Tap water in GU10, WaverleyToo few tap tests to call it.Slightly hard.
Supplied by Thames Water. 14 substances, latest on 9 October 2026. These are river and groundwater samples near GU10, not tests of treated tap water, so treat the score as a rough guide.
8.8 / 10
The tank is as full as the score. The specks are the minerals that make water hard.
What to do about it
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Households concerned about PFAS and heavy metals
Waterdrop 10UA Under Sink
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High-volume under-sink filtration without RO complexity
BRITA Marella XL + MAXTRA PRO
£25typical price
Basic chlorine and taste improvement on a budget
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What's in a glass of GU10 water
Every bubble is a substance the lab measured. The higher it floats, the closer it came to its legal limit, the dashed line at the top.
Manganese came closest to a limit, at 35% of it. 5 of 8 substances used under a quarter of theirs.
- Manganese35%
- Nitrate34%
- Iron27%
- Ammonia10%
- Nitrite5%
- Lead4%
- Chromium2%
- Copper<1%
- pH 7.72 pH
- Temperature 14.3 °C
- Conductivity 756 µS/cm
- Phosphate 0.47 mg/L
- Dissolved Oxygen 8.57 mg/L
- Zinc 0.0256 mg/L
All 14 results as a table
| Substance | Result | Legal limit | Share of limit |
|---|---|---|---|
| pH | 7.72 pH | No legal limit | – |
| Temperature | 14.3 °C | No legal limit | – |
| Conductivity | 756 µS/cm | No legal limit | – |
| Ammonia | 0.052 mg/L | 0.5 mg/L | 10% |
| Nitrate | 17 mg/L | 50 mg/L | 34% |
| Nitrite | 0.025 mg/L | 0.5 mg/L | 5% |
| Phosphate | 0.47 mg/L | No legal limit | – |
| Dissolved Oxygen | 8.57 mg/L | No legal limit | – |
| Lead | 0.000436 mg/L | 0.01 mg/L | 4% |
| Zinc | 0.0256 mg/L | No legal limit | – |
| Chromium | 0.000941 mg/L | 0.05 mg/L | 2% |
| Copper | 0.00625 mg/L | 2 mg/L | <1% |
| Manganese | 0.0175 mg/L | 0.05 mg/L | 35% |
| Iron | 0.0533 mg/L | 0.2 mg/L | 27% |
154mg of limescale minerals in every litre, typical for the GU area. GU10 has no reading of its own.
Middling hardness. Some scale, slowly
Below the point where a softener pays for itself. Descaling the kettle now and then is all most homes need.
Your river is the North Wey (Alton to Tilford), rated moderate
The Environment Agency rated the North Wey (Alton to Tilford) as moderate for ecological health in its 2025 assessment, meaning the river is noticeably changed by pollution or engineering. It is held back by phosphate and fish. It fails the chemical test, as every river, estuary and stretch of coast in England does, because of long-lasting pollutants such as mercury, PFOS (a forever chemical) and old flame retardants. Its ecological rating has improved since the previous assessment.
None of this is a test of your tap water. Environment Agency record · River health across England
GU10 in short
Tap water in GU10 (Waverley) is supplied by Thames Water in the Waverley Central zone and scores 8.8 out of 10, against an England and Wales average of 9.0. None of the 14 tested substances came close to a limit. The latest sample is from 9 October 2026.
- 2nd cleanest of 7 areas tested in WaverleyOnly 1 area in Waverley scored higher. The best is GU5 on 9.3.
- Nothing tested came within 40% of its legal limitThe highest was Manganese at 35% of the 0.05 mg/L maximum. See every reading
- Moderately hard water at 154 mg/LSome scale over time across the GU postcode area, but not enough to justify a softener for most homes. How hardness is measured
Questions about GU10 water
Is GU10 tap water safe to drink?
Based on the latest tests, GU10 (Waverley) water scores 8.8/10, which is safe. 0 of 14 tested contaminants exceeded recommended levels. Water is supplied by Thames Water.
What contaminants are in GU10 water?
We tested 14 contaminants in GU10 water. None exceeded recommended safe levels.
Who supplies water in GU10?
GU10 (Waverley) is supplied by Thames Water. You can view their full profile and compliance data on our supplier page.
Is GU10 water hard or soft?
No hardness reading has been published for GU10 itself. Across the GU postcode area the typical value is 154 mg/L CaCO3, which is classified as moderately hard. This is a moderate hardness level.
Should I use a water filter in GU10?
GU10 water scored 8.8/10 with no contaminants above recommended levels. A filter is optional but can improve taste, especially if you notice a chlorine flavour. See our filter recommendations for your area.
Are there PFAS forever chemicals in GU10 water?
No PFAS (forever chemicals) result is attached to the tap-water tests for GU10, and the Environment Agency has no PFAS detections in rivers or groundwater within 10 km of it. That reflects where sampling has happened as much as the water itself.
How clean is the river near GU10?
The Environment Agency rated the North Wey (Alton to Tilford) as moderate for ecological health in its 2025 assessment, meaning the river is noticeably changed by pollution or engineering. It is held back by phosphate and fish. It fails the chemical test, as every river, estuary and stretch of coast in England does, because of long-lasting pollutants such as mercury, PFOS (a forever chemical) and old flame retardants. Its ecological rating has improved since the previous assessment. This is a rating of the river, not of tap water in GU10, which is treated before it reaches homes.
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