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tapwater
England and Wales average 9.0

Tap water in SO32, WinchesterSafe to drink.Very hard.

Supplied by Southern Water. 7,569 samples, 23 substances, latest on 23 April 2026. Everything is inside the legal limit. One result, nitrate, sits close to the line.

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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

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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Waterdrop G3P600 Reverse Osmosis

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£550typical price

Removes nitrate, the result that stood out in SO32.

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£499typical price

Removes nitrate, the result that stood out in SO32.

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What's in a glass of SO32 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 84% of it. 18 of 19 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%Chromium: 0.00013 mg/L, <1% of the 0.05 mg/L limitChromium<1%Nitrite: 0.003 mg/L, <1% of the 0.5 mg/L limitNitrite<1%Copper: 0.013 mg/L, <1% of the 2 mg/L limitCopper<1%Selenium: 0.00037 mg/L, <1% of the 0.04 mg/L limitSelenium<1%Arsenic: 0.00019 mg/L, 2% of the 0.01 mg/L limitArsenic2%Lead: 0.0002 mg/L, 2% of the 0.01 mg/L limitLead2%Antimony: 0.0001 mg/L, 2% of the 0.005 mg/L limitAntimony2%Turbidity: 0.13 NTU, 3% of the 4 NTU limitTurbidity3%Manganese: 0.00178 mg/L, 4% of the 0.05 mg/L limitManganese4%Ammonia: 0.02 mg/L, 4% of the 0.5 mg/L limitAmmonia4%Iron: 0.00928 mg/L, 5% of the 0.2 mg/L limitIron5%Bromate: 0.00048 mg/L, 5% of the 0.01 mg/L limitBromate5%Nickel: 0.00105 mg/L, 5% of the 0.02 mg/L limitNickel5%Aluminium: 0.0113 mg/L, 6% of the 0.2 mg/L limitAluminium6%Fluoride: 0.1 mg/L, 7% of the 1.5 mg/L limitFluoride7%Trihalomethanes: 0.0142 mg/L, 14% of the 0.1 mg/L limitTrihalomethanes14%Colour: 3 mg/L Pt/Co, 15% of the 20 mg/L Pt/Co limitColour15%Nitrate: 41.8 mg/L, 84% of the 50 mg/L limitNitrate84%
  1. Nitrate84%
  2. Colour15%
  3. Trihalomethanes14%
  4. Fluoride7%
  5. Aluminium6%
  6. Nickel5%
  7. Bromate5%
  8. Iron5%
  9. Ammonia4%
  10. Manganese4%
  11. Turbidity3%
  12. Lead2%
  13. Antimony2%
  14. Arsenic2%
  15. Selenium<1%
  16. Copper<1%
  17. Nitrite<1%
  18. Chromium<1%
  19. Cadmium<1%
  • pH 7.4 pH
  • Coliform Bacteria none found
  • E. coli none found
  • Conductivity 543 µS/cm
All 23 results as a table
SubstanceResultLegal limitShare of limit
Nitrate41.8 mg/L50 mg/L
84%
Colour3 mg/L Pt/Co20 mg/L Pt/Co
15%
Turbidity0.13 NTU4 NTU
3%
pH7.4 pHNo legal limit–
Nitrite0.003 mg/L0.5 mg/L
<1%
Coliform Bacteria0 count/100mlMust be zeroNone found
E. coli0 count/100mlMust be zeroNone found
Conductivity543 µS/cmNo legal limit–
Aluminium0.0113 mg/L0.2 mg/L
6%
Iron0.00928 mg/L0.2 mg/L
5%
Manganese0.00178 mg/L0.05 mg/L
4%
Ammonia0.02 mg/L0.5 mg/L
4%
Copper0.013 mg/L2 mg/L
<1%
Lead0.0002 mg/L0.01 mg/L
2%
Trihalomethanes0.0142 mg/L0.1 mg/L
14%
Arsenic0.00019 mg/L0.01 mg/L
2%
Cadmium0.000011 mg/L0.005 mg/L
<1%
Chromium0.00013 mg/L0.05 mg/L
<1%
Nickel0.00105 mg/L0.02 mg/L
5%
Antimony0.0001 mg/L0.005 mg/L
2%
Selenium0.00037 mg/L0.04 mg/L
<1%
Bromate0.00048 mg/L0.01 mg/L
5%
Fluoride0.1 mg/L1.5 mg/L
7%

276mg of limescale minerals in every litre, typical for the SO area. SO32 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 Moors Stream, rated good

The Environment Agency rated the Moors Stream as good for ecological health in its 2025 assessment, meaning the river is only slightly changed from its natural state. 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

26

forever-chemical detections in nearby rivers and groundwater

At 1 site. The highest was PFOS at 0.004 µg/L, at Priors Hold Farm, Wallington, 8.8 km away, in July 2023. These are river and borehole samples, not tests of your tap water.

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

SO32 in short

Tap water in SO32 (Winchester) is supplied by Southern Water in the Winchester Central zone and scores 9.3 out of 10, against an England and Wales average of 9.0. 1 of 23 tested substances was close to or over a limit. The latest sample is from 23 April 2026.

  • Nitrate is within its legal limit but flagged, at 84% of the 50 mg/L maximumAnything over three quarters of a limit is flagged here as worth watching. It has not gone over. See every reading
  • 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
  • 5th cleanest of 7 areas tested in Winchester2 areas in Winchester scored lower. The best is SO21 on 9.3.

Next door

PO159.2 out of 10SO249.2 out of 10 · 276 mg/LSO219.3 out of 10 · 276 mg/LSO239.3 out of 10 · 276 mg/LSO229.3 out of 10 · 276 mg/LSO259.3 out of 10 · 276 mg/L

Questions about SO32 water

Is SO32 tap water safe to drink?

Based on the latest tests, SO32 (Winchester) water scores 9.3/10, which is safe. 1 of 23 tested contaminants exceeded recommended levels. Water is supplied by Southern Water.

What contaminants are in SO32 water?

We tested 23 contaminants in SO32 water. 1 were flagged, including Nitrate. 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 SO32?

SO32 (Winchester) is supplied by Southern Water. You can view their full profile and compliance data on our supplier page.

Is SO32 water hard or soft?

No hardness reading has been published for SO32 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 SO32?

With 1 contaminant above recommended levels in SO32, a water filter could help. A reverse osmosis or activated carbon filter is recommended for PFAS removal. See our filter recommendations for your area.

Are there PFAS forever chemicals in SO32 water?

The tap-water tests we hold for SO32 do not include a PFAS result. Environment Agency monitoring found PFAS in 26 river and groundwater samples from 1 sites within 10 km of SO32, the highest being PFOS at 0.004 µg/L about 8.8 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 SO32?

The Environment Agency rated the Moors Stream as good for ecological health in its 2025 assessment, meaning the river is only slightly changed from its natural state. 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 SO32, which is treated before it reaches homes.

Keep reading

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

River and groundwater readings near SO32

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
Conductivity945 µS/cmNone
Phosphate0.059 mg/LNone
Dissolved Oxygen7.86 mg/LNone
Nitrate0.66 mg/L50 mg/L
Nitrite0.025 mg/L0.5 mg/L
Ammonia0.031 mg/L0.5 mg/L

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We'll email you when water quality data changes for SO32.

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