Popular searches
Quick links
Hamilton takes its water from Lake Ontario and treats it at the Woodward Avenue plant, which supplies Hamilton, Stoney Creek, Dundas, Ancaster, Waterdown and parts of Flamborough and Glanbrook. The City of Hamilton describes the water as "medium" hard, at about 120 mg/L as calcium carbonate, or about 8.4 grains per imperial gallon. That is right at the 120 mg/L line between moderately hard and hard, and above Ontario's operational guideline of 80 to 100 mg/L. The City gives this as a typical value, without a date.
Data last reviewed October 24, 2026.
Hamilton ranks #10 hardest of 31 cities in the Canadian Hard Water Report 2026. See the full ranking
In other units
Source: City of Hamilton, Drinking water quality. Data for: Typical value published by the City, no date given. Checked October 24, 2026.
Some scale builds up over time, mostly where water gets heated: kettles, coffee makers and washers. A monthly clean keeps it in check.
At this hardness, grease and detergent residue are the bigger issue, so start with the dishwasher.
Only dishwashers with a built-in water softener have a hardness setting. Here is the setting for this water, worked out from each maker's own table.
| Brand | Setting |
|---|---|
| Bosch and ThermadorCanadian models with a softener. H:00 is off. | H:01 |
| GaggenauSame ranges as Bosch. The display shows the °E band. | 9-10 |
| MieleSet in °dH. Below 5, Miele says no salt is needed. | 7 |
| Fisher & PaykelDishDrawer models with a softener. 0 is off. | 1 |
Most North American dishwashers, including Bosch models sold in the United States, have no water softener and no hardness setting. With those, use rinse aid and run a dishwasher cleaner once a month.
Sources: Bosch SHX78CC5UC manual, Thermador DWHD661EFP manual, Gaggenau DF481701 manual, Miele dishwasher manual (Canada), Fisher & Paykel DishDrawer guide
Softeners take hardness in US grains per gallon: the figure in mg/L divided by 17.12, rounded up.
| Brand | Setting |
|---|---|
| Nespresso Essenza PlusHardness level, and cups between descalings | Level 1 (3,000 cups) |
| Jura E8Hardness setting | 7 °dH |
Sources: Nespresso Essenza Plus manual, Jura E8 manual, Breville Barista Touch manual, De'Longhi descaling FAQ, Keurig descaling page
Hard water leaves scale on the heating element and the drum, and more detergent residue behind.
Dissolves grease, detergent residue and limescale buildup, and removes odour-causing buildup.
Clears grease, limescale and odour buildup
Breaks down residue and odour-causing buildup inside your washer.
Removes odour and buildup from the drum and hoses
Removes limescale, mineral buildup and coffee oils inside your coffee maker.
Descales for better-tasting coffee
We use the U.S. Geological Survey scale, in mg/L as CaCO₃.
Utilities usually report hardness in mg/L as calcium carbonate (CaCO₃), which is the same as ppm. Dishwasher and softener manuals often use grains per gallon or German degrees instead. Here is how they convert:
Moderately hard, close to hard. The City of Hamilton gives a typical value of about 120 mg/L, right at the 120 mg/L line for hard water and above Ontario's operational guideline of 80 to 100 mg/L.
These rural communities get their water from small municipal well systems, not from Lake Ontario, and the City lists their hardness separately on the same page. Carlisle, Freelton and Greensville are much harder than the Lake Ontario supply, and Lynden is softer.
The City publishes it as a typical value on its drinking water quality page. Its annual water quality report covers the regulated parameters and does not include hardness. We will update this page when the City publishes a dated figure.
For dishwashers with a built-in water softener, each maker's table gives: City of Hamilton (Lake Ontario, Woodward Avenue plant): Bosch and Thermador H:01, Gaggenau 9-10, Miele 7, Fisher & Paykel 1. Most North American dishwashers, including Bosch models sold in the United States, have no water softener and no hardness setting. With those, use rinse aid and run a dishwasher cleaner once a month.
City of Hamilton (Lake Ontario, Woodward Avenue plant): 8 grains per US gallon (rounded up).
City of Hamilton (Lake Ontario, Woodward Avenue plant): 7.0 grains per US gallon, or 8.4 grains per imperial gallon.
City of Hamilton, Drinking water quality. Data for Typical value published by the City, no date given. We update this page when a new report comes out.
Writing about water in Hamilton? Copy this code into your site's HTML. The badge links back to this page and its sources.
Your cart is empty.
Shop cleaners
