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tapwater
England and Wales average 9.0

Tap water in RH9, TandridgeNickel 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.

See the filter we recommendSee everything that was tested

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

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Removes nickel, the result that stood out in RH9.

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Basic chlorine and taste improvement on a budget

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Households concerned about PFAS and heavy metals

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What's in a glass of RH9 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.

0%25%50%75%limitLegal limitSelenium: 0.0004 mg/L, 1% of the 0.04 mg/L limitSelenium1%Manganese: 0.0006 mg/L, 1% of the 0.05 mg/L limitManganese1%Boron: 0.02 mg/L, 2% of the 1 mg/L limitBoron2%Copper: 0.06 mg/L, 3% of the 2 mg/L limitCopper3%Aluminium: 0.0082 mg/L, 4% of the 0.2 mg/L limitAluminium4%Chromium: 0.0025 mg/L, 5% of the 0.05 mg/L limitChromium5%Antimony: 0.0003 mg/L, 6% of the 0.005 mg/L limitAntimony6%Mercury: 0.00007 mg/L, 7% of the 0.001 mg/L limitMercury7%Arsenic: 0.0007 mg/L, 7% of the 0.01 mg/L limitArsenic7%Cadmium: 0.0004 mg/L, 8% of the 0.005 mg/L limitCadmium8%Iron: 0.017 mg/L, 9% of the 0.2 mg/L limitIron9%Colour: 1.8 mg/L Pt/Co, 9% of the 20 mg/L Pt/Co limitColour9%Lead: 0.001 mg/L, 10% of the 0.01 mg/L limitLead10%Bromate: 0.001 mg/L, 10% of the 0.01 mg/L limitBromate10%Fluoride: 0.15 mg/L, 10% of the 1.5 mg/L limitFluoride10%Nitrate: 9.3 mg/L, 19% of the 50 mg/L limitNitrate19%Trihalomethanes: 0.02 mg/L, 20% of the 0.1 mg/L limitTrihalomethanes20%Nitrite: 0.19 mg/L, 38% of the 0.5 mg/L limitNitrite38%Nickel: 0.0228 mg/L, 114% of the 0.02 mg/L limitNickel114%
  1. Nickel114%
  2. Nitrite38%
  3. Trihalomethanes20%
  4. Nitrate19%
  5. Lead10%
  6. Bromate10%
  7. Fluoride10%
  8. Colour9%
  9. Iron9%
  10. Cadmium8%
  11. Mercury7%
  12. Arsenic7%
  13. Antimony6%
  14. Chromium5%
  15. Aluminium4%
  16. Copper3%
  17. Boron2%
  18. Manganese1%
  19. Selenium1%
  • Coliform Bacteria none found
  • E. coli none found
  • Conductivity 340 µS/cm
All 23 results as a table
SubstanceResultLegal limitShare of limit
Nickel0.0228 mg/L0.02 mg/L
114%
Coliform Bacteria0 count/100mlMust be zeroNone found
E. coli0 count/100mlMust be zeroNone found
Colour1.8 mg/L Pt/Co20 mg/L Pt/Co
9%
Conductivity340 µS/cmNo legal limit–
Fluoride0.15 mg/L1.5 mg/L
10%
Nitrate9.3 mg/L50 mg/L
19%
Nitrite0.19 mg/L0.5 mg/L
38%
Hardness (as CaCO3)141 mg/LNo legal limit–
Aluminium0.0082 mg/L0.2 mg/L
4%
Antimony0.0003 mg/L0.005 mg/L
6%
Arsenic0.0007 mg/L0.01 mg/L
7%
Boron0.02 mg/L1 mg/L
2%
Cadmium0.0004 mg/L0.005 mg/L
8%
Chromium0.0025 mg/L0.05 mg/L
5%
Copper0.06 mg/L2 mg/L
3%
Iron0.017 mg/L0.2 mg/L
9%
Lead0.001 mg/L0.01 mg/L
10%
Manganese0.0006 mg/L0.05 mg/L
1%
Mercury0.00007 mg/L0.001 mg/L
7%
Selenium0.0004 mg/L0.04 mg/L
1%
Trihalomethanes0.02 mg/L0.1 mg/L
20%
Bromate0.001 mg/L0.01 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.

Soft400 mg/L
Outside your tap

Your river is the Gibbs Brook, rated moderate

The Environment Agency rated the Gibbs Brook 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

RH9 in short

Tap water in RH9 (Tandridge) is supplied by Thames Water in the Tandridge 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
  • The cleanest tap water of the 5 areas tested in TandridgeRH9 scores 8.8 out of 10, ahead of CR3 in second place on 8.6.
  • Scores higher than all 4 neighbouring districtsThe nearest rival is CR3 on 8.6, against 8.8 here. Compare with CR3

Next door

CR38.6 out of 10 · 313 mg/LRH78.6 out of 10 · 225 mg/LRH87.8 out of 10 · 287 mg/LCR67.9 out of 10 · 257 mg/L

Questions about RH9 water

Is RH9 tap water safe to drink?

Based on the latest tests, RH9 (Tandridge) 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 RH9 water?

We tested 23 contaminants in RH9 water. 1 were flagged, including Nickel.

Who supplies water in RH9?

RH9 (Tandridge) is supplied by Thames Water. You can view their full profile and compliance data on our supplier page.

Is RH9 water hard or soft?

Water in RH9 (Tandridge) 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 RH9?

With 1 contaminant above recommended levels in RH9, 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 RH9 water?

No PFAS (forever chemicals) result is attached to the tap-water tests for RH9, 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 RH9?

The Environment Agency rated the Gibbs Brook 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 RH9, which is treated before it reaches homes.

Keep reading

How to test your waterBest water filtersFilter shower headsWater testing kitsUK water rankingsWater hardness checkerWater hardness map

River and groundwater readings near RH9

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.

SubstanceReadingDrinking water limit
Iron0.342 mg/L0.2 mg/L
pH8.37 pHNone
Temperature14.2 °CNone
Conductivity746 µS/cmNone
Nitrate8.6 mg/L50 mg/L
Nitrite0.0098 mg/L0.5 mg/L
Phosphate0.18 mg/LNone
Dissolved Oxygen9.42 mg/LNone
Ammonia0.19 mg/L0.5 mg/L
Chromium0.000889 mg/L0.05 mg/L
Zinc0.00653 mg/LNone
Nickel0.00316 mg/L0.02 mg/L
Arsenic0.00162 mg/L0.01 mg/L
Boron0.203 mg/L1 mg/L
Copper0.00373 mg/L2 mg/L

Get alerts for your area

We'll email you when water quality data changes for RH9.

Source: Thames Water test results, published through the Stream Water Data Portal; rivers and PFAS from the Environment Agency. Page updated . How we score · Where the data comes from