What bore water actually contains in WA
Western Australia draws more heavily on groundwater than any other Australian state. The Gnangara Mound supplies Perth’s northern suburbs. Regional WA — Bunbury, Geraldton, Kalgoorlie, the Pilbara — relies almost entirely on private and scheme bores. Unlike treated town supply, bore water arrives at the tap without chlorination, fluoridation, or removal of naturally occurring contaminants.
The specific chemistry depends entirely on the aquifer and location, but WA bore water commonly contains one or more of:
| Contaminant | Common WA range | ADWG health limit | Practical impact |
|---|---|---|---|
| Iron | 0.1–5+ mg/L | 0.3 mg/L (aesthetic) | Orange-brown staining on tapware, toilets, laundry |
| Manganese | 0.05–2+ mg/L | 0.5 mg/L (health) | Black staining, neurological risk above health limit |
| Hardness | 200–800+ mg/L | No health limit | Heavy scale on all appliances and fixtures |
| TDS | 500–3,000+ mg/L | 500 mg/L (aesthetic) | Noticeably salty or mineral taste, appliance damage |
| Salinity (sodium) | 100–1,000+ mg/L | 180 mg/L (aesthetic) | Salty taste, not suitable for drinking at high levels |
| pH | 5.5–9.5 (variable) | 6.5–9.5 | Low pH corrodes pipes; high pH causes scaling |
| Bacteria | Variable | E. coli: not detected | Surface-connected bores at particular risk |
| PFAS | Risk near airports/defence | ADWG 2025 values | Northern Perth suburbs, NT, QLD defence sites |
| Nitrate | Variable — agricultural areas | 50 mg/L (health) | Infant health risk above health limit |
Why bore water requires testing first
The single most common and most expensive mistake bore water buyers make is purchasing a treatment system before testing their water. A system designed for iron removal will not address salinity. A softener that addresses hardness will not remove PFAS. Without a test report, there is no basis for system selection.
A basic bore water test covering the parameters relevant to WA groundwater costs $150–$400 from an accredited laboratory. NATSWest, ALS Water, and Envirolab all operate in WA and provide results within 5–10 business days. The cost of a test is trivial compared to the cost of an incorrectly specified system.
What to test for in WA bore water: iron, manganese, hardness (calcium + magnesium), TDS, pH, sodium, nitrate, and bacteria (total coliforms and E. coli). Add PFAS if the bore is within 10km of an airport, RAAF base, or known PFAS-affected area.
Treatment technologies — matched to WA bore water problems
Iron and manganese removal
Iron is the most common WA bore water problem and causes visible orange staining on everything it contacts. Two approaches:
- Oxidation filter (birm, greensand, Katalox): Oxidises dissolved iron to a solid form that can be filtered out. Suitable for dissolved iron below 3–5 mg/L. Requires backwashing.
- Aeration + filtration: Air injection oxidises iron before a filter removes solids. More effective for higher iron levels and also addresses hydrogen sulphide (the rotten egg smell common in some WA bores).
Manganese above 0.5 mg/L (the ADWG health guideline) requires specific attention — standard iron filters are less effective against manganese. Greensand or Katalox media is preferred for combined iron/manganese removal.
Hardness and scale (softeners and TAC)
WA bore water hardness above 200 mg/L is common, and levels above 500 mg/L occur in some regional areas. At these concentrations, appliances scale within months without treatment.
- Salt-based water softener: Ion exchange removes calcium and magnesium permanently. The most effective treatment for high hardness (>300 mg/L). Requires ongoing salt, produces brine discharge, and outputs sodium-rich water (add RO for drinking).
- TAC (template-assisted crystallisation): Changes the physical form of minerals without removing them. Prevents scale adhesion. More appropriate for moderate hardness (<300 mg/L); less effective at very high levels.
High TDS and salinity
WA bore water TDS above 1,000 mg/L is not uncommon in coastal and agricultural areas. Above 500 mg/L the water has a noticeably mineral or salty taste. Above 1,500 mg/L it is unsuitable for drinking.
- Reverse osmosis: The only residential technology that reliably reduces high TDS. Removes 90–96% of dissolved salts, minerals, and most contaminants including PFAS. Essential for bore water above 1,000 mg/L TDS used for drinking.
- RO is a drinking water solution, not a whole-home solution — flow rates are too low for whole-home use at high TDS levels.
Bacteria disinfection
Bores connected to surface water pathways (shallow bores, old or poorly cased bores, bores near septic systems) can be susceptible to bacterial contamination. UV disinfection is the standard residential treatment for bore water bacteria — it requires no chemicals, leaves no residual taste, and is effective against bacteria, viruses, and Cryptosporidium at Class A dose rates.
UV must be installed after filtration — turbid or iron-stained water blocks UV penetration and renders it ineffective.
PFAS in WA bore water
PFAS from RAAF and civilian airport firefighting foam use affects bore water in documented areas of northern Perth (near Perth Airport and RAAF Pearce at Bullsbrook), regional areas near Tindal (NT), Oakey (QLD), and Williamtown (NSW). Reverse osmosis removes PFAS to below detection limits. Specialist ion exchange resin (PFAS-IX) is used for whole-home PFAS treatment but is expensive and requires specialist sizing. See our PFAS filter guide for detail.
Typical treatment combinations by WA bore type
| Bore water type | Treatment priority | Typical system | Approx. installed cost |
|---|---|---|---|
| Perth northern suburbs (Gnangara) | Hardness 200–400 mg/L, moderate iron | Iron filter + TAC or softener | $2,500–$5,000 |
| Coastal / near-ocean bore | High salinity TDS 500–2,000+ mg/L | RO for drinking + carbon whole-home | $1,500–$4,000 |
| Agricultural area bore | Nitrate, hardness, bacteria | UV + softener + RO (drinking) | $3,000–$6,000 |
| Regional WA bore (Goldfields / Pilbara) | Very high TDS and hardness | Specialist design required — test first | $4,000–$15,000+ |
| Near airport / RAAF (PFAS risk) | PFAS + hardness | RO (drinking) + confirm school/health authority guidance | $1,500–$3,500 + testing |
| Rural property with old bore | Bacteria, iron, variable chemistry | UV + iron filter + RO (drinking) | $3,000–$6,000 |
Perth WA suppliers with bore water experience
The following FilterOut-reviewed WA suppliers have documented bore water experience. FO scores are overall — see individual profiles for bore-specific services.
Before you buy — the three rules for bore water
1. Test first. Always. No system can be properly specified without a test report. $150–$400 for a test prevents thousands in wasted treatment costs.
2. Match the treatment to the actual problem. Iron filters don’t remove salinity. Softeners don’t remove bacteria. RO handles almost everything at the drinking tap but is not a whole-home solution at high TDS.
3. UV must go after filtration. If the system includes UV disinfection, it must be installed downstream of any sediment or iron filtration. Turbid water blocks UV and makes it ineffective.