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OpenStats picks for London — lead-aware filtration
Plant averages for London do not guarantee your tap is lead-free. Use NSF/ANSI 53-certified filters (Elite cartridges or Frizzlife under-sink) and a home test kit in pre-1975 housing.
London tap water: Grade B, hardness 119 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 average119 mg/L · prov. avg 178 mg/L
Lead vs provincial average0.4 μg/L · prov. avg 0.4 μg/L
Hardness
119 mg/L
Lead
0.4 μg/L
≤ 5 μg/L
pH
7.3
6.5–8.5 range
Hardness
119 mg/L
Moderate
Lead
0.4 μg/L
Max: 5 μg/L
pH
7.3
6.5–8.5
Chlorine
0.9 mg/L
Max: 4 mg/L
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Frizzlife SW20 under-sink filter
OpenStats pick for London — NSF/ANSI 53 & 42 lead reduction at the tap you drink from
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Brita 10-cup Elite pitcher
Portable NSF Elite lead claim for London renters
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Brita Elite replacement filters
Lead claim lives on the cartridge
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VARIFY 17-in-1 test kit
Plant data cannot clear London service lines
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Reading this page
London water hardness is 119 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 London 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 Huron
- Lake Erie
Treatment plants
Lake Huron Primary Water Supply System Water Treatment Plant
Regional plant north of Grand Bend treating Lake Huron water for London and other member municipalities. Board-owned; OCWA-operated; capacity about 340 ML/day.
Elgin Area Primary Water Supply System Water Treatment Plant
Regional plant east of Port Stanley treating Lake Erie water. Board-owned; OCWA-operated; capacity about 91 ML/day. Water reaches London via the Elgin-Middlesex Pumping Station.
Distribution
City of London owns and operates the local Drinking Water System (Class IV distribution / Class II treatment rating for city assets) with more than 2,100 km of pipes, reservoirs, and pumping stations. Regional boards supply bulk treated water; London is administering municipality for the Lake Huron board.
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)119 mg/L
pH (city vs Ontario avg)7.3
Lead (city vs Ontario avg)0.4 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 | 119 mg/L | No health limit (aesthetic) | Compliant |
| pH | 7.3 | 6.5–8.5 | Compliant |
| Lead | 0.4 μg/L | ≤ 5 μg/L | Compliant |
| Fluoride | 0.7 mg/L | ≤ 1.5 mg/L | Compliant |
| Chlorine (free) | 0.9 mg/L | ≤ 4 mg/L | Compliant |
| Turbidity | 2.1 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 London — lead-aware filtration
Plant averages for London do not guarantee your tap is lead-free. Use NSF/ANSI 53-certified filters (Elite cartridges or Frizzlife under-sink) and a home test kit in pre-1975 housing.
As an Amazon Associate, OpenStats earns from qualifying purchases.
· Compare options- Shop on Amazon.caFrizzlife SW20 under-sink filterOpenStats pick for London — NSF/ANSI 53 & 42 lead reduction at the tap you drink from
- Shop on Amazon.caBrita 10-cup Elite pitcherPortable NSF Elite lead claim for London renters
- Shop on Amazon.caBrita Elite replacement filtersLead claim lives on the cartridge
- Shop on Amazon.caVARIFY 17-in-1 test kitPlant data cannot clear London service lines
- Shop on Amazon.caWaterdrop G3P600 RO systemWhen home tests show multiple dissolved issues
Source · Huron Erie Water (Lake Huron and Elgin Area primary supply) consumer FAQ. Last updated 2026-10-07. Refreshed on the site's automated schedule.