Tap water in TR23, Isles of ScillySafe to drink.
Supplied by South West Water. 591 samples, 16 substances, latest on 10 December 2025. Everything is inside the legal limit, and nothing comes close to it.
9.3 / 10
The tank is as full as the score.
What to do about it
ZeroWater 12-Cup Ready-Pour
£40typical price
Households concerned about PFAS and heavy metals
Waterdrop 10UA Under Sink
£70typical price
High-volume under-sink filtration without RO complexity
BRITA Marella XL + MAXTRA PRO
£25typical price
Basic chlorine and taste improvement on a budget
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What's in a glass of TR23 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 19% of it. 15 of 15 substances used under a quarter of theirs.
- Nitrate19%
- Nickel17%
- Colour13%
- Aluminium13%
- Arsenic12%
- Lead6%
- Antimony4%
- Iron4%
- Turbidity3%
- Selenium3%
- Manganese3%
- Chromium2%
- Bromate1%
- Cadmium1%
- Copper<1%
- pH 7.2 pH
All 16 results as a table
| Substance | Result | Legal limit | Share of limit |
|---|---|---|---|
| Aluminium | 0.0257 mg/L | 0.2 mg/L | 13% |
| Antimony | 0.0002 mg/L | 0.005 mg/L | 4% |
| Arsenic | 0.0012 mg/L | 0.01 mg/L | 12% |
| Bromate | 0.000132 mg/L | 0.01 mg/L | 1% |
| Cadmium | 0.00006 mg/L | 0.005 mg/L | 1% |
| Chromium | 0.0008 mg/L | 0.05 mg/L | 2% |
| Colour | 2.6 mg/L Pt/Co | 20 mg/L Pt/Co | 13% |
| Iron | 0.0076 mg/L | 0.2 mg/L | 4% |
| Manganese | 0.00127 mg/L | 0.05 mg/L | 3% |
| Nitrate | 9.7 mg/L | 50 mg/L | 19% |
| pH | 7.2 pH | No legal limit | – |
| Selenium | 0.0012 mg/L | 0.04 mg/L | 3% |
| Turbidity | 0.13 NTU | 4 NTU | 3% |
| Copper | 0.0177 mg/L | 2 mg/L | <1% |
| Lead | 0.000588 mg/L | 0.01 mg/L | 6% |
| Nickel | 0.0033 mg/L | 0.02 mg/L | 17% |
Your coastal water is the Scilly Isles, rated good
The Environment Agency rated the Scilly Isles as good for ecological health in its 2025 assessment, meaning the coastal water 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
TR23 in short
Tap water in TR23 (Isles of Scilly) is supplied by South West Water in the Isles of Scilly Central zone and scores 9.3 out of 10, against an England and Wales average of 9.0. None of the 16 tested substances came close to a limit. The latest sample is from 10 December 2025.
- 3rd cleanest of 5 areas tested in Isles of ScillySquarely mid-table for Isles of Scilly, between TR21 on 9.3 and TR25 on 9.3.
- Nothing tested came within 40% of its legal limitThe highest was Nitrate at 19% of the 50 mg/L maximum. See every reading
- Scores higher than 0 of 4 neighbouring districtsWater here is typical for the immediate area, which usually means the same treatment works and the same supply zone.
Questions about TR23 water
Is TR23 tap water safe to drink?
Based on the latest tests, TR23 (Isles of Scilly) water scores 9.3/10, which is safe. 0 of 16 tested contaminants exceeded recommended levels. Water is supplied by South West Water.
What contaminants are in TR23 water?
We tested 16 contaminants in TR23 water. None exceeded recommended safe levels.
Who supplies water in TR23?
TR23 (Isles of Scilly) is supplied by South West Water. You can view their full profile and compliance data on our supplier page.
Should I use a water filter in TR23?
TR23 water scored 9.3/10 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 TR23 water?
No PFAS (forever chemicals) result is attached to the tap-water tests for TR23, 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 coastal water near TR23?
The Environment Agency rated the Scilly Isles as good for ecological health in its 2025 assessment, meaning the coastal water 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 coastal water, not of tap water in TR23, which is treated before it reaches homes.
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River and groundwater readings near TR23
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.
Get alerts for your area
We'll email you when water quality data changes for TR23.