Skip to main content
tapwater
England and Wales average 9.0

Tap water in TN21, WealdenSafe to drink.Slightly hard.

Supplied by Southern Water. 621 samples, 25 substances, latest on 27 April 2026. Everything is inside the legal limit, and nothing comes close to it.

See the filter we recommendSee everything that was tested

9.6 / 10

The tank is as full as the score. The specks are the minerals that make water hard.

What to do about it

ZeroWater 12-Cup Ready-Pour

ZeroWater 12-Cup Ready-Pour

£40typical price

Households concerned about PFAS and heavy metals

Check price at Amazon (opens in new tab)
Waterdrop 10UA Under Sink

Waterdrop 10UA Under Sink

£70typical price

High-volume under-sink filtration without RO complexity

Check price at Waterdrop (opens in new tab)
BRITA Marella XL + MAXTRA PRO

BRITA Marella XL + MAXTRA PRO

£25typical price

Basic chlorine and taste improvement on a budget

Check price at Amazon (opens in new tab)

We earn a commission if you buy through these links, at no extra cost to you. It never changes which product we put first. How we make money

What's in a glass of TN21 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.

Iron came closest to a limit, at 33% of it. 20 of 21 substances used under a quarter of theirs.

0%25%50%75%limitLegal limitCopper: 0.0064 mg/L, <1% of the 2 mg/L limitCopper<1%Chromium: 0.00019 mg/L, <1% of the 0.05 mg/L limitChromium<1%Antimony: 0.000029 mg/L, <1% of the 0.005 mg/L limitAntimony<1%Cadmium: 0.000031 mg/L, <1% of the 0.005 mg/L limitCadmium<1%Nickel: 0.00017 mg/L, <1% of the 0.02 mg/L limitNickel<1%Arsenic: 0.00009 mg/L, <1% of the 0.01 mg/L limitArsenic<1%Lead: 0.00009 mg/L, <1% of the 0.01 mg/L limitLead<1%Selenium: 0.00043 mg/L, 1% of the 0.04 mg/L limitSelenium1%Nitrite: 0.009 mg/L, 2% of the 0.5 mg/L limitNitrite2%Ammonia: 0.01 mg/L, 2% of the 0.5 mg/L limitAmmonia2%Turbidity: 0.13 NTU, 3% of the 4 NTU limitTurbidity3%Nitrate: 1.8 mg/L, 4% of the 50 mg/L limitNitrate4%Mercury: 0.00004 mg/L, 4% of the 0.001 mg/L limitMercury4%Aluminium: 0.0113 mg/L, 6% of the 0.2 mg/L limitAluminium6%Bromate: 0.0006 mg/L, 6% of the 0.01 mg/L limitBromate6%Manganese: 0.00301 mg/L, 6% of the 0.05 mg/L limitManganese6%Fluoride: 0.14 mg/L, 9% of the 1.5 mg/L limitFluoride9%Boron: 0.119 mg/L, 12% of the 1 mg/L limitBoron12%Trihalomethanes: 0.0124 mg/L, 12% of the 0.1 mg/L limitTrihalomethanes12%Colour: 3 mg/L Pt/Co, 15% of the 20 mg/L Pt/Co limitColour15%Iron: 0.0653 mg/L, 33% of the 0.2 mg/L limitIron33%
  1. Iron33%
  2. Colour15%
  3. Trihalomethanes12%
  4. Boron12%
  5. Fluoride9%
  6. Manganese6%
  7. Bromate6%
  8. Aluminium6%
  9. Mercury4%
  10. Nitrate4%
  11. Turbidity3%
  12. Ammonia2%
  13. Nitrite2%
  14. Selenium1%
  15. Arsenic<1%
  16. Lead<1%
  17. Nickel<1%
  18. Cadmium<1%
  19. Antimony<1%
  20. Chromium<1%
  21. Copper<1%
  • pH 7.7 pH
  • Coliform Bacteria none found
  • E. coli none found
  • Conductivity 394 µS/cm
All 25 results as a table
SubstanceResultLegal limitShare of limit
Colour3 mg/L Pt/Co20 mg/L Pt/Co
15%
Turbidity0.13 NTU4 NTU
3%
pH7.7 pHNo legal limit–
Aluminium0.0113 mg/L0.2 mg/L
6%
Iron0.0653 mg/L0.2 mg/L
33%
Manganese0.00301 mg/L0.05 mg/L
6%
Fluoride0.14 mg/L1.5 mg/L
9%
Mercury0.00004 mg/L0.001 mg/L
4%
Coliform Bacteria0 count/100mlMust be zeroNone found
E. coli0 count/100mlMust be zeroNone found
Conductivity394 µS/cmNo legal limit–
Boron0.119 mg/L1 mg/L
12%
Bromate0.0006 mg/L0.01 mg/L
6%
Trihalomethanes0.0124 mg/L0.1 mg/L
12%
Nitrate1.8 mg/L50 mg/L
4%
Nitrite0.009 mg/L0.5 mg/L
2%
Copper0.0064 mg/L2 mg/L
<1%
Arsenic0.00009 mg/L0.01 mg/L
<1%
Cadmium0.000031 mg/L0.005 mg/L
<1%
Chromium0.00019 mg/L0.05 mg/L
<1%
Nickel0.00017 mg/L0.02 mg/L
<1%
Lead0.00009 mg/L0.01 mg/L
<1%
Antimony0.000029 mg/L0.005 mg/L
<1%
Selenium0.00043 mg/L0.04 mg/L
1%
Ammonia0.01 mg/L0.5 mg/L
2%

150mg of limescale minerals in every litre, typical for the TN area. TN21 has no reading of its own.

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 Cuckmere from Warbleton to Lower Horsebridge, rated moderate

The Environment Agency rated the Cuckmere from Warbleton to Lower Horsebridge as moderate for ecological health in its 2025 assessment, meaning the river is noticeably changed by pollution or engineering. It is held back by 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

TN21 in short

Tap water in TN21 (Wealden) is supplied by Southern Water in the Wealden Central zone and scores 9.6 out of 10, against an England and Wales average of 9.0. None of the 25 tested substances came close to a limit. The latest sample is from 27 April 2026.

  • The cleanest tap water of the 7 areas tested in WealdenTN21 scores 9.6 out of 10, ahead of BN27 in second place on 9.5.
  • Scores higher than all 6 neighbouring districtsThe nearest rival is BN27 on 9.5, against 9.6 here. Compare with BN27
  • 0.6 points above the national average of 9Cleaner than the typical tested district in the UK. Compare every area

Next door

BN279.5 out of 10BN248.4 out of 10TN228.1 out of 10 · 150 mg/LTN69.3 out of 10 · 150 mg/LTN205.8 out of 10 · 150 mg/LBN267.6 out of 10

Also nearby: RH18, TN7

Questions about TN21 water

Is TN21 tap water safe to drink?

Based on the latest tests, TN21 (Wealden) water scores 9.6/10, which is safe. 0 of 25 tested contaminants exceeded recommended levels. Water is supplied by Southern Water.

What contaminants are in TN21 water?

We tested 25 contaminants in TN21 water. None exceeded recommended safe levels.

Who supplies water in TN21?

TN21 (Wealden) is supplied by Southern Water. You can view their full profile and compliance data on our supplier page.

Is TN21 water hard or soft?

No hardness reading has been published for TN21 itself. Across the TN postcode area the typical value is 150 mg/L CaCO3, which is classified as moderately hard. This is a moderate hardness level.

Should I use a water filter in TN21?

TN21 water scored 9.6/10 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 TN21 water?

No PFAS (forever chemicals) result is attached to the tap-water tests for TN21, 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 TN21?

The Environment Agency rated the Cuckmere from Warbleton to Lower Horsebridge as moderate for ecological health in its 2025 assessment, meaning the river is noticeably changed by pollution or engineering. It is held back by 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 TN21, 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 TN21

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
pH7.37 pHNone
Temperature16.8 °CNone
Nitrate0.44 mg/L50 mg/L
Phosphate0.032 mg/LNone
Dissolved Oxygen7.71 mg/LNone
Conductivity673 µS/cmNone
Ammonia0.072 mg/L0.5 mg/L
Nitrite0.13 mg/L0.5 mg/L
Turbidity1.7 NTU4 NTU

Get alerts for your area

We'll email you when water quality data changes for TN21.

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