Tap water in RM18, ThurrockSafe to drink.Very hard.
Supplied by Essex & Suffolk Water. 2,164 samples, 21 substances, latest on 8 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. The specks are the minerals that make water hard.
What to do about it
Hard water: compare softener quotes
At 270 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 RM18 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 came closest to a limit, at 20% of it. 19 of 19 substances used under a quarter of theirs.
- Iron20%
- Fluoride19%
- Nitrate19%
- Arsenic11%
- Nickel10%
- Colour9%
- Antimony7%
- Turbidity7%
- Aluminium6%
- Boron6%
- Bromate5%
- Nitrite2%
- Manganese2%
- Mercury2%
- Selenium2%
- Chromium1%
- Lead<1%
- Copper<1%
- Cadmium<1%
- Conductivity 640 µS/cm
- pH 7.4 pH
All 21 results as a table
| Substance | Result | Legal limit | Share of limit |
|---|---|---|---|
| Nitrite | 0.012 mg/L | 0.5 mg/L | 2% |
| Colour | 1.8 mg/L Pt/Co | 20 mg/L Pt/Co | 9% |
| Manganese | 0.0011 mg/L | 0.05 mg/L | 2% |
| Iron | 0.04 mg/L | 0.2 mg/L | 20% |
| Conductivity | 640 µS/cm | No legal limit | – |
| Aluminium | 0.012 mg/L | 0.2 mg/L | 6% |
| Turbidity | 0.26 NTU | 4 NTU | 7% |
| pH | 7.4 pH | No legal limit | – |
| Nitrate | 9.6 mg/L | 50 mg/L | 19% |
| Arsenic | 0.0011 mg/L | 0.01 mg/L | 11% |
| Bromate | 0.0005 mg/L | 0.01 mg/L | 5% |
| Chromium | 0.00067 mg/L | 0.05 mg/L | 1% |
| Selenium | 0.00083 mg/L | 0.04 mg/L | 2% |
| Copper | 0.0091 mg/L | 2 mg/L | <1% |
| Cadmium | 0.000018 mg/L | 0.005 mg/L | <1% |
| Nickel | 0.0019 mg/L | 0.02 mg/L | 10% |
| Antimony | 0.00037 mg/L | 0.005 mg/L | 7% |
| Lead | 0.000065 mg/L | 0.01 mg/L | <1% |
| Fluoride | 0.29 mg/L | 1.5 mg/L | 19% |
| Mercury | 0.000022 mg/L | 0.001 mg/L | 2% |
| Boron | 0.058 mg/L | 1 mg/L | 6% |
270mg of limescale minerals in every litre, typical for the RM area. RM18 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 RM18
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Your estuary is the Thames Middle, rated moderate
The Environment Agency rated the Thames Middle 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 seagrass and saltmarsh. 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
RM18 in short
Tap water in RM18 (Thurrock) is supplied by Essex & Suffolk Water in the Thurrock Central zone and scores 9.3 out of 10, against an England and Wales average of 9.0. None of the 21 tested substances came close to a limit. The latest sample is from 8 December 2025.
- The cleanest tap water of the 7 areas tested in ThurrockRM18 scores 9.3 out of 10, ahead of RM19 in second place on 9.2.
- Very hard water at 270 mg/LThe threshold for very hard is 250 mg/L. Expect visible limescale on taps and in kettles across the RM postcode area. How hardness is measured
- Nothing tested came within 40% of its legal limitThe highest was Iron at 20% of the 0.2 mg/L maximum. See every reading
Questions about RM18 water
Is RM18 tap water safe to drink?
Based on the latest tests, RM18 (Thurrock) water scores 9.3/10, which is safe. 0 of 21 tested contaminants exceeded recommended levels. Water is supplied by Essex & Suffolk Water.
What contaminants are in RM18 water?
We tested 21 contaminants in RM18 water. None exceeded recommended safe levels.
Who supplies water in RM18?
RM18 (Thurrock) is supplied by Essex & Suffolk Water. You can view their full profile and compliance data on our supplier page.
Is RM18 water hard or soft?
No hardness reading has been published for RM18 itself. Across the RM postcode area the typical value is 270 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 RM18?
RM18 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 RM18 water?
No PFAS (forever chemicals) result is attached to the tap-water tests for RM18, 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 RM18?
The Environment Agency rated the Thames Middle 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 seagrass and saltmarsh. 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 RM18, 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 RM18
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 |
|---|---|---|
| Ammonia | 0.44 mg/L | 0.5 mg/L |
| Lead | 0.0108 mg/L | 0.01 mg/L |
| pH | 7.7 pH | None |
| Conductivity | 30487 µS/cm | None |
| Temperature | 11.2 °C | None |
| Nitrate | 5.3 mg/L | 50 mg/L |
| Manganese | 0.031 mg/L | 0.05 mg/L |
| Copper | 0.006 mg/L | 2 mg/L |
| Zinc | 0.006 mg/L | None |
| Iron | 0.06 mg/L | 0.2 mg/L |
| Nickel | 0.008 mg/L | 0.02 mg/L |
| Cadmium | 0.00059 mg/L | 0.005 mg/L |
| Fluoride | 0.657 mg/L | 1.5 mg/L |
| Phosphate | 0.302 mg/L | None |
| Chromium | 0.0058 mg/L | 0.05 mg/L |
| Dissolved Oxygen | 16.9 mg/L | None |
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