Tap water in DA3, SevenoaksToo few tap tests to call it.Very hard.
Supplied by South East Water. 11 substances, latest on 9 September 2026. These are river and groundwater samples near DA3, not tests of treated tap water, so treat the score as a rough guide.
8.9 / 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 268 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
We earn a commission if you buy through these links, at no extra cost to you. It never changes which product we put first. How we make money
What's in a glass of DA3 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.
Fluoride came closest to a limit, at 9% of it. 5 of 5 substances used under a quarter of theirs.
- Fluoride9%
- Ammonia7%
- Nitrate3%
- Lead2%
- Nitrite1%
- Temperature 16.2 °C
- Phosphate 0.039 mg/L
- pH 7.31 pH
- Conductivity 716 µS/cm
- Dissolved Oxygen 5.42 mg/L
All 11 results as a table
| Substance | Result | Legal limit | Share of limit |
|---|---|---|---|
| Temperature | 16.2 °C | No legal limit | – |
| Ammonia | 0.035 mg/L | 0.5 mg/L | 7% |
| Nitrate | 1.3 mg/L | 50 mg/L | 3% |
| Nitrite | 0.0067 mg/L | 0.5 mg/L | 1% |
| Phosphate | 0.039 mg/L | No legal limit | – |
| pH | 7.31 pH | No legal limit | – |
| Conductivity | 716 µS/cm | No legal limit | – |
| Dissolved Oxygen | 5.42 mg/L | No legal limit | – |
| Lead | 0.00016 mg/L | 0.01 mg/L | 2% |
| Hardness (as CaCO3) | 285 mg/L | No legal limit | – |
| Fluoride | 0.13 mg/L | 1.5 mg/L | 9% |
268mg 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 DA3
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Your river is the Middle and Lower Darent, rated good
The Environment Agency rated the Middle and Lower Darent as good for ecological health in its 2025 assessment, meaning the river 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. Its ecological rating has improved since the previous assessment.
None of this is a test of your tap water. Environment Agency record · River health across England
DA3 in short
Tap water in DA3 (Sevenoaks) is supplied by South East Water in the Sevenoaks Central zone and scores 8.9 out of 10, against an England and Wales average of 9.0. None of the 11 tested substances came close to a limit. The latest sample is from 9 September 2026.
- Very hard water at 268 mg/LThe threshold for very hard is 250 mg/L. Expect visible limescale on taps and in kettles in DA3. How hardness is measured
- 3rd cleanest of 7 areas tested in SevenoaksOnly 2 areas in Sevenoaks scored higher. The best is TN16 on 9.3.
- Nothing tested came within 40% of its legal limitThe highest was Fluoride at 9% of the 1.5 mg/L maximum. See every reading
Questions about DA3 water
Is DA3 tap water safe to drink?
Based on the latest tests, DA3 (Sevenoaks) water scores 8.9/10, which is safe. 0 of 11 tested contaminants exceeded recommended levels. Water is supplied by South East Water.
What contaminants are in DA3 water?
We tested 11 contaminants in DA3 water. None exceeded recommended safe levels.
Who supplies water in DA3?
DA3 (Sevenoaks) is supplied by South East Water. You can view their full profile and compliance data on our supplier page.
Is DA3 water hard or soft?
Water in DA3 (Sevenoaks) has a hardness of 268 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 DA3?
DA3 water scored 8.9/10 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 DA3 water?
No PFAS (forever chemicals) result is attached to the tap-water tests for DA3, 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 DA3?
The Environment Agency rated the Middle and Lower Darent as good for ecological health in its 2025 assessment, meaning the river 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. Its ecological rating has improved since the previous assessment. This is a rating of the river, not of tap water in DA3, which is treated before it reaches homes.
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