By OpenStats · Built from official Canadian sources
Regional estimateWater quality grade
Good
Graded against Health Canada drinking water guidelines
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St. Thomas's drinking water earns Grade B (Good). Hardness is 204 mg/L (very hard), and pH is 7.2 against Health Canada's 6.5–8.5 guideline.
Lead at 0.4 μg/L is below the 5 μg/L maximum, and fluoride is 0.6 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
How St. Thomas 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.
Groundwater
Research confidence: medium
St. Thomas Water Treatment Plant
From municipal open data or regional estimate (verify locally).
All monitored parameters meet Health Canada guidelines.
Health parameters compliant; minor aesthetic factors such as hardness or pH near guideline edges.
Figure 1 · Supply chain
From watershed to tap
Ontario · 123 cities in sample
Provincial average: hardness 178 mg/L · pH 7.5 · lead 0.4 μg/L · fluoride 0.6 mg/L
| Parameter | Reading | Health Canada guideline | Status |
|---|---|---|---|
| Hardness | 204 mg/L | No health limit (aesthetic) | Compliant |
| pH | 7.2 | 6.5–8.5 | Compliant |
| Lead | 0.4 μg/L | ≤ 5 μg/L | Compliant |
| Fluoride | 0.6 mg/L | ≤ 1.5 mg/L | Compliant |
| Chlorine (free) | 0.9 mg/L | ≤ 4 mg/L | Compliant |
| Turbidity | 0.5 NTU | ≤ 1 NTU (typical target) | Compliant |
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
St. Thomas pairs 204 mg/L hardness with 0.9 mg/L chlorine — taste and scale show up together. Elite carbon for drinking, shower filter for chlorine, strips so you know when you need a softener.
As an Amazon Associate, OpenStats earns from qualifying purchases.
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