Water hardness in Fergus
519 mg/L very hard
Tap water in Fergus is very hard: 519 mg/L (30.3 gpg · 29 °dH · 51.9 °fH).
Source: Ontario Ministry of the Environment, Conservation and Parks, Drinking Water Surveillance Program, Open Government Licence – Ontario (2019) · data checked 2026-10-22
Range across supply zones: 506–531 mg/L.
This figure is over 3 years old; hardness may have changed.
Fergus is part of Centre Wellington, which relies on groundwater from limestone and dolostone aquifers. The programme reported 518.5 mg/L as CaCO3 for 2019, ranging from 506 to 531. That is above the 500 mg/L level Health Canada calls unacceptable, so a softener is a practical consideration.
Health Canada: hardness above 200 mg/L is considered poor but tolerable; above 500 mg/L unacceptable.
Water data
| Total hardness | 519 mg/L |
|---|---|
| Utility | Centre Wellington Drinking Water System |
How Fergus compares
- Tap water in Fergus is 412 % harder than the median of the 254 cities we track in Canada (101 mg/L).
- By hardness it ranks 2 of 254 in Canada (1 = hardest); 99 % of these cities have softer water.
- In Ontario it is number 1 of 120 cities; the regional median is 124 mg/L.
- Nearest city with clearly softer water: Guelph, 20 km away (332 mg/L).
Ranking of the hardest and softest water in Canada →
What it means at home
- Severe scale: heater elements and washing-machine heaters fail early.
- Detergent use is very high; taps and screens coat within days.
- Dishwasher at maximum salt setting.
- An ion-exchange softener is practically essential; RO for drinking water.
How much salt will you use for softening?
Yes. At this hardness a softener pays for itself through appliance life and detergent.
Descale a coffee machine or kettle about every 1 months (typical manufacturer guidance for this hardness).
Estimates for planning, not a quote. Check your appliance manual for exact settings.
Dishwasher setting in Fergus
| Brand | Setting for this water |
|---|---|
| Bosch | H06 |
| Miele | 29 °dH |
| AEG / Electrolux | 7 |
| Beko | 6th |
| Hoover | S4 |
| LG | H4 |
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 Fergus water hard or soft?
It is very hard: 519 mg/L as CaCO₃ (30.3 gpg, 29 °dH). The usual bands are soft < 60, moderately hard 60–120, hard 120–180 and very hard > 180 mg/L.
Is tap water in Fergus 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 Fergus water?
30.3 gpg, equal to 29 °dH, 51.9 °fH or 519 mg/L calcium carbonate.
What dishwasher salt setting should I use in Fergus?
For 519 mg/L (29 °dH) check your manufacturer's table: maximum level (5–7).
Do I need a water softener in Fergus?
Yes, unless you are only passing through: scale damages appliances within a few years.
Source
Source: Ontario Ministry of the Environment, Conservation and Parks, Drinking Water Surveillance Program, Open Government Licence – Ontario (2019). Method: figure published by the water supplier. Ontario Ministry of the Environment, Conservation and Parks, Drinking Water Surveillance Program, Open Government Licence – Ontario · Outdated figure? Tell us