Tap water in HP10, BuckinghamshireToo few tap tests to call it.Very hard.
Supplied by Thames Water. 8 substances, latest on 12 October 2026. These are river and groundwater samples near HP10, not tests of treated tap water, so treat the score as a rough guide.
9.2 / 10
The tank is as full as the score. The specks are the minerals that make water hard.
What to do about it
Hard water: compare softener quotes
At 299 mg/L a softener is the only thing that stops limescale. Filters do not soften water.
It pays for itself in most homes at this hardness, through a boiler that stays efficient and appliances that last.
ZeroWater 12-Cup Ready-Pour
£40typical price
Households concerned about PFAS and heavy metals
Waterdrop 10UA Under Sink
£70typical price
High-volume under-sink filtration without RO complexity
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What's in a glass of HP10 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.
Nitrate came closest to a limit, at 12% of it. 3 of 3 substances used under a quarter of theirs.
- Nitrate12%
- Ammonia10%
- Nitrite3%
- pH 8.09 pH
- Temperature 12.8 °C
- Conductivity 591 µS/cm
- Phosphate 0.043 mg/L
- Dissolved Oxygen 10.5 mg/L
All 8 results as a table
299mg of limescale minerals in every litre, typical for the HP area. HP10 has no reading of its own.
This is the water that furs up kettles
Very hard on the UK scale. It is fine to drink. It is hard on boilers, showers, skin and anything that heats water, and a jug or tap filter will not change that.
Softener quotes for HP10
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Your river is the Wye (High Wycombe fire station to Thames), rated poor
The Environment Agency rated the Wye (High Wycombe fire station to Thames) as poor for ecological health in its 2025 assessment, meaning the river is badly affected, with much of the expected wildlife missing. It is held back by fish and insects and other small river life. 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.
None of this is a test of your tap water. Environment Agency record · River health across England
HP10 in short
Tap water in HP10 (Buckinghamshire) is supplied by Thames Water in the Buckinghamshire Central zone and scores 9.2 out of 10, against an England and Wales average of 9.0. None of the 8 tested substances came close to a limit. The latest sample is from 12 October 2026.
- 2nd cleanest of 26 areas tested in BuckinghamshireOnly 1 area in Buckinghamshire scored higher. The best is HP19 on 9.3.
- Very hard water at 299 mg/LThe threshold for very hard is 250 mg/L. Expect visible limescale on taps and in kettles across the HP postcode area. How hardness is measured
- Nothing tested came within 40% of its legal limitThe highest was Nitrate at 12% of the 50 mg/L maximum. See every reading
Questions about HP10 water
Is HP10 tap water safe to drink?
Based on the latest tests, HP10 (Buckinghamshire) water scores 9.2/10, which is safe. 0 of 8 tested contaminants exceeded recommended levels. Water is supplied by Thames Water.
What contaminants are in HP10 water?
We tested 8 contaminants in HP10 water. None exceeded recommended safe levels.
Who supplies water in HP10?
HP10 (Buckinghamshire) is supplied by Thames Water. You can view their full profile and compliance data on our supplier page.
Is HP10 water hard or soft?
No hardness reading has been published for HP10 itself. Across the HP postcode area the typical value is 299 mg/L CaCO3, which is classified as very hard. Hard water can cause limescale buildup. A water softener or filter jug may help.
Should I use a water filter in HP10?
HP10 water scored 9.2/10 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 HP10 water?
No PFAS (forever chemicals) result is attached to the tap-water tests for HP10, 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 HP10?
The Environment Agency rated the Wye (High Wycombe fire station to Thames) as poor for ecological health in its 2025 assessment, meaning the river is badly affected, with much of the expected wildlife missing. It is held back by fish and insects and other small river life. 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. This is a rating of the river, not of tap water in HP10, which is treated before it reaches homes.
Keep reading
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