Tap Water Quality in Ob Flat, SA
Postcode 5291 · Supplied by SA Water via Mt Gambier
Quality Score
About Ob Flat
Ob Flat is a suburb of 470 residents in South Australia (postcode 5291). The median age is 48. It falls within the SA Water area. Neighbouring suburbs include Mount Gambier, Allendale East, Blackfellows Caves, Burrungule.
Most residents own their home with a mortgage (49%), while 36% own outright, while 9% rent. The median household income is $109,408 per year. The top countries of birth for residents are New Zealand (24%), United Kingdom (22%), and India (15%).
Tap water in Ob Flat is supplied by SA Water. The suburb receives water via the Mt Gambier supply zone.
Water quality summary
Based on 2025 water quality reports, Ob Flat achieves a WaterScore of 8.8 out of 10, rated excellent overall. Water hardness measures 183 mg/L, classified as hard. Residents may notice limescale buildup on appliances and fixtures. The pH level is 0.05, which is outside the ADWG guideline range of 6.5–8.5. The water is fluoridated at 0.9 mg/L, within the recommended range of 0.6–1.1 mg/L for dental health, well under the ADWG maximum of 1.5 mg/L. Chlorine, used for disinfection, measures 1.1 mg/L — well within the ADWG guideline of 5 mg/L. Some residents may notice a slight taste, which can be reduced by refrigerating water or using a carbon filter. Total dissolved solids (TDS) measure 363 mg/L, considered moderate against the ADWG guideline of 600 mg/L. Turbidity is 0.13 NTU, indicating clear water, within the ADWG guideline of 5 NTU. E. coli was not detected in testing, meeting the ADWG standard for microbiological safety.
Compare with nearby suburbs: Mount Gambier , Allendale East , Blackfellows Caves
Census Data
Suburb snapshot
Population
Median Age
Median Income
Owner-occupied
183/200 mg/L
53% above South Australia avg
115% above national avg
Recommended filters for Ob Flat
Products matched to your water profile
iSpring
RCC7AK 6-Stage Under-Sink RO (with Alkaline Re-min)
4.6 · 13,756 ratings on Amazon
Ideal for Ob Flat — reduces hardness from 183 mg/L, removes chlorine taste and odour.
AO Smith
Salt-Free Whole House Descaler (6yr / 600,000 Gal)
4.3 · 1,517 ratings on Amazon
Ideal for Ob Flat — helps reduce limescale buildup from hard water (183 mg/L) without removing hardness minerals.
BRITA
Marella 2.4L Fridge Water Filter Jug (Maxtra+)
4.7 · 16,095 ratings on Amazon
Ideal for Ob Flat — removes chlorine taste and odour.
Comparison
How Ob Flat compares
Compared to South Australia and national averages
| Metric | Ob Flat | SA Avg | National Avg |
|---|---|---|---|
| Hardness | 183 mg/L | 119.3 mg/L | 85.1 mg/L |
| pH | 0.05 | 3.2 | 8.4 |
| Fluoride | 0.9 mg/L | 0.5 mg/L | 0.7 mg/L |
| Chlorine | 1.1 mg/L | — | — |
| Turbidity | 0.13 NTU | 0.1 NTU | 0.4 NTU |
| TDS | 363 mg/L | 341.5 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 | 172 | mg/L | No limit | Measured |
| Aluminium | 0.001 | mg/L | < 0.2 | Good |
| Calcium | 42 | mg/L | No limit | Measured |
| Chloride | 80 | mg/L | < 250 | Good |
| Free Chlorine | 1.1 | mg/L | < 5 | Good |
| Total Chlorine | 1.1 | mg/L | < 5 | Good |
| Colour | 1 | HU | < 15 | Good |
| Copper | 0.0159 | mg/L | < 2 | Good |
| E. coli | 0 | cfu/100mL | < 0 | Compliant |
| Fluoride | 0.9 | mg/L | < 1.5 | Good |
| Hardness | 183 | PPM or mg/L | < 200 | Near limit |
| Iron | 0.0009 | mg/L | < 0.3 | Good |
| Lead | 0.0004 | mg/L | < 0.01 | Good |
| Magnesium | 18.8 | mg/L | No limit | Measured |
| Manganese | 0.0001 | mg/L | < 0.1 | Good |
| Nitrate | 13.87 | mg/L | < 50 | Good |
| pH | 0.05 | µg/L | 6.5 – 8.5 | Outside range |
| Sodium | 53.6 | mg/L | < 180 | Good |
| Sulfate | 14.6 | mg/L | < 500 | Good |
| Total Dissolved Solids | 363 | mg/L | < 600 | Good |
| Turbidity | 0.13 | NTU | < 5 | Good |
Safety
Safety assessment
Of 21 parameters tested, most fall within Australian Drinking Water Guidelines with 1 exception: pH at 0.05 µg/L. E. coli was not detected, meeting the ADWG standard for microbiological safety.
Based on comparison with Australian Drinking Water Guidelines (ADWG)
Explained
What these numbers mean
Hard (183 mg/L)
Water Hardness
Your water is classified as hard. Expect noticeable limescale on heating elements, showerheads, and taps. Soap and shampoo may not lather as freely, requiring more product. Some residents report drier skin or hair. Periodic descaling of kettles and hot water systems is recommended to maintain efficiency.
Outside Range
pH Level
pH of 0.05 is outside the ideal range of 6.5–8.5. The ADWG recommends pH between 6.5 and 8.5 for drinking water.
Fluoridated
Fluoride
Fluoride at 0.9 mg/L. Within the recommended 0.6–1.1 mg/L range for dental health.
Chlorine
Disinfection
Chlorine measured at 1.1 mg/L, well within the ADWG guideline of 5 mg/L. Used for disinfection to keep water safe. May affect taste slightly — refrigerating water or using a carbon filter can help.
Learn more about these measurements in our water quality glossary — including Hardness , pH , Fluoride , and ADWG guidelines .
Advice
Practical tips for residents
Reduce Chlorine Taste
Ob Flat's chlorine level is 1.1 mg/L. An activated carbon jug filter or benchtop unit can noticeably reduce chlorine taste and odour from tap water.
Watch for Limescale
Ob Flat has hard water at 183 mg/L. Wipe taps and showerheads periodically with vinegar to prevent limescale buildup on fixtures.
Fluoride in Your Water
Fluoride measures 0.9 mg/L in Ob Flat. Australian guidelines allow up to 1.5 mg/L. This is added by utilities to support dental health in the community.
Consider a Filter for TDS
Total dissolved solids measure 363 mg/L. A reverse osmosis filter can reduce dissolved minerals if you prefer a cleaner taste in drinking water.
Slightly Acidic Water
pH measures 0.05 in Ob Flat, which is slightly acidic. Running the tap for 30 seconds before drinking can flush any metals that dissolve more readily in acidic water.
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FAQ
Frequently asked questions
Is tap water safe to drink in Ob Flat?
How hard is the water in Ob Flat?
What water utility supplies Ob Flat?
Does Ob Flat water have fluoride?
What is the water quality score for Ob Flat?
What is the population of Ob Flat?
Supplier
Water utility
- Utility
- SA Water
- Supply Zone
- Mt Gambier
- Data Source
- SA Water — water quality performance results november 2025
Nearby
Nearby suburbs
Same water utility, similar water quality
Similar Quality
Suburbs with similar water quality
Suburbs scoring between 7.8 and 9.8
Utility reports average the grid — not your home
Ob Flat'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 Adelaide and SA
In-depth articles on the water supply that serves Ob Flat
Related
Explore more
Related pages for Ob Flat, SA
Is tap water safe?
Safety assessment
Water hardness
183 mg/L
Best water filter
Filter recommendations
South Australia water quality
State coverage
SA Water
Water utility
Compare with Mount Gambier
Ob Flat vs Mount Gambier
Compare with Allendale East
Ob Flat vs Allendale East
Compare with Blackfellows Caves
Ob Flat vs Blackfellows Caves
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 SA Water (2025 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.