Skip to main content
tapwater
England and Wales average 9.0

Tap water in TN15, Tonbridge and MallingSafe to drink.Slightly hard.

Supplied by Southern Water. 1,084 samples, 22 substances, latest on 24 March 2026. 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. 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 TN15 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 59% of it. 17 of 18 substances used under a quarter of theirs.

0%25%50%75%limitLegal limitCadmium: 0.000011 mg/L, <1% of the 0.005 mg/L limitCadmium<1%Nitrite: 0.002 mg/L, <1% of the 0.5 mg/L limitNitrite<1%Copper: 0.0133 mg/L, <1% of the 2 mg/L limitCopper<1%Chromium: 0.0004 mg/L, <1% of the 0.05 mg/L limitChromium<1%Lead: 0.00009 mg/L, <1% of the 0.01 mg/L limitLead<1%Bromate: 0.0001 mg/L, 1% of the 0.01 mg/L limitBromate1%Selenium: 0.00052 mg/L, 1% of the 0.04 mg/L limitSelenium1%Ammonia: 0.01 mg/L, 2% of the 0.5 mg/L limitAmmonia2%Antimony: 0.0001 mg/L, 2% of the 0.005 mg/L limitAntimony2%Arsenic: 0.00024 mg/L, 2% of the 0.01 mg/L limitArsenic2%Aluminium: 0.0061 mg/L, 3% of the 0.2 mg/L limitAluminium3%Turbidity: 0.13 NTU, 3% of the 4 NTU limitTurbidity3%Manganese: 0.0017 mg/L, 3% of the 0.05 mg/L limitManganese3%Iron: 0.0073 mg/L, 4% of the 0.2 mg/L limitIron4%Trihalomethanes: 0.00437 mg/L, 4% of the 0.1 mg/L limitTrihalomethanes4%Nickel: 0.00196 mg/L, 10% of the 0.02 mg/L limitNickel10%Colour: 3 mg/L Pt/Co, 15% of the 20 mg/L Pt/Co limitColour15%Nitrate: 29.7 mg/L, 59% of the 50 mg/L limitNitrate59%
  1. Nitrate59%
  2. Colour15%
  3. Nickel10%
  4. Trihalomethanes4%
  5. Iron4%
  6. Manganese3%
  7. Turbidity3%
  8. Aluminium3%
  9. Arsenic2%
  10. Ammonia2%
  11. Antimony2%
  12. Selenium1%
  13. Bromate1%
  14. Lead<1%
  15. Chromium<1%
  16. Copper<1%
  17. Nitrite<1%
  18. Cadmium<1%
  • Conductivity 592 µS/cm
  • pH 7.9 pH
  • Coliform Bacteria none found
  • E. coli none found
All 22 results as a table
SubstanceResultLegal limitShare of limit
Conductivity592 µS/cmNo legal limit–
Iron0.0073 mg/L0.2 mg/L
4%
Colour3 mg/L Pt/Co20 mg/L Pt/Co
15%
Turbidity0.13 NTU4 NTU
3%
pH7.9 pHNo legal limit–
Nitrate29.7 mg/L50 mg/L
59%
Ammonia0.01 mg/L0.5 mg/L
2%
Aluminium0.0061 mg/L0.2 mg/L
3%
Manganese0.0017 mg/L0.05 mg/L
3%
Copper0.0133 mg/L2 mg/L
<1%
Lead0.00009 mg/L0.01 mg/L
<1%
Coliform Bacteria0 count/100mlMust be zeroNone found
E. coli0 count/100mlMust be zeroNone found
Nickel0.00196 mg/L0.02 mg/L
10%
Antimony0.0001 mg/L0.005 mg/L
2%
Selenium0.00052 mg/L0.04 mg/L
1%
Trihalomethanes0.00437 mg/L0.1 mg/L
4%
Nitrite0.002 mg/L0.5 mg/L
<1%
Arsenic0.00024 mg/L0.01 mg/L
2%
Cadmium0.000011 mg/L0.005 mg/L
<1%
Chromium0.0004 mg/L0.05 mg/L
<1%
Bromate0.0001 mg/L0.01 mg/L
1%

150mg of limescale minerals in every litre, typical for the TN area. TN15 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 Bourne (Medway), rated poor

The Environment Agency rated the Bourne (Medway) as poor for ecological health in its 2025 assessment, meaning the river is badly affected, with much of the expected wildlife missing. It is held back by water plants and algae, dissolved oxygen and 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. Its ecological rating has dropped since the previous assessment.

None of this is a test of your tap water. Environment Agency record · River health across England

TN15 in short

Tap water in TN15 (Tonbridge and Malling) is supplied by Southern Water in the Tonbridge and Malling Central zone and scores 9.5 out of 10, against an England and Wales average of 9.0. None of the 22 tested substances came close to a limit. The latest sample is from 24 March 2026.

  • The cleanest tap water of the 7 areas tested in Tonbridge and MallingTN15 scores 9.5 out of 10, ahead of ME20 in second place on 9.4.
  • Nitrate is the reading closest to its limit, at 59% of the 50 mg/L maximumIt passed with room to spare, and everything else tested sat further below its limit. See every reading
  • Scores higher than all 6 neighbouring districtsThe nearest rival is ME20 on 9.4, against 9.5 here. Compare with ME20

Next door

ME69.1 out of 10ME209.4 out of 10ME197.7 out of 10TN106.9 out of 10 · 150 mg/LTN96.9 out of 10 · 150 mg/LTN116.9 out of 10 · 150 mg/L

Questions about TN15 water

Is TN15 tap water safe to drink?

Based on the latest tests, TN15 (Tonbridge and Malling) water scores 9.5/10, which is safe. 0 of 22 tested contaminants exceeded recommended levels. Water is supplied by Southern Water.

What contaminants are in TN15 water?

We tested 22 contaminants in TN15 water. None exceeded recommended safe levels.

Who supplies water in TN15?

TN15 (Tonbridge and Malling) is supplied by Southern Water. You can view their full profile and compliance data on our supplier page.

Is TN15 water hard or soft?

No hardness reading has been published for TN15 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 TN15?

TN15 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 TN15 water?

No PFAS (forever chemicals) result is attached to the tap-water tests for TN15, 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 TN15?

The Environment Agency rated the Bourne (Medway) as poor for ecological health in its 2025 assessment, meaning the river is badly affected, with much of the expected wildlife missing. It is held back by water plants and algae, dissolved oxygen and 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. Its ecological rating has dropped since the previous assessment. This is a rating of the river, not of tap water in TN15, 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 TN15

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
Trihalomethanes0.0007 mg/L0.1 mg/L
Lead0.00005 mg/L0.01 mg/L
Zinc0.0095 mg/LNone
Nickel0.00081 mg/L0.02 mg/L
Manganese0.00084 mg/L0.05 mg/L
Copper0.00048 mg/L2 mg/L
Dissolved Oxygen8.32 mg/LNone
Nitrate16.1 mg/L50 mg/L
Nitrite0.012 mg/L0.5 mg/L
pH7.79 pHNone
Temperature11.5 °CNone
Ammonia0.043 mg/L0.5 mg/L
Phosphate0.084 mg/LNone

Get alerts for your area

We'll email you when water quality data changes for TN15.

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