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.

SoftLittle scale, soap lathers easily, and a softener is rarely worth it.

Moderately hardSome kettle and showerhead scale over time, but most homes get by without a softener.

HardNoticeable scale on fixtures and in kettles and water heaters; many homes choose to soften.

Very hardHeavy scale that shortens the life of water heaters and appliances; a softener is the norm.

Regional baselineNo 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	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.