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tapwater
England and Wales average 9.0

Tap water in CT18, Folkestone and HytheSafe to drink.

Supplied by Southern Water. 679 samples, 24 substances, latest on 19 December 2025. Everything is inside the legal limit, and nothing comes close to it.

See the filter we recommendSee everything that was tested

9.5 / 10

The tank is as full as the score.

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What's in a glass of CT18 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.

Nitrate came closest to a limit, at 48% of it. 20 of 21 substances used under a quarter of theirs.

0%25%50%75%limitLegal limitCopper: 0.007 mg/L, <1% of the 2 mg/L limitCopper<1%Antimony: 0.000027 mg/L, <1% of the 0.005 mg/L limitAntimony<1%Manganese: 0.000363 mg/L, <1% of the 0.05 mg/L limitManganese<1%Chromium: 0.000404 mg/L, <1% of the 0.05 mg/L limitChromium<1%Selenium: 0.000352 mg/L, <1% of the 0.04 mg/L limitSelenium<1%Aluminium: 0.00199 mg/L, <1% of the 0.2 mg/L limitAluminium<1%Cadmium: 0.000054 mg/L, 1% of the 0.005 mg/L limitCadmium1%Arsenic: 0.000135 mg/L, 1% of the 0.01 mg/L limitArsenic1%Nitrite: 0.01 mg/L, 2% of the 0.5 mg/L limitNitrite2%Mercury: 0.000023 mg/L, 2% of the 0.001 mg/L limitMercury2%Turbidity: 0.1 NTU, 3% of the 4 NTU limitTurbidity3%Nickel: 0.000611 mg/L, 3% of the 0.02 mg/L limitNickel3%Trihalomethanes: 0.00439 mg/L, 4% of the 0.1 mg/L limitTrihalomethanes4%Iron: 0.00897 mg/L, 4% of the 0.2 mg/L limitIron4%Boron: 0.046 mg/L, 5% of the 1 mg/L limitBoron5%Fluoride: 0.085 mg/L, 6% of the 1.5 mg/L limitFluoride6%Lead: 0.000673 mg/L, 7% of the 0.01 mg/L limitLead7%Colour: 2 mg/L Pt/Co, 10% of the 20 mg/L Pt/Co limitColour10%Ammonia: 0.06 mg/L, 12% of the 0.5 mg/L limitAmmonia12%Bromate: 0.00147 mg/L, 15% of the 0.01 mg/L limitBromate15%Nitrate: 23.8 mg/L, 48% of the 50 mg/L limitNitrate48%
  1. Nitrate48%
  2. Bromate15%
  3. Ammonia12%
  4. Colour10%
  5. Lead7%
  6. Fluoride6%
  7. Boron5%
  8. Iron4%
  9. Trihalomethanes4%
  10. Nickel3%
  11. Turbidity3%
  12. Mercury2%
  13. Nitrite2%
  14. Arsenic1%
  15. Cadmium1%
  16. Aluminium<1%
  17. Selenium<1%
  18. Chromium<1%
  19. Manganese<1%
  20. Antimony<1%
  21. Copper<1%
  • E. coli none found
  • Coliform Bacteria none found
  • Conductivity 493 µS/cm
All 24 results as a table
SubstanceResultLegal limitShare of limit
Iron0.00897 mg/L0.2 mg/L
4%
E. coli0 count/100mlMust be zeroNone found
Coliform Bacteria0 count/100mlMust be zeroNone found
Nitrate23.8 mg/L50 mg/L
48%
Nickel0.000611 mg/L0.02 mg/L
3%
Conductivity493 µS/cmNo legal limit–
Cadmium0.000054 mg/L0.005 mg/L
1%
Turbidity0.1 NTU4 NTU
3%
Mercury0.000023 mg/L0.001 mg/L
2%
Manganese0.000363 mg/L0.05 mg/L
<1%
Chromium0.000404 mg/L0.05 mg/L
<1%
Colour2 mg/L Pt/Co20 mg/L Pt/Co
10%
Nitrite0.01 mg/L0.5 mg/L
2%
Arsenic0.000135 mg/L0.01 mg/L
1%
Selenium0.000352 mg/L0.04 mg/L
<1%
Boron0.046 mg/L1 mg/L
5%
Lead0.000673 mg/L0.01 mg/L
7%
Aluminium0.00199 mg/L0.2 mg/L
<1%
Fluoride0.085 mg/L1.5 mg/L
6%
Trihalomethanes0.00439 mg/L0.1 mg/L
4%
Bromate0.00147 mg/L0.01 mg/L
15%
Copper0.007 mg/L2 mg/L
<1%
Ammonia0.06 mg/L0.5 mg/L
12%
Antimony0.000027 mg/L0.005 mg/L
<1%
Outside your tap

Your river is the Upper Dour, rated bad

The Environment Agency rated the Upper Dour as bad for ecological health in its 2025 assessment, meaning the river is severely damaged, with most of the expected wildlife missing. It is held back by fish. 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

CT18 in short

Tap water in CT18 (Folkestone and Hythe) is supplied by Southern Water in the Folkestone and Hythe Central zone and scores 9.5 out of 10, against an England and Wales average of 9.0. None of the 24 tested substances came close to a limit. The latest sample is from 19 December 2025.

  • The cleanest tap water of the 6 areas tested in Folkestone and HytheCT18 scores 9.5 out of 10, ahead of CT19 in second place on 9.4.
  • Scores higher than all 5 neighbouring districtsThe nearest rival is CT19 on 9.4, against 9.5 here. Compare with CT19
  • Nitrate is the reading closest to its limit, at 48% of the 50 mg/L maximumIt passed with room to spare, and everything else tested sat further below its limit. See every reading

Next door

CT199.4 out of 10CT209.4 out of 10CT219.4 out of 10TN289.2 out of 10 · 150 mg/LTN299.1 out of 10 · 150 mg/L

Questions about CT18 water

Is CT18 tap water safe to drink?

Based on the latest tests, CT18 (Folkestone and Hythe) water scores 9.5/10, which is safe. 0 of 24 tested contaminants exceeded recommended levels. Water is supplied by Southern Water.

What contaminants are in CT18 water?

We tested 24 contaminants in CT18 water. None exceeded recommended safe levels.

Who supplies water in CT18?

CT18 (Folkestone and Hythe) 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 CT18?

CT18 water scored 9.5/10 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 CT18 water?

No PFAS (forever chemicals) result is attached to the tap-water tests for CT18, 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 CT18?

The Environment Agency rated the Upper Dour as bad for ecological health in its 2025 assessment, meaning the river is severely damaged, with most of the expected wildlife missing. It is held back by fish. 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 CT18, 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 CT18

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
pH8.27 pHNone
Temperature15.3 °CNone
Conductivity682 µS/cmNone
Nitrate1.5 mg/L50 mg/L
Nitrite0.0042 mg/L0.5 mg/L
Phosphate0.086 mg/LNone
Dissolved Oxygen9.87 mg/LNone
Ammonia0.043 mg/L0.5 mg/L
Copper0.0063 mg/L2 mg/L
PFAS (total)0.0011 µg/LNone

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We'll email you when water quality data changes for CT18.

Source: Southern 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