Tap Water Quality in Derby, WA
Postcode 6728 · Supplied by Water Corporation via North West
Quality Score
About Derby
Derby is a suburb of 3,222 residents in Western Australia (postcode 6728). The median age is 35. It falls within the Water Corporation area. Neighbouring suburbs include Jarlmadangah Burru, Camballin, Geegully Creek, Kimbolton.
Most residents rent (61%), while 17% own outright, while 14% own their home with a mortgage. The median household income is $89,076 per year. The top countries of birth for residents are New Zealand (24%), United Kingdom (19%), and India (9%).
Tap water in Derby is supplied by Water Corporation. The suburb receives water via the North West supply zone.
Water quality summary
Based on recent water quality reports, Derby achieves a WaterScore of 9.6 out of 10, rated excellent overall. Water hardness measures 54 mg/L, classified as soft. This is gentle on appliances and skin, with minimal limescale buildup expected. The pH level is 7.85, which is within the ADWG guideline range of 6.5–8.5. Fluoride levels are very low at 0.1 mg/L, indicating the water is not significantly fluoridated. Total dissolved solids (TDS) measure 157 mg/L, considered low against the ADWG guideline of 600 mg/L. Turbidity is 0.1 NTU, indicating clear water, within the ADWG guideline of 5 NTU.
Compare with nearby suburbs: Jarlmadangah Burru , Camballin , Geegully Creek
Census Data
Suburb snapshot
Population
Median Age
Median Income
Owner-occupied
Recommended filters for Derby
Products matched to your water profile
BRITA
Marella 2.4L Fridge Water Filter Jug (Maxtra+)
4.7 · 16,095 ratings on Amazon
A reliable marella 2.4l fridge water filter jug (maxtra+) suitable for Derby's water profile.
ZeroWater
23-Cup Dispenser (incl. TDS Meter)
4.3 · 27,123 ratings on Amazon
A reliable 23-cup dispenser (incl. tds meter) suitable for Derby's water profile.
Purewell
8.5L Stainless Steel Gravity System
4.4 · 1,137 ratings on Amazon
A reliable 8.5l stainless steel gravity system suitable for Derby's water profile.
Comparison
How Derby compares
Compared to Western Australia and national averages
| Metric | Derby | WA Avg | National Avg |
|---|---|---|---|
| Hardness | 54 mg/L | 122.1 mg/L | 85.1 mg/L |
| pH | 7.85 | 8 | 8.4 |
| Fluoride | 0.1 mg/L | 0.8 mg/L | 0.7 mg/L |
| Turbidity | 0.1 NTU | 0.2 NTU | 0.4 NTU |
| TDS | 157 mg/L | 463.8 mg/L | 275.7 mg/L |
Full Results
Detailed water quality data
All values compared against Australian Drinking Water Guidelines (ADWG)
| Parameter | Value | Unit | ADWG Guideline | Status |
|---|---|---|---|---|
| Alkalinity | 49 | mg/L CaCO3 | No limit | Measured |
| Aluminium | 0.008 | mg/L | < 0.2 | Good |
| Chloride | 42 | mg/L | < 250 | Good |
| Hardness | 54 | mg/L CaCO3 | < 200 | Good |
| Iron | 0.009 | mg/L | < 0.3 | Good |
| Manganese | 0.005 | mg/L | < 0.1 | Good |
| pH | 7.85 | pH units | 6.5 – 8.5 | Normal |
| Sodium | 21 | mg/L | < 180 | Good |
| Sulfate | 0.15 | mg/L | < 500 | Good |
| Total Dissolved Solids | 157 | mg/L | < 600 | Good |
| Colour | 1 | HU | < 15 | Good |
| Turbidity | 0.1 | NTU | < 5 | Good |
| Fluoride | 0.1 | mg/L | < 1.5 | Good |
| Nitrate | 0.44 | mg/L | < 50 | Good |
| Trihalomethanes | 0.052 | mg/L | < 0.25 | Good |
Safety
Safety assessment
Based on 15 parameters tested, all results fall within Australian Drinking Water Guidelines.
Based on comparison with Australian Drinking Water Guidelines (ADWG)
Explained
What these numbers mean
Soft (54 mg/L)
Water Hardness
Your water is classified as soft, which means minimal limescale buildup on fixtures and appliances. Soap and shampoo will lather easily, and you should notice no drying effects on skin or hair. Hot water systems and kettles are unlikely to suffer scale-related efficiency losses.
Normal Range
pH Level
pH of 7.85 is within the ideal range of 6.5–8.5. The ADWG recommends pH between 6.5 and 8.5 for drinking water.
Low fluoride
Fluoride
Fluoride at 0.1 mg/L. Below the recommended range.
Data unavailable
Disinfection
Chlorine data is not currently available for Derby.
Learn more about these measurements in our water quality glossary — including Hardness , pH , Fluoride , and ADWG guidelines .
Advice
Practical tips for residents
Soft Water Advantage
Derby's water is soft at 54 mg/L. You can use less soap and detergent, as it lathers easily with softer water.
Fluoride in Your Water
Fluoride measures 0.1 mg/L in Derby. Australian guidelines allow up to 1.5 mg/L. This is added by utilities to support dental health in the community.
Flush After Absence
If your home has been unoccupied for several days, run the kitchen tap for 30 seconds before drinking. This clears stale water that has been sitting in pipes.
Get water quality alerts
We'll email you when Derby's water data is updated.
FAQ
Frequently asked questions
Is tap water safe to drink in Derby?
How hard is the water in Derby?
What water utility supplies Derby?
Does Derby water have fluoride?
What is the water quality score for Derby?
What is the population of Derby?
Supplier
Water utility
- Utility
- Water Corporation
- Supply Zone
- North West
- Data Source
- Water Corporation — WC North West Aesthetic Tables, WC North West Health Tables
Nearby
Nearby suburbs
Same water utility, similar water quality
Similar Quality
Suburbs with similar water quality
Suburbs scoring between 8.6 and 10.0
Utility reports average the grid — not your home
Derby's water meets ADWG standards at the source, but old pipes, roof tanks, and ageing plumbing can add lead, copper or bacteria before the water reaches your tap. These won't show up in your utility report.
Check your own tap before buying a filter or assuming the suburb average matches your home.
Tetra
EasyStrips 6-in-1 Water Test (100 strips)
4.6 · 8,650 ratings on Amazon
Tests 6 parameters in 60 seconds: hardness, chlorine, pH, nitrate, nitrite, alkalinity. Cheapest way to verify your utility data.
Test my tap →Sponsored Amazon link. Check Amazon for current price and availability.
Heavy Metals
Drinking Water Test Kit (Lead, Copper, Iron, Mercury)
4.2 · 250 ratings on Amazon
20 tests. Detects lead, copper, iron, mercury — the things utility reports miss. Mobile-app results, EPA-standard thresholds.
Check metals kit →Sponsored Amazon link. Check Amazon for current price and availability.
Guides for Perth and WA
In-depth articles on the water supply that serves Derby
Related
Explore more
Related pages for Derby, WA
Is tap water safe?
Safety assessment
Water hardness
54 mg/L
Best water filter
Filter recommendations
Western Australia water quality
State coverage
Water Corporation
Water utility
Compare with Jarlmadangah Burru
Derby vs Jarlmadangah Burru
Compare with Camballin
Derby vs Camballin
Compare with Geegully Creek
Derby vs Geegully Creek
Disclaimer: The information on this page is for general informational purposes only and does not constitute medical advice, health recommendations, or professional guidance. Water quality data is sourced from Water Corporation (annual report) and reflects conditions at the time of utility testing — it may not reflect real-time water quality at your tap. Actual water quality can vary due to local plumbing, seasonal changes, and distance from the treatment plant. For specific health concerns, consult a qualified health professional. For the most current water quality information, contact your local water utility directly. See our Terms of Use.