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tapwater
England and Wales average 9.0

Tap water in GU5, WaverleySafe to drink.Moderately soft.

Supplied by Thames Water. 74 samples, 23 substances, latest on 31 December 2025. Everything is inside the legal limit, and nothing comes close to it.

See the filter we recommendSee everything that was tested

9.3 / 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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What's in a glass of GU5 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.

Nitrite came closest to a limit, at 38% of it. 18 of 19 substances used under a quarter of theirs.

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: 0.04 mg/L, 2% of the 2 mg/L limitCopper2%Aluminium: 0.0082 mg/L, 4% of the 0.2 mg/L limitAluminium4%Iron: 0.009 mg/L, 5% of the 0.2 mg/L limitIron5%Chromium: 0.0025 mg/L, 5% of the 0.05 mg/L limitChromium5%Fluoride: 0.08 mg/L, 5% of the 1.5 mg/L limitFluoride5%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%Nickel: 0.0016 mg/L, 8% of the 0.02 mg/L limitNickel8%Lead: 0.0009 mg/L, 9% of the 0.01 mg/L limitLead9%Colour: 1.8 mg/L Pt/Co, 9% of the 20 mg/L Pt/Co limitColour9%Bromate: 0.001 mg/L, 10% of the 0.01 mg/L limitBromate10%Trihalomethanes: 0.015 mg/L, 15% of the 0.1 mg/L limitTrihalomethanes15%Nitrate: 9.4 mg/L, 19% of the 50 mg/L limitNitrate19%Nitrite: 0.19 mg/L, 38% of the 0.5 mg/L limitNitrite38%
  1. Nitrite38%
  2. Nitrate19%
  3. Trihalomethanes15%
  4. Bromate10%
  5. Lead9%
  6. Colour9%
  7. Cadmium8%
  8. Nickel8%
  9. Mercury7%
  10. Arsenic7%
  11. Antimony6%
  12. Fluoride5%
  13. Chromium5%
  14. Iron5%
  15. Aluminium4%
  16. Boron2%
  17. Copper2%
  18. Manganese1%
  19. Selenium1%
  • Coliform Bacteria none found
  • E. coli none found
  • Conductivity 287 µS/cm
All 23 results as a table
SubstanceResultLegal limitShare of limit
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%
Conductivity287 µS/cmNo legal limit–
Fluoride0.08 mg/L1.5 mg/L
5%
Nitrate9.4 mg/L50 mg/L
19%
Nitrite0.19 mg/L0.5 mg/L
38%
Hardness (as CaCO3)88 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%
Copper0.04 mg/L2 mg/L
2%
Iron0.009 mg/L0.2 mg/L
5%
Lead0.0009 mg/L0.01 mg/L
9%
Manganese0.0006 mg/L0.05 mg/L
1%
Mercury0.00007 mg/L0.001 mg/L
7%
Nickel0.0016 mg/L0.02 mg/L
8%
Selenium0.0004 mg/L0.04 mg/L
1%
Trihalomethanes0.015 mg/L0.1 mg/L
15%
Bromate0.001 mg/L0.01 mg/L
10%

88mg of limescale minerals in every litre

Soft water. Kind to kettles, boilers and skin

You will not need a softener here, and you will use less soap and detergent than most of England.

Soft400 mg/L
Outside your tap

Your river is the Cranleigh Waters, rated moderate

The Environment Agency rated the Cranleigh Waters 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 and water plants and algae. 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

GU5 in short

Tap water in GU5 (Waverley) is supplied by Thames Water in the Waverley Central zone and scores 9.3 out of 10, against an England and Wales average of 9.0. None of the 23 tested substances came close to a limit. The latest sample is from 31 December 2025.

  • The cleanest tap water of the 7 areas tested in WaverleyGU5 scores 9.3 out of 10, ahead of GU10 in second place on 8.9.
  • Scores higher than all 7 neighbouring districtsThe nearest rival is GU4 on 9.1, against 9.3 here. Compare with GU4
  • Nothing tested came within 40% of its legal limitThe highest was Nitrite at 38% of the 0.5 mg/L maximum. See every reading

Next door

GU98.8 out of 10 · 204 mg/LGU68.6 out of 10 · 225 mg/LGU77.8 out of 10 · 287 mg/LGU88.8 out of 10 · 141 mg/LGU278.6 out of 10 · 225 mg/LGU108.9 out of 10 · 154 mg/LGU49.1 out of 10 · 75 mg/L

Questions about GU5 water

Is GU5 tap water safe to drink?

Based on the latest tests, GU5 (Waverley) water scores 9.3/10, which is safe. 0 of 23 tested contaminants exceeded recommended levels. Water is supplied by Thames Water.

What contaminants are in GU5 water?

We tested 23 contaminants in GU5 water. None exceeded recommended safe levels.

Who supplies water in GU5?

GU5 (Waverley) is supplied by Thames Water. You can view their full profile and compliance data on our supplier page.

Is GU5 water hard or soft?

Water in GU5 (Waverley) has a hardness of 88 mg/L CaCO3, which is classified as moderately soft. This is a moderate hardness level.

Should I use a water filter in GU5?

GU5 water scored 9.3/10 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 GU5 water?

No PFAS (forever chemicals) result is attached to the tap-water tests for GU5, 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 GU5?

The Environment Agency rated the Cranleigh Waters 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 and water plants and algae. 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 GU5, 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 GU5

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
Iron0.2 mg/L0.2 mg/L
pH7.92 pHNone
Temperature21.1 °CNone
Conductivity451 µS/cmNone
Nitrate5.5 mg/L50 mg/L
Nitrite0.019 mg/L0.5 mg/L
Phosphate0.18 mg/LNone
Dissolved Oxygen8.63 mg/LNone
Ammonia0.055 mg/L0.5 mg/L
Zinc0.073 mg/LNone
Chromium0.001 mg/L0.05 mg/L
Nickel0.002 mg/L0.02 mg/L
Copper0.004 mg/L2 mg/L
Manganese0.02 mg/L0.05 mg/L

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We'll email you when water quality data changes for GU5.

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