PFAS NEMP 3.1: What Changed for Site Investigations in Australia

PFAS NEMP 3.1 is now the current national guidance for managing PFAS contamination in Australia. Released in May 2026, it is a targeted update to NEMP 3.0, not a full rewrite. For consultants, property owners and regulators, the practical question is which criteria changed, and whether open site investigations need to be re-screened. NEMP values are screening and investigation values unless adopted into a specific regulatory instrument or approval condition – confirm state and territory implementation before relying on national values alone.

How NEMP 3.1 rolled out

The update follows a clear sequence of national science and policy steps:

• June 2025: NHMRC published revised PFAS values in the Australian Drinking Water Guidelines (ADWG).
• March 2026 (ANZG publication page dated 1 April 2026): DCCEEW released final PFOS default guideline values (DGVs) for freshwater under the Australian and New Zealand Guidelines for Fresh and Marine Water Quality (ANZG), endorsed across state and territory technical groups.
• May 2026: HEPA released PFAS NEMP 3.1, incorporating the new ADWG values and updated PFOS freshwater and marine interim values. DCCEEW confirmed this as the current version on 16 June 2026.

NEMP remains nationally agreed guidance developed through the Heads of EPA Australia and New Zealand (HEPA). It is adaptive by design: jurisdictions implement it through their own contaminated land and water quality frameworks, so adoption timing can vary slightly by state, but new assessments should reference 3.1.

Because NEMP 3.1 only incorporates the revised drinking water values and updated PFOS freshwater and interim marine water values, the supporting and ancillary documents remain unchanged from NEMP 3.0 and are to be used with NEMP 3.1. No other PFAS NEMP criteria were re-derived in the 3.1 update, subject to site-specific risk assessment where required.

What changed from NEMP 3.0 to 3.1

NEMP 3.1 makes two substantive changes for most site investigations – to drinking water criteria and to the PFOS ecological water values. Most of the NEMP 3.0 framework (investigation logic, soil criteria, recreational water values, PFOA interim ecological water values, waste and biosolids guidance, risk-based assessment structure) is unchanged.

Summary of changed guideline values (3.0 to 3.1)

Drinking water quality guideline values (NEMP Table 4) – adopting the NHMRC June 2025 ADWG values:

Analyte	NEMP 3.0 (legacy ADWG)	NEMP 3.1 (ADWG June 2025)	Direction
PFOS	0.07 µg/L (70 ng/L, combined with PFHxS)	0.008 µg/L (8 ng/L)	Much stricter
PFHxS	combined with PFOS at 0.07 µg/L	0.03 µg/L (30 ng/L), separate	Stricter; now a separate limit
PFOA	0.56 µg/L (560 ng/L)	0.2 µg/L (200 ng/L)	Stricter
PFBS	no ADWG value	1 µg/L (1,000 ng/L)	New value

PFOS ecological water quality guideline values (NEMP Table 8) – freshwater, with interim marine values updated to mirror them – adopting the final ANZG 2026 PFOS package:

Guideline	NEMP 3.0 (2016 interim)	NEMP 3.1 (ANZG 2026 final)	Direction
99% species protection	0.00023 µg/L	0.02 µg/L	Less stringent (~87x higher)
95% species protection	2016 interim (superseded)	0.9 µg/L	Revised
90% species protection	2016 interim (superseded)	4 µg/L	Revised
80% species protection	2016 interim (superseded)	20 µg/L	Revised
Biota screening threshold	not in 3.0	0.0005 µg/L (0.5 ng/L)	New

Unchanged in 3.1 (carried over from 3.0) – included so the full picture is visible at a glance:

Criterion (NEMP table)	Value (unchanged)
Recreational water HBGVs (Table 4, NHMRC 2019)	PFOS+PFHxS 2 µg/L; PFOA 10 µg/L
PFOA ecological water interim, freshwater and marine (Table 8)	99% 19 µg/L; 95% 220; 90% 632; 80% 1,824 µg/L
PFHxS ecological water (Table 8)	no separate PFHxS freshwater DGV in NEMP 3.1; PFHxS remains relevant for drinking water, soil and biota comparisons where specified
Soil human-health investigation levels (Table 5), PFOS+PFHxS / PFOA	HIL A 0.003 / 0.06; HIL B 2 / 20; HIL C 1 / 10; HIL D 20 / 50 mg/kg
Soil ecological values (Table 6), PFOS / PFOA	direct 1 / 10 mg/kg; indirect 0.003 / 0.003 mg/kg; reptile interim 0.005 mg/kg PFOA
Biota guideline values (Table 7), PFOS+PFHxS / PFOA	mammalian diet 3.1 / 2.8 µg/kg; avian diet 8.2 / 2.4 µg/kg; bird egg 0.2 / 0.015 µg/g
Landfill acceptance and biosolids criteria (Tables 11-12)	unchanged from 3.0

1. Drinking water (ADWG) – generally stricter for PFOS

NEMP 3.1 adopts the June 2025 ADWG health-based values. The headline shift for site work is that PFOS and PFHxS are now separate limits, and PFOS is much lower than the legacy combined trigger many practitioners still have in memory.

Analyte	Previous ADWG (legacy)	ADWG from June 2025 (in NEMP 3.1)
PFOS	70 ng/L (formerly grouped with PFHxS)	8 ng/L
PFHxS	(grouped with PFOS at 70 ng/L)	30 ng/L
PFOA	560 ng/L (legacy)	200 ng/L
PFBS	no prior ADWG value	1,000 ng/L

For site investigations, this matters wherever groundwater or surface water is assessed against a drinking water receptor – private bores, potential future potable use, or supply catchments. A result that sat below old ADWG may now exceed the updated PFOS or PFHxS limits.

The shift is confined to the drinking-water pathway because it is the only one keyed to the NHMRC tolerable daily intakes (TDIs), which were revised in 2025. The FSANZ 2017 TDIs that underpin the soil HILs, recreational water values and biosolids criteria are unchanged – which is why those criteria did not move in 3.1.

2. Freshwater and marine PFOS ecological values – revised (not a simple tightening)

NEMP 3.1 replaces interim PFOS freshwater DGVs with the final ANZG 2026 PFOS package (published 1 April 2026). Marine interim PFOS values were also updated to align with the freshwater revision.

For ecological screening, practitioners typically apply the 99% species protection DGV for bioaccumulative PFAS such as PFOS in slightly to moderately disturbed systems, per ANZG practice. Under the final 2026 values, the 99% PFOS freshwater DGV is 0.02 µg/L (20 ng/L), with 95% at 0.9 µg/L. ACLCA notes this 99% value is materially higher (less stringent) than the interim PFOS freshwater value carried in earlier NEMP editions – so some surface water datasets may show fewer PFOS ecological exceedances at the 99% tier than under old interim tables, even while drinking water screening became stricter.

Although NEMP Table 8 lists PFOS DGVs at 99%, 95%, 90% and 80% species protection levels, the bioaccumulative nature of PFOS affects how those values should be selected. For bioaccumulative PFAS, NEMP adopts the ANZG approach of using the 99% species protection DGV for slightly to moderately disturbed systems, and the 95% DGV for highly disturbed systems that would otherwise use 90% or 80%, unless legislation or the relevant regulator specifies a different level of protection.

That split outcome is important: do not assume every PFAS criterion moved in the same direction.

3. What did not change

• Recreational water HBGVs (NEMP Table 4) – unchanged; carried in from NHMRC 2019 and retained in 3.1 (PFOS+PFHxS 2 µg/L, PFOA 10 µg/L)
• PFOA freshwater and marine interim ecological values – unchanged in 3.1 (DCCEEW, June 2026)
• PFAS soil human-health criteria (NEMP Table 5) and soil ecological direct/indirect values (Table 6) – unchanged from 3.0
• PFHxS ecological water – NEMP 3.1 Table 8 does not list a separate PFHxS freshwater DGV; PFHxS remains relevant for drinking water, soil and biota comparisons where specified by NEMP
• Risk-based framework, investigation tiers, sampling and QA/QC guidance from NEMP 3.0 – retained

Recreational and public open space values – which apply when

Practitioners often conflate three different ideas: public open space soil criteria, recreational water contact criteria, and ecological disturbance tiers for modified urban waterways. NEMP 3.1 does not merge them. Pick the pathway from the conceptual site model.

1. Soil – public open space / recreational land use (NEMP Table 5)

Use NEMP Table 5 public open space (HIL C) values when the site is, or will be, used as parks, playgrounds, playing fields, ovals, secondary schools (non-agricultural soil) or similar public open space. Under NEMP 3.1 these soil human-health values are unchanged:

Land use (NEMP Table 5)	PFOS + PFHxS	PFOA	When to apply
Residential with garden / accessible soil (HIL A)	0.003 mg/kg	0.06 mg/kg	Housing, daycare, preschool, primary schools; home-grown produce pathway
Residential minimal soil access (HIL B)	2 mg/kg	20 mg/kg	Paved yards, flats, high-rise; no home produce
Public open space / recreational (HIL C)	1 mg/kg	10 mg/kg	Parks, playgrounds, sportsgrounds, footpaths
Commercial / industrial (HIL D)	20 mg/kg	50 mg/kg	Adult worker exposure only

The HIL A values assume home-grown produce makes up 10% of fruit and vegetable intake. Where it exceeds that, a site-specific value applies – for example, at 50% produce the HIL A screen falls to 0.001 mg/kg PFOS+PFHxS and 0.01 mg/kg PFOA.

Apply the most conservative relevant land use. If a commercial site borders a park or proposed public open space, include HIL C (or HIL A for sensitive residential) as a secondary comparison. NEMP excludes undeveloped urban bushland and reserves from generic HIL C – those need site-specific assessment.

Soil ecological values (Table 6) apply across all land uses and do not vary by recreational category.

2. Water – recreational contact (NEMP Table 4)

NEMP Table 4 carries recreational water health-based guideline values (HBGVs) for primary-contact recreation – swimming, diving and similar incidental ingestion of natural fresh, estuarine or marine water. These values follow the NHMRC 2019 recreational-water methodology and were carried into NEMP 3.0; they are unchanged in 3.1. They replaced the earlier Health 2017 recreational triggers (0.7 µg/L PFOS+PFHxS and 5.6 µg/L PFOA) that some legacy reports still reference:

Analyte	Recreational water HBGV (NEMP Table 4)	Compare to ADWG (potable, June 2025)
PFOS + PFHxS (combined)	2 µg/L (2,000 ng/L)	8 ng/L PFOS + 30 ng/L PFHxS separate
PFOA	10 µg/L (10,000 ng/L)	200 ng/L

Recreational HBGVs are higher than drinking water limits because assumed ingestion during swimming is intermittent and lower in volume than lifetime potable use. A PFOS result can exceed ADWG in a bore yet sit below the recreational HBGV for a connected swimming reach – that is expected, not a contradiction.

When to use recreational water values:

• Surface water or connected groundwater on sites where people swim or ingest water incidentally during recreation.
• Creeks, lakes, estuaries and coastal waters downstream of a PFAS source where the human-health question is recreational contact, not potable supply.
• Council or landowner enquiries about closing or reopening a swimming spot.

For dewatering, excavation water or other site works where incidental ingestion by workers or site users is plausible, the exposure pathway should be addressed through a site-specific human health risk assessment. Recreational water HBGVs may provide a useful reference point where exposure resembles recreational contact, but they should not be presented as automatic occupational wet-work criteria.

When not to use them:

• Drinking water – use ADWG June 2025, not recreational values.
• Swimming pools, spas and hydrotherapy pools – excluded from NHMRC recreational water guidance.
• Ecological protection – use ANZG/NEMP Table 8 DGVs and the biota screen, not recreational HBGVs.
• Consumption of fish or shellfish – separate dietary risk assessment; not covered by recreational water HBGVs.

Heavy or frequent recreational use (for example extended surfing) may warrant site-specific recreational guidance in consultation with the state or territory health regulator. NHMRC is revising its broader recreational water quality guidance; until that publishes, NEMP Table 4 remains the national reference for recreational PFAS screening in site investigations.

3. Do not confuse with ambient background (NEMP Table 1) or ecological disturbance tiers

NEMP Table 1 ambient land-use classes (remote, agricultural, urban, mixed, marine) and the reference concentrations in Tables 2-3 are for contextualising background or ambient PFAS in a catchment. They are not a substitute for site-specific investigation criteria or recreational HBGVs.

Ecological disturbance tiers for PFOS should follow the bioaccumulative PFAS approach above: 99% DGV for slightly to moderately disturbed freshwater, and 95% DGV for highly disturbed systems that would otherwise use 90% or 80%, unless the regulator specifies otherwise. Human-health screening for swimmers on the same water body still uses the recreational HBGVs above.

Why freshwater ecology and drinking water can tell different stories

DCCEEW explicitly notes that freshwater ecological guideline values and drinking water health values are derived differently – continuous aquatic exposure versus intermittent human exposure, and different species sensitivity endpoints. On PFAS sites it is common to see:

• groundwater or surface water above ADWG for PFOS while still being assessed for ecological receptors;
• ecological PFOS comparisons that change tier when the 2026 DGVs are applied;
• a need to assess biota and food-chain pathways separately, because DGVs alone do not resolve tissue accumulation in higher-order consumers.

iEnvi’s TOPA and PFAS precursor work remains relevant where total oxidisable precursors may understate long-term PFOS risk in groundwater.

When to use the conservative biota PFOS criteria

NEMP 3.1 carries a separate, much tighter PFOS biota screening threshold in Table 8: 0.0005 µg/L (0.5 ng/L) in freshwater. This is not the same as the 99% species protection DGV (0.02 µg/L). It exists because PFOS bioaccumulates in aquatic food chains, and water-column DGVs alone may not flag risk to fish, invertebrates or wildlife that consume aquatic prey.

Recent Australian field work has shown surface water PFOS can sit below draft DGVs while biota tissue concentrations still exceed wildlife diet guidelines. The biota screening threshold is the conservative early trigger for that pathway.

Apply the biota screen when all of the following are true

• PFAS is in scope – AFFF, aviation, industrial, landfill leachate, defence or other PFOS-impacted sites.
• A freshwater ecological pathway exists – groundwater or surface water discharges to creeks, wetlands, lakes, estuaries or other receiving waters with aquatic habitat.
• Aquatic or dietary receptors are plausible – fish, macroinvertebrates, waterbirds, piscivorous birds or mammals, or other wildlife that may consume aquatic biota.
• You are screening water results – surface water, or groundwater where the conceptual site model treats it as feeding a freshwater receptor.

How to use it in practice

• Run the biota threshold alongside the relevant water-column DGV (typically 99% species protection for PFOS in slightly to moderately disturbed freshwater), not instead of it.
• An exceedance triggers further assessment: biota tissue sampling, comparison against NEMP Table 7 biota guideline values, wildlife diet assessment, and food-chain risk evaluation where warranted.
• A result below the 99% DGV can still exceed the biota screen – do not clear a site on water-column comparison alone where the biota pathway is active.
• In highly disturbed systems, apply the 95% PFOS DGV per NEMP’s bioaccumulative PFAS approach, but still check the biota screening threshold where PFOS bioaccumulation and aquatic receptors are in the conceptual site model.
• For marine and estuarine receptors, use the interim marine values in NEMP 3.1 Table 8 and assess whether biota and wildlife diet pathways need the same stepped assessment.

At iEnvi we apply this threshold on PFAS investigations wherever surface water or connected groundwater is being screened for ecological receptors. Our screening approach includes the Table 8 biota value alongside 99% PFOS DGVs. If the biota screen is exceeded, we scope biota sampling or wildlife diet assessment rather than treating the water result as ecologically acceptable by default.

What NEMP 3.1 means for industry

Property owners, acquirers and facility managers

If you hold a PFAS investigation from 2024-2025 based on NEMP 3.0 and old ADWG, ask whether the report’s water receptor conclusions still stand. Acquisition due diligence and lease baseline reviews should state which NEMP version and ADWG revision were used. A clean PFOS result against legacy drinking water limits is not automatically clean under June 2025 ADWG.

Industrial, aviation and defence legacy sites

Soil investigation and remediation criteria are largely stable, so soil-focused closure arguments may not shift. However, groundwater plumes discharging to surface water or used for potable supply need re-comparison against 3.1 water criteria.

Regulators and councils

Expect consistency pressure: EPA and water authority reviewers will increasingly expect NEMP 3.1 tables, current ADWG for potable pathways, and ANZG 2026 PFOS DGVs for freshwater ecology. Marine PFOS interim values should be taken from 3.1 rather than superseded interim tables.

Laboratories and data systems

Reporting limits should remain low enough to assess against 8 ng/L PFOS in groundwater used for drinking water. LORs that were acceptable for legacy ADWG may be marginal for current potable screening.

Wider regulatory context

NEMP 3.1 lands within a fast-moving regulatory picture, and re-screening and due-diligence decisions should account for what is coming:

• IChEMS: PFOS, PFOA, PFHxS and related substances have been listed in Schedule 7 from 1 July 2025. Import, manufacture, export and use are prohibited unless exempted, with disposal requirements also applying. DCCEEW has also consulted on proposed IChEMS standards for additional PFAS classes, indicating that the regulatory framework is continuing to expand beyond the original priority PFAS group.
• Senate Select Committee on PFAS: its final report (November 2025) made 47 recommendations directed at a nationally consistent approach to PFAS management and remediation, signalling further reform
• Jurisdictional adoption: states implement NEMP through their own frameworks, so adoption timing and any state-specific criteria should be confirmed with the relevant regulator before relying on the national values alone

How iEnvi is applying this to site investigations

Our field and reporting criteria for new PFAS work from mid-2026 onward:

1. Cite PFAS NEMP 3.1 as the national reference for new PSI, DSI, groundwater and remediation reporting.
2. Flag PFAS as a COPC on AFFF, aviation, industrial fluorochemical, landfill leachate and legacy fire-training sites – unchanged logic from 3.0.
3. Potable pathways: compare groundwater to ADWG June 2025 values (PFOS 8 ng/L, PFHxS 30 ng/L, PFOA 200 ng/L, PFBS 1,000 ng/L).
4. Freshwater ecological receptors: apply final ANZG 2026 PFOS DGVs at the appropriate species-protection level (typically 99% for slightly to moderately disturbed systems; 95% for highly disturbed systems per NEMP’s bioaccumulative PFAS approach).
5. Soil: continue NEMP 3.0/3.1 soil human-health (Table 5) and ecological (Table 6) criteria by land use – select HIL A/B/C/D from current and proposed use; add adjacent public open space as a secondary comparison where relevant.
6. Recreational surface water: where primary-contact recreation is in the CSM, compare to NEMP Table 4 recreational HBGVs (NHMRC 2019; PFOS+PFHxS 2 µg/L, PFOA 10 µg/L) – not legacy 0.7/5.6 µg/L triggers. For wet-work or excavation water, use site-specific human health risk assessment; recreational HBGVs may inform the assessment where exposure resembles recreational contact.
7. PFOA surface water: continue interim NEMP values until updated.
8. Biota pathway: apply the Table 8 PFOS biota screening threshold (0.5 ng/L) on all freshwater ecological water screening where PFOS is a COPC; exceedance triggers biota tissue work or wildlife diet assessment, not automatic sign-off on water-column DGVs alone.
9. Analytical scope: PFOS, PFOA, PFHxS, PFBS and precursors/TOPA where the conceptual site model warrants it; align LORs to the tightest applicable criterion.
10. Legacy reports: re-screen open matters where water receptor decisions hinged on old ADWG, interim PFOS DGVs, or pre-NHMRC 2019 recreational values (0.7/5.6 µg/L); document whether conclusions change.

Internal guideline sets are being maintained against NEMP 3.1 / ANZG 2026 – always verify against the published NEMP and ANZG tables before issuing a signed report.

Practical checklist for practitioners

• Download PFAS NEMP 3.1 from DCCEEW and retire 3.0 from new work.
• Update report templates: version footer, ADWG revision date, PFOS DGV source (ANZG April 2026).
• Separate drinking water, recreational contact, ecological freshwater DGV and biota screening threshold comparisons – four different pathways, four different criteria sets.
• Match soil Table 5 land use to actual and proposed use; do not default commercial criteria on a park or playground site.
• Re-screen active projects using legacy recreational triggers (0.7/5.6 µg/L) against NEMP Table 4.
• Confirm state and territory adoption before relying on national NEMP values alone.

References

• DCCEEW – PFAS NEMP 3.1 (HEPA 2025) and PFAS chemicals management hub
• NHMRC – Updated Australian Drinking Water Guidelines (June 2025)
• NHMRC – Guidance on PFAS in recreational water (2019; current until revised recreational water guidelines publish)
• ANZG – PFOS in freshwater DGVs (April 2026)
• PFAS NEMP 3.0 (2024/25) – superseded except where soil and unchanged water criteria are referenced

For PFAS investigation, groundwater assessment, contaminated land advice or acquisition due diligence under the current framework, contact iEnvi.