Water hardness by Ontario municipality
How hard the tap water is where you live, in milligrams per litre and grains per gallon where verified. Every Ontario municipality has an answer: verified utility figures where available, and a source-water baseline everywhere else.
New here? Hard water, explained: what the number means, whether it is safe to drink, and how to test your own tap.
Soft Little scale, soap lathers easily, and a softener is rarely worth it.
Moderately hard Some kettle and showerhead scale over time, but most homes get by without a softener.
Hard Noticeable scale on fixtures and in kettles and water heaters; many homes choose to soften.
Very hard Heavy scale that shortens the life of water heaters and appliances; a softener is the norm.
Regional baseline No municipal number is verified yet. Use the source-water baseline and test your own tap.
Find your water hardness
Enter a town name or the first three postal-code characters.
| City | Region | Hardness (mg/L) | Grains/gal | Band | Coverage |
|---|---|---|---|---|---|
| Guelph/Eramosa | Wellington | 570 mg/L | 33.3 | Very hard | Municipal figure |
| Woodstock | Oxford | 324 to 693 | 18.9 to 40.5 | Very hard | Municipal figure |
| Centre Wellington | Wellington | 423 to 540 | 24.7 to 31.6 | Very hard | Municipal figure |
| Cambridge | Waterloo and Wellington | about 340 to 615 | 20 to 36 | Very hard | Municipal figure |
| Guelph | Waterloo and Wellington | 359 to 564 | 21 to 33 | Very hard | Municipal figure |
| East Zorra-Tavistock | Oxford | 412-492 mg/L as CaCO3 | 24.1 to 28.8 | Very hard | Municipal figure |
| Kitchener | Waterloo and Wellington | about 290 to 615 | 17 to 36 | Very hard | Municipal figure |
| Ingersoll | Oxford | 355 to 495 | 20.8 to 28.9 | Very hard | Municipal figure |
| Huron East | Huron | 282-610 mg/L as CaCO3 | 16.5 to 35.7 | Very hard | Municipal figure |
| Zorra | Oxford | 231 to 574 | 13.5 to 33.6 | Very hard | Municipal figure |
| Mississippi Mills | Lanark | ~393 (well averages 376-406) | 23.0 to 22.0 | Very hard | Municipal figure |
| Moonbeam | Cochrane | about 350 | 20.5 | Very hard | Municipal figure |
| Orangeville | Dufferin | 325 mg/L | 19.0 | Very hard | Municipal figure |
| Halton Hills | Halton | 324 mg/L | 18.9 | Very hard | Municipal figure |
| Tillsonburg | Oxford | 253-377 mg/L | 14.8 to 22.0 | Very hard | Municipal figure |
| Kingston | Frontenac | 113 to 486 mg/L across four water treatment plants | 6.6 to 28.4 | Very hard | Municipal figure |
| Huron-Kinloss | Bruce | 206-765 mg/L as CaCO3 | 12.0 to 44.7 | Hard | Municipal figure |
| Scugog | Durham | 274-316 mg/L as CaCO3 | 16.0 to 18.5 | Hard | Municipal figure |
| Clearview | Simcoe | 294 (system values range 103-409) | 17.2 to 6.0 | Hard | Municipal figure |
| Casselman | Prescott and Russell | 273-306 mg/L as CaCO3 (YTD treated average 291 mg/L) | 16.0 to 17.9 | Hard | Municipal figure |
| Norfolk County | Norfolk | 289 mg/L as CaCO3 (Simcoe system range 248-329) | 16.9 to 0.2 | Hard | Municipal figure |
| Stirling-Rawdon | Hastings | 270 mg/L as CaCO3 (range 243-297) | 15.8 to 0.2 | Hard | Municipal figure |
| Whitchurch-Stouffville | York | 202-301 mg/L | 11.8 to 17.6 | Hard | Municipal figure |
| Southgate | Grey | 250 mg/L as CaCO3 | 14.6 to 0.2 | Hard | Municipal figure |
| York, Regional Municipality of | York | 116 to 329 | 6.8 to 19.2 | Hard | Municipal figure |
| Cavan Monaghan | Peterborough | 220 mg/L as CaCO3 | 12.9 to 0.2 | Hard | Municipal figure |
| Severn | Simcoe | 126-303 mg/L as CaCO3 | 7.4 to 17.7 | Hard | Municipal figure |
| Kawartha Lakes | Kawartha Lakes | 25 to 380 mg/L across 21 drinking water systems | 1.5 to 22.2 | Hard | Municipal figure |
| King | York | 116 to 285 mg/L across York Region systems serving the Township of King | 6.8 to 16.7 | Hard | Municipal figure |
| Uxbridge | Durham | 186 mg/L | 10.9 | Hard | Municipal figure |
| South-West Oxford | Oxford | 180 mg/L as CaCO3 | 10.5 to 0.2 | Hard | Municipal figure |
| East Gwillimbury | York | 167-329 mg/L as CaCO3 | 9.8 to 19.2 | Hard | Municipal figure |
| Georgina | York | 147 mg/L | 8.6 | Moderately hard | Municipal figure |
| Central Elgin | Elgin | 141 mg/L as CaCO3 | 8.2 to 0.2 | Moderately hard | Municipal figure |
| Malahide | Elgin | 141 | 8.2 | Moderately hard | Municipal figure |
| Southwold | Elgin | 141 mg/L as CaCO3 | 8.2 to 0.2 | Moderately hard | Municipal figure |
| South Frontenac | Frontenac | 134 mg/L as CaCO3 | 7.8 to 0.2 | Moderately hard | Municipal figure |
| Lincoln | Niagara | 131 | 7.7 | Moderately hard | Municipal figure |
| St. Catharines | Niagara | 131 mg/L as CaCO3 | 7.7 to 0.2 | Moderately hard | Municipal figure |
| Thorold | Niagara | 126-136 mg/L | 7.4 to 8.0 | Moderately hard | Municipal figure |
| Bradford West Gwillimbury | Simcoe | 130 | 7.6 | Moderately hard | Municipal figure |
| West Lincoln | Niagara | 130 mg/L | 7.6 | Moderately hard | Municipal figure |
| Haldimand County | Haldimand | about 127 mg/L | 7.4 | Moderately hard | Municipal figure |
| Welland | Niagara | 126 mg/L | 7.4 | Moderately hard | Municipal figure |
| Ajax | Durham | 125 | 7.3 | Moderately hard | Municipal figure |
| Brampton | Peel | 120 to 130 | 7.0 to 7.6 | Moderately hard | Municipal figure |
| Clarington | Durham | 125 | 7.3 | Moderately hard | Municipal figure |
| Durham, Regional Municipality of | Durham | 125 mg/L as CaCO3 | 7.3 to 0.2 | Moderately hard | Municipal figure |
| Mississauga | Peel | 120 to 130 | 7.0 to 7.6 | Moderately hard | Municipal figure |
| Oshawa | Durham | 125 mg/L | 7.3 | Moderately hard | Municipal figure |
| Pickering | Durham | 125 | 7.3 | Moderately hard | Municipal figure |
| Whitby | Durham | 125 mg/L | 7.3 | Moderately hard | Municipal figure |
| Dutton/Dunwich | Elgin | 124 mg/L as CaCO3 | 7.3 to 0.2 | Moderately hard | Municipal figure |
| Halton, Regional Municipality of | Halton | 124 mg/L | 7.3 | Moderately hard | Municipal figure |
| Oakville | Halton | 124 mg/L | 7.3 | Moderately hard | Municipal figure |
| Fort Erie | Niagara | 123 mg/L | 7.2 | Moderately hard | Municipal figure |
| Lakeshore | Essex | 89.90 to 214.80 mg/L as CaCO3 (average 122.62) | 5.3 to 12.6 | Moderately hard | Municipal figure |
| Markham | York | 123 | 7.2 | Moderately hard | Municipal figure |
| Niagara Falls | Niagara | 123 mg/L | 7.2 | Moderately hard | Municipal figure |
| Niagara-on-the-Lake | Niagara | 123 mg/L | 7.2 | Moderately hard | Municipal figure |
| Port Colborne | Niagara | 123 mg/L | 7.2 | Moderately hard | Municipal figure |
| Innisfil | Simcoe | 53.7 to 189 | 3.1 to 11.1 | Moderately hard | Municipal figure |
| Toronto | Greater Toronto | about 121 (116 to 131) | about 7 | Moderately hard | Municipal figure |
| Greater Napanee | Lennox and Addington | about 120 mg/L as CaCO3 | 7.0 to 0.2 | Moderately hard | Municipal figure |
| Hamilton | Hamilton and area | about 120 | about 8 | Moderately hard | Municipal figure |
| Leamington | Essex | 120 | 7.0 | Moderately hard | Municipal figure |
| Port Hope | Northumberland | 120 mg/L | 7.0 | Moderately hard | Municipal figure |
| Loyalist | Lennox and Addington | 116-118 mg/L as CaCO3 | 6.8 to 6.9 | Moderately hard | Municipal figure |
| St. Thomas | Elgin | 116 mg/L as CaCO3 | 6.8 to 0.2 | Moderately hard | Municipal figure |
| Lucan Biddulph | Middlesex | 114 | 6.7 | Moderately hard | Municipal figure |
| South Huron | Huron | 114 mg/L as CaCO3 | 6.7 to 0.2 | Moderately hard | Municipal figure |
| Strathroy-Caradoc | Middlesex | 114 mg/L as CaCO3 | 6.7 to 0.2 | Moderately hard | Municipal figure |
| Tecumseh | Essex | mid 90's to 125 | 5.3 to 7.3 | Moderately hard | Municipal figure |
| Windsor | Essex | 95-125 mg/L | 5.6 to 7.3 | Moderately hard | Municipal figure |
| Bluewater | Huron | 107 | 6.3 | Moderately hard | Municipal figure |
| LaSalle | Essex | 90 to 125 mg/L as CaCO3 | 5.3 to 7.3 | Moderately hard | Municipal figure |
| London | Middlesex | 96-115 mg/L as CaCO3 | 5.6 to 6.7 | Moderately hard | Municipal figure |
| Renfrew | Renfrew | 64.2-144 mg/L | 3.8 to 8.4 | Moderately hard | Municipal figure |
| St. Clair | Lambton | 102.5 mg/L as CaCO3 | 6.0 to 0.2 | Moderately hard | Municipal figure |
| Lambton Shores | Lambton | approximately 98 to 106 mg/L as CaCO3 (West Lambton Shores via LAWSS about 98; East Lambton Shores via LHPWSS about 106) | 5.7 to 6.2 | Moderately hard | Municipal figure |
| Deseronto | Hastings | 98 | 5.7 | Moderately hard | Municipal figure |
| Sarnia | Lambton | 98 mg/L as CaCO3 | 5.7 to 0.2 | Moderately hard | Municipal figure |
| Kapuskasing | Cochrane | 80 | 4.7 | Moderately hard | Municipal figure |
| Perth | Lanark | 79.6 mg/L | 4.7 | Moderately hard | Municipal figure |
| Billings | Manitoulin | 73.7 | 4.3 | Soft | Municipal figure |
| Thunder Bay | Thunder Bay | 45.8 mg/L | 2.7 | Soft | Municipal figure |
| Russell | Prescott and Russell | 45 mg/L | 2.6 | Soft | Municipal figure |
| Arnprior | Renfrew | 44 | 2.6 | Soft | Municipal figure |
| Ottawa | Eastern Ontario | about 30 | about 2.5 | Soft | Municipal figure |
| Elliot Lake | Algoma | 20 mg/L as CaCO3 (annual average) | 1.2 to 0.2 | Soft | Municipal figure |
| Addington Highlands | Lennox and Addington | regional baseline | test your tap | Regional baseline | Regional baseline |
| Adelaide-Metcalfe | Middlesex | regional baseline | test your tap | Regional baseline | Regional baseline |
| Adjala-Tosorontio | Simcoe | regional baseline | test your tap | Regional baseline | Regional baseline |
| Admaston/Bromley | Renfrew | regional baseline | test your tap | Regional baseline | Regional baseline |
| Alberton | Rainy River | regional baseline | test your tap | Regional baseline | Regional baseline |
| Alfred and Plantagenet | Prescott and Russell | regional baseline | test your tap | Regional baseline | Regional baseline |
| Algonquin Highlands | Haliburton | regional baseline | test your tap | Regional baseline | Regional baseline |
| Alnwick/Haldimand | Northumberland | regional baseline | test your tap | Regional baseline | Regional baseline |
| Amaranth | Dufferin | regional baseline | test your tap | Regional baseline | Regional baseline |
| Amherstburg | Essex | regional baseline | test your tap | Regional baseline | Regional baseline |
| Armour | Parry Sound | regional baseline | test your tap | Regional baseline | Regional baseline |
| Armstrong | Timiskaming | regional baseline | test your tap | Regional baseline | Regional baseline |
| Arran-Elderslie | Bruce | regional baseline | test your tap | Regional baseline | Regional baseline |
| Ashfield-Colborne-Wawanosh | Huron | regional baseline | test your tap | Regional baseline | Regional baseline |
| Asphodel-Norwood | Peterborough | regional baseline | test your tap | Regional baseline | Regional baseline |
| Assiginack | Manitoulin | regional baseline | test your tap | Regional baseline | Regional baseline |
| Athens | Leeds and Grenville | regional baseline | test your tap | Regional baseline | Regional baseline |
| Atikokan | Rainy River | regional baseline | test your tap | Regional baseline | Regional baseline |
| Augusta | Leeds and Grenville | regional baseline | test your tap | Regional baseline | Regional baseline |
| Aurora | York | regional baseline | test your tap | Regional baseline | Regional baseline |
| Aylmer | Elgin | regional baseline | test your tap | Regional baseline | Regional baseline |
| Baldwin | Sudbury | regional baseline | test your tap | Regional baseline | Regional baseline |
| Bancroft | Hastings | regional baseline | test your tap | Regional baseline | Regional baseline |
| Barrie | Simcoe | regional baseline | test your tap | Regional baseline | Regional baseline |
| Bayham | Elgin | regional baseline | test your tap | Regional baseline | Regional baseline |
| Beckwith | Lanark | regional baseline | test your tap | Regional baseline | Regional baseline |
| Belleville | Hastings | regional baseline | test your tap | Regional baseline | Regional baseline |
| Black River-Matheson | Cochrane | regional baseline | test your tap | Regional baseline | Regional baseline |
| Blandford-Blenheim | Oxford | regional baseline | test your tap | Regional baseline | Regional baseline |
| Blind River | Algoma | regional baseline | test your tap | Regional baseline | Regional baseline |
| Bonfield | Nipissing | regional baseline | test your tap | Regional baseline | Regional baseline |
| Bonnechere Valley | Renfrew | regional baseline | test your tap | Regional baseline | Regional baseline |
| Bracebridge | Muskoka | regional baseline | test your tap | Regional baseline | Regional baseline |
| Brant County | Brant | regional baseline | test your tap | Regional baseline | Regional baseline |
| Brantford | Brant | regional baseline | test your tap | Regional baseline | Regional baseline |
| Brethour | Timiskaming | regional baseline | test your tap | Regional baseline | Regional baseline |
| Brighton | Northumberland | regional baseline | test your tap | Regional baseline | Regional baseline |
| Brock | Durham | regional baseline | test your tap | Regional baseline | Regional baseline |
| Brockton | Bruce | regional baseline | test your tap | Regional baseline | Regional baseline |
| Brockville | Leeds and Grenville | regional baseline | test your tap | Regional baseline | Regional baseline |
| Brooke-Alvinston | Lambton | regional baseline | test your tap | Regional baseline | Regional baseline |
| Bruce County | Bruce | regional baseline | test your tap | Regional baseline | Regional baseline |
| Bruce Mines | Algoma | regional baseline | test your tap | Regional baseline | Regional baseline |
| Brudenell, Lyndoch and Raglan | Renfrew | regional baseline | test your tap | Regional baseline | Regional baseline |
| Burk’s Falls | Parry Sound | regional baseline | test your tap | Regional baseline | Regional baseline |
| Burlington | Halton | regional baseline | test your tap | Regional baseline | Regional baseline |
| Burpee and Mills | Manitoulin | regional baseline | test your tap | Regional baseline | Regional baseline |
| Caledon | Peel | regional baseline | test your tap | Regional baseline | Regional baseline |
| Callander | Parry Sound | regional baseline | test your tap | Regional baseline | Regional baseline |
| Calvin | Nipissing | regional baseline | test your tap | Regional baseline | Regional baseline |
| Carleton Place | Lanark | regional baseline | test your tap | Regional baseline | Regional baseline |
| Carling | Parry Sound | regional baseline | test your tap | Regional baseline | Regional baseline |
| Carlow/Mayo | Hastings | regional baseline | test your tap | Regional baseline | Regional baseline |
| Casey | Timiskaming | regional baseline | test your tap | Regional baseline | Regional baseline |
| Central Frontenac | Frontenac | regional baseline | test your tap | Regional baseline | Regional baseline |
| Central Huron | Huron | regional baseline | test your tap | Regional baseline | Regional baseline |
| Central Manitoulin | Manitoulin | regional baseline | test your tap | Regional baseline | Regional baseline |
| Centre Hastings | Hastings | regional baseline | test your tap | Regional baseline | Regional baseline |
| Chamberlain | Timiskaming | regional baseline | test your tap | Regional baseline | Regional baseline |
| Champlain | Prescott and Russell | regional baseline | test your tap | Regional baseline | Regional baseline |
| Chapleau | Sudbury | regional baseline | test your tap | Regional baseline | Regional baseline |
| Chapple | Rainy River | regional baseline | test your tap | Regional baseline | Regional baseline |
| Charlton and Dack | Timiskaming | regional baseline | test your tap | Regional baseline | Regional baseline |
| Chatham-Kent | Chatham-Kent | regional baseline | test your tap | Regional baseline | Regional baseline |
| Chatsworth | Grey | regional baseline | test your tap | Regional baseline | Regional baseline |
| Chisholm | Nipissing | regional baseline | test your tap | Regional baseline | Regional baseline |
| Clarence-Rockland | Prescott and Russell | regional baseline | test your tap | Regional baseline | Regional baseline |
| Cobalt | Timiskaming | regional baseline | test your tap | Regional baseline | Regional baseline |
| Cobourg | Northumberland | regional baseline | test your tap | Regional baseline | Regional baseline |
| Cochrane | Cochrane | regional baseline | test your tap | Regional baseline | Regional baseline |
| Cockburn Island | Manitoulin | regional baseline | test your tap | Regional baseline | Regional baseline |
| Coleman | Timiskaming | regional baseline | test your tap | Regional baseline | Regional baseline |
| Collingwood | Simcoe | regional baseline | test your tap | Regional baseline | Regional baseline |
| Conmee | Thunder Bay | regional baseline | test your tap | Regional baseline | Regional baseline |
| Cornwall | Stormont, Dundas and Glengarry | regional baseline | test your tap | Regional baseline | Regional baseline |
| Cramahe | Northumberland | regional baseline | test your tap | Regional baseline | Regional baseline |
| Dawn-Euphemia | Lambton | regional baseline | test your tap | Regional baseline | Regional baseline |
| Dawson | Rainy River | regional baseline | test your tap | Regional baseline | Regional baseline |
| Deep River | Renfrew | regional baseline | test your tap | Regional baseline | Regional baseline |
| Dorion | Thunder Bay | regional baseline | test your tap | Regional baseline | Regional baseline |
| Douro-Dummer | Peterborough | regional baseline | test your tap | Regional baseline | Regional baseline |
| Drummond/North Elmsley | Lanark | regional baseline | test your tap | Regional baseline | Regional baseline |
| Dryden | Kenora | regional baseline | test your tap | Regional baseline | Regional baseline |
| Dubreuilville | Algoma | regional baseline | test your tap | Regional baseline | Regional baseline |
| Dufferin County | Dufferin | regional baseline | test your tap | Regional baseline | Regional baseline |
| Dysart et al | Haliburton | regional baseline | test your tap | Regional baseline | Regional baseline |
| Ear Falls | Kenora | regional baseline | test your tap | Regional baseline | Regional baseline |
| East Ferris | Nipissing | regional baseline | test your tap | Regional baseline | Regional baseline |
| East Garafraxa | Dufferin | regional baseline | test your tap | Regional baseline | Regional baseline |
| East Hawkesbury | Prescott and Russell | regional baseline | test your tap | Regional baseline | Regional baseline |
| Edwardsburgh/Cardinal | Leeds and Grenville | regional baseline | test your tap | Regional baseline | Regional baseline |
| Elgin County | Elgin | regional baseline | test your tap | Regional baseline | Regional baseline |
| Elizabethtown-Kitley | Leeds and Grenville | regional baseline | test your tap | Regional baseline | Regional baseline |
| Emo | Rainy River | regional baseline | test your tap | Regional baseline | Regional baseline |
| Englehart | Timiskaming | regional baseline | test your tap | Regional baseline | Regional baseline |
| Enniskillen | Lambton | regional baseline | test your tap | Regional baseline | Regional baseline |
| Erin | Wellington | regional baseline | test your tap | Regional baseline | Regional baseline |
| Espanola | Sudbury | regional baseline | test your tap | Regional baseline | Regional baseline |
| Essa | Simcoe | regional baseline | test your tap | Regional baseline | Regional baseline |
| Essex | Essex | regional baseline | test your tap | Regional baseline | Regional baseline |
| Essex County | Essex | regional baseline | test your tap | Regional baseline | Regional baseline |
| Evanturel | Timiskaming | regional baseline | test your tap | Regional baseline | Regional baseline |
| Faraday | Hastings | regional baseline | test your tap | Regional baseline | Regional baseline |
| Fauquier-Strickland | Cochrane | regional baseline | test your tap | Regional baseline | Regional baseline |
| Fort Frances | Rainy River | regional baseline | test your tap | Regional baseline | Regional baseline |
| French River | Sudbury | regional baseline | test your tap | Regional baseline | Regional baseline |
| Front of Yonge | Leeds and Grenville | regional baseline | test your tap | Regional baseline | Regional baseline |
| Frontenac County | Frontenac | regional baseline | test your tap | Regional baseline | Regional baseline |
| Frontenac Islands | Frontenac | regional baseline | test your tap | Regional baseline | Regional baseline |
| Gananoque | Leeds and Grenville | regional baseline | test your tap | Regional baseline | Regional baseline |
| Gauthier | Timiskaming | regional baseline | test your tap | Regional baseline | Regional baseline |
| Georgian Bay | Muskoka | regional baseline | test your tap | Regional baseline | Regional baseline |
| Georgian Bluffs | Grey | regional baseline | test your tap | Regional baseline | Regional baseline |
| Gillies | Thunder Bay | regional baseline | test your tap | Regional baseline | Regional baseline |
| Goderich | Huron | regional baseline | test your tap | Regional baseline | Regional baseline |
| Gordon/Barrie Island | Manitoulin | regional baseline | test your tap | Regional baseline | Regional baseline |
| Gore Bay | Manitoulin | regional baseline | test your tap | Regional baseline | Regional baseline |
| Grand Valley | Dufferin | regional baseline | test your tap | Regional baseline | Regional baseline |
| Gravenhurst | Muskoka | regional baseline | test your tap | Regional baseline | Regional baseline |
| Greater Madawaska | Renfrew | regional baseline | test your tap | Regional baseline | Regional baseline |
| Greater Sudbury | Sudbury | regional baseline | test your tap | Regional baseline | Regional baseline |
| Greenstone | Thunder Bay | regional baseline | test your tap | Regional baseline | Regional baseline |
| Grey County | Grey | regional baseline | test your tap | Regional baseline | Regional baseline |
| Grey Highlands | Grey | regional baseline | test your tap | Regional baseline | Regional baseline |
| Grimsby | Niagara | regional baseline | test your tap | Regional baseline | Regional baseline |
| Haliburton County | Haliburton | regional baseline | test your tap | Regional baseline | Regional baseline |
| Hamilton | Northumberland | regional baseline | test your tap | Regional baseline | Regional baseline |
| Hanover | Grey | regional baseline | test your tap | Regional baseline | Regional baseline |
| Harley | Timiskaming | regional baseline | test your tap | Regional baseline | Regional baseline |
| Harris | Timiskaming | regional baseline | test your tap | Regional baseline | Regional baseline |
| Hastings County | Hastings | regional baseline | test your tap | Regional baseline | Regional baseline |
| Hastings Highlands | Hastings | regional baseline | test your tap | Regional baseline | Regional baseline |
| Havelock-Belmont-Methuen | Peterborough | regional baseline | test your tap | Regional baseline | Regional baseline |
| Hawkesbury | Prescott and Russell | regional baseline | test your tap | Regional baseline | Regional baseline |
| Head, Clara and Maria | Renfrew | regional baseline | test your tap | Regional baseline | Regional baseline |
| Hearst | Cochrane | regional baseline | test your tap | Regional baseline | Regional baseline |
| Highlands East | Haliburton | regional baseline | test your tap | Regional baseline | Regional baseline |
| Hilliard | Timiskaming | regional baseline | test your tap | Regional baseline | Regional baseline |
| Hilton | Algoma | regional baseline | test your tap | Regional baseline | Regional baseline |
| Hilton Beach | Algoma | regional baseline | test your tap | Regional baseline | Regional baseline |
| Hornepayne | Algoma | regional baseline | test your tap | Regional baseline | Regional baseline |
| Horton | Renfrew | regional baseline | test your tap | Regional baseline | Regional baseline |
| Howick | Huron | regional baseline | test your tap | Regional baseline | Regional baseline |
| Hudson | Timiskaming | regional baseline | test your tap | Regional baseline | Regional baseline |
| Huntsville | Muskoka | regional baseline | test your tap | Regional baseline | Regional baseline |
| Huron County | Huron | regional baseline | test your tap | Regional baseline | Regional baseline |
| Huron Shores | Algoma | regional baseline | test your tap | Regional baseline | Regional baseline |
| Ignace | Kenora | regional baseline | test your tap | Regional baseline | Regional baseline |
| Iroquois Falls | Cochrane | regional baseline | test your tap | Regional baseline | Regional baseline |
| James | Timiskaming | regional baseline | test your tap | Regional baseline | Regional baseline |
| Jocelyn | Algoma | regional baseline | test your tap | Regional baseline | Regional baseline |
| Johnson | Algoma | regional baseline | test your tap | Regional baseline | Regional baseline |
| Joly | Parry Sound | regional baseline | test your tap | Regional baseline | Regional baseline |
| Kearney | Parry Sound | regional baseline | test your tap | Regional baseline | Regional baseline |
| Kenora | Kenora | regional baseline | test your tap | Regional baseline | Regional baseline |
| Kerns | Timiskaming | regional baseline | test your tap | Regional baseline | Regional baseline |
| Killaloe, Hagarty and Richards | Renfrew | regional baseline | test your tap | Regional baseline | Regional baseline |
| Killarney | Sudbury | regional baseline | test your tap | Regional baseline | Regional baseline |
| Kincardine | Bruce | regional baseline | test your tap | Regional baseline | Regional baseline |
| Kingsville | Essex | regional baseline | test your tap | Regional baseline | Regional baseline |
| Kirkland Lake | Timiskaming | regional baseline | test your tap | Regional baseline | Regional baseline |
| La Vallee | Rainy River | regional baseline | test your tap | Regional baseline | Regional baseline |
| Laird | Algoma | regional baseline | test your tap | Regional baseline | Regional baseline |
| Lake of Bays | Muskoka | regional baseline | test your tap | Regional baseline | Regional baseline |
| Lake of the Woods | Rainy River | regional baseline | test your tap | Regional baseline | Regional baseline |
| Lambton County | Lambton | regional baseline | test your tap | Regional baseline | Regional baseline |
| Lanark County | Lanark | regional baseline | test your tap | Regional baseline | Regional baseline |
| Lanark Highlands | Lanark | regional baseline | test your tap | Regional baseline | Regional baseline |
| Larder Lake | Timiskaming | regional baseline | test your tap | Regional baseline | Regional baseline |
| Latchford | Timiskaming | regional baseline | test your tap | Regional baseline | Regional baseline |
| Laurentian Hills | Renfrew | regional baseline | test your tap | Regional baseline | Regional baseline |
| Laurentian Valley | Renfrew | regional baseline | test your tap | Regional baseline | Regional baseline |
| Leeds and Grenville | Leeds and Grenville | regional baseline | test your tap | Regional baseline | Regional baseline |
| Leeds and the Thousand Islands | Leeds and Grenville | regional baseline | test your tap | Regional baseline | Regional baseline |
| Lennox and Addington County | Lennox and Addington | regional baseline | test your tap | Regional baseline | Regional baseline |
| Limerick | Hastings | regional baseline | test your tap | Regional baseline | Regional baseline |
| Macdonald, Meredith and Aberdeen Additional | Algoma | regional baseline | test your tap | Regional baseline | Regional baseline |
| Machar | Parry Sound | regional baseline | test your tap | Regional baseline | Regional baseline |
| Machin | Kenora | regional baseline | test your tap | Regional baseline | Regional baseline |
| Madawaska Valley | Renfrew | regional baseline | test your tap | Regional baseline | Regional baseline |
| Madoc | Hastings | regional baseline | test your tap | Regional baseline | Regional baseline |
| Magnetawan | Parry Sound | regional baseline | test your tap | Regional baseline | Regional baseline |
| Manitouwadge | Thunder Bay | regional baseline | test your tap | Regional baseline | Regional baseline |
| Mapleton | Wellington | regional baseline | test your tap | Regional baseline | Regional baseline |
| Marathon | Thunder Bay | regional baseline | test your tap | Regional baseline | Regional baseline |
| Markstay-Warren | Sudbury | regional baseline | test your tap | Regional baseline | Regional baseline |
| Marmora and Lake | Hastings | regional baseline | test your tap | Regional baseline | Regional baseline |
| Matachewan | Timiskaming | regional baseline | test your tap | Regional baseline | Regional baseline |
| Mattawa | Nipissing | regional baseline | test your tap | Regional baseline | Regional baseline |
| Mattawan | Nipissing | regional baseline | test your tap | Regional baseline | Regional baseline |
| Mattice-Val CA´tA© | Cochrane | regional baseline | test your tap | Regional baseline | Regional baseline |
| McDougall | Parry Sound | regional baseline | test your tap | Regional baseline | Regional baseline |
| McGarry | Timiskaming | regional baseline | test your tap | Regional baseline | Regional baseline |
| McKellar | Parry Sound | regional baseline | test your tap | Regional baseline | Regional baseline |
| McMurrich/Monteith | Parry Sound | regional baseline | test your tap | Regional baseline | Regional baseline |
| McNab/Braeside | Renfrew | regional baseline | test your tap | Regional baseline | Regional baseline |
| Meaford | Grey | regional baseline | test your tap | Regional baseline | Regional baseline |
| Melancthon | Dufferin | regional baseline | test your tap | Regional baseline | Regional baseline |
| Merrickville-Wolford | Leeds and Grenville | regional baseline | test your tap | Regional baseline | Regional baseline |
| Middlesex Centre | Middlesex | regional baseline | test your tap | Regional baseline | Regional baseline |
| Middlesex County | Middlesex | regional baseline | test your tap | Regional baseline | Regional baseline |
| Midland | Simcoe | regional baseline | test your tap | Regional baseline | Regional baseline |
| Milton | Halton | regional baseline | test your tap | Regional baseline | Regional baseline |
| Minden Hills | Haliburton | regional baseline | test your tap | Regional baseline | Regional baseline |
| Minto | Wellington | regional baseline | test your tap | Regional baseline | Regional baseline |
| Mono | Dufferin | regional baseline | test your tap | Regional baseline | Regional baseline |
| Montague | Lanark | regional baseline | test your tap | Regional baseline | Regional baseline |
| Moosonee | Cochrane | regional baseline | test your tap | Regional baseline | Regional baseline |
| Morley | Rainy River | regional baseline | test your tap | Regional baseline | Regional baseline |
| Morris-Turnberry | Huron | regional baseline | test your tap | Regional baseline | Regional baseline |
| Mulmur | Dufferin | regional baseline | test your tap | Regional baseline | Regional baseline |
| Muskoka | Muskoka | regional baseline | test your tap | Regional baseline | Regional baseline |
| Muskoka Lakes | Muskoka | regional baseline | test your tap | Regional baseline | Regional baseline |
| Nairn and Hyman | Sudbury | regional baseline | test your tap | Regional baseline | Regional baseline |
| Neebing | Thunder Bay | regional baseline | test your tap | Regional baseline | Regional baseline |
| New Tecumseth | Simcoe | regional baseline | test your tap | Regional baseline | Regional baseline |
| Newbury | Middlesex | regional baseline | test your tap | Regional baseline | Regional baseline |
| Newmarket | York | regional baseline | test your tap | Regional baseline | Regional baseline |
| Niagara, Regional Municipality of | Niagara | regional baseline | test your tap | Regional baseline | Regional baseline |
| Nipigon | Thunder Bay | regional baseline | test your tap | Regional baseline | Regional baseline |
| Nipissing | Parry Sound | regional baseline | test your tap | Regional baseline | Regional baseline |
| North Algona Wilberforce | Renfrew | regional baseline | test your tap | Regional baseline | Regional baseline |
| North Bay | Nipissing | regional baseline | test your tap | Regional baseline | Regional baseline |
| North Dumfries | Waterloo | regional baseline | test your tap | Regional baseline | Regional baseline |
| North Dundas | Stormont, Dundas and Glengarry | regional baseline | test your tap | Regional baseline | Regional baseline |
| North Frontenac | Frontenac | regional baseline | test your tap | Regional baseline | Regional baseline |
| North Glengarry | Stormont, Dundas and Glengarry | regional baseline | test your tap | Regional baseline | Regional baseline |
| North Grenville | Leeds and Grenville | regional baseline | test your tap | Regional baseline | Regional baseline |
| North Huron | Huron | regional baseline | test your tap | Regional baseline | Regional baseline |
| North Kawartha | Peterborough | regional baseline | test your tap | Regional baseline | Regional baseline |
| North Middlesex | Middlesex | regional baseline | test your tap | Regional baseline | Regional baseline |
| North Perth | Perth | regional baseline | test your tap | Regional baseline | Regional baseline |
| North Stormont | Stormont, Dundas and Glengarry | regional baseline | test your tap | Regional baseline | Regional baseline |
| Northeastern Manitoulin and The Islands | Manitoulin | regional baseline | test your tap | Regional baseline | Regional baseline |
| Northern Bruce Peninsula | Bruce | regional baseline | test your tap | Regional baseline | Regional baseline |
| Northumberland County | Northumberland | regional baseline | test your tap | Regional baseline | Regional baseline |
| Norwich | Oxford | regional baseline | test your tap | Regional baseline | Regional baseline |
| O’Connor | Thunder Bay | regional baseline | test your tap | Regional baseline | Regional baseline |
| Oil Springs | Lambton | regional baseline | test your tap | Regional baseline | Regional baseline |
| Oliver Paipoonge | Thunder Bay | regional baseline | test your tap | Regional baseline | Regional baseline |
| Opasatika | Cochrane | regional baseline | test your tap | Regional baseline | Regional baseline |
| Orillia | Simcoe | regional baseline | test your tap | Regional baseline | Regional baseline |
| Oro-Medonte | Simcoe | regional baseline | test your tap | Regional baseline | Regional baseline |
| Otonabee-South Monaghan | Peterborough | regional baseline | test your tap | Regional baseline | Regional baseline |
| Owen Sound | Grey | regional baseline | test your tap | Regional baseline | Regional baseline |
| Oxford County | Oxford | regional baseline | test your tap | Regional baseline | Regional baseline |
| Papineau-Cameron | Nipissing | regional baseline | test your tap | Regional baseline | Regional baseline |
| Parry Sound | Parry Sound | regional baseline | test your tap | Regional baseline | Regional baseline |
| Peel, Regional Municipality of | Peel | regional baseline | test your tap | Regional baseline | Regional baseline |
| Pelee | Essex | regional baseline | test your tap | Regional baseline | Regional baseline |
| Pelham | Niagara | regional baseline | test your tap | Regional baseline | Regional baseline |
| Pembroke | Renfrew | regional baseline | test your tap | Regional baseline | Regional baseline |
| Penetanguishene | Simcoe | regional baseline | test your tap | Regional baseline | Regional baseline |
| Perry | Parry Sound | regional baseline | test your tap | Regional baseline | Regional baseline |
| Perth County | Perth | regional baseline | test your tap | Regional baseline | Regional baseline |
| Perth East | Perth | regional baseline | test your tap | Regional baseline | Regional baseline |
| Perth South | Perth | regional baseline | test your tap | Regional baseline | Regional baseline |
| Petawawa | Renfrew | regional baseline | test your tap | Regional baseline | Regional baseline |
| Peterborough | Peterborough | regional baseline | test your tap | Regional baseline | Regional baseline |
| Peterborough County | Peterborough | regional baseline | test your tap | Regional baseline | Regional baseline |
| Petrolia | Lambton | regional baseline | test your tap | Regional baseline | Regional baseline |
| Pickle Lake | Kenora | regional baseline | test your tap | Regional baseline | Regional baseline |
| Plummer Additional | Algoma | regional baseline | test your tap | Regional baseline | Regional baseline |
| Plympton-Wyoming | Lambton | regional baseline | test your tap | Regional baseline | Regional baseline |
| Point Edward | Lambton | regional baseline | test your tap | Regional baseline | Regional baseline |
| Powassan | Parry Sound | regional baseline | test your tap | Regional baseline | Regional baseline |
| Prescott | Leeds and Grenville | regional baseline | test your tap | Regional baseline | Regional baseline |
| Prescott and Russell | Prescott and Russell | regional baseline | test your tap | Regional baseline | Regional baseline |
| Prince | Algoma | regional baseline | test your tap | Regional baseline | Regional baseline |
| Prince Edward County | Prince Edward | regional baseline | test your tap | Regional baseline | Regional baseline |
| Puslinch | Wellington | regional baseline | test your tap | Regional baseline | Regional baseline |
| Quinte West | Hastings | regional baseline | test your tap | Regional baseline | Regional baseline |
| Rainy River | Rainy River | regional baseline | test your tap | Regional baseline | Regional baseline |
| Ramara | Simcoe | regional baseline | test your tap | Regional baseline | Regional baseline |
| Red Lake | Kenora | regional baseline | test your tap | Regional baseline | Regional baseline |
| Red Rock | Thunder Bay | regional baseline | test your tap | Regional baseline | Regional baseline |
| Renfrew County | Renfrew | regional baseline | test your tap | Regional baseline | Regional baseline |
| Richmond Hill | York | regional baseline | test your tap | Regional baseline | Regional baseline |
| Rideau Lakes | Leeds and Grenville | regional baseline | test your tap | Regional baseline | Regional baseline |
| Ryerson | Parry Sound | regional baseline | test your tap | Regional baseline | Regional baseline |
| Sables-Spanish Rivers | Sudbury | regional baseline | test your tap | Regional baseline | Regional baseline |
| Saugeen Shores | Bruce | regional baseline | test your tap | Regional baseline | Regional baseline |
| Sault Ste. Marie | Algoma | regional baseline | test your tap | Regional baseline | Regional baseline |
| Schreiber | Thunder Bay | regional baseline | test your tap | Regional baseline | Regional baseline |
| Seguin | Parry Sound | regional baseline | test your tap | Regional baseline | Regional baseline |
| Selwyn | Peterborough | regional baseline | test your tap | Regional baseline | Regional baseline |
| Shelburne | Dufferin | regional baseline | test your tap | Regional baseline | Regional baseline |
| Shuniah | Thunder Bay | regional baseline | test your tap | Regional baseline | Regional baseline |
| Simcoe County | Simcoe | regional baseline | test your tap | Regional baseline | Regional baseline |
| Sioux Lookout | Kenora | regional baseline | test your tap | Regional baseline | Regional baseline |
| Sioux Narrows-Nestor Falls | Kenora | regional baseline | test your tap | Regional baseline | Regional baseline |
| Smiths Falls | Lanark | regional baseline | test your tap | Regional baseline | Regional baseline |
| Smooth Rock Falls | Cochrane | regional baseline | test your tap | Regional baseline | Regional baseline |
| South Algonquin | Nipissing | regional baseline | test your tap | Regional baseline | Regional baseline |
| South Bruce | Bruce | regional baseline | test your tap | Regional baseline | Regional baseline |
| South Bruce Peninsula | Bruce | regional baseline | test your tap | Regional baseline | Regional baseline |
| South Dundas | Stormont, Dundas and Glengarry | regional baseline | test your tap | Regional baseline | Regional baseline |
| South Glengarry | Stormont, Dundas and Glengarry | regional baseline | test your tap | Regional baseline | Regional baseline |
| South River | Parry Sound | regional baseline | test your tap | Regional baseline | Regional baseline |
| South Stormont | Stormont, Dundas and Glengarry | regional baseline | test your tap | Regional baseline | Regional baseline |
| Southwest Middlesex | Middlesex | regional baseline | test your tap | Regional baseline | Regional baseline |
| Spanish | Algoma | regional baseline | test your tap | Regional baseline | Regional baseline |
| Springwater | Simcoe | regional baseline | test your tap | Regional baseline | Regional baseline |
| St. Joseph | Algoma | regional baseline | test your tap | Regional baseline | Regional baseline |
| St. Marys | Perth | regional baseline | test your tap | Regional baseline | Regional baseline |
| St.-Charles | Sudbury | regional baseline | test your tap | Regional baseline | Regional baseline |
| Stone Mills | Lennox and Addington | regional baseline | test your tap | Regional baseline | Regional baseline |
| Stormont, Dundas and Glengarry | Stormont, Dundas and Glengarry | regional baseline | test your tap | Regional baseline | Regional baseline |
| Stratford | Perth | regional baseline | test your tap | Regional baseline | Regional baseline |
| Strong | Parry Sound | regional baseline | test your tap | Regional baseline | Regional baseline |
| Sundridge | Parry Sound | regional baseline | test your tap | Regional baseline | Regional baseline |
| Tarbutt | Algoma | regional baseline | test your tap | Regional baseline | Regional baseline |
| Tay | Simcoe | regional baseline | test your tap | Regional baseline | Regional baseline |
| Tay Valley | Lanark | regional baseline | test your tap | Regional baseline | Regional baseline |
| Tehkummah | Manitoulin | regional baseline | test your tap | Regional baseline | Regional baseline |
| Temagami | Nipissing | regional baseline | test your tap | Regional baseline | Regional baseline |
| Temiskaming Shores | Timiskaming | regional baseline | test your tap | Regional baseline | Regional baseline |
| Terrace Bay | Thunder Bay | regional baseline | test your tap | Regional baseline | Regional baseline |
| Thames Centre | Middlesex | regional baseline | test your tap | Regional baseline | Regional baseline |
| The Archipelago | Parry Sound | regional baseline | test your tap | Regional baseline | Regional baseline |
| The Blue Mountains | Grey | regional baseline | test your tap | Regional baseline | Regional baseline |
| The Nation Municipality | Prescott and Russell | regional baseline | test your tap | Regional baseline | Regional baseline |
| The North Shore | Algoma | regional baseline | test your tap | Regional baseline | Regional baseline |
| Thessalon | Algoma | regional baseline | test your tap | Regional baseline | Regional baseline |
| Thornloe | Timiskaming | regional baseline | test your tap | Regional baseline | Regional baseline |
| Timmins | Cochrane | regional baseline | test your tap | Regional baseline | Regional baseline |
| Tiny | Simcoe | regional baseline | test your tap | Regional baseline | Regional baseline |
| Trent Hills | Northumberland | regional baseline | test your tap | Regional baseline | Regional baseline |
| Trent Lakes | Peterborough | regional baseline | test your tap | Regional baseline | Regional baseline |
| Tudor and Cashel | Hastings | regional baseline | test your tap | Regional baseline | Regional baseline |
| Tweed | Hastings | regional baseline | test your tap | Regional baseline | Regional baseline |
| Tyendinaga | Hastings | regional baseline | test your tap | Regional baseline | Regional baseline |
| Val Rita-Harty | Cochrane | regional baseline | test your tap | Regional baseline | Regional baseline |
| Vaughan | York | regional baseline | test your tap | Regional baseline | Regional baseline |
| Wainfleet | Niagara | regional baseline | test your tap | Regional baseline | Regional baseline |
| Warwick | Lambton | regional baseline | test your tap | Regional baseline | Regional baseline |
| Wasaga Beach | Simcoe | regional baseline | test your tap | Regional baseline | Regional baseline |
| Waterloo | Waterloo and Wellington | regional baseline | test your tap | Regional baseline | Regional baseline |
| Waterloo, Regional Municipality of | Waterloo | regional baseline | test your tap | Regional baseline | Regional baseline |
| Wawa | Algoma | regional baseline | test your tap | Regional baseline | Regional baseline |
| Wellesley | Waterloo | regional baseline | test your tap | Regional baseline | Regional baseline |
| Wellington County | Wellington | regional baseline | test your tap | Regional baseline | Regional baseline |
| Wellington North | Wellington | regional baseline | test your tap | Regional baseline | Regional baseline |
| West Elgin | Elgin | regional baseline | test your tap | Regional baseline | Regional baseline |
| West Grey | Grey | regional baseline | test your tap | Regional baseline | Regional baseline |
| West Nipissing | Nipissing | regional baseline | test your tap | Regional baseline | Regional baseline |
| West Perth | Perth | regional baseline | test your tap | Regional baseline | Regional baseline |
| Westport | Leeds and Grenville | regional baseline | test your tap | Regional baseline | Regional baseline |
| White River | Algoma | regional baseline | test your tap | Regional baseline | Regional baseline |
| Whitestone | Parry Sound | regional baseline | test your tap | Regional baseline | Regional baseline |
| Whitewater Region | Renfrew | regional baseline | test your tap | Regional baseline | Regional baseline |
| Wilmot | Waterloo | regional baseline | test your tap | Regional baseline | Regional baseline |
| Wollaston | Hastings | regional baseline | test your tap | Regional baseline | Regional baseline |
| Woolwich | Waterloo | regional baseline | test your tap | Regional baseline | Regional baseline |
Tap a municipality for what its number or baseline means for kettles, water heaters, and whether a softener is worth it, with the source and checked date.
❦
Water hardness questions
How is water hardness measured?
By the dissolved calcium and magnesium in the water, given either in milligrams per litre as calcium carbonate (mg/L) or in grains per gallon (gpg). One grain per gallon equals about 17.1 mg/L. The higher the number, the more scale the water leaves behind.
Which Ontario municipalities have the hardest water?
The verified hard-water standouts are groundwater communities such as Guelph, Kitchener, Waterloo, and Cambridge. Great Lakes surface-water systems, including Toronto and Hamilton, tend to sit in the moderate band. Baseline rows should be tested at the tap before buying a softener.
Do I need a water softener?
It depends on the number. Soft and moderately hard supplies usually do not need one. Hard and very hard supplies leave scale that shortens the life of water heaters and appliances, so a softener is common, and near-universal in the groundwater cities. Find your city below for the local figure.
How this page was made
Verified figures are municipal or regional published values, gathered from utility pages and reports. Baseline rows use source-water guidance and are clearly labeled, last checked on 2026-06-24. Bands used here: soft under 60 mg/L, moderately hard 60 to 130 mg/L, hard 130 to 180 mg/L, very hard over 180 mg/L. Where a utility uses its own word for the same number, that word is quoted on the city page.
Hardness varies by neighbourhood, season, and which well or plant serves your street, especially on groundwater systems. These are the municipal published figures as of the verified date, good for planning, not a substitute for a home test or your utility's current report.