Latest full year: 2024 · Source: UKHSA, Legionellosis in residents of England and Wales
Current as of November 2025. The next release is expected around November 2026.See the source release.
One page, four datasets. Beyond the surveillance figures below, the Index tracks enforcement prosecutions and fines, water hardness and scale risk for 242 towns, and what 20 councils ask of landlords - plus regional and sector sub-pages.
472Cases in 2024
England & Wales
England & Wales
604Record high, set in 2023
13Deaths in 2024
2.8%Case fatality rate, 2024
01 / THE TREND
Cases over time, 2017 to 2024
Reported legionellosis fell sharply in 2020 and 2021 while international travel was restricted, then rebounded to a record 604 cases in 2023 before easing to 472 in 2024.
Legionnaires' disease is a severe lung infection caught by breathing in fine water droplets that contain Legionella bacteria. It is not spread from person to person. The surveillance count is only the cases confirmed and reported to UKHSA, so it is a floor, not the true total: milder cases are often not tested. Even so, the direction of travel matters, and the trend has been upward across the decade once the pandemic years are set aside.
Managing the risk in your building
Free legionella risk assessment template
A structured Word document following the five-step approach in ACOP L8. Covers risk identification, written scheme, monitoring, and records. If it isn't written down, you can't evidence it.
Follows ACoP L8 and HSG274 Part 2. Free. No spam.
02 / HOW PEOPLE ARE EXPOSED
Where the risk comes from
In 2024, just over half of all cases were community-acquired, linked to the home, workplace, or a building in the wider community, rather than to travel abroad.
Community-acquired51.6% · 239 cases
Infection linked to the home or wider community, including travel within the UK.
Travel abroad43.8% · 203 cases
Associated with travel outside the UK in the incubation period.
Healthcare-associated4.5% · 21 cases
Onset linked to a hospital or other healthcare setting.
The community-acquired share is the one that concerns duty holders most directly. It is the part of the burden that traces back to buildings in ordinary use, care homes, offices, hotels, gyms, and rented housing, where a water system was not adequately controlled. That is the risk a legionella risk assessment exists to manage.
03 / WHO IS AFFECTED
Age and the people most at risk
Legionnaires' disease overwhelmingly affects older adults. In 2024, nearly two in three confirmed cases were in people aged 60 or over, and cases in men outnumbered women by more than two to one.
Aged 70 and over34.1% · 158 cases
Aged 60 to 6929.8% · 138 cases
Aged 50 to 5921.4% · 99 cases
Under 5014.7% · 68 cases
This age profile is why premises housing older or more vulnerable people, care homes, sheltered housing, and hospitals, carry a heavier duty. The same exposure that causes a mild illness in a healthy 30-year-old can be fatal for an 80-year-old with a lung condition. It is also why the case fatality rate, though falling, is never trivial: 2.8% of confirmed cases died in 2024.
04 / HIGHEST-BURDEN REGIONS
Where cases are concentrated
Reported cases vary widely by region. These are the regions with the highest confirmed counts and rates in the most recent detailed year, 2023. Rates are per 100,000 residents.
| Region | Year | Cases | Rate per 100,000 |
|---|---|---|---|
| South East | 2023 | 100 | not stated |
| West Midlands | 2023 | 71 | 1.2 |
| East Midlands | 2023 | 58 | 1.2 |
| Wales | 2023 | 43 | 1.4 |
| North East | 2023 | 17 | 0.6 |
By rate, the East and West Midlands carried the joint-highest burden in 2023 at 1.2 per 100,000, and in 2024 the East Midlands rose to 1.3 per 100,000, the highest of any English region. The South East consistently reports the most cases by count because it has the largest population. Full region-by-region counts for every English region are not published in the surveillance text; the figures above are those UKHSA states explicitly.
05 / THE ORGANISM AND THE SEASON
What causes it and when it peaks
Almost all confirmed disease is caused by Legionella pneumophila, and cases cluster in the warm months.
- Legionella pneumophila caused 96.5% of cases in 2024 (447 of 463 Legionnaires' disease cases). Serogroup 1 is the single most commonly identified type.
- Cases peak in late summer. The most cases in 2024 were reported in August, and the majority fell between June and October, when warmer ambient temperatures help the bacteria multiply in poorly controlled systems.
- The count is an underestimate. Only laboratory-confirmed, reported cases appear in the surveillance data. Milder illness that is never tested does not.
06 / ENFORCEMENT
Prosecutions and fines: what the courts have handed down
The duty holder's real jeopardy is prosecution, not the disease. The tracker holds 28 UK legionella prosecutions totalling £8.6m in fines from 2005 to 2024; 14 involved a death or outbreak, and the largest single fine was £1.8m. Each case is verified against its primary source on the enforcement tracker.
| Sector | Prosecutions | Total fines | Involving a death |
|---|---|---|---|
| Care home | 5 | £2.36m | 4 |
| Security | 1 | £1.8m | – |
| Manufacturing | 5 | £1.04m | – |
| Retail | 1 | £1m | 1 |
| Housing | 1 | £900k | – |
| Facilities management | 1 | £600k | 1 |
| Healthcare | 6 | £522k | 4 |
| Hospitality | 4 | £215k | 3 |
| Local authority leisure | 2 | £152k | 1 |
| Water treatment | 1 | £24k | – |
| Dry cleaning | 1 | £100 | – |
Fines are the total across tracked prosecutions in each sector. Cases with no fine (for example a conditional discharge) count as prosecutions but add nothing to the fines column. A single outbreak can lift a sector sharply, so read the case count next to the total.
07 / WATER HARDNESS AND SCALE RISK
Water hardness by town, and what it means for hot water systems
Hard water lays down limescale where water is heated or stored, and scale - with the biofilm it shelters - is where Legionella finds habitat. This dataset maps 242 UK towns to their water hardness with honest, per-row confidence: 129 towns carry a reported figure, 91 a band inferred from the water company's own statement, 10 have conflicting values (withheld), and 12 have nothing we could source.
Last reviewed August 2026. Every row names its source; aggregator figures are unverified finding aids until confirmed against the water company's checker.
Check a town or postcode
The checker below is the embeddable version of this dataset: town or postcode in, hardness band and scale risk out, with the confidence label intact. It is free for councils, landlord associations and agents to embed.
Embed this checker on your site
Copy this HTML. Every embed carries an attribution link back to this Index.
<iframe src="https://legionellacheck.org.uk/embed/scale-risk" width="100%" height="600" style="border:0;max-width:540px" title="Water hardness and scale-risk checker" loading="lazy"></iframe> <!-- Data: LegionellaCheck Legionella Index - https://legionellacheck.org.uk/legionella-index -->
The two scales
Hardness is reported in mg/l CaCO₃ and classified on the Drinking Water Inspectorate's five-band scale. Scale risk follows the DWI's guidance, citing WHO figures, that scaling begins around 200 mg/l CaCO₃ in hot water systems, while water below 100 mg/l can be more corrosive to pipework. Source: DWI, Water hardness (Open Government Licence).
| Hardness (mg/l CaCO₃) | DWI classification | Scale risk in hot water systems |
|---|---|---|
| Up to 100 | Soft | Low (note: can be more corrosive) |
| 100–150 | Slightly hard | Moderate |
| 150–200 | Moderately hard | Moderate |
| 200–300 | Hard | High |
| Over 300 | Very hard | Very high |
How to read the confidence labels
- Two agreeing sources - unverified: two independent aggregator datasets report the same value. Published, flagged for spot-checking against the company checker.
- Single source - unverified: one aggregator reports a value. Treat as a strong hint, not a measurement.
- Company statement - band only: no number exists in public, but the water company's own published statement supports a band. Scale risk marked * is indicative, derived from that band.
- Conflict - withheld: the two aggregators disagree, so we publish neither value. The disagreement itself is shown.
- No sourced data: nothing trustworthy found; the company postcode checker is the route.
| Town | Region | Water company | Hardness (mg/l CaCO₃) | Hardness band | Scale risk | Evidence |
|---|---|---|---|---|---|---|
| Aberdeen | Scotland | Scottish Water | 12 | Soft | Low | Single source - unverified (MyTapWater) Approximate as reported by the source ("~12"). |
| Aberystwyth | Wales | 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). |
| Aldershot | South East England | South East Water | 197 | Moderately hard | Moderate | Single source - unverified (WaterGrade) |
| Andover | South East England | Wessex Water | — | Moderately hard to very hard * | — | Company statement - band only Water company corrected to Wessex Water (research section 7). Band inferred from the company regional profile; no published zone value sourced yet. |
| Ashford | South East England | Southern Water | — | Hard * | High * | Company statement - band only (Southern Water) Southern Water states most of its supply is hard, from underground chalk aquifers. |
| Aylesbury | South East England | Anglian Water | 287 | Hard | High | Single source - unverified (MyTapWater) |
| Ayr | Scotland | Scottish Water | — | Soft (~10-50 mg/l) * | Low * | Company statement - band only (Scottish Water) Scottish Water Factsheet 12 describes most supplies as soft to slightly hard; zone values are published only on request. |
| Bangor | Wales | 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). |
| Barking | London | Thames Water | 342 | Very hard | Very high | Single source - unverified (WaterGrade) |
| Barnet | London | Affinity Water | 270 | Hard | High | Single source - unverified (WaterGrade) |
| Barnsley | Yorkshire and the Humber | Yorkshire Water | 211.5 | Hard | High | Single source - unverified (WaterGrade) |
| Barnstaple | South West England | South West Water | — | Soft to moderately soft * | Low * | Company statement - band only Band inferred from the company regional profile; no published zone value sourced yet. |
| Barrow-in-Furness | North West England | United Utilities | — | Soft to moderately soft * | Low * | Company statement - band only (United Utilities) United Utilities states the majority of water in its region is soft or very soft (statement quoted in a hosted planning document). |
| Barry | Wales | 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). |
| Basildon | East of England | Essex & Suffolk Water | 265 | Hard | High | Single source - unverified (WaterGrade) |
| Basingstoke | South East England | South East Water | 288 | Hard | High | Single source - unverified (WaterGrade) |
| Bath | South West England | Wessex Water | 300.7 | Very hard | Very high | Single source - unverified (WaterGrade) |
| Batley | Yorkshire and the Humber | Yorkshire Water | 158.9 | Moderately hard | Moderate | Single source - unverified (WaterGrade) |
| Bedford | East of England | Anglian Water | — | Hard to very hard * | High to very high * | Company statement - band only (Anglian Water) Anglian Water states all water in its region is classed as hard to very hard. |
| Berwick-upon-Tweed | North East England | Northumbrian Water | — | Soft to slightly hard (~50-115 mg/l by zone) * | Low to moderate * | Company statement - band only (Northumbrian Water) Band inferred from Northumbrian Water zone reports (e.g. zone T203 avg 101.11 mg/l CaCO3). |
| Birmingham | West Midlands | Severn Trent Water | 72 | Soft | Low | Two agreeing sources - unverified (MyTapWater + WaterGrade) Two independent aggregators agree; still to be spot-checked against the company checker. |
| Blackburn | North West England | United Utilities | 99.5 | Soft | Low | Single source - unverified (WaterGrade) |
| Blackpool | North West England | United Utilities | Withheld | — | — | Conflict: MyTapWater 58 vs WaterGrade 175.8 - withheld The two compiled values disagree, so neither is published; verify via the company checker. |
| Blyth | North East England | Northumbrian Water | — | Soft to slightly hard (~50-115 mg/l by zone) * | Low to moderate * | Company statement - band only (Northumbrian Water) Band inferred from Northumbrian Water zone reports (e.g. zone T203 avg 101.11 mg/l CaCO3). |
| Bolton | North West England | United Utilities | Withheld | — | — | Conflict: MyTapWater 60 vs WaterGrade 115.4 - withheld The two compiled values disagree, so neither is published; verify via the company checker. |
| Boston | East Midlands | Anglian Water | — | Hard to very hard * | High to very high * | Company statement - band only (Anglian Water) Water company corrected to Anglian Water (research section 7). Anglian Water states all water in its region is classed as hard to very hard. |
| Bournemouth | South West England | Bournemouth Water | 295.4 | Hard | High | Single source - unverified (WaterGrade) WaterGrade "Poole Town" zone; the zone naming is Wessex-styled, so company attribution is murky - flagged for verification. |
| Bradford | Yorkshire and the Humber | Yorkshire Water | 60-65 | Soft | Low | Two agreeing sources - unverified (MyTapWater + WaterGrade) Two independent aggregators agree; still to be spot-checked against the company checker. |
| Braintree | East of England | Anglian Water | 350 | Very hard | Very high | Single source - unverified (MyTapWater) |
| Bridgend | Wales | 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). |
| Bridgwater | South West England | Wessex Water | — | Moderately hard to very hard * | — | Company statement - band only Band inferred from the company regional profile; no published zone value sourced yet. |
| Bridlington | Yorkshire and the Humber | Yorkshire Water | — | — | — | No sourced data The supply company spans soft upland and hard groundwater zones, so no town-level value or band can be inferred; use the company postcode water-quality checker. |
| Brighton | South East England | Southern Water | 290 | Hard | High | Single source - unverified (MyTapWater) |
| Bristol | South West England | Bristol Water | — | Moderately hard to very hard * | — | Company statement - band only (Bristol Water) MyTapWater reports 120 mg/l CaCO3 for Bristol, contradicting Bristol Water's own "moderately hard to very hard" statement; the aggregator figure is treated as suspect and withheld in favour of the official band. |
| Bromley | London | Thames Water | 282 | Hard | High | Single source - unverified (WaterGrade) |
| Bromsgrove | West Midlands | Severn Trent Water | 192.4 | Moderately hard | Moderate | Single source - unverified (WaterGrade) |
| Burnley | North West England | United Utilities | 36.1 | Soft | Low | Single source - unverified (WaterGrade) |
| Bury | North West England | United Utilities | 48.4 | Soft | Low | Single source - unverified (WaterGrade) |
| Bury St Edmunds | East of England | Anglian Water | — | Hard to very hard * | High to very high * | Company statement - band only (Anglian Water) Anglian Water states all water in its region is classed as hard to very hard. |
| Caerphilly | Wales | 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). |
| Cambridge | East of England | Cambridge Water | 301-310 | Very hard | Very high | Two agreeing sources - unverified (MyTapWater + WaterGrade) Two independent aggregators agree; still to be spot-checked against the company checker. |
| Cannock | West Midlands | Severn Trent Water | 250.3 | Hard | High | Single source - unverified (WaterGrade) |
| Canterbury | South East England | Southern Water | — | Hard * | High * | Company statement - band only (Southern Water) Southern Water states most of its supply is hard, from underground chalk aquifers. |
| Cardiff | Wales | Dŵr Cymru Welsh Water | 45 | Soft | Low | Single source - unverified (MyTapWater) |
| Carlisle | North West England | United Utilities | — | Soft to moderately soft * | Low * | Company statement - band only (United Utilities) United Utilities states the majority of water in its region is soft or very soft (statement quoted in a hosted planning document). |
| Carmarthen | Wales | 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). |
| Chatham | South East England | Southern Water | — | Hard * | High * | Company statement - band only (Southern Water) Southern Water states most of its supply is hard, from underground chalk aquifers. |
| Chelmsford | East of England | Essex & Suffolk Water | 260 | Hard | High | Single source - unverified (MyTapWater) |
| Cheltenham | South West England | Wessex Water | 265.8 | Hard | High | Single source - unverified (WaterGrade) |
| Chester | North West England | United Utilities | Withheld | — | — | Conflict: MyTapWater 62 vs WaterGrade 172.3 - withheld The two compiled values disagree, so neither is published; verify via the company checker. |
| Chester-le-Street | North East England | Northumbrian Water | — | Soft to slightly hard (~50-115 mg/l by zone) * | Low to moderate * | Company statement - band only (Northumbrian Water) Band inferred from Northumbrian Water zone reports (e.g. zone T203 avg 101.11 mg/l CaCO3). |
| Chesterfield | East Midlands | Severn Trent Water | 68.3 | Soft | Low | Single source - unverified (WaterGrade) Soft despite the company profile - plausible reservoir supply, but flagged for verification. |
| Chichester | South East England | Portsmouth Water | — | Moderately hard to hard (~230-300 mg/l) * | High * | Company statement - band only (Portsmouth Water) Water company corrected to Portsmouth Water (research section 7). Portsmouth Water describes its chalk South Downs supply as moderately hard. |
| Clacton-on-Sea | East of England | Affinity Water | — | — | — | No sourced data No trustworthy value or company statement sourced for this town yet; use the company postcode water-quality checker. |
| Coalville | East Midlands | Severn Trent Water | 278.7 | Hard | High | Single source - unverified (WaterGrade) |
| Coatbridge | Scotland | Scottish Water | — | Soft (~10-50 mg/l) * | Low * | Company statement - band only (Scottish Water) Scottish Water Factsheet 12 describes most supplies as soft to slightly hard; zone values are published only on request. |
| Colchester | East of England | Essex & Suffolk Water | — | — | — | No sourced data No trustworthy value or company statement sourced for this town yet; use the company postcode water-quality checker. |
| Corby | East Midlands | Anglian Water | — | Hard to very hard * | High to very high * | Company statement - band only (Anglian Water) Water company corrected to Anglian Water (research section 7). Anglian Water states all water in its region is classed as hard to very hard. |
| Coventry | West Midlands | Severn Trent Water | 180-201 | Moderately hard to Hard | Moderate to high | Two agreeing sources - unverified (MyTapWater + WaterGrade) Two independent aggregators agree; still to be spot-checked against the company checker. |
| Cramlington | North East England | Northumbrian Water | — | Soft to slightly hard (~50-115 mg/l by zone) * | Low to moderate * | Company statement - band only (Northumbrian Water) Band inferred from Northumbrian Water zone reports (e.g. zone T203 avg 101.11 mg/l CaCO3). |
| Crawley | South East England | Southern Water | 251 | Hard | High | Single source - unverified (MyTapWater) |
| Crewe | North West England | United Utilities | 132.2 | Slightly hard | Moderate | Single source - unverified (WaterGrade) |
| Croydon | London | Thames Water | — | Hard to very hard (>200 mg/l typical) * | High to very high * | Company statement - band only (Thames Water) Thames Water Access Code 2025 states most supplies in its region are hard (>200 mg/l as CaCO3). |
| Darlington | North East England | Northumbrian Water | — | Soft to slightly hard (~50-115 mg/l by zone) * | Low to moderate * | Company statement - band only (Northumbrian Water) Band inferred from Northumbrian Water zone reports (e.g. zone T203 avg 101.11 mg/l CaCO3). |
| Dartford | South East England | Thames Water | 310 | Very hard | Very high | Single source - unverified (WaterGrade) |
| Derby | East Midlands | Severn Trent Water | 160 | Moderately hard | Moderate | Two agreeing sources - unverified (MyTapWater + WaterGrade) Two independent aggregators agree; still to be spot-checked against the company checker. |
| Dewsbury | Yorkshire and the Humber | Yorkshire Water | 259.2 | Hard | High | Single source - unverified (WaterGrade) |
| Doncaster | Yorkshire and the Humber | Yorkshire Water | 254.5 | Hard | High | Single source - unverified (WaterGrade) |
| Dover | South East England | Southern Water | 285 | Hard | High | Single source - unverified (MyTapWater) |
| Dudley | West Midlands | Severn Trent Water | 199.4 | Moderately hard | Moderate | Single source - unverified (WaterGrade) Shared supply zone with Walsall and West Bromwich. |
| Dumfries | Scotland | Scottish Water | — | Soft (~10-50 mg/l) * | Low * | Company statement - band only (Scottish Water) Scottish Water Factsheet 12 describes most supplies as soft to slightly hard; zone values are published only on request. |
| Dundee | Scotland | Scottish Water | 20 | Soft | Low | Single source - unverified (MyTapWater) Approximate as reported by the source ("~20"). |
| Dunfermline | Scotland | Scottish Water | — | Soft (~10-50 mg/l) * | Low * | Company statement - band only (Scottish Water) Scottish Water Factsheet 12 describes most supplies as soft to slightly hard; zone values are published only on request. |
| Durham | North East England | Northumbrian Water | — | Soft to slightly hard (~50-115 mg/l by zone) * | Low to moderate * | Company statement - band only (Northumbrian Water) Band inferred from Northumbrian Water zone reports (e.g. zone T203 avg 101.11 mg/l CaCO3). |
| Ealing | London | Thames Water | 263 | Hard | High | Single source - unverified (WaterGrade) |
| East Kilbride | Scotland | Scottish Water | — | Soft (~10-50 mg/l) * | Low * | Company statement - band only (Scottish Water) Scottish Water Factsheet 12 describes most supplies as soft to slightly hard; zone values are published only on request. |
| Eastbourne | South East England | South East Water | — | Hard to very hard * | High to very high * | Company statement - band only Band inferred from the company regional profile; no published zone value sourced yet. |
| Edinburgh | Scotland | Scottish Water | ~30 (zones ~15-68) | Soft | Low | Single source - unverified (MyTapWater) Approximate as reported ("~30"); reported zone span ~15-68 mg/l. |
| Ely | East of England | Anglian Water | — | Hard to very hard * | High to very high * | Company statement - band only (Anglian Water) Anglian Water states all water in its region is classed as hard to very hard. |
| Enfield | London | Thames Water | — | Hard to very hard (>200 mg/l typical) * | High to very high * | Company statement - band only (Thames Water) Thames Water Access Code 2025 states most supplies in its region are hard (>200 mg/l as CaCO3). |
| Exeter | South West England | South West Water | 40 | Soft | Low | Single source - unverified (MyTapWater) |
| Falkirk | Scotland | Scottish Water | — | Soft (~10-50 mg/l) * | Low * | Company statement - band only (Scottish Water) Scottish Water Factsheet 12 describes most supplies as soft to slightly hard; zone values are published only on request. |
| Fareham | South East England | Portsmouth Water | — | Moderately hard to hard (~230-300 mg/l) * | High * | Company statement - band only (Portsmouth Water) Portsmouth Water describes its chalk South Downs supply as moderately hard. |
| Farnborough | South East England | South East Water | 288 | Hard | High | Single source - unverified (WaterGrade) |
| Flint | Wales | 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). |
| Folkestone | South East England | Southern Water | 285 | Hard | High | Single source - unverified (MyTapWater) |
| Gateshead | North East England | Northumbrian Water | — | Soft to slightly hard (~50-115 mg/l by zone) * | Low to moderate * | Company statement - band only (Northumbrian Water) Band inferred from Northumbrian Water zone reports (e.g. zone T203 avg 101.11 mg/l CaCO3). |
| Gillingham | South East England | Southern Water | 275.1 | Hard | High | Single source - unverified (WaterGrade) |
| Glasgow | Scotland | Scottish Water | 15 | Soft | Low | Single source - unverified (MyTapWater) Approximate as reported by the source ("~15"). |
| Glenrothes | Scotland | Scottish Water | — | Soft (~10-50 mg/l) * | Low * | Company statement - band only (Scottish Water) Scottish Water Factsheet 12 describes most supplies as soft to slightly hard; zone values are published only on request. |
| Gloucester | South West England | Wessex Water | Withheld | — | — | Conflict: MyTapWater 130 vs WaterGrade 280.8 - withheld The two compiled values disagree, so neither is published; verify via the company checker. |
| Goole | Yorkshire and the Humber | Yorkshire Water | — | — | — | No sourced data The supply company spans soft upland and hard groundwater zones, so no town-level value or band can be inferred; use the company postcode water-quality checker. |
| Gosport | South East England | Portsmouth Water | — | Moderately hard to hard (~230-300 mg/l) * | High * | Company statement - band only (Portsmouth Water) Portsmouth Water describes its chalk South Downs supply as moderately hard. |
| Grantham | East Midlands | Severn Trent Water | — | — | — | No sourced data The supply company spans soft upland and hard groundwater zones, so no town-level value or band can be inferred; use the company postcode water-quality checker. |
| Gravesend | South East England | Thames Water | 310 | Very hard | Very high | Single source - unverified (WaterGrade) |
| Grays | East of England | Essex & Suffolk Water | 310 | Very hard | Very high | Single source - unverified (WaterGrade) |
| Great Yarmouth | East of England | Essex & Suffolk Water | — | — | — | No sourced data No trustworthy value or company statement sourced for this town yet; use the company postcode water-quality checker. |
| Greenock | Scotland | Scottish Water | — | Soft (~10-50 mg/l) * | Low * | Company statement - band only (Scottish Water) Scottish Water Factsheet 12 describes most supplies as soft to slightly hard; zone values are published only on request. |
| Grimsby | Yorkshire and the Humber | Anglian Water | — | Hard to very hard * | High to very high * | Company statement - band only (Anglian Water) Anglian Water states all water in its region is classed as hard to very hard. |
| Guildford | South East England | Thames Water | 206 | Hard | High | Single source - unverified (WaterGrade) |
| Halifax | Yorkshire and the Humber | Yorkshire Water | 97.2 | Soft | Low | Single source - unverified (WaterGrade) |
| Hamilton | Scotland | Scottish Water | — | Soft (~10-50 mg/l) * | Low * | Company statement - band only (Scottish Water) Scottish Water Factsheet 12 describes most supplies as soft to slightly hard; zone values are published only on request. |
| Harlow | East of England | Affinity Water | 330 | Very hard | Very high | Single source - unverified (WaterGrade) |
| Harrogate | Yorkshire and the Humber | Yorkshire Water | 64.3 | Soft | Low | Single source - unverified (WaterGrade) |
| Harrow | London | Affinity Water | 363 | Very hard | Very high | Single source - unverified (WaterGrade) |
| Hartlepool | North East England | Northumbrian Water | — | Soft to slightly hard (~50-115 mg/l by zone) * | Low to moderate * | Company statement - band only (Northumbrian Water) Band inferred from Northumbrian Water zone reports (e.g. zone T203 avg 101.11 mg/l CaCO3). |
| Hastings | South East England | Southern Water | — | Hard * | High * | Company statement - band only (Southern Water) Southern Water states most of its supply is hard, from underground chalk aquifers. |
| Havant | South East England | Portsmouth Water | — | Moderately hard to hard (~230-300 mg/l) * | High * | Company statement - band only (Portsmouth Water) Portsmouth Water describes its chalk South Downs supply as moderately hard. |
| Hemel Hempstead | East of England | Affinity Water | 283 | Hard | High | Single source - unverified (WaterGrade) |
| Hexham | North East England | Northumbrian Water | — | Soft to slightly hard (~50-115 mg/l by zone) * | Low to moderate * | Company statement - band only (Northumbrian Water) Band inferred from Northumbrian Water zone reports (e.g. zone T203 avg 101.11 mg/l CaCO3). |
| High Wycombe | South East England | Thames Water | 288 | Hard | High | Single source - unverified (WaterGrade) |
| Hinckley | East Midlands | Severn Trent Water | 227.2 | Hard | High | Single source - unverified (WaterGrade) |
| Hounslow | London | Thames Water | 263 | Hard | High | Single source - unverified (WaterGrade) |
| Huddersfield | Yorkshire and the Humber | Yorkshire Water | Withheld | — | — | Conflict: MyTapWater 68 vs WaterGrade 138.9 - withheld The two compiled values disagree, so neither is published; verify via the company checker. |
| Hull | Yorkshire and the Humber | Yorkshire Water | 380 | Very hard | Very high | Single source - unverified (MyTapWater) |
| Huntingdon | East of England | Anglian Water | — | Hard to very hard * | High to very high * | Company statement - band only (Anglian Water) Anglian Water states all water in its region is classed as hard to very hard. |
| Ilford | London | Thames Water | — | Hard to very hard (>200 mg/l typical) * | High to very high * | Company statement - band only (Thames Water) Thames Water Access Code 2025 states most supplies in its region are hard (>200 mg/l as CaCO3). |
| Ilkeston | East Midlands | Severn Trent Water | 290.6 | Hard | High | Single source - unverified (WaterGrade) |
| Inverness | Scotland | Scottish Water | 8 | Soft | Low | Single source - unverified (MyTapWater) Approximate as reported by the source ("~8"). |
| Ipswich | East of England | Anglian Water | 260 | Hard | High | Single source - unverified (MyTapWater) |
| Keighley | Yorkshire and the Humber | Yorkshire Water | — | — | — | No sourced data The supply company spans soft upland and hard groundwater zones, so no town-level value or band can be inferred; use the company postcode water-quality checker. |
| Kettering | East Midlands | Anglian Water | — | Hard to very hard * | High to very high * | Company statement - band only (Anglian Water) Water company corrected to Anglian Water (research section 7). Anglian Water states all water in its region is classed as hard to very hard. |
| Kidderminster | West Midlands | Severn Trent Water | 225 | Hard | High | Single source - unverified (WaterGrade) |
| Kilmarnock | Scotland | Scottish Water | — | Soft (~10-50 mg/l) * | Low * | Company statement - band only (Scottish Water) Scottish Water Factsheet 12 describes most supplies as soft to slightly hard; zone values are published only on request. |
| King's Lynn | East of England | Anglian Water | — | Hard to very hard * | High to very high * | Company statement - band only (Anglian Water) Anglian Water states all water in its region is classed as hard to very hard. |
| Kingston upon Thames | London | Thames Water | — | Hard to very hard (>200 mg/l typical) * | High to very high * | Company statement - band only (Thames Water) Thames Water Access Code 2025 states most supplies in its region are hard (>200 mg/l as CaCO3). |
| Kirkcaldy | Scotland | Scottish Water | — | Soft (~10-50 mg/l) * | Low * | Company statement - band only (Scottish Water) Scottish Water Factsheet 12 describes most supplies as soft to slightly hard; zone values are published only on request. |
| Lancaster | North West England | United Utilities | 71.5 | Soft | Low | Single source - unverified (WaterGrade) |
| Leeds | Yorkshire and the Humber | Yorkshire Water | Withheld | — | — | Conflict: MyTapWater 65 vs WaterGrade 154.9 - withheld The two compiled values disagree, so neither is published; verify via the company checker. |
| Leicester | East Midlands | Severn Trent Water | 240-279 | Hard | High | Two agreeing sources - unverified (MyTapWater + WaterGrade) Two independent aggregators agree; still to be spot-checked against the company checker. |
| Lincoln | East Midlands | Anglian Water | 220 | Hard | High | Single source - unverified (MyTapWater) Water company corrected to Anglian Water (research section 7). |
| Liverpool | North West England | United Utilities | Withheld | — | — | Conflict: MyTapWater 55 vs WaterGrade 121.6 - withheld The two compiled values disagree, so neither is published; verify via the company checker. |
| Livingston | Scotland | Scottish Water | — | Soft (~10-50 mg/l) * | Low * | Company statement - band only (Scottish Water) Scottish Water Factsheet 12 describes most supplies as soft to slightly hard; zone values are published only on request. |
| Llanelli | Wales | 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). |
| London | London | Thames Water | 260-320 | Hard to Very hard | High to very high | Two agreeing sources - unverified (MyTapWater + WaterGrade) Two independent aggregators agree; still to be spot-checked against the company checker. |
| Long Eaton | East Midlands | Severn Trent Water | 258.9 | Hard | High | Single source - unverified (WaterGrade) |
| Loughborough | East Midlands | Severn Trent Water | 274.9 | Hard | High | Single source - unverified (WaterGrade) |
| Lowestoft | East of England | Essex & Suffolk Water | — | — | — | No sourced data No trustworthy value or company statement sourced for this town yet; use the company postcode water-quality checker. |
| Luton | East of England | Affinity Water | 320-328 | Very hard | Very high | Two agreeing sources - unverified (MyTapWater + WaterGrade) Two independent aggregators agree; still to be spot-checked against the company checker. |
| Macclesfield | North West England | United Utilities | 125.5 | Slightly hard | Moderate | Single source - unverified (WaterGrade) |
| Maidstone | South East England | South East Water | — | Hard to very hard * | High to very high * | Company statement - band only Band inferred from the company regional profile; no published zone value sourced yet. |
| Manchester | North West England | United Utilities | 55-60 | Soft | Low | Two agreeing sources - unverified (MyTapWater + WaterGrade) Two independent aggregators agree; still to be spot-checked against the company checker. |
| Mansfield | East Midlands | Severn Trent Water | 372.8 | Very hard | Very high | Single source - unverified (WaterGrade) |
| Margate | South East England | Southern Water | — | Hard * | High * | Company statement - band only (Southern Water) Southern Water states most of its supply is hard, from underground chalk aquifers. |
| Melton Mowbray | East Midlands | Severn Trent Water | 351.3 | Very hard | Very high | Single source - unverified (WaterGrade) |
| Merthyr Tydfil | Wales | 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). |
| Middlesbrough | North East England | Northumbrian Water | 52 | Soft | Low | Single source - unverified (MyTapWater) |
| Milton Keynes | South East England | Anglian Water | 280 | Hard | High | Single source - unverified (MyTapWater) |
| Morpeth | North East England | Northumbrian Water | — | Soft to slightly hard (~50-115 mg/l by zone) * | Low to moderate * | Company statement - band only (Northumbrian Water) Band inferred from Northumbrian Water zone reports (e.g. zone T203 avg 101.11 mg/l CaCO3). |
| Motherwell | Scotland | Scottish Water | — | Soft (~10-50 mg/l) * | Low * | Company statement - band only (Scottish Water) Scottish Water Factsheet 12 describes most supplies as soft to slightly hard; zone values are published only on request. |
| Neath | Wales | 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). |
| Newark-on-Trent | East Midlands | Severn Trent Water | 210.5 | Hard | High | Single source - unverified (WaterGrade) |
| Newcastle upon Tyne | North East England | Northumbrian Water | 50 | Soft | Low | Single source - unverified (MyTapWater) |
| Newport | Wales | 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. |
| Newton Abbot | South West England | South West Water | — | Soft to moderately soft * | Low * | Company statement - band only Band inferred from the company regional profile; no published zone value sourced yet. |
| Northampton | East Midlands | Anglian Water | — | Hard to very hard * | High to very high * | Company statement - band only (Anglian Water) Water company corrected to Anglian Water (research section 7). Anglian Water states all water in its region is classed as hard to very hard. |
| Norwich | East of England | Anglian Water | 250 | Hard | High | Single source - unverified (MyTapWater) |
| Nottingham | East Midlands | Severn Trent Water | 170-226 | Moderately hard to Hard | Moderate to high | Two agreeing sources - unverified (MyTapWater + WaterGrade) Two independent aggregators agree; still to be spot-checked against the company checker. |
| Nuneaton | West Midlands | Severn Trent Water | 259.3 | Hard | High | Single source - unverified (WaterGrade) |
| Oban | Scotland | Scottish Water | — | Soft (~10-50 mg/l) * | Low * | Company statement - band only (Scottish Water) Scottish Water Factsheet 12 describes most supplies as soft to slightly hard; zone values are published only on request. |
| Oldham | North West England | United Utilities | 46 | Soft | Low | Single source - unverified (WaterGrade) |
| Oxford | South East England | Thames Water | 276-280 | Hard | High | Two agreeing sources - unverified (MyTapWater + WaterGrade) Two independent aggregators agree; still to be spot-checked against the company checker. |
| Paisley | Scotland | Scottish Water | — | Soft (~10-50 mg/l) * | Low * | Company statement - band only (Scottish Water) Scottish Water Factsheet 12 describes most supplies as soft to slightly hard; zone values are published only on request. |
| Perth | Scotland | Scottish Water | — | Soft (~10-50 mg/l) * | Low * | Company statement - band only (Scottish Water) Scottish Water Factsheet 12 describes most supplies as soft to slightly hard; zone values are published only on request. |
| Peterborough | East of England | Anglian Water | 200 | Moderately hard | High | Single source - unverified (MyTapWater) |
| Plymouth | South West England | South West Water | 35 | Soft | Low | Single source - unverified (MyTapWater) |
| Pontypridd | Wales | 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). |
| Poole | South West England | Bournemouth Water | 295.4 | Hard | High | Single source - unverified (WaterGrade) WaterGrade "Poole Town" zone; the zone naming is Wessex-styled, so company attribution is murky - flagged for verification. |
| Port Talbot | Wales | 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). |
| Portsmouth | South East England | Portsmouth Water | 230 | Hard | High | Single source - unverified (MyTapWater) |
| Preston | North West England | United Utilities | 140.8 | Slightly hard | Moderate | Single source - unverified (WaterGrade) |
| Ramsgate | South East England | Southern Water | — | Hard * | High * | Company statement - band only (Southern Water) Southern Water states most of its supply is hard, from underground chalk aquifers. |
| Reading | South East England | Thames Water | 260-280 | Hard | High | Two agreeing sources - unverified (MyTapWater + WaterGrade) Two independent aggregators agree; still to be spot-checked against the company checker. |
| Redditch | West Midlands | Severn Trent Water | 205.9 | Hard | High | Single source - unverified (WaterGrade) |
| Rhyl | Wales | 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). |
| Richmond upon Thames | London | Thames Water | 251 | Hard | High | Single source - unverified (WaterGrade) |
| Rochdale | North West England | United Utilities | 49.2 | Soft | Low | Single source - unverified (WaterGrade) |
| Romford | London | Thames Water | — | Hard to very hard (>200 mg/l typical) * | High to very high * | Company statement - band only (Thames Water) Thames Water Access Code 2025 states most supplies in its region are hard (>200 mg/l as CaCO3). |
| Rotherham | Yorkshire and the Humber | Yorkshire Water | 304.7 | Very hard | Very high | Single source - unverified (WaterGrade) |
| Rugby | West Midlands | Severn Trent Water | 296.9 | Hard | High | Single source - unverified (WaterGrade) |
| Ryde | South East England | Southern Water | — | Hard * | High * | Company statement - band only (Southern Water) Southern Water states most of its supply is hard, from underground chalk aquifers. |
| Salford | North West England | United Utilities | 46 | Soft | Low | Single source - unverified (WaterGrade) |
| Salisbury | South West England | Wessex Water | 292.3 | Hard | High | Single source - unverified (WaterGrade) |
| Scarborough | Yorkshire and the Humber | Yorkshire Water | — | — | — | No sourced data The supply company spans soft upland and hard groundwater zones, so no town-level value or band can be inferred; use the company postcode water-quality checker. |
| Scunthorpe | Yorkshire and the Humber | Anglian Water | 241.2 | Hard | High | Single source - unverified (WaterGrade) |
| Selby | Yorkshire and the Humber | Yorkshire Water | — | — | — | No sourced data The supply company spans soft upland and hard groundwater zones, so no town-level value or band can be inferred; use the company postcode water-quality checker. |
| Sheffield | Yorkshire and the Humber | Yorkshire Water | 46-70 | Soft | Low | Two agreeing sources - unverified (MyTapWater + WaterGrade) Two independent aggregators agree; still to be spot-checked against the company checker. |
| Shrewsbury | West Midlands | Severn Trent Water | 330.7 | Very hard | Very high | Single source - unverified (WaterGrade) |
| Slough | South East England | Thames Water | 301 | Very hard | Very high | Single source - unverified (WaterGrade) |
| Solihull | West Midlands | Severn Trent Water | 81.8 | Soft | Low | Single source - unverified (WaterGrade) |
| South Shields | North East England | Northumbrian Water | — | Soft to slightly hard (~50-115 mg/l by zone) * | Low to moderate * | Company statement - band only (Northumbrian Water) Band inferred from Northumbrian Water zone reports (e.g. zone T203 avg 101.11 mg/l CaCO3). |
| Southampton | South East England | Southern Water | 220 | Hard | High | Single source - unverified (MyTapWater) |
| Southend-on-Sea | East of England | Essex & Suffolk Water | — | — | — | No sourced data No trustworthy value or company statement sourced for this town yet; use the company postcode water-quality checker. |
| Southport | North West England | United Utilities | 291.1 | Hard | High | Single source - unverified (WaterGrade) |
| Southsea | South East England | Portsmouth Water | — | Moderately hard to hard (~230-300 mg/l) * | High * | Company statement - band only (Portsmouth Water) Portsmouth Water describes its chalk South Downs supply as moderately hard. |
| St Albans | East of England | Affinity Water | 338 | Very hard | Very high | Single source - unverified (WaterGrade) |
| St Helens | North West England | United Utilities | 192.2 | Moderately hard | Moderate | Single source - unverified (WaterGrade) |
| Stafford | West Midlands | Severn Trent Water | 292.7 | Hard | High | Single source - unverified (WaterGrade) |
| Stevenage | East of England | Affinity Water | 320 | Very hard | Very high | Single source - unverified (WaterGrade) |
| Stirling | Scotland | Scottish Water | — | Soft (~10-50 mg/l) * | Low * | Company statement - band only (Scottish Water) Scottish Water Factsheet 12 describes most supplies as soft to slightly hard; zone values are published only on request. |
| Stockport | North West England | United Utilities | — | Soft to moderately soft * | Low * | Company statement - band only (United Utilities) United Utilities states the majority of water in its region is soft or very soft (statement quoted in a hosted planning document). |
| Stockton-on-Tees | North East England | Northumbrian Water | — | Soft to slightly hard (~50-115 mg/l by zone) * | Low to moderate * | Company statement - band only (Northumbrian Water) Band inferred from Northumbrian Water zone reports (e.g. zone T203 avg 101.11 mg/l CaCO3). |
| Stoke-on-Trent | West Midlands | Severn Trent Water | 150-157 | Slightly hard to Moderately hard | Moderate | Two agreeing sources - unverified (MyTapWater + WaterGrade) Two independent aggregators agree; still to be spot-checked against the company checker. |
| Stratford-upon-Avon | West Midlands | Severn Trent Water | 377.8 | Very hard | Very high | Single source - unverified (WaterGrade) |
| Sudbury | East of England | Anglian Water | 290 | Hard | High | Single source - unverified (MyTapWater) |
| Sunderland | North East England | Northumbrian Water | 48 | Soft | Low | Single source - unverified (MyTapWater) |
| Sutton | London | SES Water | 265.8 | Hard | High | Single source - unverified (WaterGrade) |
| Sutton Coldfield | West Midlands | Severn Trent Water | — | — | — | No sourced data The supply company spans soft upland and hard groundwater zones, so no town-level value or band can be inferred; use the company postcode water-quality checker. |
| Swansea | Wales | Dŵr Cymru Welsh Water | 35 | Soft | Low | Single source - unverified (MyTapWater) |
| Swindon | South West England | Wessex Water | 270-287 | Hard | High | Two agreeing sources - unverified (MyTapWater + WaterGrade) Two independent aggregators agree; still to be spot-checked against the company checker. |
| Tamworth | West Midlands | Severn Trent Water | 277.1 | Hard | High | Single source - unverified (WaterGrade) |
| Taunton | South West England | Wessex Water | — | Moderately hard to very hard * | — | Company statement - band only Band inferred from the company regional profile; no published zone value sourced yet. |
| Telford | West Midlands | Severn Trent Water | 364 | Very hard | Very high | Single source - unverified (WaterGrade) |
| Torquay | South West England | South West Water | — | Soft to moderately soft * | Low * | Company statement - band only Band inferred from the company regional profile; no published zone value sourced yet. |
| Trowbridge | South West England | Wessex Water | 276.8 | Hard | High | Single source - unverified (WaterGrade) |
| Truro | South West England | South West Water | — | Soft to moderately soft * | Low * | Company statement - band only Band inferred from the company regional profile; no published zone value sourced yet. |
| Tunbridge Wells | South East England | South East Water | — | Hard to very hard * | High to very high * | Company statement - band only Band inferred from the company regional profile; no published zone value sourced yet. |
| Twickenham | London | Thames Water | 251 | Hard | High | Single source - unverified (WaterGrade) |
| Uxbridge | London | Affinity Water | 308 | Very hard | Very high | Single source - unverified (WaterGrade) |
| Wakefield | Yorkshire and the Humber | Yorkshire Water | 245 | Hard | High | Single source - unverified (MyTapWater) |
| Walsall | West Midlands | Severn Trent Water | 199.4 | Moderately hard | Moderate | Single source - unverified (WaterGrade) Shared supply zone with Dudley and West Bromwich. |
| Warrington | North West England | United Utilities | 207.3 | Hard | High | Single source - unverified (WaterGrade) |
| Warwick | West Midlands | Severn Trent Water | 328.8 | Very hard | Very high | Single source - unverified (WaterGrade) |
| Washington | North East England | Northumbrian Water | — | Soft to slightly hard (~50-115 mg/l by zone) * | Low to moderate * | Company statement - band only (Northumbrian Water) Band inferred from Northumbrian Water zone reports (e.g. zone T203 avg 101.11 mg/l CaCO3). |
| Waterlooville | South East England | Portsmouth Water | — | Moderately hard to hard (~230-300 mg/l) * | High * | Company statement - band only (Portsmouth Water) Portsmouth Water describes its chalk South Downs supply as moderately hard. |
| Watford | East of England | Affinity Water | 353 | Very hard | Very high | Single source - unverified (WaterGrade) |
| Wellingborough | East Midlands | Anglian Water | — | Hard to very hard * | High to very high * | Company statement - band only (Anglian Water) Water company corrected to Anglian Water (research section 7). Anglian Water states all water in its region is classed as hard to very hard. |
| Wembley | London | Affinity Water | 295 | Hard | High | Single source - unverified (WaterGrade) |
| West Bromwich | West Midlands | Severn Trent Water | 199.4 | Moderately hard | Moderate | Single source - unverified (WaterGrade) Shared supply zone with Walsall and Dudley. |
| Weston-super-Mare | South West England | Wessex Water | — | Moderately hard to very hard * | — | Company statement - band only Band inferred from the company regional profile; no published zone value sourced yet. |
| Weymouth | South West England | Wessex Water | 284.5 | Hard | High | Single source - unverified (WaterGrade) |
| Wigan | North West England | United Utilities | 111.1 | Slightly hard | Moderate | Single source - unverified (WaterGrade) |
| Winchester | South East England | South East Water | — | Hard to very hard * | High to very high * | Company statement - band only Supplier attribution to verify (South East Water vs Southern Water, research section 7). Band inferred from the company regional profile; no published zone value sourced yet. |
| Wisbech | East of England | Anglian Water | — | Hard to very hard * | High to very high * | Company statement - band only (Anglian Water) Anglian Water states all water in its region is classed as hard to very hard. |
| Woking | South East England | Thames Water | 273 | Hard | High | Single source - unverified (WaterGrade) |
| Wolverhampton | West Midlands | Severn Trent Water | Withheld | — | — | Conflict: MyTapWater 140 vs WaterGrade 250.3 - withheld The two compiled values disagree, so neither is published; verify via the company checker. |
| Worcester | West Midlands | Severn Trent Water | Withheld | — | — | Conflict: MyTapWater 125 vs WaterGrade 241.5 - withheld The two compiled values disagree, so neither is published; verify via the company checker. |
| Worksop | East Midlands | Severn Trent Water | 299.3 | Hard | High | Single source - unverified (WaterGrade) |
| Worthing | South East England | Southern Water | — | Hard * | High * | Company statement - band only (Southern Water) Southern Water states most of its supply is hard, from underground chalk aquifers. |
| Wrexham | Wales | 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). |
| Yeovil | South West England | Wessex Water | 172.4 | Moderately hard | Moderate | Single source - unverified (WaterGrade) |
| York | Yorkshire and the Humber | Yorkshire Water | 180-243 | Moderately hard to Hard | Moderate to high | Two agreeing sources - unverified (MyTapWater + WaterGrade) Two independent aggregators agree; still to be spot-checked against the company checker. |
No towns match that filter.
* Inferred from the water company's published statement, not a measured town value. Hardness varies by supply zone within a town; the company's postcode water-quality checker is authoritative for a specific address. Northern Ireland is not covered (NI Water publishes zone data separately under OGL, but no towns in our location set are in NI).
Method and honesty rules for this dataset
There is no single authoritative open dataset mapping GB towns to hardness values; the authoritative figures sit with each water company's postcode checker and zone reports. This table was compiled on 2 August 2026 from two independent aggregator compilations (MyTapWater town values, WaterGrade zone-attributed values) cross-checked against official water company statements, on the Open Government Licence DWI classification scale. Aggregator values are finding aids: each is published with its source and an unverified flag, and should be confirmed against the company checker before being relied on. One aggregator (WaterHard.uk) was excluded entirely after its values showed synthetic interpolation patterns. Where the two sources conflict, we withhold the number. Where only a company statement exists, we show the band and say so. Where nothing exists, the row says nothing exists.
08 / COUNCIL DUTIES
What your council adds to the national duty
The underlying legionella duty does not vary by council: the Health and Safety at Work etc. Act 1974 and the COSHH Regulations 2002 apply to every landlord in the UK (HSE: Legionella and landlords' responsibilities). What varies is licensing. Selective licensing (Housing Act 2004 Part 3) and additional HMO licensing (Part 2, s.56) are discretionary local designations, and some councils write legionella into the licence conditions themselves. This is the verified starter set: 5 councils make it an explicit condition, 3 publish guidance or standards, 3 were checked and do not, and 9 are verified-live schemes whose conditions we have not yet read.
Last reviewed August 2026. Designations are expanding fast under the Selective Licensing General Approval 2024 (in force 23 December 2024), so each row carries its own verification date.
| Council | Nation | Scheme | In force | Legionella in licensing? |
|---|---|---|---|---|
| Durham County Council 103 designated areas (~27% of the county, ~38% of the private rented sector) Condition 12, verbatim: "Landlords of domestic accommodation should ensure a risk assessment is carried out for Legionella bacteria at the outset of each tenancy and thereafter maintain control measures to minimise the risk." Source document | England | Selective licensing | 1 Apr 2022 onwards | Explicit licence condition |
| Bristol City Council Additional HMO licensing citywide; selective licensing in Bishopston & Ashley Down, Cotham and Easton wards (both 5 years) HMO licence condition 3.3 "Asbestos and Legionella": "Comply with current statutory requirements relating to the safe management of … Legionella species risks" (references HSE legionella guidance). Applies to mandatory and additional HMO licences. Source document | England | Additional HMO licensing + Selective licensing | 6 Aug 2024 onwards | Explicit licence condition |
| Coventry City Council Citywide: 3-4 person HMOs and s.257 HMOs Private Rented Sector Code of Practice (applied to licensed HMOs), §7.1.5: "A risk assessment for the control of legionella bacteria must be carried out and all recommendations should be adhered to." Source document | England | Additional HMO licensing | 4 May 2020 onwards | Explicit licence condition |
| 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 |
| Stirling Council Short-term lets (national licensing scheme, locally administered) "You must assess the risk from exposure to legionella within the premises… You must keep a record… and provide a copy of the risk assessment… to Stirling Council with your licence application." Source document | Scotland | Short-term let licensing | n/a | Explicit licence condition |
| Westminster City Council 15 wards Council's Standards for Rental Accommodation: "Landlords must carry out a Legionella risk assessment for all rented properties… hot water stored at 60°C or above, cold below 20°C…" Source document | England | Selective licensing | 24 Nov 2025 onwards | Guidance / standards only |
| Midlothian Council No licensing scheme; landlord guidance published Publishes a full Legionella Risk Assessment template and guidelines for landlords (self-assessment permitted for simple systems). Source document | Scotland | No licensing scheme | n/a | Guidance / standards only |
| Bath & North East Somerset Council HMO licensing inspection regime HMO inspection checklist includes: "Has the legionella risk assessment been reviewed, and all control measures implemented?" Source document | England | No licensing scheme | n/a | Guidance / standards only |
| Oxford City Council Citywide Full 23-condition document scanned: zero legionella or water-system mentions. Source document | England | Selective licensing | 1 Sep 2022 onwards | Checked - not in conditions |
| Birmingham City Council Selective: 25 wards. Additional: citywide. Fees £700/£755; 5 years Official selective licensing conditions PDF scanned: no legionella. (Additional licensing conditions not yet scanned.) Source document | England | Selective licensing + Additional HMO licensing | 5 Jun 2023 onwards | Checked - not in conditions |
| Liverpool City Council 16 wards (~80% of the city's private rented sector) Official 2022-27 licence conditions (September 2022) scanned: no legionella. Source document | England | Selective licensing | 1 Apr 2022 – 31 Mar 2027 | Checked - not in conditions |
| London Borough of Newham Selective: 22 wards (excl. Royal Victoria and Stratford Olympic Park), £750. Additional: borough-wide, in force 1 January 2023 | England | Selective licensing + Additional HMO licensing | 1 Jun 2023 onwards | Not yet verified |
| London Borough of Tower Hamlets Additional: borough-wide. Selective: Whitechapel, Weavers, Spitalfields & Banglatown areas (HMOs there moved to additional licensing from 1 April 2024) | England | Additional HMO licensing + Selective licensing | 1 Apr 2024 onwards | Not yet verified |
| London Borough of Waltham Forest Near-borough-wide | England | Selective licensing | 1 May 2025 – 30 Apr 2030 | Not yet verified |
| Brighton & Hove City Council Additional: citywide (live 2024). Selective: Kemptown, Moulsecoomb & Bevendean, Queen's Park, Whitehawk & Marina wards (live 2024) | England | Additional HMO licensing + Selective licensing | n/a | Not yet verified |
| Nottingham City Council Second scheme, ~30,000 homes (first scheme ran 1 August 2018 - 2023) | England | Selective licensing | 1 Dec 2023 onwards | Not yet verified |
| Leicester City Council In force from October 2022: parts of Braunstone Park & Rowley Fields, Fosse, Westcotes, Stoneygate and Saffron wards | England | Selective licensing | n/a | Not yet verified |
| Leeds City Council Expanded to East, South and West Leeds | England | Selective licensing | 9 Feb 2026 onwards | Not yet verified |
| Sefton Council 2023-2028 schemes. Selective: Bootle. Additional: Seaforth, Waterloo, Brighton-le-Sands, Central Southport | England | Selective licensing + Additional HMO licensing | n/a | Not yet verified |
| North Lincolnshire Council Designated area(s) - see council page | England | Selective licensing | 20 Mar 2025 – 19 Mar 2030 | Not yet verified |
Around 60 selective licensing schemes operate in England; this 20-council set spans both scheme types and three nations, and rows marked "Not yet verified" have had their scheme existence confirmed but their conditions documents not yet scanned. Scotland's short-term let licensing and Wales's Rent Smart Wales are different frameworks, so rows are not like-for-like across nations. If your council's entry is wrong or out of date, tell us - corrections are honoured.
09 / REGIONAL AND SECTOR INDEXES
The Index by region and by sector
Each region page pulls together that region's surveillance figure (where UKHSA publishes one), its tracked enforcement cases, its towns' water hardness, and its councils. Sector pages aggregate the enforcement record by industry.
Regions
- London - 17 towns, 1 tracked enforcement case
- South East England - 39 towns, 3 tracked enforcement cases
- South West England - 20 towns, 1 tracked enforcement case
- East of England - 26 towns, 4 tracked enforcement cases
- East Midlands - 20 towns, 3 tracked enforcement cases
- West Midlands - 22 towns, 4 tracked enforcement cases
- Yorkshire and the Humber - 21 towns, 0 tracked enforcement cases
- North West England - 22 towns, 5 tracked enforcement cases
- North East England - 16 towns, 1 tracked enforcement case
- Wales - 17 towns, 3 tracked enforcement cases
- Scotland - 22 towns, 3 tracked enforcement cases
Sectors
- Care homes - 5 prosecutions, £2.36m in fines
- Healthcare - 6 prosecutions, £522k in fines
- Hospitality - 4 prosecutions, £215k in fines
- Manufacturing - 5 prosecutions, £1.04m in fines
- Housing and landlords - 1 prosecution, £900k in fines
- Retail - 1 prosecution, £1m in fines
- Facilities management - 1 prosecution, £600k in fines
- Security - 1 prosecution, £1.8m in fines
- Local authority leisure - 2 prosecutions, £152k in fines
- Water treatment - 1 prosecution, £24k in fines
- Dry cleaning - 1 prosecution, £100 in fines
Method and sources
Figures are for residents of England and Wales and are drawn from the UK Health Security Agency's national surveillance of legionellosis, collected through the National Enhanced Legionnaires' disease Surveillance Scheme (NELSS). "Cases" counts laboratory-confirmed legionellosis, comprising Legionnaires' disease, non-pneumonic legionellosis, and Pontiac fever. Exposure, age, and organism breakdowns are for the most recent full year (2024) and are calculated on Legionnaires' disease cases. Case counts are affected by testing and reporting practice and represent a minimum, not the true number of infections.
Primary sources: UKHSA, Legionellosis in residents of England and Wales: 2024, and Legionellosis in residents of England and Wales: 2017 to 2023, published on GOV.UK. Contains public sector information licensed under the Open Government Licence v3.0. This page is an independent synthesis and is not affiliated with or endorsed by UKHSA.
Enforcement figures are the curated record documented on the enforcement tracker (HSE, COPFS and local-authority sources, Crown copyright under OGL). Water-hardness figures carry per-row sources and confidence labels as set out above. Council-duty rows link their primary council documents and carry per-row verification dates.
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.