Skip to main content
tapwater
England and Wales average 9.0

Tap water in LL40, GwyneddSafe to drink.

Supplied by Dŵr Cymru Welsh Water. 1,030 samples, 23 substances, latest on 8 December 2024. Everything is inside the legal limit, and nothing comes close to it.

See the filter we recommendSee everything that was tested

9.6 / 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 LL40 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.

Colour came closest to a limit, at 23% of it. 20 of 20 substances used under a quarter of theirs.

0%25%50%75%limitLegal limitChromium: 0.000092 mg/L, <1% of the 0.05 mg/L limitChromium<1%Cadmium: 0.000025 mg/L, <1% of the 0.005 mg/L limitCadmium<1%Antimony: 0.000028 mg/L, <1% of the 0.005 mg/L limitAntimony<1%Selenium: 0.00023 mg/L, <1% of the 0.04 mg/L limitSelenium<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%Iron: 0.004 mg/L, 2% of the 0.2 mg/L limitIron2%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%Bromate: 0.00031 mg/L, 3% of the 0.01 mg/L limitBromate3%Aluminium: 0.007 mg/L, 3% of the 0.2 mg/L limitAluminium3%Mercury: 0.000042 mg/L, 4% of the 0.001 mg/L limitMercury4%Nitrate: 2.61 mg/L, 5% of the 50 mg/L limitNitrate5%Turbidity: 0.27 NTU, 7% of the 4 NTU limitTurbidity7%Fluoride: 0.11 mg/L, 7% of the 1.5 mg/L limitFluoride7%Nitrite: 0.056 mg/L, 11% of the 0.5 mg/L limitNitrite11%Trihalomethanes: 0.018 mg/L, 18% of the 0.1 mg/L limitTrihalomethanes18%Colour: 4.6 mg/L Pt/Co, 23% of the 20 mg/L Pt/Co limitColour23%
  1. Colour23%
  2. Trihalomethanes18%
  3. Nitrite11%
  4. Fluoride7%
  5. Turbidity7%
  6. Nitrate5%
  7. Mercury4%
  8. Aluminium3%
  9. Bromate3%
  10. Nickel3%
  11. Copper3%
  12. Boron3%
  13. Iron2%
  14. Lead2%
  15. Manganese1%
  16. Arsenic1%
  17. Selenium<1%
  18. Antimony<1%
  19. Cadmium<1%
  20. Chromium<1%
  • Coliform Bacteria none found
  • E. coli none found
  • Conductivity 140 µS/cm
All 23 results as a table
SubstanceResultLegal limitShare of limit
Coliform Bacteria0 count/100mlMust be zeroNone found
Selenium0.00023 mg/L0.04 mg/L
<1%
Antimony0.000028 mg/L0.005 mg/L
<1%
E. coli0 count/100mlMust be zeroNone found
Chromium0.000092 mg/L0.05 mg/L
<1%
Lead0.00016 mg/L0.01 mg/L
2%
Mercury0.000042 mg/L0.001 mg/L
4%
Cadmium0.000025 mg/L0.005 mg/L
<1%
Nickel0.00059 mg/L0.02 mg/L
3%
Arsenic0.00011 mg/L0.01 mg/L
1%
Nitrite0.056 mg/L0.5 mg/L
11%
Aluminium0.007 mg/L0.2 mg/L
3%
Copper0.058 mg/L2 mg/L
3%
Iron0.004 mg/L0.2 mg/L
2%
Fluoride0.11 mg/L1.5 mg/L
7%
Manganese0.00068 mg/L0.05 mg/L
1%
Turbidity0.27 NTU4 NTU
7%
Nitrate2.61 mg/L50 mg/L
5%
Colour4.6 mg/L Pt/Co20 mg/L Pt/Co
23%
Conductivity140 µS/cmNo legal limit–
Trihalomethanes0.018 mg/L0.1 mg/L
18%
Bromate0.00031 mg/L0.01 mg/L
3%
Boron0.028 mg/L1 mg/L
3%

LL40 in short

Tap water in LL40 (Gwynedd) is supplied by Dŵr Cymru Welsh Water in the Gwynedd Central zone and scores 9.6 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 8 December 2024.

  • 10th cleanest of 23 areas tested in GwyneddSquarely mid-table for Gwynedd, between LL35 on 9.7 and LL53 on 9.5.
  • 0.6 points above the national average of 9Cleaner than the typical tested district in the UK. Compare every area
  • Nothing tested came within 40% of its legal limitThe highest was Colour at 23% of the 20 mg/L Pt/Co maximum. See every reading

Next door

LL559.6 out of 10LL579.6 out of 10LL239.6 out of 10LL469.6 out of 10LL499.6 out of 10LL539.5 out of 10LL389.6 out of 10LL439.7 out of 10LL479.7 out of 10LL519.5 out of 10

Questions about LL40 water

Is LL40 tap water safe to drink?

Based on the latest tests, LL40 (Gwynedd) water scores 9.6/10, which is safe. 0 of 23 tested contaminants exceeded recommended levels. Water is supplied by Dŵr Cymru Welsh Water.

What contaminants are in LL40 water?

We tested 23 contaminants in LL40 water. None exceeded recommended safe levels.

Who supplies water in LL40?

LL40 (Gwynedd) 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 LL40?

LL40 water scored 9.6/10 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 LL40 water?

No PFAS (forever chemicals) result is attached to the tap-water tests for LL40, 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 LL40.

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