Tap water in BN25, LewesToo few tap tests to call it.
Supplied by Southern Water. 9 substances, latest on 27 August 2026. These are river and groundwater samples near BN25, not tests of treated tap water, so treat the score as a rough guide.
9.0 / 10
The tank is as full as the score.
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 BN25 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 20% of it. 3 of 3 substances used under a quarter of theirs.
- Ammonia20%
- Nitrite6%
- Nitrate4%
- pH 7.58 pH
- Temperature 19.4 °C
- Conductivity 520 µS/cm
- Phosphate 0.022 mg/L
- Dissolved Oxygen 7.48 mg/L
- PFAS (total) 0.011 µg/L
All 9 results as a table
| Substance | Result | Legal limit | Share of limit |
|---|---|---|---|
| pH | 7.58 pH | No legal limit | – |
| Temperature | 19.4 °C | No legal limit | – |
| Conductivity | 520 µS/cm | No legal limit | – |
| Ammonia | 0.099 mg/L | 0.5 mg/L | 20% |
| Nitrate | 2 mg/L | 50 mg/L | 4% |
| Nitrite | 0.032 mg/L | 0.5 mg/L | 6% |
| Phosphate | 0.022 mg/L | No legal limit | – |
| Dissolved Oxygen | 7.48 mg/L | No legal limit | – |
| PFAS (total) | 0.011 µg/L | No legal limit | – |
Your coastal water is the Sussex, rated moderate
The Environment Agency rated the Sussex as moderate for ecological health in its 2025 assessment, meaning the coastal water is noticeably changed by pollution or engineering. 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
BN25 in short
Tap water in BN25 (Lewes) is supplied by Southern Water in the Lewes Central zone and scores 9.0 out of 10, against an England and Wales average of 9.0. None of the 9 tested substances came close to a limit. The latest sample is from 27 August 2026.
- The lowest score of the 5 areas tested in LewesBN25 scores 9 out of 10. The best in Lewes, BN10, scores 9.3.
- Every one of the 4 neighbouring districts scores higherBN9 next door scores 9.3, against 9 here. Supply zones, not distance, explain the gap. See BN9
- Nothing tested came within 40% of its legal limitThe highest was Ammonia at 20% of the 0.5 mg/L maximum. See every reading
Questions about BN25 water
Is BN25 tap water safe to drink?
Based on the latest tests, BN25 (Lewes) water scores 9/10, which is safe. 0 of 9 tested contaminants exceeded recommended levels. Water is supplied by Southern Water.
What contaminants are in BN25 water?
We tested 9 contaminants in BN25 water. None exceeded recommended safe levels. PFAS (forever chemicals) were also detected at 0.011 µg/L in nearby environmental monitoring.
Who supplies water in BN25?
BN25 (Lewes) is supplied by Southern Water. You can view their full profile and compliance data on our supplier page.
Should I use a water filter in BN25?
BN25 water scored 9/10 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 BN25 water?
Yes, PFAS (per- and polyfluoroalkyl substances) have been detected in BN25 at 0.011 µg/L from environmental monitoring. The UK currently has no legal limit for PFAS in drinking water. Reverse osmosis and activated carbon filters can reduce PFAS levels.
How clean is the coastal water near BN25?
The Environment Agency rated the Sussex as moderate for ecological health in its 2025 assessment, meaning the coastal water is noticeably changed by pollution or engineering. 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 coastal water, not of tap water in BN25, 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 kitsUK water rankingsWater hardness checkerWater hardness map
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