Part of the Legionella Data Index · compiled 2 August 2026
43Confirmed cases, 2023 (1.4 per 100k)
3Enforcement cases tracked
£139kTotal fines in tracked cases
17Towns in the hardness dataset
01 / SURVEILLANCE
Legionnaires' disease in Wales
The most recent regional figure UKHSA states explicitly: 43 confirmed cases of legionellosis in Wales in 2023, a rate of 1.4 per 100,000 residents.
Whatever the regional count, the duties do not change: a non-domestic water system in Wales still needs a risk assessment, a written scheme of control, and the records to show the scheme is being followed. Source: UKHSA national surveillance (Open Government Licence).
02 / ENFORCEMENT
Prosecutions tracked in Wales
The tracker holds 3 legionella prosecutions from Wales, totalling £139k in fines (2005–2015).
| Defendant | Year | Sector | Fine | Prosecutor |
|---|---|---|---|---|
|
Coilcolor Limited A Newport steel-coating firm ran two cooling towers from 2009 with no risk assessment, no written scheme, no water-treatment programme and missing drift eliminators, exposing staff and the public to aerosol. The HSE served prohibition notices stopping the towers being used. Source
|
2015 | Manufacturing | £75k | HSE |
|
DEBA UK Ltd A risk-assessment contractor (not the care-home operator) carried out inadequate legionella risk assessments in 2007 that wrongly rated two Craegmoor Healthcare nursing homes in Wales as low risk, where controls were in fact inadequate. No outbreak or death resulted. Pleaded guilty to three charges under HSWA s3(1) and was fined £24,000 plus £17,276 costs at Abertillery Magistrates' Court in August 2009. Notable as a prosecution of the assessor rather than the duty-holder. Source
|
2009 | Water treatment | £24k | HSE |
|
Copthorne Hotel Cardiff (Millennium & Copthorne Hotels) Death/outbreak A Legionnaires' disease outbreak from July 1999 to February 2000 was traced to an incorrectly installed humidifier in a buffet unit. Two guests died and five others fell ill. The hotel pleaded guilty at Cardiff Crown Court in November 2005 to two breaches of the HSWA 1974 and was fined £40,000 plus £15,000 costs. A named health-and-safety consultant was separately prosecuted as an individual and is not recorded here. Source
|
2005 | Hospitality | £40k | HSE |
The full UK record, its curation rules and the per-sector breakdown are on the Legionella Enforcement Tracker; sector views sit under the Index.
03 / WATER HARDNESS
Water hardness in Wales towns
2 of 17 towns here carry a reported hardness figure; the rest show a band inferred from the water company's own statement, or an honest gap. Every row names its source and confidence. Scale risk uses the DWI/WHO anchor: scaling begins around 200 mg/l CaCO₃.
| Town | Water company | Hardness (mg/l CaCO₃) | Hardness band | Scale risk | Evidence |
|---|---|---|---|---|---|
| Aberystwyth | Dŵr Cymru Welsh Water | — | Soft (~30-90 mg/l) * | Low * | Company statement - band only (Dŵr Cymru Welsh Water) Band inferred from the Dŵr Cymru regional profile (generally soft upland supplies). |
| Bangor | Dŵr Cymru Welsh Water | — | Soft (~30-90 mg/l) * | Low * | Company statement - band only (Dŵr Cymru Welsh Water) Band inferred from the Dŵr Cymru regional profile (generally soft upland supplies). |
| Barry | Dŵr Cymru Welsh Water | — | Soft (~30-90 mg/l) * | Low * | Company statement - band only (Dŵr Cymru Welsh Water) Band inferred from the Dŵr Cymru regional profile (generally soft upland supplies). |
| Bridgend | Dŵr Cymru Welsh Water | — | Soft (~30-90 mg/l) * | Low * | Company statement - band only (Dŵr Cymru Welsh Water) Band inferred from the Dŵr Cymru regional profile (generally soft upland supplies). |
| Caerphilly | Dŵr Cymru Welsh Water | — | Soft (~30-90 mg/l) * | Low * | Company statement - band only (Dŵr Cymru Welsh Water) Band inferred from the Dŵr Cymru regional profile (generally soft upland supplies). |
| Cardiff | Dŵr Cymru Welsh Water | 45 | Soft | Low | Single source - unverified (MyTapWater) |
| Carmarthen | Dŵr Cymru Welsh Water | — | Soft (~30-90 mg/l) * | Low * | Company statement - band only (Dŵr Cymru Welsh Water) Band inferred from the Dŵr Cymru regional profile (generally soft upland supplies). |
| Flint | Dŵr Cymru Welsh Water | — | Soft (~30-90 mg/l) * | Low * | Company statement - band only (Dŵr Cymru Welsh Water) Band inferred from the Dŵr Cymru regional profile (generally soft upland supplies). |
| Llanelli | Dŵr Cymru Welsh Water | — | Soft (~30-90 mg/l) * | Low * | Company statement - band only (Dŵr Cymru Welsh Water) Band inferred from the Dŵr Cymru regional profile (generally soft upland supplies). |
| Merthyr Tydfil | Dŵr Cymru Welsh Water | — | Soft (~30-90 mg/l) * | Low * | Company statement - band only (Dŵr Cymru Welsh Water) Band inferred from the Dŵr Cymru regional profile (generally soft upland supplies). |
| Neath | Dŵr Cymru Welsh Water | — | Soft (~30-90 mg/l) * | Low * | Company statement - band only (Dŵr Cymru Welsh Water) Band inferred from the Dŵr Cymru regional profile (generally soft upland supplies). |
| Newport | Dŵr Cymru Welsh Water | Withheld | — | — | Conflict: MyTapWater 45 vs WaterGrade 322.6 - withheld The WaterGrade value almost certainly mis-maps Newport; neither figure is published. |
| Pontypridd | Dŵr Cymru Welsh Water | — | Soft (~30-90 mg/l) * | Low * | Company statement - band only (Dŵr Cymru Welsh Water) Band inferred from the Dŵr Cymru regional profile (generally soft upland supplies). |
| Port Talbot | Dŵr Cymru Welsh Water | — | Soft (~30-90 mg/l) * | Low * | Company statement - band only (Dŵr Cymru Welsh Water) Band inferred from the Dŵr Cymru regional profile (generally soft upland supplies). |
| Rhyl | Dŵr Cymru Welsh Water | — | Soft (~30-90 mg/l) * | Low * | Company statement - band only (Dŵr Cymru Welsh Water) Band inferred from the Dŵr Cymru regional profile (generally soft upland supplies). |
| Swansea | Dŵr Cymru Welsh Water | 35 | Soft | Low | Single source - unverified (MyTapWater) |
| Wrexham | Dŵr Cymru Welsh Water | — | Soft (~30-90 mg/l) * | Low * | Company statement - band only (Dŵr Cymru Welsh Water) Band inferred from the Dŵr Cymru regional profile (generally soft upland supplies). |
* Band or scale risk inferred from the water company's own published statement, not a measured town value. Figures labelled "unverified" come from aggregator sites and should be confirmed against the company's postcode water-quality checker before being relied on. How this dataset is built.
04 / COUNCIL DUTIES
What councils in Wales ask of landlords
The national legionella duty is the same everywhere; what varies locally is property licensing and whether legionella is written into licence conditions. These verified councils fall in Wales:
| Council | Nation | Scheme | In force | Legionella in licensing? |
|---|---|---|---|---|
| Newport City Council All HMOs with 3 or more unrelated occupiers HMO licence application guidance, "Water Supply safety - Legionella": "The landlord must carry out risk assessments on their properties to assess the potential risk of exposure to legionella… must consider the domestic hot and cold-water systems, water tanks, water heaters, and the water temperature." Source document | Wales | Additional HMO licensing | n/a | Explicit licence condition |
Important
This page is general guidance only. Legionella risk varies with the specific water system, its use, and the people exposed to it. You should consult a competent legionella risk assessor for advice on your premises. LegionellaCheck is an independent information service and is not affiliated with HSE, UKAS, the Legionella Control Association, or any water hygiene company. This site does not provide medical advice. If you suspect Legionnaires' disease, contact NHS 111 or your GP.