Tap water in GL15, Forest of DeanSafe to drink.Very hard.
Supplied by Severn Trent. 867 samples, 20 substances, latest on 22 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
Hard water: compare softener quotes
At 258 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.
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
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What's in a glass of GL15 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 39% of it. 16 of 17 substances used under a quarter of theirs.
- Nitrate39%
- Lead13%
- Aluminium11%
- Nickel5%
- Copper5%
- Trihalomethanes4%
- Fluoride4%
- Colour4%
- Arsenic4%
- Iron3%
- Turbidity3%
- Manganese1%
- Antimony1%
- Selenium1%
- Chromium<1%
- Nitrite<1%
- Cadmium<1%
- Conductivity 214 µS/cm
- pH 7.77 pH
- Phosphate 0.021 mg/L
All 20 results as a table
| Substance | Result | Legal limit | Share of limit |
|---|---|---|---|
| Iron | 0.007 mg/L | 0.2 mg/L | 3% |
| Conductivity | 214 µS/cm | No legal limit | – |
| Trihalomethanes | 0.00427 mg/L | 0.1 mg/L | 4% |
| Manganese | 0.00073 mg/L | 0.05 mg/L | 1% |
| Copper | 0.0979 mg/L | 2 mg/L | 5% |
| Fluoride | 0.06 mg/L | 1.5 mg/L | 4% |
| Arsenic | 0.00036 mg/L | 0.01 mg/L | 4% |
| Colour | 0.8 mg/L Pt/Co | 20 mg/L Pt/Co | 4% |
| Cadmium | 0.00001 mg/L | 0.005 mg/L | <1% |
| Chromium | 0.00042 mg/L | 0.05 mg/L | <1% |
| Nickel | 0.001 mg/L | 0.02 mg/L | 5% |
| Turbidity | 0.12 NTU | 4 NTU | 3% |
| Lead | 0.00126 mg/L | 0.01 mg/L | 13% |
| Antimony | 0.000059 mg/L | 0.005 mg/L | 1% |
| Selenium | 0.0004 mg/L | 0.04 mg/L | 1% |
| pH | 7.77 pH | No legal limit | – |
| Nitrate | 19.7 mg/L | 50 mg/L | 39% |
| Nitrite | 0.003 mg/L | 0.5 mg/L | <1% |
| Aluminium | 0.021 mg/L | 0.2 mg/L | 11% |
| Phosphate | 0.021 mg/L | No legal limit | – |
258mg of limescale minerals in every litre, typical for the GL area. GL15 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.
Softener quotes for GL15
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Your river is the Cannop Bk - source to R Severn Estuary, rated moderate
The Environment Agency rated the Cannop Bk - source to R Severn Estuary as moderate for ecological health in its 2025 assessment, meaning the river is noticeably changed by pollution or engineering. 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
GL15 in short
Tap water in GL15 (Forest of Dean) is supplied by Severn Trent in the Forest of Dean Central zone and scores 9.4 out of 10, against an England and Wales average of 9.0. None of the 20 tested substances came close to a limit. The latest sample is from 22 December 2025.
- Very hard water at 258 mg/LThe threshold for very hard is 250 mg/L. Expect visible limescale on taps and in kettles across the GL postcode area. How hardness is measured
- 3rd cleanest of 6 areas tested in Forest of DeanSquarely mid-table for Forest of Dean, between GL14 on 9.6 and GL18 on 9.
- Nothing tested came within 40% of its legal limitThe highest was Nitrate at 39% of the 50 mg/L maximum. See every reading
Questions about GL15 water
Is GL15 tap water safe to drink?
Based on the latest tests, GL15 (Forest of Dean) water scores 9.4/10, which is safe. 0 of 20 tested contaminants exceeded recommended levels. Water is supplied by Severn Trent.
What contaminants are in GL15 water?
We tested 20 contaminants in GL15 water. None exceeded recommended safe levels.
Who supplies water in GL15?
GL15 (Forest of Dean) is supplied by Severn Trent. You can view their full profile and compliance data on our supplier page.
Is GL15 water hard or soft?
No hardness reading has been published for GL15 itself. Across the GL postcode area the typical value is 258 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 GL15?
GL15 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 GL15 water?
No PFAS (forever chemicals) result is attached to the tap-water tests for GL15, 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 GL15?
The Environment Agency rated the Cannop Bk - source to R Severn Estuary as moderate for ecological health in its 2025 assessment, meaning the river is noticeably changed by pollution or engineering. 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 GL15, which is treated before it reaches homes.
Keep reading
- Best Water Softener UKHarvey, Kinetico, BWT, Monarch and Water2Buy compared, with real costs
- Do I Need a Water Softener?The hardness bands, the symptoms, and a postcode check
- UK Water Hardness MapIs your water hard or soft, and does it matter?
- Is UK Tap Water Safe?Everything you need to know about tap water safety in the UK
- Do I need a water softener?The hardness bands, the symptoms, and when the answer is no
- Best water softener UKHarvey, Kinetico, BWT, Monarch and Water2Buy compared
- Water softener costUnit, fitting and salt, and how long the payback takes
- Installation explainedWhere it goes, the bypass tap, the drain, DIY or plumber
- Harvey vs KineticoThe two premium twin-cylinder brands, side by side
- Softener salt guideTablet, block or granular, and how much you get through
- Salt-free softenersConditioners and electronic descalers, honestly assessed
How to test your waterBest water filtersFilter shower headsWater testing kitsUK water rankingsWater hardness checkerWater hardness map
River and groundwater readings near GL15
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 |
|---|---|---|
| Lead | 0.00694 mg/L | 0.01 mg/L |
| pH | 7.93 pH | None |
| Temperature | 19.6 °C | None |
| Conductivity | 32118 µS/cm | None |
| Cadmium | 0.00008 mg/L | 0.005 mg/L |
| Nitrate | 2.14 mg/L | 50 mg/L |
| Chromium | 0.00397 mg/L | 0.05 mg/L |
| Copper | 0.00296 mg/L | 2 mg/L |
| Zinc | 0.0185 mg/L | None |
| Nickel | 0.0028 mg/L | 0.02 mg/L |
| Dissolved Oxygen | 7.85 mg/L | None |
| Mercury | 0.000203 mg/L | 0.001 mg/L |
Get alerts for your area
We'll email you when water quality data changes for GL15.