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tapwater
England and Wales average 9.0

Tap water in PO40, Isle of WightSafe to drink.

Supplied by Southern Water. 5,491 samples, 22 substances, latest on 29 April 2026. Everything is inside the legal limit. One result, nitrate, sits close to the line.

See the filter we recommendSee everything that was tested

9.2 / 10

The tank is as full as the score.

What to do about it

Waterdrop G3P600 Reverse Osmosis

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Removes nitrate, the result that stood out in PO40.

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Osmio PRO-III Ultimate Whole House

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Removes nitrate, the result that stood out in PO40.

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ZeroWater 12-Cup Ready-Pour

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Removes nitrate, the result that stood out in PO40.

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What's in a glass of PO40 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 75% of it. 16 of 18 substances used under a quarter of theirs.

0%25%50%75%limitLegal limitChromium: 0.00019 mg/L, <1% of the 0.05 mg/L limitChromium<1%Cadmium: 0.000031 mg/L, <1% of the 0.005 mg/L limitCadmium<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%Arsenic: 0.00012 mg/L, 1% of the 0.01 mg/L limitArsenic1%Antimony: 0.000067 mg/L, 1% of the 0.005 mg/L limitAntimony1%Nitrite: 0.009 mg/L, 2% of the 0.5 mg/L limitNitrite2%Turbidity: 0.13 NTU, 3% of the 4 NTU limitTurbidity3%Manganese: 0.00178 mg/L, 4% of the 0.05 mg/L limitManganese4%Aluminium: 0.0113 mg/L, 6% of the 0.2 mg/L limitAluminium6%Copper: 0.149 mg/L, 7% of the 2 mg/L limitCopper7%Ammonia: 0.039 mg/L, 8% of the 0.5 mg/L limitAmmonia8%Bromate: 0.00079 mg/L, 8% of the 0.01 mg/L limitBromate8%Nickel: 0.00164 mg/L, 8% of the 0.02 mg/L limitNickel8%Iron: 0.0228 mg/L, 11% of the 0.2 mg/L limitIron11%Colour: 3 mg/L Pt/Co, 15% of the 20 mg/L Pt/Co limitColour15%Trihalomethanes: 0.0273 mg/L, 27% of the 0.1 mg/L limitTrihalomethanes27%Nitrate: 37.7 mg/L, 75% of the 50 mg/L limitNitrate75%
  1. Nitrate75%
  2. Trihalomethanes27%
  3. Colour15%
  4. Iron11%
  5. Nickel8%
  6. Bromate8%
  7. Ammonia8%
  8. Copper7%
  9. Aluminium6%
  10. Manganese4%
  11. Turbidity3%
  12. Nitrite2%
  13. Antimony1%
  14. Arsenic1%
  15. Selenium1%
  16. Lead<1%
  17. Cadmium<1%
  18. Chromium<1%
  • Conductivity 555 µS/cm
  • pH 7.6 pH
  • Coliform Bacteria none found
  • E. coli none found
All 22 results as a table
SubstanceResultLegal limitShare of limit
Nitrate37.7 mg/L50 mg/L
75%
Conductivity555 µS/cmNo legal limit–
Colour3 mg/L Pt/Co20 mg/L Pt/Co
15%
Turbidity0.13 NTU4 NTU
3%
pH7.6 pHNo legal limit–
Iron0.0228 mg/L0.2 mg/L
11%
Manganese0.00178 mg/L0.05 mg/L
4%
Lead0.00009 mg/L0.01 mg/L
<1%
Coliform Bacteria0 count/100mlMust be zeroNone found
E. coli0 count/100mlMust be zeroNone found
Aluminium0.0113 mg/L0.2 mg/L
6%
Trihalomethanes0.0273 mg/L0.1 mg/L
27%
Bromate0.00079 mg/L0.01 mg/L
8%
Nitrite0.009 mg/L0.5 mg/L
2%
Ammonia0.039 mg/L0.5 mg/L
8%
Copper0.149 mg/L2 mg/L
7%
Arsenic0.00012 mg/L0.01 mg/L
1%
Cadmium0.000031 mg/L0.005 mg/L
<1%
Chromium0.00019 mg/L0.05 mg/L
<1%
Nickel0.00164 mg/L0.02 mg/L
8%
Antimony0.000067 mg/L0.005 mg/L
1%
Selenium0.00043 mg/L0.04 mg/L
1%
Outside your tap

Your estuary is the Western Yar, rated moderate

The Environment Agency rated the Western Yar as moderate for ecological health in its 2025 assessment, meaning the estuary is noticeably changed by pollution or engineering. It is held back by nitrogen and seaweed. 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

PO40 in short

Tap water in PO40 (Isle of Wight) is supplied by Southern Water in the Isle of Wight Central zone and scores 9.2 out of 10, against an England and Wales average of 9.0. 1 of 22 tested substances was close to or over a limit. The latest sample is from 29 April 2026.

  • Nitrate is within its legal limit but flagged, at 75% 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
  • 9th cleanest of 12 areas tested in Isle of Wight3 areas in Isle of Wight scored lower. The best is PO31 on 9.3.
  • Scores higher than 2 of 10 neighbouring districtsWater here is typical for the immediate area, which usually means the same treatment works and the same supply zone.

Next door

PO329.1 out of 10PO379.2 out of 10PO389.2 out of 10PO419.2 out of 10PO359.3 out of 10PO339.3 out of 10PO319.3 out of 10PO399.1 out of 10PO309.2 out of 10PO369.3 out of 10

Questions about PO40 water

Is PO40 tap water safe to drink?

Based on the latest tests, PO40 (Isle of Wight) water scores 9.2/10, which is safe. 1 of 22 tested contaminants exceeded recommended levels. Water is supplied by Southern Water.

What contaminants are in PO40 water?

We tested 22 contaminants in PO40 water. 1 were flagged, including Nitrate.

Who supplies water in PO40?

PO40 (Isle of Wight) 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 PO40?

With 1 contaminant above recommended levels in PO40, a water filter could help. A filter jug or under-sink filter can reduce most common contaminants. See our filter recommendations for your area.

Are there PFAS forever chemicals in PO40 water?

No PFAS (forever chemicals) result is attached to the tap-water tests for PO40, 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 estuary near PO40?

The Environment Agency rated the Western Yar as moderate for ecological health in its 2025 assessment, meaning the estuary is noticeably changed by pollution or engineering. It is held back by nitrogen and seaweed. 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 estuary, not of tap water in PO40, which is treated before it reaches homes.

Keep reading

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

River and groundwater readings near PO40

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
pH7.45 pHNone
Temperature17.7 °CNone
Conductivity281 µS/cmNone
Nitrate1.9 mg/L50 mg/L
Phosphate0.037 mg/LNone
Dissolved Oxygen8.53 mg/LNone
Nitrite0.0048 mg/L0.5 mg/L
Ammonia0.049 mg/L0.5 mg/L

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We'll email you when water quality data changes for PO40.

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