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OpenStats picks for Oshawa — chlorine + hardness
Oshawa pairs 125 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.
Oshawa tap water: Grade B, hardness 125 mg/L
By OpenStats · Built from official Canadian sources
Direct municipal dataB
Water quality grade
Good
Graded against Health Canada drinking water guidelines
Lead within guidelinepH in range
Hardness vs provincial average125 mg/L · prov. avg 178 mg/L
Lead vs provincial average0.5 μg/L · prov. avg 0.4 μg/L
Hardness
125 mg/L
Lead
0.5 μg/L
≤ 5 μg/L
pH
7.6
6.5–8.5 range
Hardness
125 mg/L
Hard
Lead
0.5 μg/L
Max: 5 μg/L
pH
7.6
6.5–8.5
Chlorine
1 mg/L
Max: 4 mg/L
SponsoredAlso consider
Brita 10-cup Elite pitcher
OpenStats pick for Oshawa — 1.0 mg/L chlorine taste on 125 mg/L water
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SR SUN RISE 20-stage shower filter
Oshawa’s 1.0 mg/L chlorine — bestselling shower filter on Amazon.ca
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Frizzlife SW20 under-sink filter
NSF 53 lead reduction for Oshawa older plumbing
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Brita Elite replacement filters
Six-month Elite cartridges for Oshawa
As an Amazon Associate, OpenStats earns from qualifying purchases.
Partner
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Municipal reports cover the plant. A Tap Score kit tests the water at a Oshawa tap for a broader contaminant panel.
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Waterdrop filtration systems
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Reading this page
Oshawa water hardness is 125 mg/L, from the city's published water quality reporting.
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 Oshawa 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
- Lake Ontario
Treatment plants
Oshawa Water Supply Plant
Region of Durham Class Four Lake Ontario plant with approved capacity 134,000 m³/day. Primary plant for Oshawa and Courtice, interconnected with Whitby and Ajax systems.
Whitby Water Supply Plant
Interconnected Durham Lake Ontario plant (118,000 m³/day) that can also supply Oshawa when systems are transferred.
Ajax Water Supply Plant
Interconnected Durham Lake Ontario plant that can provide limited backup supply into the Whitby/Oshawa/Courtice network.
Distribution
Oshawa, Whitby, Ajax, Pickering, Brooklin, and Courtice share an interconnected Durham Region trunk and distribution network. Region owns and operates treatment and distribution; fluoride is added for the Oshawa/Whitby/Ajax/Pickering service area.
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)125 mg/L
pH (city vs Ontario avg)7.6
Lead (city vs Ontario avg)0.5 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 | 125 mg/L | No health limit (aesthetic) | Compliant |
| pH | 7.6 | 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 | 1.4 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 Oshawa — chlorine + hardness
Oshawa pairs 125 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.
· Compare options- Shop on Amazon.caBrita 10-cup Elite pitcherOpenStats pick for Oshawa — 1.0 mg/L chlorine taste on 125 mg/L water
- Shop on Amazon.caSR SUN RISE 20-stage shower filterOshawa’s 1.0 mg/L chlorine — bestselling shower filter on Amazon.ca
- Shop on Amazon.caFrizzlife SW20 under-sink filterNSF 53 lead reduction for Oshawa older plumbing
- Shop on Amazon.caBrita Elite replacement filtersSix-month Elite cartridges for Oshawa
- Shop on Amazon.caVARIFY hardness test strips125 mg/L at Oshawa — pitchers do not soften; strips decide if you need a softener
Source · Region of Durham About Water (hardness table). Last updated 2026-10-07. Refreshed on the site's automated schedule.