NSW EPA Updates PFAS NEMP Position Statement, Clarifying Pragmatic Approach to 0.0005 µg/L PFOS Biota Screening Threshold

NSW EPA Updates PFAS NEMP Position Statement: What the 0.0005 µg/L PFOS Biota Screening Threshold Means for Site Investigations

Overview

The New South Wales Environment Protection Authority (NSW EPA) released an updated Position Statement on the PFAS National Environmental Management Plan (NEMP), formally aligning state regulatory guidance with the PFAS NEMP 3.1 framework published by the Heads of EPA Australia and New Zealand. This update is not a minor administrative revision. It introduces several substantive changes to the technical thresholds and assessment triggers that practitioners must apply when investigating PFAS-contaminated sites in New South Wales, and it carries significant flow-on implications for project scoping, sampling design, and risk characterisation.

The most consequential change is the formal adoption of the Australian and New Zealand Guidelines for Fresh and Marine Water Quality (ANZG) freshwater biota screening threshold for perfluorooctane sulfonate (PFOS) of 0.0005 µg/L, equivalent to 0.5 ng/L. This concentration is extraordinarily low. It reflects the well-documented capacity of PFOS to bioaccumulate in aquatic organisms and biomagnify through the food chain, ultimately reaching air-breathing predators including piscivorous birds and mammals that feed on aquatic prey. The threshold is designed to protect those apex predators, not aquatic organisms themselves, which means standard water quality monitoring alone cannot determine whether a meaningful ecological risk exists at a given site.

The update also integrates the revised Australian Drinking Water Guidelines (ADWG) published by the National Health and Medical Research Council (NHMRC), and references the ANZG freshwater ecological guideline values for PFOS. Taken together, these changes represent the most substantive recalibration of PFAS assessment criteria in New South Wales since the original PFAS NEMP guidance was introduced, and practitioners advising developers, councils, and transacting parties need to understand precisely what has changed and what it requires of them.

Key details of the PFAS NEMP 3.1 updates adopted by NSW EPA

The centrepiece of the update is the 0.0005 µg/L (0.5 ng/L) PFOS freshwater biota screening threshold derived from the ANZG guidelines. This value applies to surface water and is intended as a trigger for further ecological assessment rather than a remediation target in its own right. To place this in context, 0.5 ng/L is approximately 14 times lower than the previous ANZG default trigger value that many practitioners had been applying, and it is routinely exceeded in stormwater runoff from urban, commercial, and light-industrial catchments across New South Wales. Detection at or above this concentration does not automatically constitute an unacceptable risk; it indicates that a more detailed, receptor-focused evaluation is required.

The NSW EPA has been explicit in its updated position statement that it does not expect routine or widespread biota sampling in all cases where the 0.0005 µg/L threshold is exceeded. This clarification is critically important for practitioners scoping Detailed Site Investigations (DSIs) and Sampling Analysis and Quality Plans (SAQPs). The regulator has confirmed that a site-specific, risk-based approach must be applied. This requires consultants to map the actual conceptual site model (CSM) for a given location, identify whether viable exposure pathways exist between contaminated surface water and relevant ecological receptors, and determine whether those receptors are present in sufficient numbers and with sufficient site contact to warrant biological tissue sampling. The EPA has explicitly framed this approach as a mechanism to avoid unnecessary ecological disturbance to aquatic fauna populations.

On the marine water front, the NSW EPA’s updated position applies freshwater ecological guideline values for PFOS to marine and estuarine waters on an interim basis, pending the development of dedicated marine-specific guideline values under ANZG. This is a pragmatic but technically conservative position. It means that assessments of PFAS contamination affecting estuaries, coastal waterways, and marine receiving environments in New South Wales must currently use the same 0.0005 µg/L threshold as freshwater assessments, even though salinity, tidal dynamics, and species assemblages differ substantially. Practitioners should document this interim application clearly in their reports, noting that marine-specific values may be released and supersede this approach.

Two further updates are embedded within the revised position statement. First, the updated NHMRC Australian Drinking Water Guidelines have been integrated, updating the PFAS-specific drinking water quality criteria that inform human health risk assessments at sites affecting or potentially affecting potable supply. Second, the NSW EPA has flagged that the state’s Biosolids Resource Recovery Order and Exemption framework will be progressively updated to incorporate PFAS NEMP 3.1 guidance, including land application thresholds and testing requirements for biosolids containing PFAS. This has direct relevance to wastewater treatment plant operators, agricultural land managers, and councils managing biosolids reuse programmes.

Australian context: how this fits within the national PFAS regulatory framework

Australia’s approach to PFAS site assessment is governed at the national level by the PFAS NEMP, which is administered jointly by the Heads of EPA Australia and New Zealand. The PFAS NEMP establishes the overarching framework, including investigation levels, screening criteria, and risk assessment methodology, while individual state and territory EPAs issue jurisdiction-specific guidance that applies and interprets the national framework within their respective regulatory contexts.

References and related sources

• Primary source: www.epa.nsw.gov.au
• oup.com
• nsw.gov.au
• nsw.gov.au
• nsw.gov.au
• PFAS National Environmental Management Plan (NEMP)
• ANZG Water Quality Guidelines
• NSW EPA

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This is an iEnvi Machete news summary. Prepared by iEnvi to summarise the source article for contaminated land, groundwater, remediation, approvals and site risk professionals.

Published: 07 Jul 2026

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