Welsh Water Hardness: Soft 20-120 ppm

Welsh Water (Dwr Cymru) Water Hardness Summary

Welsh Water (Dwr Cymru) water is slightly hard, averaging 68 ppm as calcium carbonate, ranging from 20 to 120 ppm across 214 postcode districts in Wales & Herefordshire.

Average hardness	68 ppm (Slightly Hard)
Hardness range	20 to 120 ppm
Classification	Slightly Hard
Districts served	214
Region	Wales & Herefordshire

Average hardness

68 ppm (Slightly Hard)

Hardness range

20 to 120 ppm

Classification

Slightly Hard

Districts served

214

Region

Wales & Herefordshire

About Welsh Water (Dwr Cymru)

Welsh Water supplies 3 million customers across most of Wales and parts of western England. Welsh upland reservoirs provide predominantly soft water from ancient rock geology.

At 68 ppm on average, Welsh Water (Dwr Cymru) ranks as slightly hard water. See how it compares across the UK in our 50 softest water areas ranking.

Worth reading: our water softener guide compares the options for Welsh Water (Dwr Cymru) customers, and our limescale removal guide has quick fixes for kettles, taps, and boilers.

Cross-check this against Welsh Water (Dwr Cymru)'s own data: Welsh Water (Dwr Cymru) water hardness report. Read the hardness explanation here, then enter your postcode on the linked drinking water quality checker to see your area's calcium and magnesium levels.

Welsh Water (Dwr Cymru) vs Other UK Water Companies

Average hardness across the 15 largest UK water suppliers, hardest first. Your supplier is highlighted.

Rank	Water company	Avg ppm	Classification	Districts
1	Anglian Water	321 ppm	Very Hard	261
2	Thames Water	302 ppm	Very Hard	412
3	South East Water	297 ppm	Hard	17
4	Affinity Water	268 ppm	Hard	32
5	Southern Water	263 ppm	Hard	131
6	Portsmouth Water	261 ppm	Hard	34
7	SES Water	239 ppm	Hard	7
8	Wessex Water	231 ppm	Hard	123
9	Severn Trent Water	222 ppm	Hard	345
10	Yorkshire Water	215 ppm	Hard	217
11	Northumbrian Water	101 ppm	Slightly Hard	122
12	South West Water	80 ppm	Slightly Hard	129
13	United Utilities	77 ppm	Slightly Hard	242
14	Welsh Water (Dwr Cymru)	68 ppm	Slightly Hard	214
15	Scottish Water	54 ppm	Soft	3

Areas Served by Welsh Water (Dwr Cymru)

Every postcode district, sorted by hardness.

Postcode	Town	Hardness	PPM	Level
SY10	Oswestry	120	120 ppm	Slightly Hard
NP19	Newport	119	119 ppm	Slightly Hard
NP18	Newport	118	118 ppm	Slightly Hard
SA39	Pencader	117	117 ppm	Slightly Hard
LD8	Presteigne	116	116 ppm	Slightly Hard
NP16	Chepstow	116	116 ppm	Slightly Hard
SA38	Newcastle Emlyn	116	116 ppm	Slightly Hard
LD7	Knighton	115	115 ppm	Slightly Hard
NP15	Usk	115	115 ppm	Slightly Hard
SA37	Boncath	115	115 ppm	Slightly Hard
SA69	Saundersfoot	115	115 ppm	Slightly Hard
LD6	Rhayader	114	114 ppm	Slightly Hard
SA36	Glogue	114	114 ppm	Slightly Hard
SA68	Kilgetty	114	114 ppm	Slightly Hard
LD5	Llanwrtyd Wells	113	113 ppm	Slightly Hard
NP13	Abertillery	113	113 ppm	Slightly Hard
SA35	Llanfyrnach	113	113 ppm	Slightly Hard
SA67	Narberth	113	113 ppm	Slightly Hard
LD4	Llangammarch Wells	112	112 ppm	Slightly Hard
NP12	Blackwood	112	112 ppm	Slightly Hard
NP44	Cwmbran	112	112 ppm	Slightly Hard
SA34	Whitland	112	112 ppm	Slightly Hard
SA66	Clynderwen	112	112 ppm	Slightly Hard
LD3	Brecon	111	111 ppm	Slightly Hard
NP11	Newport	111	111 ppm	Slightly Hard
SA33	Carmarthen	111	111 ppm	Slightly Hard
SA65	Fishguard	111	111 ppm	Slightly Hard
LD2	Builth Wells	110	110 ppm	Slightly Hard
NP10	Newport	110	110 ppm	Slightly Hard
SA32	Carmarthen	110	110 ppm	Slightly Hard
SA64	Goodwick	110	110 ppm	Slightly Hard
CF39	Porth	109	109 ppm	Slightly Hard
LD1	Llandrindod Wells	109	109 ppm	Slightly Hard
LL39	Arthog	109	109 ppm	Slightly Hard
SA31	Carmarthen	109	109 ppm	Slightly Hard
SA63	Clarbeston Road	109	109 ppm	Slightly Hard
CF38	Pontypridd	108	108 ppm	Slightly Hard
LL38	Fairbourne	108	108 ppm	Slightly Hard
SA62	Haverfordwest	108	108 ppm	Slightly Hard
CF37	Pontypridd	107	107 ppm	Slightly Hard
LL37	Llwyngwril	107	107 ppm	Slightly Hard
LL69	Penysarn	107	107 ppm	Slightly Hard
SA61	Haverfordwest	107	107 ppm	Slightly Hard
CF36	Porthcawl	106	106 ppm	Slightly Hard
LL36	Tywyn	106	106 ppm	Slightly Hard
LL68	Amlwch	106	106 ppm	Slightly Hard
CF35	Bridgend	105	105 ppm	Slightly Hard
LL35	Aberdovey	105	105 ppm	Slightly Hard
LL67	Cemaes Bay	105	105 ppm	Slightly Hard
CF34	Maesteg	104	104 ppm	Slightly Hard
LL34	Penmaenmawr	104	104 ppm	Slightly Hard
LL66	Rhosgoch	104	104 ppm	Slightly Hard
CF33	Bridgend	103	103 ppm	Slightly Hard
LL33	Llanfairfechan	103	103 ppm	Slightly Hard
LL65	Holyhead	103	103 ppm	Slightly Hard
CF32	Bridgend	102	102 ppm	Slightly Hard
CF64	Penarth	102	102 ppm	Slightly Hard
LL32	Conwy	102	102 ppm	Slightly Hard
LL64	Rhosneigr	102	102 ppm	Slightly Hard
CF31	Bridgend	101	101 ppm	Slightly Hard
CF63	Barry	101	101 ppm	Slightly Hard
LL31	Llandudno Junction	101	101 ppm	Slightly Hard
LL63	Ty Croes	101	101 ppm	Slightly Hard
CF62	Barry	100	100 ppm	Slightly Hard
LL30	Llandudno	100	100 ppm	Slightly Hard
LL62	Bodorgan	100	100 ppm	Slightly Hard
CF61	Llantwit Major	99	99 ppm	Slightly Hard
LL61	Llanfairpwllgwyngyll	99	99 ppm	Slightly Hard
LL60	Gaerwen	98	98 ppm	Slightly Hard
LL29	Colwyn Bay	76	76 ppm	Slightly Hard
LL28	Colwyn Bay	75	75 ppm	Slightly Hard
SA20	Llandovery	75	75 ppm	Slightly Hard
CF5	Cardiff	74	74 ppm	Slightly Hard
LL27	Trefriw	74	74 ppm	Slightly Hard
LL59	Menai Bridge	74	74 ppm	Slightly Hard
LL26	Llanrwst	73	73 ppm	Slightly Hard
LL58	Beaumaris	73	73 ppm	Slightly Hard
CF3	Cardiff	72	72 ppm	Slightly Hard
LL25	Dolwyddelan	72	72 ppm	Slightly Hard
LL57	Bangor	72	72 ppm	Slightly Hard
CF2	Cardiff	71	71 ppm	Slightly Hard
CF24	Cardiff	71	71 ppm	Slightly Hard
LL24	Betws Y Coed	71	71 ppm	Slightly Hard
LL56	Y Felinheli	71	71 ppm	Slightly Hard
CF23	Cardiff	70	70 ppm	Slightly Hard
LL23	Bala	70	70 ppm	Slightly Hard
LL55	Caernarfon	70	70 ppm	Slightly Hard
LL22	Abergele	69	69 ppm	Slightly Hard
LL54	Caernarfon	69	69 ppm	Slightly Hard
LL21	Corwen	68	68 ppm	Slightly Hard
LL53	Pwllheli	68	68 ppm	Slightly Hard
LL20	Llangollen	67	67 ppm	Slightly Hard
LL52	Criccieth	67	67 ppm	Slightly Hard
CF83	Caerphilly	66	66 ppm	Slightly Hard
LL51	Garndolbenmaen	66	66 ppm	Slightly Hard
SA9	Swansea	66	66 ppm	Slightly Hard
CF82	Hengoed	65	65 ppm	Slightly Hard
SA8	Swansea	65	65 ppm	Slightly Hard
CF81	Bargoed	64	64 ppm	Slightly Hard
NP8	Crickhowell	64	64 ppm	Slightly Hard
SA7	Swansea	64	64 ppm	Slightly Hard
NP7	Abergavenny	63	63 ppm	Slightly Hard
SA6	Swansea	63	63 ppm	Slightly Hard
SA5	Swansea	62	62 ppm	Slightly Hard
HR9	Ross On Wye	61	61 ppm	Slightly Hard
SA4	Swansea	61	61 ppm	Slightly Hard
HR8	Ledbury	60	60 ppm	Soft
NP4	Pontypool	60	60 ppm	Soft
SA3	Swansea	60	60 ppm	Soft
HR7	Bromyard	59	59 ppm	Soft
SA2	Swansea	59	59 ppm	Soft
HR6	Leominster	58	58 ppm	Soft
SA1	Swansea	58	58 ppm	Soft
HR5	Kington	57	57 ppm	Soft
SY25	Tregaron	57	57 ppm	Soft
HR4	Hereford	56	56 ppm	Soft
SY24	Bow Street	56	56 ppm	Soft
HR3	Hereford	55	55 ppm	Soft
SY23	Aberystwyth	55	55 ppm	Soft
HR2	Hereford	54	54 ppm	Soft
SY22	Llanymynech	54	54 ppm	Soft
HR1	Hereford	53	53 ppm	Soft
SY21	Welshpool	53	53 ppm	Soft
SY20	Machynlleth	52	52 ppm	Soft
SA19	Llandeilo	51	51 ppm	Soft
SA18	Ammanford	50	50 ppm	Soft
SY9	Bishops Castle	50	50 ppm	Soft
SA17	Kidwelly	49	49 ppm	Soft
SY8	Ludlow	49	49 ppm	Soft
NP26	Caldicot	48	48 ppm	Soft
SA16	Burry Port	48	48 ppm	Soft
SA48	Lampeter	48	48 ppm	Soft
SY7	Craven Arms	48	48 ppm	Soft
NP25	Monmouth	47	47 ppm	Soft
SA15	Llanelli	47	47 ppm	Soft
SA47	Llanarth	47	47 ppm	Soft
SY6	Church Stretton	47	47 ppm	Soft
NP24	New Tredegar	46	46 ppm	Soft
SA14	Llanelli	46	46 ppm	Soft
SA46	Aberaeron	46	46 ppm	Soft
SY5	Shrewsbury	46	46 ppm	Soft
NP23	Ebbw Vale	45	45 ppm	Soft
SA13	Port Talbot	45	45 ppm	Soft
SA45	New Quay	45	45 ppm	Soft
SY4	Shrewsbury	45	45 ppm	Soft
NP22	Tredegar	44	44 ppm	Soft
SA12	Port Talbot	44	44 ppm	Soft
SA44	Llandysul	44	44 ppm	Soft
SY3	Shrewsbury	44	44 ppm	Soft
LL19	Prestatyn	43	43 ppm	Soft
SA11	Neath	43	43 ppm	Soft
SA43	Cardigan	43	43 ppm	Soft
SY2	Shrewsbury	43	43 ppm	Soft
LL18	Rhyl	42	42 ppm	Soft
NP20	Newport	42	42 ppm	Soft
SA10	Neath	42	42 ppm	Soft
SA42	Newport	42	42 ppm	Soft
SY1	Shrewsbury	42	42 ppm	Soft
LL17	St Asaph	41	41 ppm	Soft
LL49	Porthmadog	41	41 ppm	Soft
SA41	Crymych	41	41 ppm	Soft
SA73	Milford Haven	41	41 ppm	Soft
CF48	Merthyr Tydfil	40	40 ppm	Soft
LL16	Denbigh	40	40 ppm	Soft
LL48	Penrhyndeudraeth	40	40 ppm	Soft
SA40	Llanybydder	40	40 ppm	Soft
SA72	Pembroke Dock	40	40 ppm	Soft
CF15	Cardiff	39	39 ppm	Soft
CF47	Merthyr Tydfil	39	39 ppm	Soft
LL15	Ruthin	39	39 ppm	Soft
LL47	Talsarnau	39	39 ppm	Soft
SA71	Pembroke	39	39 ppm	Soft
CF14	Cardiff	38	38 ppm	Soft
CF46	Treharris	38	38 ppm	Soft
LL14	Wrexham	38	38 ppm	Soft
LL46	Harlech	38	38 ppm	Soft
LL78	Brynteg	38	38 ppm	Soft
SA70	Tenby	38	38 ppm	Soft
CF45	Mountain Ash	37	37 ppm	Soft
LL13	Wrexham	37	37 ppm	Soft
LL45	Llanbedr	37	37 ppm	Soft
LL77	Llangefni	37	37 ppm	Soft
CF44	Aberdare	36	36 ppm	Soft
LL12	Wrexham	36	36 ppm	Soft
LL44	Dyffryn Ardudwy	36	36 ppm	Soft
LL76	Llanbedrgoch	36	36 ppm	Soft
CF11	Cardiff	35	35 ppm	Soft
CF43	Ferndale	35	35 ppm	Soft
LL11	Wrexham	35	35 ppm	Soft
LL43	Talybont	35	35 ppm	Soft
LL75	Pentraeth	35	35 ppm	Soft
CF10	Cardiff	34	34 ppm	Soft
CF42	Treorchy	34	34 ppm	Soft
LL42	Barmouth	34	34 ppm	Soft
LL74	Tyn Y Gongl	34	34 ppm	Soft
CF41	Pentre	33	33 ppm	Soft
LL41	Blaenau Ffestiniog	33	33 ppm	Soft
LL73	Marianglas	33	33 ppm	Soft
CF40	Tonypandy	32	32 ppm	Soft
CF72	Pontyclun	32	32 ppm	Soft
LL40	Dolgellau	32	32 ppm	Soft
LL72	Moelfre	32	32 ppm	Soft
CF71	Cowbridge	31	31 ppm	Soft
LL71	Llannerch Y Medd	31	31 ppm	Soft
LL70	Dulas	30	30 ppm	Soft
SY19	Llanbrynmair	28	28 ppm	Soft
SY18	Llanidloes	27	27 ppm	Soft
SY17	Caersws	26	26 ppm	Soft
SY16	Newtown	25	25 ppm	Soft
SY15	Montgomery	24	24 ppm	Soft
SY14	Malpas	23	23 ppm	Soft
SY13	Whitchurch	22	22 ppm	Soft
SY12	Ellesmere	21	21 ppm	Soft
SY11	Oswestry	20	20 ppm	Soft

Test Your Water on Welsh Water (Dwr Cymru)

At 68 ppm on average, your water is slightly hard. A home testing kit lets you verify the exact hardness for your postcode and check for other contaminants.

TESPERT 16-in-1 Water Testing Kit

From ~£10

Home water test strips that check hardness, pH, chlorine, lead, and 12 other parameters. Results in around 60 seconds. 125 strips per pack.

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Common questions about Welsh Water (Dwr Cymru) water hardness

How do I check Welsh Water (Dwr Cymru) hardness by postcode?

Enter your postcode in the checker on the WaterHard.uk homepage, or find your district in the table above. Welsh Water (Dwr Cymru) serves 214 postcode districts across Wales & Herefordshire, ranging from 20 to 120 ppm.

Is there a Welsh Water (Dwr Cymru) hardness checker or map?

Welsh Water (Dwr Cymru) publishes water quality data by postcode, but it can be scattered across PDF reports. WaterHard.uk compiles it into the searchable table above so you can find your district's reading in one place.

How hard is Welsh Water (Dwr Cymru) water in my area?

It depends on your exact postcode. Welsh Water (Dwr Cymru) supplies range from 20 ppm to 120 ppm, averaging 68 ppm (slightly hard) across 214 postcode districts in Wales & Herefordshire. Use the table above to find your specific district.

Is Welsh Water (Dwr Cymru) water hard or soft?

Welsh Water (Dwr Cymru) averages 68 ppm, classified as slightly hard. Most households on Welsh Water (Dwr Cymru) see little to no limescale build-up, though individual postcodes can vary, so check the table above for your district.

Welsh Water (Dwr Cymru) Hardness

Free Hard Water Action Plan