By OpenStats · Built from official Canadian sources
Direct municipal dataWater quality grade
Good
Graded against Health Canada drinking water guidelines
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St. Catharines water hardness is 130 mg/L with pH 7.5.
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. Catharines 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
Decew Falls Water Treatment Plant
Niagara Region conventional plant at 2700 Decew Road, St. Catharines. Three treatment trains; combined rated capacity 227,300 m³/day. Screening, coagulation/flocculation/sedimentation, filtration, sodium hypochlorite disinfection with UV enhancement. Canal water reaches the plant by a gravity supply channel about 5.4 km long.
City owns a Class II stand-alone distribution system (about 605 km of watermains, ~3,580 hydrants) in three pressure zones inside the urban boundary. Potable water is purchased wholesale from Niagara Region’s Decew plant, which also serves Thorold, Niagara-on-the-Lake, and parts of Lincoln.
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
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 | 130 mg/L | No health limit (aesthetic) | Compliant |
| pH | 7.5 | 6.5–8.5 | Compliant |
| Lead | 0.6 μg/L | ≤ 5 μg/L | Compliant |
| Fluoride | 0.5 mg/L | ≤ 1.5 mg/L | Compliant |
| Chlorine (free) | 1.1 mg/L | ≤ 4 mg/L | Compliant |
| Turbidity | 2.3 NTU | ≤ 1 NTU (typical target) | Exceeds guideline |
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St. Catharines pairs 130 mg/L hardness with 1.1 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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