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OpenStats picks for Cornwall — moderate hardness
Cornwall at 130 mg/L is hard enough for kettle scale but often below whole-house softener urgency. Carbon filtration for taste plus hardness strips before you overspend.
Cornwall tap water: Grade B, hardness 130 mg/L
By OpenStats · Built from official Canadian sources
Regional estimateB
Water quality grade
Good
Graded against Health Canada drinking water guidelines
Lead within guidelinepH in range
Hardness vs provincial average130 mg/L · prov. avg 178 mg/L
Lead vs provincial average0.2 μg/L · prov. avg 0.4 μg/L
Hardness
130 mg/L
Lead
0.2 μg/L
≤ 5 μg/L
pH
7.3
6.5–8.5 range
Hardness
130 mg/L
Hard
Lead
0.2 μg/L
Max: 5 μg/L
pH
7.3
6.5–8.5
Chlorine
0.7 mg/L
Max: 4 mg/L
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OpenStats pick for Cornwall at 130 mg/L — everyday chlorine taste
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Brita replacement filters
Recurring cartridge supply
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Reading this page
Cornwall's drinking water earns Grade B (Good). Hardness is 130 mg/L (hard), and pH is 7.3 against Health Canada's 6.5–8.5 guideline.
Lead at 0.2 μg/L is below the 5 μg/L maximum, and fluoride is 0.7 mg/L against a guideline of ≤ 1.5 mg/L.
How to use this page: read the headline metric and provincial comparison first, then supply and treatment notes, then the source footer for the underlying dataset.
Watershed to tap
Supply and treatment
How Cornwall draws, treats, and distributes drinking water, from municipal and utility publications. Chemistry grades above come from separate parameter records; this section does not invent plant lab figures.
Source type
Surface water
Research confidence: high
Source waters
- Saint Lawrence River
Treatment plants
Cornwall Water Purification Plant
Class 3 plant at 861 Second Street West. Intake and zebra-mussel control facilities at the base of R.H. Saunders Dam. Chemically assisted coagulation/flocculation, filtration, UV, and chlorine disinfection.
Distribution
Includes Boundary Road Reservoir and Tollgate Road elevated storage feeding the Class 3 city distribution system.
Health parameters meet Health Canada limits; turbidity above the 1 NTU typical target.
Health parameters meet Health Canada limits; turbidity exceeds the typical 1 NTU aesthetic target.
Figure 1 · Supply chain
From watershed to tap
Compared to provincial average
Ontario · 123 cities in sample
Hardness (city vs Ontario avg)130 mg/L
pH (city vs Ontario avg)7.3
Lead (city vs Ontario avg)0.2 μg/L
Fluoride (city vs Ontario avg)0.7 mg/L
Provincial average: hardness 178 mg/L · pH 7.5 · lead 0.4 μg/L · fluoride 0.6 mg/L
Full parameters
| Parameter | Reading | Health Canada guideline | Status |
|---|---|---|---|
| Hardness | 130 mg/L | No health limit (aesthetic) | Compliant |
| pH | 7.3 | 6.5–8.5 | Compliant |
| Lead | 0.2 μg/L | ≤ 5 μg/L | Compliant |
| Fluoride | 0.7 mg/L | ≤ 1.5 mg/L | Compliant |
| Chlorine (free) | 0.7 mg/L | ≤ 4 mg/L | Compliant |
| Turbidity | 1.1 NTU | ≤ 1 NTU (typical target) | Exceeds guideline |
Alberta water licences
WaterRegister.ca
On a private well or holding an Alberta water allocation licence? Water Register maps EPA licence records, transfer comparables, and watershed context across the province.
Explore WaterRegister.ca →OpenStats pick
OpenStats picks for Cornwall — moderate hardness
Cornwall at 130 mg/L is hard enough for kettle scale but often below whole-house softener urgency. Carbon filtration for taste plus hardness strips before you overspend.
As an Amazon Associate, OpenStats earns from qualifying purchases.
· Compare options- Shop on Amazon.caBrita Denali pitcherOpenStats pick for Cornwall at 130 mg/L — everyday chlorine taste
- Shop on Amazon.caWaterdrop 15UA under-sink filterSkip the pitcher wait in Cornwall
- Shop on Amazon.caVARIFY hardness test stripsConfirm 130 mg/L before a softener
- Shop on Amazon.caBrita replacement filtersRecurring cartridge supply
Source · ECCC / municipal open data (seed). Last updated 2026-09-01. Refreshed on the site's automated schedule.