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tapwater
England and Wales average 9.0

Tap water in BL7, Blackburn with DarwenSafe to drink.Soft.

Supplied by United Utilities. 1,235 samples, 16 substances, latest on 17 December 2024. Everything is inside the legal limit, and nothing comes close to it.

See the filter we recommendSee everything that was tested

9.2 / 10

The tank is as full as the score. The specks are the minerals that make water hard.

What to do about it

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Households concerned about PFAS and heavy metals

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High-volume under-sink filtration without RO complexity

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Basic chlorine and taste improvement on a budget

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What's in a glass of BL7 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.

Bromate came closest to a limit, at 50% of it. 15 of 16 substances used under a quarter of theirs.

0%25%50%75%limitLegal limitCopper: 0.0000168 mg/L, <1% of the 2 mg/L limitCopper<1%Aluminium: 0.00271 mg/L, 1% of the 0.2 mg/L limitAluminium1%Nitrite: 0.0075 mg/L, 2% of the 0.5 mg/L limitNitrite2%Chromium: 0.00083 mg/L, 2% of the 0.05 mg/L limitChromium2%Manganese: 0.0009 mg/L, 2% of the 0.05 mg/L limitManganese2%Cadmium: 0.00009 mg/L, 2% of the 0.005 mg/L limitCadmium2%Selenium: 0.00085 mg/L, 2% of the 0.04 mg/L limitSelenium2%Nitrate: 2.04 mg/L, 4% of the 50 mg/L limitNitrate4%Turbidity: 0.2 NTU, 5% of the 4 NTU limitTurbidity5%Lead: 0.00055 mg/L, 6% of the 0.01 mg/L limitLead6%Antimony: 0.00031 mg/L, 6% of the 0.005 mg/L limitAntimony6%Ammonia: 0.0321 mg/L, 6% of the 0.5 mg/L limitAmmonia6%Nickel: 0.0017 mg/L, 9% of the 0.02 mg/L limitNickel9%Iron: 0.0173 mg/L, 9% of the 0.2 mg/L limitIron9%Trihalomethanes: 0.0233 mg/L, 23% of the 0.1 mg/L limitTrihalomethanes23%Bromate: 0.00496 mg/L, 50% of the 0.01 mg/L limitBromate50%
  1. Bromate50%
  2. Trihalomethanes23%
  3. Iron9%
  4. Nickel9%
  5. Ammonia6%
  6. Antimony6%
  7. Lead6%
  8. Turbidity5%
  9. Nitrate4%
  10. Selenium2%
  11. Manganese2%
  12. Cadmium2%
  13. Chromium2%
  14. Nitrite2%
  15. Aluminium1%
  16. Copper<1%
All 16 results as a table
SubstanceResultLegal limitShare of limit
Turbidity0.2 NTU4 NTU
5%
Nitrate2.04 mg/L50 mg/L
4%
Nitrite0.0075 mg/L0.5 mg/L
2%
Ammonia0.0321 mg/L0.5 mg/L
6%
Aluminium0.00271 mg/L0.2 mg/L
1%
Iron0.0173 mg/L0.2 mg/L
9%
Manganese0.0009 mg/L0.05 mg/L
2%
Cadmium0.00009 mg/L0.005 mg/L
2%
Chromium0.00083 mg/L0.05 mg/L
2%
Antimony0.00031 mg/L0.005 mg/L
6%
Selenium0.00085 mg/L0.04 mg/L
2%
Copper0.0000168 mg/L2 mg/L
<1%
Nickel0.0017 mg/L0.02 mg/L
9%
Lead0.00055 mg/L0.01 mg/L
6%
Bromate0.00496 mg/L0.01 mg/L
50%
Trihalomethanes0.0233 mg/L0.1 mg/L
23%

23mg of limescale minerals in every litre, typical for the BL area. BL7 has no reading of its own.

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.

Soft400 mg/L
Outside your tap

Your river is the Bradshaw Brook, rated moderate

The Environment Agency rated the Bradshaw Brook 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

Within 10 km

138

forever-chemical detections in nearby rivers and groundwater

At 10 sites. The highest was PFOA at 0.28 µg/L, at River Darwen Below Jack Keys Reservoir, 6.0 km away, in December 2024. These are river and borehole samples, not tests of your tap water.

Every PFAS sample around Blackburn · Which filters remove PFAS · PFAS explained

BL7 in short

Tap water in BL7 (Blackburn with Darwen) is supplied by United Utilities in the Blackburn with Darwen Central zone and scores 9.2 out of 10, against an England and Wales average of 9.0. None of the 16 tested substances came close to a limit. The latest sample is from 17 December 2024.

  • The lowest score of the 4 areas tested in BlackburnBL7 scores 9.2 out of 10. The best in Blackburn, BB1, scores 9.6. Every area in Blackburn
  • Bromate is the reading closest to its limit, at 50% of the 0.01 mg/L maximumIt passed with room to spare, and everything else tested sat further below its limit. See every reading
  • Soft water at 23 mg/LLimescale is not a problem across the BL postcode area, so skip softeners and scale filters entirely. How hardness is measured

Next door

BB39.5 out of 10 · 17 mg/LBB19.6 out of 10 · 39 mg/LBB29.3 out of 10 · 39 mg/LBL19.2 out of 10 · 24 mg/LBL29.4 out of 10 · 37 mg/L

Questions about BL7 water

Is BL7 tap water safe to drink?

Based on the latest tests, BL7 (Blackburn with Darwen) water scores 9.2/10, which is safe. 0 of 16 tested contaminants exceeded recommended levels. Water is supplied by United Utilities.

What contaminants are in BL7 water?

We tested 16 contaminants in BL7 water. None exceeded recommended safe levels. PFAS (forever chemicals) were also measured in rivers and groundwater within 10 km, though not in the tap-water tests themselves.

Who supplies water in BL7?

BL7 (Blackburn with Darwen) is supplied by United Utilities. You can view their full profile and compliance data on our supplier page.

Is BL7 water hard or soft?

No hardness reading has been published for BL7 itself. Across the BL postcode area the typical value is 23 mg/L CaCO3, which is classified as soft. Soft water is gentle on appliances and skin.

Should I use a water filter in BL7?

BL7 water scored 9.2/10 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 BL7 water?

The tap-water tests we hold for BL7 do not include a PFAS result. Environment Agency monitoring found PFAS in 138 river and groundwater samples from 10 sites within 10 km of BL7, the highest being PFOA at 0.28 µg/L about 6 km away. These are environmental samples, not tests of tap water. The UK currently has no legal limit for PFAS in drinking water; the Drinking Water Inspectorate uses a 0.1 µg/L guideline for individual compounds. Reverse osmosis filters can reduce PFAS levels.

How clean is the river near BL7?

The Environment Agency rated the Bradshaw Brook 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 BL7, which is treated before it reaches homes.

Keep reading

PFAS explainedHow to test your waterBest water filtersFilter shower headsWater testing kitsAll of BlackburnUK water rankingsWater hardness checkerWater hardness map

River and groundwater readings near BL7

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.

SubstanceReadingDrinking water limit
pH7.69 pHNone
Temperature17.1 °CNone
Conductivity91 µS/cmNone
Ammonia0.049 mg/L0.5 mg/L
Nitrate0.38 mg/L50 mg/L
Phosphate0.019 mg/LNone
Dissolved Oxygen9.55 mg/LNone
Nitrite0.0046 mg/L0.5 mg/L

Get alerts for your area

We'll email you when water quality data changes for BL7.

Source: United Utilities test results, published through the Stream Water Data Portal; rivers and PFAS from the Environment Agency. Page updated . How we score · Where the data comes from