Water hardness in St. John's
38 mg/L soft
Tap water in St. John's is soft: 38 mg/L (2.2 gpg · 2.1 °dH · 3.8 °fH).
Source: Government of Newfoundland and Labrador, Tap Water Quality for Public Water Supplies (Winter, Spring, Summer, Fall 2025) (2025-11-25) · data checked 2026-10-20
Range across supply zones: 24–57 mg/L.
St. John's is supplied from surface water ponds, which pick up little calcium from the surrounding bedrock. The provincial results for 2025 give a median of 38 mg/L as CaCO3, with seasonal readings between 24 and 57. The water is soft, and scale is rarely a concern.
Health Canada: hardness above 200 mg/L is considered poor but tolerable; above 500 mg/L unacceptable.
Water data
| Total hardness | 38 mg/L |
|---|---|
| Utility | St. John's public water supply |
How St. John's compares
- Tap water in St. John's is 62 % softer than the median of the 254 cities we track in Canada (101 mg/L).
- By hardness it ranks 182 of 254 in Canada (1 = hardest); 28 % of these cities have softer water.
- In Newfoundland and Labrador it is number 14 of 55 cities; the regional median is 23 mg/L.
- Nearest city with clearly softer water: Mount Pearl, 8 km away (26 mg/L).
- Nearest city with clearly harder water: Wabana, 19 km away (120 mg/L).
Ranking of the hardest and softest water in Canada →
What it means at home
- Little or no limescale in kettles, water heaters or washing machines.
- Soap lathers easily; water does not dry skin or hair.
- Dishwasher: salt setting at minimum or off.
- No softener needed; a jug filter only changes taste.
How much salt will you use for softening?
No. Water this soft does not need softening.
Descale a coffee machine or kettle about every 6 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in St. John's
| Brand | Setting for this water |
|---|---|
| Bosch | H00 |
| Miele | 2 °dH |
| AEG / Electrolux | 1 |
| Beko | 1st |
| Hoover | S0 |
| LG | H0 |
From each brand's manual for the model family named in the source; your model may differ, so check its manual. All brands and how to change the setting →
FAQ
Is St. John's water hard or soft?
It is soft: 38 mg/L as CaCO₃ (2.2 gpg, 2.1 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in St. John's safe to drink?
Hardness is not a health issue; it is about limescale, taste and appliances. Mains water must meet national drinking-water standards. Health Canada: hardness above 200 mg/L is considered poor but tolerable; above 500 mg/L unacceptable.
How many grains per gallon is St. John's water?
2.2 gpg, equal to 2.1 °dH, 3.8 °fH or 38 mg/L calcium carbonate.
What dishwasher salt setting should I use in St. John's?
For 38 mg/L (2.1 °dH) check your manufacturer's table: level 0–1, usually no salt.
Do I need a water softener in St. John's?
No. With soft water a softener adds nothing.
Source
Source: Government of Newfoundland and Labrador, Tap Water Quality for Public Water Supplies (Winter, Spring, Summer, Fall 2025) (2025-11-25). Method: figure published by the water supplier. Government of Newfoundland and Labrador, Tap Water Quality for Public Water Supplies (Winter, Spring, Summer, Fall 2025) · Outdated figure? Tell us