and exposure pathways (e.g., groundwater supply, dewatering, off-site receptors)
  
• Early engagement in the concept and design of monitoring programs can significantly de-risk development and remediation timelines
  

For detailed assessment services, see our Groundwater and Surface Water capability.

Designing Efficient Monitoring Networks for PFAS Groundwater

Setting the strategic framework

When designing a monitoring network for PFAS-impacted groundwater in Australia, we recommend taking a structured step-wise approach:

1. Source characterisation – Identify likely PFAS sources (fire-fighting foam training areas, industrial processes, landfills, on-site chemical uses).
   
   
2. Conceptual Site Model (CSM) – Map contamination sources, pathways (soil–groundwater interface, preferential conduits), receptors (groundwater bores, dewatering points, surface water bodies) and conceptual migration zones.
   
   
3. Monitoring objectives – Define clear aims: e.g., early detection of plume migration; dewatering compliance; post-remediation validation; receptor assurance.
   
   
4. Well/point selection – Place sentinel wells at likely migration pathways, receptor zones and along hydraulic gradients. For PFAS this frequently means:
   
   
   • Up-gradient background wells (baseline or ambient PFAS levels)
     
   • Down-gradient “pathway” wells between source and receptor
     
   • Receptor wells near groundwater supplies, dewatering discharge outlets or surface water bodies
     
     
5. Sampling and analytical methods – Ensure selected laboratories are proficient in ultra-trace PFAS analysis, with appropriate QA/QC and detection limits.
   
   
6. Frequency and triggers – Determine monitoring intervals and trigger values (for example, comparison to guideline values or site-specific response levels).
   
   
7. Reporting and response framework – Build in clear response pathways if PFAS exceed thresholds: further investigation, expanded network, remediation linkage.
   

Practical design considerations

• Multi-level monitoring: For aquifers with vertical stratification, multi-level wells provide better resolution of PFAS migration at different depths – this prevents missing vertical migration that a single well screen may not detect.

• ‍Well integrity and hydraulics: Bore integrity, annular seal, well screen placement and sampling methodology are critical to avoid cross-contamination or artefacts given the very low concentrations relevant for PFAS.

• Baseline/ambient levels: Many areas (especially urban/industrial) show low-level PFAS detection. For example, in Western Australia an ambient groundwater investigation found PFAS in 91 % of sampling locations. Establishing site-specific baseline is essential for interpreting detected levels.

• ‍Trigger-response plan: A practical monitoring network must embed a Trigger and Response Plan (TARP), defining when escalation or remediation action is required. The example from a mining ground water PFAS plan in WA describes a four-level monitoring trigger system.

• Integration with soil and surface water: PFAS erodes the boundaries between groundwater, soil and surface water monitoring. Your program may need to include soil pore-water, surface water discharge, and groundwater in a holistic monitoring strategy.
  

Outcomes we aim to deliver

By utilising well-designed monitoring networks, we help our clients achieve:

• Early detection of PFAS migration and reduced risk of unnoticed plume growth‍
• ‍Compliance with modern regulatory expectations (including PFAS NEMP) and improved audit readiness‍
• Quantification of exposure risk to receptors (e.g., groundwater supply bores, dewatering discharges)‍
• Support for remediation design, dewatering management, redevelopment planning and liability management
  

For groundwater and surface water assessment services refer to our Groundwater & Surface Water Assessments capability.

EPA Reporting Expectations in Australia: What You Need to Know

National and state frameworks

Handling PFAS contamination and groundwater monitoring involves navigating multiple regulatory frameworks. Key documents include:

• The PFAS NEMP 3.0 — providing nationally consistent guidance and investigation values for PFAS in soil, groundwater and surface water.
• The National Health and Medical Research Council (NHMRC) review of PFAS in drinking water guidelines, updated in 2025 setting health based guideline values for PFOA, PFOS, PFHxS and PFBS.
• State-level programs such as the NSW Environment Protection Authority PFAS Investigation Program, which identifies legacy PFAS sites and monitors groundwater across NSW.

What this means for your groundwater monitoring and reporting

1. Triggering circumstances – Many state EPAs require notification when PFAS groundwater concentrations exceed investigation levels (for soil or groundwater) or when contamination is identified at development sites. Aligning your monitoring program with those thresholds is critical.
   
   
2. Data quality and laboratories – Regulatory acceptance of PFAS data demands accredited laboratories with ultra-trace detection capability. At Nova Group Pacific we ensure sample analyses are undertaken by NATA-accredited labs.
3. Reporting format – Reports should clearly state: the CSM, monitoring network design, analytical results compared to guideline values, interpretation of trends or migration, and recommended next steps. Reports must be technically robust yet accessible for regulatory review.
   
   
4. Remediation linkage – Where PFAS exceed investigation levels, monitoring results feed into remediation planning or dewatering management. In these cases, the monitoring network must support validation post-remediation or ongoing management.
   
   
5. Stakeholder management – Groundwater monitoring for PFAS often involves sensitive stakeholder issues (neighbouring landowners, councils, water supply authorities). Transparent reporting and clear communications mitigate risk.
   
   
6. Continuous update – Because PFAS science and regulatory guidance are evolving (for example changes in health-based drinking water values), it is critical to design monitoring programs with flexibility to respond to future direction.

How Nova Group Pacific supports compliance

As part of our end-to-end contaminated land and groundwater capabilities, we assist clients with:

• Designing monitoring networks to meet current EPA expectations
  
• Interpreting PFAS analytical results in the context of the PFAS NEMP, NHMRC guidelines and state policy
  
• Preparing regulatory-ready reports and advising on remediation & validation options
  
• Managing stakeholder engagements, audit readiness and long-term monitoring commitments
  

Securing Your Project’s Groundwater Monitoring Strategy

In an era where PFAS and other emerging contaminants are reshaping environmental practice, a well-designed groundwater monitoring network is not a nice-to-have — it is a project imperative. For developers, industrial operators, councils and other stakeholders, key actions today include:

• Integrating PFAS-specific considerations into your site strategy and monitoring design
  
• Leveraging qualified consultants to design networks, interpret results and guide regulatory engagement
  
• Ensuring monitoring programs are flexible, future-proofed and compliant with evolving EPA standards
  

At Nova Group Pacific, we bring deep experience in groundwater and contaminated land investigations, PFAS risk management and regulatory compliance. If you are planning a development, managing an industrial site or facing potential PFAS contamination, we encourage you to speak with our experts.

Book a consultation today and let us help you design a PFAS-ready monitoring network that supports compliance, risk mitigation and project success.