Ajax Water Hardness & Quality Report (2026)
Water Hardness
Source
lake
pH Level
7.7
neutral = 7.0
Lead
0.002 mg/L
✓ Below action level
TDS
354.2 mg/L
Est. Daily Cost
$0.44
energy & soap waste
Source: Health Canada Water Quality · Updated 2026
0–60
mg/L
Soft
61–120
mg/L
Moderately Hard
121–180
mg/L
Hard
180+
mg/L
Very Hard
Appliance Damage Report
In Ajax, your appliances are currently losing 22% efficiency due to mineral buildup.
| Appliance | In Ajax | Soft Water City | Efficiency Loss |
|---|---|---|---|
| Kettle | 4.1 yrs | 8.5 yrs | -52% |
| Washing Machine | 7.4 yrs | 12 yrs | -38% |
| Water Heater | 8.9 yrs | 15 yrs | -41% |
Regional Water Comparison
How Ajax compares to its nearest neighbours
| City | Hardness | Mineralization | Risk |
|---|---|---|---|
| ▶ Ajax, Ontario | 166.5 mg/L | High | 🟠 Hard |
| Whitby, Ontario | 193.5 mg/L | Very High | 🔴 Very Hard |
| Pickering, Ontario | 261 mg/L | Very High | 🔴 Very Hard |
| Brooklin, Ontario | 203 mg/L | Very High | 🔴 Very Hard |
| Centennial Scarborough, Ontario | 232.5 mg/L | Very High | 🔴 Very Hard |
National Benchmark
How Ajax compares to the Canada average
| Benchmark | Hardness | Appliance Risk |
|---|---|---|
| ▶ Ajax | 166.5 mg/L | 🟠 Moderate |
| Canada National Avg | 141 mg/L | 🟠 Moderate |
| Vancouver Top Rated | 3 mg/L | 🟢 None |
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What Makes Ajax's Water Unique?
Local geology and source profile
Ajax's drinking water is managed by the Region of Durham, drawing from Lake Ontario at the Ajax Water Treatment Plant — Durham Region's principal lake intake facility, located on the Ajax lakeshore. Water undergoes coagulation, sedimentation, ozonation, biofiltration, filtration, and chloramination, fully meeting the Guidelines for Canadian Drinking Water Quality (GCDWQ). Hardness at the tap in Ajax measures 166.5 mg/L (9.7 gpg) — classified as hard by Health Canada, elevated compared to Oshawa (115 mg/L) in the same regional system, reflecting local distribution zone characteristics and potential groundwater contributions in the Ajax supply area.
Ajax draws from Lake Ontario's eastern basin, which accumulates dissolved minerals from the Great Lakes watershed — particularly from Silurian dolomite and limestone formations in the Ontario lowlands. The Ajax distribution zone appears to incorporate a higher proportion of local Ordovician limestone aquifer groundwater relative to the Oshawa zone, elevating measured hardness above the Lake Ontario baseline at the regional intake. The Iroquois shoreline plain and Lake Irbodiment glaciolacustrine deposits underlying Ajax also contain calcareous material that may contribute to local groundwater hardness.
At 166.5 mg/L, Ajax homeowners notice regular scale deposits on kettle elements, showerheads, and inside hot water tanks — descaling every four to six weeks is typical. Hot water tank heating elements benefit from annual inspection; Durham Region recommends periodic tank flushing to maintain efficiency and extend appliance lifespan. An inline scale inhibitor or a whole-home water softener is a worthwhile investment for Ajax households with new high-efficiency appliances or tankless water heating systems.
Geology & Source: Supplied by Region of Durham from Lake Ontario via the Ajax Water Treatment Plant — Great Lakes Silurian dolomite basin chemistry produces hard water at 166.5 mg/L (9.7 gpg) in the Ajax distribution zone.