Tap water in BS40, North SomersetToo few tap tests to call it.
Supplied by Bristol Water. 10 substances, latest on 8 May 2026. These are river and groundwater samples near BS40, not tests of treated tap water, so treat the score as a rough guide.
9.6 / 10
The tank is as full as the score.
What to do about it
ZeroWater 12-Cup Ready-Pour
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Households concerned about PFAS and heavy metals
Waterdrop 10UA Under Sink
£70typical price
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 BS40 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.
Ammonia came closest to a limit, at 9% of it. 4 of 4 substances used under a quarter of theirs.
- Ammonia9%
- Nitrate5%
- Nitrite1%
- Copper<1%
- pH 7.79 pH
- Temperature 12.2 °C
- Conductivity 823 µS/cm
- Phosphate 0.087 mg/L
- Dissolved Oxygen 9.65 mg/L
- Zinc 0.0801 mg/L
All 10 results as a table
| Substance | Result | Legal limit | Share of limit |
|---|---|---|---|
| pH | 7.79 pH | No legal limit | – |
| Temperature | 12.2 °C | No legal limit | – |
| Conductivity | 823 µS/cm | No legal limit | – |
| Nitrate | 2.3 mg/L | 50 mg/L | 5% |
| Nitrite | 0.0066 mg/L | 0.5 mg/L | 1% |
| Phosphate | 0.087 mg/L | No legal limit | – |
| Dissolved Oxygen | 9.65 mg/L | No legal limit | – |
| Ammonia | 0.047 mg/L | 0.5 mg/L | 9% |
| Copper | 0.0017 mg/L | 2 mg/L | <1% |
| Zinc | 0.0801 mg/L | No legal limit | – |
Your river is the Yeo - source to conf Congresbury Yeo, rated moderate
The Environment Agency rated the Yeo - source to conf Congresbury Yeo 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. 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
5
forever-chemical detections in nearby rivers and groundwater
At 1 site. The highest was PFBA at 0.002 µg/L, at Chew Stoke Stream, 4.2 km away, in February 2024. These are river and borehole samples, not tests of your tap water.
Every PFAS sample around Bristol · Which filters remove PFAS · PFAS explained
BS40 in short
Tap water in BS40 (North Somerset) is supplied by Bristol Water in the North Somerset Central zone and scores 9.6 out of 10, against an England and Wales average of 9.0. None of the 10 tested substances came close to a limit. The latest sample is from 8 May 2026.
- The cleanest tap water of the 10 areas tested in BristolBS40 scores 9.6 out of 10, ahead of BS49 in second place on 9.5. Every area in Bristol
- Scores higher than all 9 neighbouring districtsThe nearest rival is BS49 on 9.5, against 9.6 here. Compare with BS49
- 0.6 points above the national average of 9Cleaner than the typical tested district in the UK. Compare every area
Questions about BS40 water
Is BS40 tap water safe to drink?
Based on the latest tests, BS40 (North Somerset) water scores 9.6/10, which is safe. 0 of 10 tested contaminants exceeded recommended levels. Water is supplied by Bristol Water.
What contaminants are in BS40 water?
We tested 10 contaminants in BS40 water. None exceeded recommended safe levels. PFAS (forever chemicals) were also measured in rivers and groundwater within 10 km, though not in the tap-water tests themselves.
Who supplies water in BS40?
BS40 (North Somerset) is supplied by Bristol Water. You can view their full profile and compliance data on our supplier page.
Should I use a water filter in BS40?
BS40 water scored 9.6/10 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 BS40 water?
The tap-water tests we hold for BS40 do not include a PFAS result. Environment Agency monitoring found PFAS in 5 river and groundwater samples from 1 sites within 10 km of BS40, the highest being PFBA at 0.002 µg/L about 4.2 km away. These are environmental samples, not tests of tap water. The UK currently has no legal limit for PFAS in drinking water; the Drinking Water Inspectorate uses a 0.1 µg/L guideline for individual compounds. Reverse osmosis filters can reduce PFAS levels.
How clean is the river near BS40?
The Environment Agency rated the Yeo - source to conf Congresbury Yeo 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. 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 BS40, which is treated before it reaches homes.
Keep reading
- Best Filter for PFAS RemovalThe filters with independent certification to remove forever chemicals
- PFAS Forever ChemicalsWhat PFAS are and how to reduce your exposure at home
- Is UK Tap Water Safe?Everything you need to know about tap water safety in the UK
- Best Water Filters UKEvery filter type compared on what it actually removes
PFAS explainedHow to test your waterBest water filtersFilter shower headsWater testing kitsAll of BristolUK water rankingsWater hardness checkerWater hardness map
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