Tap water in CM22, UttlesfordIron is over the limit.Very hard.
Supplied by Anglian Water. 11 substances, latest on 21 September 2026. Iron came in above the legal limit. Everything else passed.
7.3 / 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 350 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.

Waterdrop G3P600 Reverse Osmosis
£550typical price
Maximum contaminant removal including PFAS and fluoride

Waterdrop 10UA Under Sink
£70typical price
High-volume under-sink filtration without RO complexity
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What's in a glass of CM22 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.
Iron is over its legal limit, at 325% of it.
- Iron325%
- Nitrate58%
- Ammonia12%
- Nitrite3%
- Copper<1%
- pH 7.96 pH
- Temperature 19 °C
- Conductivity 1313 µS/cm
- Phosphate 0.72 mg/L
- Dissolved Oxygen 8.78 mg/L
- Zinc 0.00832 mg/L
All 11 results as a table
| Substance | Result | Legal limit | Share of limit |
|---|---|---|---|
| Iron | 0.65 mg/L | 0.2 mg/L | 325% |
| pH | 7.96 pH | No legal limit | – |
| Temperature | 19 °C | No legal limit | – |
| Conductivity | 1313 µS/cm | No legal limit | – |
| Nitrate | 29 mg/L | 50 mg/L | 58% |
| Nitrite | 0.013 mg/L | 0.5 mg/L | 3% |
| Phosphate | 0.72 mg/L | No legal limit | – |
| Dissolved Oxygen | 8.78 mg/L | No legal limit | – |
| Ammonia | 0.06 mg/L | 0.5 mg/L | 12% |
| Copper | 0.002 mg/L | 2 mg/L | <1% |
| Zinc | 0.00832 mg/L | No legal limit | – |
350mg of limescale minerals in every litre
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 CM22
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Your river is the Pincey Brook, rated moderate
The Environment Agency rated the Pincey Brook as moderate for ecological health in its 2025 assessment, meaning the river is noticeably changed by pollution or engineering. It is held back by phosphate and insects and other small river life. 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
CM22 in short
Tap water in CM22 (Uttlesford) is supplied by Anglian Water in the Uttlesford Central zone and scores 7.3 out of 10, against an England and Wales average of 9.0. 1 of 11 tested substances was close to or over a limit. The latest sample is from 21 September 2026.
- Iron was measured at 0.65 mg/L, 3.3 times the UK limitIt is the only one of 11 tested substances to go over its limit. See the full results
- Among the hardest water in the country at 350 mg/LVery hard starts at 250 mg/L. At this level kettles scale up within weeks and a softener is a normal purchase in CM22. How hardness is measured
- 4th cleanest of 5 areas tested in Uttlesford1 area in Uttlesford scored lower. The best is CB10 on 9.7.
Questions about CM22 water
Is CM22 tap water safe to drink?
Based on the latest tests, CM22 (Uttlesford) water scores 7.3/10, which is safe. 1 of 11 tested contaminants exceeded recommended levels. Water is supplied by Anglian Water.
What contaminants are in CM22 water?
We tested 11 contaminants in CM22 water. 1 were flagged, including Iron.
Who supplies water in CM22?
CM22 (Uttlesford) is supplied by Anglian Water. You can view their full profile and compliance data on our supplier page.
Is CM22 water hard or soft?
Water in CM22 (Uttlesford) has a hardness of 350 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 CM22?
With 1 contaminant above recommended levels in CM22, 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 CM22 water?
No PFAS (forever chemicals) result is attached to the tap-water tests for CM22, 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 CM22?
The Environment Agency rated the Pincey Brook as moderate for ecological health in its 2025 assessment, meaning the river is noticeably changed by pollution or engineering. It is held back by phosphate and insects and other small river life. 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 CM22, which is treated before it reaches homes.
Keep reading
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