By OpenStats · Built from official Canadian sources
Regional estimateWater quality grade
Good
Graded against Health Canada drinking water guidelines
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Longueuil's drinking water earns Grade B (Good). Hardness is 181 mg/L (very hard), and pH is 7.9 against Health Canada's 6.5–8.5 guideline.
Lead at 0.5 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
How Longueuil 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.
Surface water
Research confidence: high
Usine Mario-Petrone (usine locale)
Agglomeration filtration plant; UV disinfection added 2015; renamed from usine locale in 2022.
Usine Louise-Gravel (usine régionale)
Agglomeration filtration plant; UV disinfection added 2015; renamed from usine régionale in 2022.
Usine Le Royer
Greenfield Park / Le Moyne sector plant; UV disinfection added 2019.
Agglomeration of Longueuil treats St. Lawrence water at three plants, stores it in six major reservoirs, and distributes via agglomeration transmission mains (~86 km) plus local networks (~1,700 km agglomeration-wide; Longueuil city ~995 km). Serves Longueuil, Boucherville, Brossard, Saint-Bruno-de-Montarville, and Saint-Lambert.
Health parameters meet Health Canada limits; turbidity above the 1 NTU typical target and very hard water.
Health parameters meet Health Canada limits; turbidity exceeds the typical 1 NTU aesthetic target.
Figure 1 · Supply chain
From watershed to tap
Quebec · 34 cities in sample
Provincial average: hardness 183 mg/L · pH 7.5 · lead 0.3 μg/L · fluoride 0.6 mg/L
| Parameter | Reading | Health Canada guideline | Status |
|---|---|---|---|
| Hardness | 181 mg/L | No health limit (aesthetic) | Compliant |
| pH | 7.9 | 6.5–8.5 | Compliant |
| Lead | 0.5 μg/L | ≤ 5 μg/L | Compliant |
| Fluoride | 0.7 mg/L | ≤ 1.5 mg/L | Compliant |
| Chlorine (free) | 1 mg/L | ≤ 4 mg/L | Compliant |
| Turbidity | 2.2 NTU | ≤ 1 NTU (typical target) | Exceeds guideline |
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Longueuil pairs 181 mg/L hardness with 1.0 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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