Skip to main content
tapwater
England and Wales average 9.0

Tap water in NP11, CaerphillySafe to drink.

Supplied by Dŵr Cymru Welsh Water. 1,399 samples, 23 substances, latest on 20 December 2024. Everything is inside the legal limit, and nothing comes close to it.

See the filter we recommendSee everything that was tested

9.4 / 10

The tank is as full as the score.

What to do about it

ZeroWater 12-Cup Ready-Pour

ZeroWater 12-Cup Ready-Pour

£40typical price

Households concerned about PFAS and heavy metals

Check price at Amazon (opens in new tab)
Waterdrop 10UA Under Sink

Waterdrop 10UA Under Sink

£70typical price

High-volume under-sink filtration without RO complexity

Check price at Waterdrop (opens in new tab)
BRITA Marella XL + MAXTRA PRO

BRITA Marella XL + MAXTRA PRO

£25typical price

Basic chlorine and taste improvement on a budget

Check price at Amazon (opens in new tab)

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 NP11 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.

Nitrite came closest to a limit, at 38% of it. 19 of 20 substances used under a quarter of theirs.

0%25%50%75%limitLegal limitCadmium: 0.000025 mg/L, <1% of the 0.005 mg/L limitCadmium<1%Selenium: 0.00023 mg/L, <1% of the 0.04 mg/L limitSelenium<1%Antimony: 0.000034 mg/L, <1% of the 0.005 mg/L limitAntimony<1%Arsenic: 0.00011 mg/L, 1% of the 0.01 mg/L limitArsenic1%Manganese: 0.00068 mg/L, 1% of the 0.05 mg/L limitManganese1%Lead: 0.00016 mg/L, 2% of the 0.01 mg/L limitLead2%Aluminium: 0.005 mg/L, 3% of the 0.2 mg/L limitAluminium3%Boron: 0.028 mg/L, 3% of the 1 mg/L limitBoron3%Copper: 0.058 mg/L, 3% of the 2 mg/L limitCopper3%Nickel: 0.00059 mg/L, 3% of the 0.02 mg/L limitNickel3%Chromium: 0.0015 mg/L, 3% of the 0.05 mg/L limitChromium3%Mercury: 0.000042 mg/L, 4% of the 0.001 mg/L limitMercury4%Turbidity: 0.27 NTU, 7% of the 4 NTU limitTurbidity7%Bromate: 0.00068 mg/L, 7% of the 0.01 mg/L limitBromate7%Fluoride: 0.11 mg/L, 7% of the 1.5 mg/L limitFluoride7%Iron: 0.021 mg/L, 11% of the 0.2 mg/L limitIron11%Nitrate: 9.52 mg/L, 19% of the 50 mg/L limitNitrate19%Colour: 4.6 mg/L Pt/Co, 23% of the 20 mg/L Pt/Co limitColour23%Trihalomethanes: 0.023 mg/L, 23% of the 0.1 mg/L limitTrihalomethanes23%Nitrite: 0.19 mg/L, 38% of the 0.5 mg/L limitNitrite38%
  1. Nitrite38%
  2. Colour23%
  3. Trihalomethanes23%
  4. Nitrate19%
  5. Iron11%
  6. Fluoride7%
  7. Bromate7%
  8. Turbidity7%
  9. Mercury4%
  10. Chromium3%
  11. Nickel3%
  12. Copper3%
  13. Boron3%
  14. Aluminium3%
  15. Lead2%
  16. Manganese1%
  17. Arsenic1%
  18. Antimony<1%
  19. Selenium<1%
  20. Cadmium<1%
  • E. coli none found
  • Coliform Bacteria none found
  • Conductivity 290 µS/cm
All 23 results as a table
SubstanceResultLegal limitShare of limit
Fluoride0.11 mg/L1.5 mg/L
7%
Mercury0.000042 mg/L0.001 mg/L
4%
Chromium0.0015 mg/L0.05 mg/L
3%
Arsenic0.00011 mg/L0.01 mg/L
1%
Copper0.058 mg/L2 mg/L
3%
Cadmium0.000025 mg/L0.005 mg/L
<1%
Manganese0.00068 mg/L0.05 mg/L
1%
Aluminium0.005 mg/L0.2 mg/L
3%
Nitrite0.19 mg/L0.5 mg/L
38%
Iron0.021 mg/L0.2 mg/L
11%
Nitrate9.52 mg/L50 mg/L
19%
Turbidity0.27 NTU4 NTU
7%
E. coli0 count/100mlMust be zeroNone found
Coliform Bacteria0 count/100mlMust be zeroNone found
Colour4.6 mg/L Pt/Co20 mg/L Pt/Co
23%
Conductivity290 µS/cmNo legal limit–
Selenium0.00023 mg/L0.04 mg/L
<1%
Antimony0.000034 mg/L0.005 mg/L
<1%
Lead0.00016 mg/L0.01 mg/L
2%
Nickel0.00059 mg/L0.02 mg/L
3%
Bromate0.00068 mg/L0.01 mg/L
7%
Trihalomethanes0.023 mg/L0.1 mg/L
23%
Boron0.028 mg/L1 mg/L
3%

NP11 in short

Tap water in NP11 (Caerphilly) is supplied by Dŵr Cymru Welsh Water in the Caerphilly Central zone and scores 9.4 out of 10, against an England and Wales average of 9.0. None of the 23 tested substances came close to a limit. The latest sample is from 20 December 2024.

  • The lowest score of the 6 areas tested in CaerphillyNP11 scores 9.4 out of 10. The best in Caerphilly, NP24, scores 9.7.
  • Nothing tested came within 40% of its legal limitThe highest was Nitrite at 38% of the 0.5 mg/L maximum. See every reading
  • Scores higher than 0 of 5 neighbouring districtsWater here is typical for the immediate area, which usually means the same treatment works and the same supply zone.

Next door

CF839.5 out of 10CF829.4 out of 10CF819.4 out of 10NP249.7 out of 10NP129.5 out of 10

Questions about NP11 water

Is NP11 tap water safe to drink?

Based on the latest tests, NP11 (Caerphilly) water scores 9.4/10, which is safe. 0 of 23 tested contaminants exceeded recommended levels. Water is supplied by Dŵr Cymru Welsh Water.

What contaminants are in NP11 water?

We tested 23 contaminants in NP11 water. None exceeded recommended safe levels.

Who supplies water in NP11?

NP11 (Caerphilly) is supplied by Dŵr Cymru Welsh Water. You can view their full profile and compliance data on our supplier page.

Should I use a water filter in NP11?

NP11 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 NP11 water?

No PFAS (forever chemicals) result is attached to the tap-water tests for NP11, 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.

Keep reading

How to test your waterBest water filtersFilter shower headsWater testing kitsUK water rankingsWater hardness checkerWater hardness map

Get alerts for your area

We'll email you when water quality data changes for NP11.

Source: Dŵr Cymru Welsh Water 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