Whole-house filtration and point-of-use RO divide a PFAS treatment job by flow and required assurance.
Evidence snapshot
- NHMRC (2025): The Australian Drinking Water Guidelines are a risk-management framework, not a single national pass/fail law. They separate health-based, aesthetic and operational considerations.
- NSF (2026): NSF standard numbers are not quality rankings. NSF/ANSI 42 covers stated aesthetic claims, 53 health-effect claims, 44 softeners, 55 UV and 58 point-of-use RO; the exact certified claim still has to be checked.
- NHMRC (2025): NHMRC's 2025 values are 8 ng/L for PFOS, 200 ng/L for PFOA, 30 ng/L for PFHxS and 1,000 ng/L for PFBS. A result must be matched to the named compound and unit.
- US EPA (2025): For a household PFAS filter, the EPA recommends checking a specific certified reduction claim and replacing the filter as directed. Technology type alone is not proof of lifetime performance.
These figures and standards are reference points, not a diagnosis of one home. Local water data, premises plumbing, flow and maintenance determine how they apply.
A PFAS result is compound-specific and time-specific
Start with the property itself. Use a PFAS method suitable for the named compounds and keep the reporting limit and units visible. Nanograms per litre and micrograms per litre differ by a factor of 1,000. A non-detect only means the named compound was below that method's reporting limit in that sample. Any reduction claim should name the exact model, flow, tested capacity and replacement point.
The limit to keep visible
Current Australian PFAS values are compound-specific and measured at nanogram-per-litre levels.
Official guidance describes population-level or supply-level risk; a component test describes stated test conditions; a household observation describes one property. None should silently stand in for another. Connect them only where the source, configuration and operating conditions genuinely match.
Measure flow and pressure under the same conditions
Carbon, ion exchange and high-pressure membranes have different capacities and waste or replacement implications.
Record static pressure and pressure at a known flowing outlet before and after treatment. A shower that feels weak is useful evidence, but it cannot separate a loaded cartridge from a partly closed valve or a wider supply change. Ask for the clean-system pressure drop and the design flow in litres per minute. Repeat the same check after service so the figures are comparable.
Keep the sample, unit and reporting limit together
Inlet and treated-water testing over time is more useful than a one-day removal percentage.
Write the sample point, date, method, unit and laboratory reporting limit beside the result. A kitchen first-draw sample answers a different question from water collected after a two-minute flush. For a treatment check, use matched inlet and outlet samples and the same method. Do not use taste, colour or a TDS pen as a substitute for analysis of a named contaminant.
A practical household check
| Record | What to capture | Why it changes the decision |
|---|---|---|
| Treatment target | Name the substance or household result | Stops stage-count shopping |
| Peak flow | Record simultaneous showers and outlets | Protects pressure and contact time |
| Ownership | Price parts and service for 10 years | Exposes the real cost |
Use the same notes when requesting more than one quote. Suppliers then have to answer the same water, flow and ownership brief rather than redefining the problem around their preferred product.
Where Water Analytics Australia fits
WAA's role is to turn the household brief into a proportionate design. That starts with source water, treatment goal, realistic peak flow, available pressure, installation access and the preferred service approach. Depending on the job, the answer may be whole-home staged treatment, point-of-use RO, the benchtop system or a combination. The written proposal should explain why each stage is present, the conditions behind each claim and what the customer will need to maintain.
Related WAA guides
- Is Reverse Osmosis Worth It for Australian Tap Water?
- Whole-House Water Filter New Build Plumbing Checklist
- WAA Full Home Water Refining Systems
Common questions
What belongs in a comparable quote?
Ask for equipment, plumbing scope, design flow, clean pressure drop, consumables, service labour and the evidence behind each treatment claim. Compare the same ownership period and household peak demand.
What is the most useful measurement?
Use the measurement that matches the decision. Use a PFAS method suitable for the named compounds and keep the reporting limit and units visible. Nanograms per litre and micrograms per litre differ by a factor of 1,000. A non-detect only means the named compound was below that method's reporting limit in that sample. Any reduction claim should name the exact model, flow, tested capacity and replacement point.
What should WAA receive before recommending a system?
Provide the postcode, water source, household size, bathroom count, busiest-use pattern, observed issue, desired result and any laboratory report with its units and sample point.
Sources and further reading
- NHMRC: Australian Drinking Water Guidelines, version 4.0
- NSF: Standards for water treatment systems
- NHMRC: Updated Australian Drinking Water Guidelines: PFAS values
- US EPA: Identifying drinking water filters certified to reduce PFAS
- US EPA WaterSense: Point-of-use reverse osmosis systems
- Water Analytics Australia: Full Home Water Refining Systems
The next useful step
Write down the source, the result you want, peak-use flow and the evidence already available. Then ask for a recommendation that gives every stage a defined job, states the operating assumptions and includes the service plan. That is enough detail to compare a WAA proposal with any alternative without relying on fear or brochure language.