Tap water in PL18, CornwallSafe to drink.Soft.
Supplied by South West Water. 113 samples, 9 substances, latest on 18 December 2025. Everything is inside the legal limit, and nothing comes close to it.
9.4 / 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
£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 PL18 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.
Nickel came closest to a limit, at 17% of it. 8 of 8 substances used under a quarter of theirs.
- Nickel17%
- Aluminium13%
- Colour10%
- Iron4%
- Turbidity3%
- Manganese1%
- Lead1%
- Copper<1%
- pH 7.7 pH
All 9 results as a table
26mg of limescale minerals in every litre
Soft water. Kind to kettles, boilers and skin
You will not need a softener here, and you will use less soap and detergent than most of England.
Your river is the Lower River Tamar, rated moderate
The Environment Agency rated the Lower River Tamar as moderate for ecological health in its 2025 assessment, meaning the river is noticeably changed by pollution or engineering. It is held back by water plants and algae. 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
PL18 in short
Tap water in PL18 (Cornwall) is supplied by South West Water in the Cornwall Central zone and scores 9.4 out of 10, against an England and Wales average of 9.0. None of the 9 tested substances came close to a limit. The latest sample is from 18 December 2025.
- Every one of the 10 neighbouring districts scores higherEX23 next door scores 9.5, against 9.4 here. Supply zones, not distance, explain the gap. See EX23
- 35th cleanest of 45 areas tested in Cornwall10 areas in Cornwall scored lower. The best is EX23 on 9.5.
- Soft water at 26 mg/LLimescale is not a problem in PL18, so skip softeners and scale filters entirely. How hardness is measured
Questions about PL18 water
Is PL18 tap water safe to drink?
Based on the latest tests, PL18 (Cornwall) water scores 9.4/10, which is safe. 0 of 9 tested contaminants exceeded recommended levels. Water is supplied by South West Water.
What contaminants are in PL18 water?
We tested 9 contaminants in PL18 water. None exceeded recommended safe levels.
Who supplies water in PL18?
PL18 (Cornwall) is supplied by South West Water. You can view their full profile and compliance data on our supplier page.
Is PL18 water hard or soft?
Water in PL18 (Cornwall) has a hardness of 26 mg/L CaCO3, which is classified as soft. Soft water is gentle on appliances and skin.
Should I use a water filter in PL18?
PL18 water scored 9.4/10 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 PL18 water?
No PFAS (forever chemicals) result is attached to the tap-water tests for PL18, 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 PL18?
The Environment Agency rated the Lower River Tamar as moderate for ecological health in its 2025 assessment, meaning the river is noticeably changed by pollution or engineering. It is held back by water plants and algae. 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 PL18, which is treated before it reaches homes.
Keep reading
- Is UK Tap Water Safe?Everything you need to know about tap water safety in the UK
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- How to Test Your Tap WaterFrom DIY strips to professional lab analysis
- Best Water Filter Jug UKBRITA vs ZeroWater vs the rest, tested against real data
How to test your waterBest water filtersFilter shower headsWater testing kitsUK water rankingsWater hardness checkerWater hardness map
River and groundwater readings near PL18
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.
| Substance | Reading | Drinking water limit |
|---|---|---|
| Iron | 0.215 mg/L | 0.2 mg/L |
| pH | 7.56 pH | None |
| Temperature | 14.7 °C | None |
| Conductivity | 161 µS/cm | None |
| Nitrate | 2.3 mg/L | 50 mg/L |
| Nitrite | 0.015 mg/L | 0.5 mg/L |
| Phosphate | 0.075 mg/L | None |
| Dissolved Oxygen | 10.1 mg/L | None |
| Turbidity | 1.9 NTU | 4 NTU |
| Ammonia | 0.032 mg/L | 0.5 mg/L |
| Copper | 0.00137 mg/L | 2 mg/L |
| Zinc | 0.00193 mg/L | None |
Get alerts for your area
We'll email you when water quality data changes for PL18.