Tap water in KT22, Mole ValleyNickel is over the limit.Slightly hard.
Supplied by Thames Water. 74 samples, 23 substances, latest on 31 December 2025. Nickel came in above the legal limit. Everything else passed.
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

Waterdrop G3P600 Reverse Osmosis
£550typical price
Removes nickel, the result that stood out in KT22.

BRITA Marella XL + MAXTRA PRO
£25typical price
Basic chlorine and taste improvement on a budget

ZeroWater 12-Cup Ready-Pour
£40typical price
Households concerned about PFAS and heavy metals
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What's in a glass of KT22 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.
Nickel is over its legal limit, at 114% of it.
- Nickel114%
- Nitrite38%
- Trihalomethanes20%
- Nitrate19%
- Lead10%
- Bromate10%
- Fluoride10%
- Colour9%
- Iron9%
- Cadmium8%
- Mercury7%
- Arsenic7%
- Antimony6%
- Chromium5%
- Aluminium4%
- Copper3%
- Boron2%
- Manganese1%
- Selenium1%
- Coliform Bacteria none found
- E. coli none found
- Conductivity 340 µS/cm
All 23 results as a table
| Substance | Result | Legal limit | Share of limit |
|---|---|---|---|
| Nickel | 0.0228 mg/L | 0.02 mg/L | 114% |
| Coliform Bacteria | 0 count/100ml | Must be zero | None found |
| E. coli | 0 count/100ml | Must be zero | None found |
| Colour | 1.8 mg/L Pt/Co | 20 mg/L Pt/Co | 9% |
| Conductivity | 340 µS/cm | No legal limit | – |
| Fluoride | 0.15 mg/L | 1.5 mg/L | 10% |
| Nitrate | 9.3 mg/L | 50 mg/L | 19% |
| Nitrite | 0.19 mg/L | 0.5 mg/L | 38% |
| Hardness (as CaCO3) | 141 mg/L | No legal limit | – |
| Aluminium | 0.0082 mg/L | 0.2 mg/L | 4% |
| Antimony | 0.0003 mg/L | 0.005 mg/L | 6% |
| Arsenic | 0.0007 mg/L | 0.01 mg/L | 7% |
| Boron | 0.02 mg/L | 1 mg/L | 2% |
| Cadmium | 0.0004 mg/L | 0.005 mg/L | 8% |
| Chromium | 0.0025 mg/L | 0.05 mg/L | 5% |
| Copper | 0.06 mg/L | 2 mg/L | 3% |
| Iron | 0.017 mg/L | 0.2 mg/L | 9% |
| Lead | 0.001 mg/L | 0.01 mg/L | 10% |
| Manganese | 0.0006 mg/L | 0.05 mg/L | 1% |
| Mercury | 0.00007 mg/L | 0.001 mg/L | 7% |
| Selenium | 0.0004 mg/L | 0.04 mg/L | 1% |
| Trihalomethanes | 0.02 mg/L | 0.1 mg/L | 20% |
| Bromate | 0.001 mg/L | 0.01 mg/L | 10% |
141mg of limescale minerals in every litre
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 Mole - Leatherhead to Hersham, rated moderate
The Environment Agency rated the Mole - Leatherhead to Hersham 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
KT22 in short
Tap water in KT22 (Mole Valley) is supplied by Thames Water in the Mole Valley Central zone and scores 8.8 out of 10, against an England and Wales average of 9.0. 1 of 23 tested substances was close to or over a limit. The latest sample is from 31 December 2025.
- Nickel was measured at 0.023 mg/L, 14% over the UK limitIt is the only one of 23 tested substances to go over its limit. See the full results
- 3rd cleanest of 6 areas tested in Mole ValleySquarely mid-table for Mole Valley, between RH3 on 9.4 and KT21 on 7.8.
- Moderately hard water at 141 mg/LSome scale over time in KT22, but not enough to justify a softener for most homes. How hardness is measured
Questions about KT22 water
Is KT22 tap water safe to drink?
Based on the latest tests, KT22 (Mole Valley) water scores 8.8/10, which is safe. 1 of 23 tested contaminants exceeded recommended levels. Water is supplied by Thames Water.
What contaminants are in KT22 water?
We tested 23 contaminants in KT22 water. 1 were flagged, including Nickel.
Who supplies water in KT22?
KT22 (Mole Valley) is supplied by Thames Water. You can view their full profile and compliance data on our supplier page.
Is KT22 water hard or soft?
Water in KT22 (Mole Valley) has a hardness of 141 mg/L CaCO3, which is classified as moderately hard. This is a moderate hardness level.
Should I use a water filter in KT22?
With 1 contaminant above recommended levels in KT22, 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 KT22 water?
No PFAS (forever chemicals) result is attached to the tap-water tests for KT22, 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 KT22?
The Environment Agency rated the Mole - Leatherhead to Hersham 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 KT22, which is treated before it reaches homes.
Keep reading
- Best Water Filters UKEvery filter type compared on what it actually removes
- Is UK Tap Water Safe?Everything you need to know about tap water safety in the UK
- How to Test Your Tap WaterFrom DIY strips to professional lab analysis
- Best Water Filter Jug UKBRITA vs ZeroWater vs the rest, tested against real data
How to test your waterBest water filtersFilter shower headsWater testing kitsUK water rankingsWater hardness checkerWater hardness map
River and groundwater readings near KT22
Environment Agency samples from rivers, groundwater and reservoirs nearby. Not your tap water. For scale they are shown against drinking water limits; rivers are judged against much stricter environmental standards, and on those every river in England fails for chemicals.
| Substance | Reading | Drinking water limit |
|---|---|---|
| pH | 7.62 pH | None |
| Temperature | 16.6 °C | None |
| Conductivity | 555 µS/cm | None |
| Nitrate | 8.8 mg/L | 50 mg/L |
| Nitrite | 0.016 mg/L | 0.5 mg/L |
| Phosphate | 0.3 mg/L | None |
| Dissolved Oxygen | 7.77 mg/L | None |
| Aluminium | 0.021 mg/L | 0.2 mg/L |
| Copper | 0.0027 mg/L | 2 mg/L |
| Manganese | 0.011 mg/L | 0.05 mg/L |
| Iron | 0.061 mg/L | 0.2 mg/L |
| Ammonia | 0.037 mg/L | 0.5 mg/L |
| Nickel | 0.0033 mg/L | 0.02 mg/L |
| Hardness (as CaCO3) | 203 mg/L | None |
| PFAS (total) | 0.0052 µg/L | None |
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