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tapwater
England and Wales average 9.0

Tap water in SO52, Test ValleySafe to drink.Very hard.

Supplied by Southern Water. 7,020 samples, 25 substances, latest on 25 April 2026. Everything is inside the legal limit, and nothing comes close to it.

Get softener quotes for SO52See everything that was tested

9.1 / 10

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

What to do about it

Hard water: compare softener quotes

At 276 mg/L a softener is the only thing that stops limescale. Filters do not soften water.

It pays for itself in most homes at this hardness, through a boiler that stays efficient and appliances that last.

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What's in a glass of SO52 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 69% of it. 19 of 21 substances used under a quarter of theirs.

0%25%50%75%limitLegal limitCopper: 0.0084 mg/L, <1% of the 2 mg/L limitCopper<1%Nitrite: 0.004 mg/L, <1% of the 0.5 mg/L limitNitrite<1%Lead: 0.00009 mg/L, <1% of the 0.01 mg/L limitLead<1%Selenium: 0.0005 mg/L, 1% of the 0.04 mg/L limitSelenium1%Chromium: 0.001 mg/L, 2% of the 0.05 mg/L limitChromium2%Cadmium: 0.00012 mg/L, 2% of the 0.005 mg/L limitCadmium2%Turbidity: 0.13 NTU, 3% of the 4 NTU limitTurbidity3%Manganese: 0.00178 mg/L, 4% of the 0.05 mg/L limitManganese4%Mercury: 0.00004 mg/L, 4% of the 0.001 mg/L limitMercury4%Boron: 0.04 mg/L, 4% of the 1 mg/L limitBoron4%Iron: 0.00928 mg/L, 5% of the 0.2 mg/L limitIron5%Fluoride: 0.08 mg/L, 5% of the 1.5 mg/L limitFluoride5%Aluminium: 0.0113 mg/L, 6% of the 0.2 mg/L limitAluminium6%Bromate: 0.00059 mg/L, 6% of the 0.01 mg/L limitBromate6%Antimony: 0.0003 mg/L, 6% of the 0.005 mg/L limitAntimony6%Ammonia: 0.039 mg/L, 8% of the 0.5 mg/L limitAmmonia8%Arsenic: 0.001 mg/L, 10% of the 0.01 mg/L limitArsenic10%Colour: 3 mg/L Pt/Co, 15% of the 20 mg/L Pt/Co limitColour15%Nickel: 0.0038 mg/L, 19% of the 0.02 mg/L limitNickel19%Trihalomethanes: 0.0325 mg/L, 33% of the 0.1 mg/L limitTrihalomethanes33%Nitrate: 34.4 mg/L, 69% of the 50 mg/L limitNitrate69%
  1. Nitrate69%
  2. Trihalomethanes33%
  3. Nickel19%
  4. Colour15%
  5. Arsenic10%
  6. Ammonia8%
  7. Antimony6%
  8. Bromate6%
  9. Aluminium6%
  10. Fluoride5%
  11. Iron5%
  12. Mercury4%
  13. Boron4%
  14. Manganese4%
  15. Turbidity3%
  16. Cadmium2%
  17. Chromium2%
  18. Selenium1%
  19. Lead<1%
  20. Nitrite<1%
  21. Copper<1%
  • Coliform Bacteria none found
  • E. coli none found
  • Conductivity 567 µS/cm
  • pH 7.5 pH
All 25 results as a table
SubstanceResultLegal limitShare of limit
Nitrate34.4 mg/L50 mg/L
69%
Ammonia0.039 mg/L0.5 mg/L
8%
Aluminium0.0113 mg/L0.2 mg/L
6%
Iron0.00928 mg/L0.2 mg/L
5%
Manganese0.00178 mg/L0.05 mg/L
4%
Copper0.0084 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
Conductivity567 µS/cmNo legal limit–
Colour3 mg/L Pt/Co20 mg/L Pt/Co
15%
Turbidity0.13 NTU4 NTU
3%
pH7.5 pHNo legal limit–
Trihalomethanes0.0325 mg/L0.1 mg/L
33%
Nitrite0.004 mg/L0.5 mg/L
<1%
Bromate0.00059 mg/L0.01 mg/L
6%
Arsenic0.001 mg/L0.01 mg/L
10%
Cadmium0.00012 mg/L0.005 mg/L
2%
Chromium0.001 mg/L0.05 mg/L
2%
Nickel0.0038 mg/L0.02 mg/L
19%
Antimony0.0003 mg/L0.005 mg/L
6%
Selenium0.0005 mg/L0.04 mg/L
1%
Fluoride0.08 mg/L1.5 mg/L
5%
Mercury0.00004 mg/L0.001 mg/L
4%
Boron0.04 mg/L1 mg/L
4%

276mg of limescale minerals in every litre, typical for the SO area. SO52 has no reading of its own.

This is the water that furs up kettles

Very hard on the UK scale. It is fine to drink. It is hard on boilers, showers, skin and anything that heats water, and a jug or tap filter will not change that.

Soft400 mg/L

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Outside your tap

Your river is the Tanner's Brook, rated moderate

The Environment Agency rated the Tanner's 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 fish and insects and other small river life. 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

Within 10 km

236

forever-chemical detections in nearby rivers and groundwater

At 6 sites. The highest was PFOS at 0.011 µg/L, at Tadburn Lake at Romsey By-Pass, 3.9 km away, in March 2024. These are river and borehole samples, not tests of your tap water.

Every PFAS sample around Southampton · Which filters remove PFAS · PFAS explained

SO52 in short

Tap water in SO52 (Test Valley) is supplied by Southern Water in the Test Valley Central zone and scores 9.1 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 25 April 2026.

  • Nitrate is the reading closest to its limit, at 69% of the 50 mg/L maximumIt passed with room to spare, and everything else tested sat further below its limit. See every reading
  • 4th cleanest of 5 areas tested in Test Valley1 area in Test Valley scored lower. The best is SP10 on 9.4.
  • Very hard water at 276 mg/LThe threshold for very hard is 250 mg/L. Expect visible limescale on taps and in kettles across the SO postcode area. How hardness is measured

Next door

SO209.3 out of 10 · 276 mg/LSO519.0 out of 10 · 276 mg/LSP119.2 out of 10 · 355 mg/LSP109.4 out of 10 · 297 mg/LSO169.3 out of 10 · 276 mg/L

Questions about SO52 water

Is SO52 tap water safe to drink?

Based on the latest tests, SO52 (Test Valley) water scores 9.1/10, which is safe. 0 of 25 tested contaminants exceeded recommended levels. Water is supplied by Southern Water.

What contaminants are in SO52 water?

We tested 25 contaminants in SO52 water. None exceeded recommended safe levels. PFAS (forever chemicals) were also measured in rivers and groundwater within 10 km, though not in the tap-water tests themselves.

Who supplies water in SO52?

SO52 (Test Valley) is supplied by Southern Water. You can view their full profile and compliance data on our supplier page.

Is SO52 water hard or soft?

No hardness reading has been published for SO52 itself. Across the SO postcode area the typical value is 276 mg/L CaCO3, which is classified as very hard. Hard water can cause limescale buildup. A water softener or filter jug may help.

Should I use a water filter in SO52?

SO52 water scored 9.1/10 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 SO52 water?

The tap-water tests we hold for SO52 do not include a PFAS result. Environment Agency monitoring found PFAS in 236 river and groundwater samples from 6 sites within 10 km of SO52, the highest being PFOS at 0.011 µg/L about 3.9 km away. These are environmental samples, not tests of tap water. The UK currently has no legal limit for PFAS in drinking water; the Drinking Water Inspectorate uses a 0.1 µg/L guideline for individual compounds. Reverse osmosis filters can reduce PFAS levels.

How clean is the river near SO52?

The Environment Agency rated the Tanner's 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 fish and insects and other small river life. 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 SO52, which is treated before it reaches homes.

Keep reading

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

River and groundwater readings near SO52

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
pH7.98 pHNone
Temperature15.4 °CNone
Conductivity573 µS/cmNone
Nitrate8 mg/L50 mg/L
Nitrite0.014 mg/L0.5 mg/L
Dissolved Oxygen8.88 mg/LNone
Ammonia0.032 mg/L0.5 mg/L
Phosphate0.014 mg/LNone
Copper0.00138 mg/L2 mg/L
Zinc0.0136 mg/LNone
PFAS (total)0.0031 µg/LNone

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We'll email you when water quality data changes for SO52.

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