- Hardness Hard water · 128 mg/L as CaCO3 Older records · 1999–2019 · 40 samples
- Sodium level Above the diet notice level · 29 mg/L Older records · 2011–2019 · 18 samples
Standouts
Systems where the everyday numbers stand out — hardness, sodium, and similar above the usual band. Long-term plant averages, not a safety ranking — hard water is a soap-and-kettle thing, not a warning.
128 of 157 monitored systems stand out on at least one reading. What the numbers mean · Ontario standards
Showing 128 systems
- Hardness Very hard water · 283 mg/L as CaCO3 Older records · 1998–2019 · 127 samples
- Sodium level Above the diet notice level · 48.2 mg/L Older records · 2011–2019 · 36 samples
- Hardness Very hard water · 495 mg/L as CaCO3 Older records · 1998–2019 · 31 samples
- Sodium level Above the diet notice level · 50.4 mg/L Older records · 2011–2019 · 12 samples
- Hardness Hard water · 140 mg/L as CaCO3 Older records · 2011–2015 · 12 samples
- Sodium level Above the diet notice level · 25.8 mg/L Older records · 2011–2015 · 12 samples
- Hardness Hard water · 137 mg/L as CaCO3 Older records · 1999–2019 · 46 samples
- Sodium level Above the diet notice level · 27.1 mg/L Older records · 2008–2019 · 17 samples
- Hardness Hard water · 86 mg/L as CaCO3 Older records · 1998–2023 · 33 samples
- Sodium level Above the diet notice level · 37.1 mg/L Older records · 2011–2023 · 14 samples
- Hardness Very hard water · 195 mg/L as CaCO3 Older records · 1998–2016 · 17 samples
- Sodium level Above the diet notice level · 53.4 mg/L Older records · 2011–2016 · 16 samples
- Hardness Very hard water · 358 mg/L as CaCO3 Older records · 1998–2019 · 43 samples
- Sodium level Above the diet notice level · 23 mg/L Older records · 2012–2019 · 10 samples
- Hardness Very hard water · 357 mg/L as CaCO3 Recent average · 2019 · 3 samples
- Sodium level Above the diet notice level · 57.7 mg/L Recent average · 2019 · 3 samples
- Hardness Very hard water · 258 mg/L as CaCO3 Older records · 2000 · 4 samples
- Fluoride Above the Ontario health standard · 2.08 mg/L Older records · 2000 · 4 samples
- Hardness Very hard water · 325 mg/L as CaCO3 Older records · 1998–2002 · 25 samples
- Fluoride Above the Ontario health standard · 2.02 mg/L Older records · 1998–2002 · 25 samples
- Hardness Hard water · 136 mg/L as CaCO3 Older records · 2000–2019 · 49 samples
- Sodium level Above the diet notice level · 27.4 mg/L Older records · 2011–2019 · 21 samples
- Hardness Very hard water · 191 mg/L as CaCO3 Older records · 1998–2016 · 40 samples
- Sodium level Above the diet notice level · 27.7 mg/L Older records · 2011–2016 · 12 samples
- Hardness Very hard water · 320 mg/L as CaCO3 Older records · 1998–2015 · 27 samples
- Sodium level Above the diet notice level · 49.5 mg/L Older records · 2011–2015 · 8 samples
- Hardness Very hard water · 246 mg/L as CaCO3 Older records · 1998–2016 · 32 samples
- Sodium level Above the diet notice level · 33.5 mg/L Older records · 2011–2016 · 12 samples
- Hardness Hard water · 161 mg/L as CaCO3 Older records · 1998–2019 · 27 samples
- Sodium level Above the diet notice level · 20.1 mg/L Older records · 2011–2019 · 11 samples
- Hardness Very hard water · 282 mg/L as CaCO3 Older records · 1998–2016 · 42 samples
- Sodium level Above the diet notice level · 22.6 mg/L Older records · 2011–2016 · 12 samples
- Hardness Very hard water · 310 mg/L as CaCO3 Older records · 1998–2015 · 28 samples
- Sodium level Above the diet notice level · 43.6 mg/L Older records · 2011–2015 · 11 samples
- Hardness Hard water · 128 mg/L as CaCO3 Older records · 1998–2019 · 107 samples
- Sodium level Above the diet notice level · 25.9 mg/L Older records · 2011–2019 · 28 samples
- Hardness Very hard water · 289 mg/L as CaCO3 Older records · 1998–2019 · 43 samples
- Sodium level Above the diet notice level · 28.7 mg/L Older records · 2011–2019 · 13 samples
- Hardness Very hard water · 311 mg/L as CaCO3 Older records · 1998–2015 · 26 samples
- Sodium level Above the diet notice level · 26.1 mg/L Older records · 2011–2015 · 10 samples
- Hardness Hard water · 76 mg/L as CaCO3 Older records · 2000 · 3 samples
- Hardness Hard water · 119 mg/L as CaCO3 Older records · 1999–2005 · 15 samples
- Hardness Hard water · 105 mg/L as CaCO3 Older records · 1998–2015 · 36 samples
- Hardness Very hard water · 190 mg/L as CaCO3 Older records · 1998–2015 · 31 samples
- Hardness Very hard water · 232 mg/L as CaCO3 Older records · 1998–2007 · 32 samples
- Hardness Hard water · 115 mg/L as CaCO3 Older records · 1998–2019 · 141 samples
- Hardness Very hard water · 244 mg/L as CaCO3 Older records · 2000–2014 · 20 samples
- Hardness Hard water · 137 mg/L as CaCO3 Older records · 1998–2007 · 25 samples
- Hardness Very hard water · 331 mg/L as CaCO3 Older records · 1998–2005 · 15 samples
- Hardness Very hard water · 363 mg/L as CaCO3 Older records · 2000–2016 · 69 samples
- Hardness Very hard water · 373 mg/L as CaCO3 Older records · 2001–2015 · 131 samples
- Hardness Hard water · 117 mg/L as CaCO3 Older records · 1998–2015 · 37 samples
- Hardness Hard water · 120 mg/L as CaCO3 Older records · 1998–2015 · 45 samples
- Hardness Very hard water · 358 mg/L as CaCO3 Older records · 1998–2007 · 78 samples
- Hardness Very hard water · 272 mg/L as CaCO3 Older records · 1998–2005 · 54 samples
- Hardness Hard water · 121 mg/L as CaCO3 Older records · 1998–2015 · 32 samples
- Hardness Hard water · 96 mg/L as CaCO3 Older records · 1999–2000 · 8 samples
- Hardness Hard water · 116 mg/L as CaCO3 Older records · 1998–2015 · 28 samples
- Hardness Hard water · 120 mg/L as CaCO3 Older records · 2013–2015 · 8 samples
- Hardness Hard water · 99 mg/L as CaCO3 Older records · 1998–2015 · 67 samples
- Hardness Hard water · 120 mg/L as CaCO3 Older records · 1998–2006 · 16 samples
- Hardness Hard water · 121 mg/L as CaCO3 Older records · 1998–2015 · 28 samples
- Hardness Hard water · 87 mg/L as CaCO3 Older records · 1998–2015 · 49 samples
- Hardness Hard water · 118 mg/L as CaCO3 Older records · 1998–2016 · 40 samples
- Hardness Hard water · 110 mg/L as CaCO3 Older records · 1998–2011 · 193 samples
- Hardness Hard water · 69 mg/L as CaCO3 Older records · 1998–2019 · 50 samples
- Hardness Very hard water · 318 mg/L as CaCO3 Older records · 1998–2016 · 48 samples
- Hardness Very hard water · 373 mg/L as CaCO3 Older records · 1998–2016 · 49 samples
- Hardness Hard water · 106 mg/L as CaCO3 Older records · 1998–2015 · 54 samples
- Hardness Hard water · 64 mg/L as CaCO3 Older records · 2000 · 4 samples
- Hardness Hard water · 119 mg/L as CaCO3 Older records · 1998–2015 · 27 samples
- Hardness Hard water · 108 mg/L as CaCO3 Older records · 1998–2015 · 29 samples
- Hardness Hard water · 81 mg/L as CaCO3 Older records · 1999–2002 · 14 samples
- Hardness Hard water · 116 mg/L as CaCO3 Older records · 1998–2001 · 6 samples
- Sodium level Above the diet notice level · 57.5 mg/L Older records · 2009–2019 · 50 samples
- Hardness Hard water · 91 mg/L as CaCO3 Older records · 1998–2019 · 75 samples
- Hardness Hard water · 86 mg/L as CaCO3 Older records · 1998–2019 · 56 samples
- Hardness Hard water · 122 mg/L as CaCO3 Older records · 1998–2015 · 25 samples
- Hardness Hard water · 124 mg/L as CaCO3 Older records · 1998–2015 · 30 samples
- Hardness Hard water · 122 mg/L as CaCO3 Older records · 1998–2014 · 29 samples
- Hardness Hard water · 120 mg/L as CaCO3 Older records · 1998–2015 · 47 samples
- Hardness Very hard water · 284 mg/L as CaCO3 Older records · 2000–2004 · 8 samples
- Hardness Hard water · 118 mg/L as CaCO3 Older records · 1999–2000 · 8 samples
- Hardness Very hard water · 196 mg/L as CaCO3 Older records · 2012–2015 · 5 samples
- Hardness Hard water · 119 mg/L as CaCO3 Older records · 1998–2015 · 31 samples
- Hardness Hard water · 105 mg/L as CaCO3 Older records · 1998–2015 · 40 samples
- Sodium level Above the diet notice level · 27.2 mg/L Older records · 2008–2013 · 9 samples
- Hardness Very hard water · 515 mg/L as CaCO3 Older records · 1998–2007 · 35 samples
- Hardness Very hard water · 278 mg/L as CaCO3 Older records · 1998–2007 · 86 samples
- Hardness Hard water · 112 mg/L as CaCO3 Older records · 2011–2016 · 34 samples
- Hardness Hard water · 124 mg/L as CaCO3 Older records · 1998–2016 · 58 samples
- Hardness Very hard water · 190 mg/L as CaCO3 Older records · 1998–2015 · 27 samples
- Hardness Very hard water · 280 mg/L as CaCO3 Older records · 1999–2003 · 16 samples
- Hardness Hard water · 82 mg/L as CaCO3 Older records · 2000–2004 · 15 samples
- Hardness Hard water · 77 mg/L as CaCO3 Older records · 2000 · 4 samples
- Hardness Hard water · 80 mg/L as CaCO3 Older records · 1998–2019 · 42 samples
- Hardness Very hard water · 306 mg/L as CaCO3 Older records · 1999–2019 · 26 samples
- Hardness Hard water · 121 mg/L as CaCO3 Older records · 1998–2015 · 32 samples
- Hardness Hard water · 123 mg/L as CaCO3 Older records · 1998–2015 · 29 samples
- Hardness Hard water · 117 mg/L as CaCO3 Older records · 1998–2015 · 37 samples
- Hardness Hard water · 74 mg/L as CaCO3 Older records · 1998–2019 · 60 samples
- Hardness Very hard water · 205 mg/L as CaCO3 Older records · 1998–2019 · 154 samples
- Hardness Hard water · 122 mg/L as CaCO3 Older records · 1998–2015 · 34 samples
- Hardness Hard water · 159 mg/L as CaCO3 Older records · 1998–2019 · 29 samples
- Hardness Very hard water · 223 mg/L as CaCO3 Older records · 1998–2015 · 51 samples
- Hardness Hard water · 123 mg/L as CaCO3 Older records · 1998–2019 · 41 samples
- Hardness Very hard water · 270 mg/L as CaCO3 Older records · 2000–2001 · 4 samples
- Hardness Hard water · 122 mg/L as CaCO3 Older records · 1998–2016 · 23 samples
- Hardness Hard water · 121 mg/L as CaCO3 Older records · 1998–2007 · 15 samples
- pH balance Slightly basic · 9.4 Recent average · 2019–2020 · 15 samples
- pH balance Slightly basic · 9.4 Recent average · 2019 · 11 samples
- Hardness Hard water · 90 mg/L as CaCO3 Older records · 1998–2015 · 26 samples
- Sodium level Above the diet notice level · 22 mg/L Older records · 2011–2019 · 22 samples
- Hardness Very hard water · 204 mg/L as CaCO3 Older records · 1998–2002 · 12 samples
- Hardness Hard water · 98 mg/L as CaCO3 Older records · 1998–2015 · 39 samples
- Hardness Hard water · 92 mg/L as CaCO3 Older records · 1998–2016 · 43 samples
- Hardness Hard water · 119 mg/L as CaCO3 Older records · 1998–2015 · 29 samples
- Hardness Hard water · 123 mg/L as CaCO3 Older records · 2005–2015 · 13 samples
- Hardness Hard water · 120 mg/L as CaCO3 Older records · 1998–2016 · 43 samples
- Hardness Hard water · 123 mg/L as CaCO3 Older records · 2009–2019 · 24 samples
- Hardness Hard water · 115 mg/L as CaCO3 Older records · 1998–2019 · 213 samples
- Hardness Hard water · 125 mg/L as CaCO3 Older records · 2012–2015 · 10 samples
- Hardness Hard water · 112 mg/L as CaCO3 Older records · 2001–2019 · 170 samples
- Hardness Hard water · 121 mg/L as CaCO3 Older records · 1998–2016 · 57 samples
- Hardness Hard water · 72 mg/L as CaCO3 Older records · 1998–2015 · 29 samples
- Hardness Hard water · 78 mg/L as CaCO3 Older records · 1998–2004 · 20 samples
- Hardness Hard water · 96 mg/L as CaCO3 Older records · 1998–2015 · 39 samples
- Hardness Hard water · 109 mg/L as CaCO3 Older records · 1998–2015 · 29 samples
- Hardness Hard water · 73 mg/L as CaCO3 Older records · 1998–2016 · 68 samples
- Hardness Very hard water · 243 mg/L as CaCO3 Older records · 1998–2005 · 13 samples
- Hardness Hard water · 101 mg/L as CaCO3 Older records · 1998–2019 · 45 samples
- Hardness Hard water · 116 mg/L as CaCO3 Older records · 1998–2001 · 9 samples
- Hardness Hard water · 118 mg/L as CaCO3 Older records · 1998–2015 · 43 samples
- Hardness Hard water · 97 mg/L as CaCO3 Older records · 1998–2015 · 22 samples
- Hardness Very hard water · 234 mg/L as CaCO3 Older records · 2000 · 3 samples
- Hardness Hard water · 125 mg/L as CaCO3 Older records · 1998–2015 · 38 samples
- Hardness Very hard water · 552 mg/L as CaCO3 Older records · 1998–2015 · 38 samples
- Hardness Very hard water · 245 mg/L as CaCO3 Older records · 1998–2002 · 15 samples
- Hardness Hard water · 120 mg/L as CaCO3 Older records · 1998–2016 · 26 samples
- Hardness Hard water · 120 mg/L as CaCO3 Older records · 1998–2015 · 32 samples
- Hardness Hard water · 121 mg/L as CaCO3 Older records · 1998–2015 · 31 samples
- Hardness Hard water · 121 mg/L as CaCO3 Older records · 1998–2015 · 29 samples
- Hardness Very hard water · 364 mg/L as CaCO3 Older records · 1998–2007 · 38 samples
- Hardness Hard water · 122 mg/L as CaCO3 Older records · 1998–2016 · 40 samples
- Hardness Hard water · 120 mg/L as CaCO3 Older records · 1998–2006 · 15 samples
- Hardness Hard water · 105 mg/L as CaCO3 Older records · 1998–2015 · 44 samples
- Hardness Very hard water · 343 mg/L as CaCO3 Older records · 1998–2002 · 14 samples
Numbers lean on samples from 2019 onward when there are enough, checked against the longer record — so one odd year doesn’t move a note; chips marked “older records” didn’t have enough recent samples. City links come from the municipality field on public records; a few systems are missing that field. Schools, child-care centres, and most small private systems aren’t listed — these readings only exist where a plant joined the long-term monitoring program.