Tap water in HP7, BuckinghamshireToo few tap tests to call it.Very hard.
Supplied by Thames Water. 9 substances, latest on 2 October 2026. These are river and groundwater samples near HP7, not tests of treated tap water, so treat the score as a rough guide.
7.9 / 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.
Waterdrop G3P600 Reverse Osmosis
£550typical price
Maximum contaminant removal including PFAS and fluoride
Waterdrop 10UA Under Sink
£70typical price
High-volume under-sink filtration without RO complexity
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What's in a glass of HP7 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.
Iron came closest to a limit, at 100% of it. 3 of 4 substances used under a quarter of theirs.
- Iron100%
- Nitrate9%
- Ammonia8%
- Nitrite7%
- pH 8.01 pH
- Temperature 11.7 °C
- Conductivity 637 µS/cm
- Phosphate 0.091 mg/L
- Dissolved Oxygen 9.78 mg/L
All 9 results as a table
| Substance | Result | Legal limit | Share of limit |
|---|---|---|---|
| Iron | 0.2 mg/L | 0.2 mg/L | 100% |
| pH | 8.01 pH | No legal limit | – |
| Temperature | 11.7 °C | No legal limit | – |
| Conductivity | 637 µS/cm | No legal limit | – |
| Ammonia | 0.04 mg/L | 0.5 mg/L | 8% |
| Nitrate | 4.7 mg/L | 50 mg/L | 9% |
| Nitrite | 0.033 mg/L | 0.5 mg/L | 7% |
| Phosphate | 0.091 mg/L | No legal limit | – |
| Dissolved Oxygen | 9.78 mg/L | No legal limit | – |
299mg of limescale minerals in every litre, typical for the HP area. HP7 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 HP7
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Your river is the Misbourne, rated poor
The Environment Agency rated the Misbourne 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. 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 dropped since the previous assessment.
None of this is a test of your tap water. Environment Agency record · River health across England
HP7 in short
Tap water in HP7 (Buckinghamshire) is supplied by Thames Water in the Buckinghamshire Central zone and scores 7.9 out of 10, against an England and Wales average of 9.0. 1 of 9 tested substances was close to or over a limit. The latest sample is from 2 October 2026.
- Iron is within its legal limit but flagged, at 100% of the 0.2 mg/L maximumAnything over three quarters of a limit is flagged here as worth watching. It has not gone over. See every reading
- 23rd cleanest of 26 areas tested in Buckinghamshire3 areas in Buckinghamshire scored lower. 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
Questions about HP7 water
Is HP7 tap water safe to drink?
Based on the latest tests, HP7 (Buckinghamshire) water scores 7.9/10, which is safe. 1 of 9 tested contaminants exceeded recommended levels. Water is supplied by Thames Water.
What contaminants are in HP7 water?
We tested 9 contaminants in HP7 water. 1 were flagged, including Iron.
Who supplies water in HP7?
HP7 (Buckinghamshire) is supplied by Thames Water. You can view their full profile and compliance data on our supplier page.
Is HP7 water hard or soft?
No hardness reading has been published for HP7 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 HP7?
With 1 contaminant above recommended levels in HP7, a water filter could help. A filter jug or under-sink filter can reduce most common contaminants. See our filter recommendations for your area.
Are there PFAS forever chemicals in HP7 water?
No PFAS (forever chemicals) result is attached to the tap-water tests for HP7, 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 HP7?
The Environment Agency rated the Misbourne 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. 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 dropped since the previous assessment. This is a rating of the river, not of tap water in HP7, which is treated before it reaches homes.
Keep reading
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