Regional groundwater summary • Ontario Historical Log Extraction
Bottom Line Up Front
In Thunder Bay, the median completed well is 130 ft deep.
A published hardness range for this place and aquifer is under 60 to above 180 mg/L as CaCO₃. That is a regional estimate, not a test of your well. Source: Estimate based on Health Canada hardness bands.
Most production draws from Crystalline Bedrock (about 51% of local wells).
These municipal aggregates support planning only — they do not replace an accredited laboratory potability test for your own well.
Interactive Well Depth & Modeled Typical Strata
Drag the indicator line or tap a stratum below to read the recorded depth range
Modelled Depth
130 FT
Area median
Drilling cost
$9,100–$19,500
Estimate
Published hardness
under 60 to above 180 mg/L as CaCO₃
Modeled typical strata — placeholder from median depth + aquifer type; not local driller logs.
Local measurements compared against Ontario provincial benchmarks.
| Hydrogeological Metric | From the registry or a cited study | ON Provincial Benchmark |
|---|---|---|
| Total Registered Wells | 8,684 | — |
| Median Well Depth | 130 ft | 103 ft provincial median |
| Average Well Depth | 148.6 ft | — |
| Dominant Aquifer | Crystalline Bedrock | — |
| Hardness | under 60 to above 180 mg/L as CaCO₃ — Estimate. Estimate based on Health Canada hardness bands | — |
| Drilling cost | $9,100–$19,500 — Estimate. Typical drilling prices in Canada, about $70–$150 per foot | — |
| Domestic Household Use | 93% of wells | — |
Approximate boundary of Thunder Bay
Shaded area is an approximate municipal outline for orientation only. Well records are aggregated across the entire Thunder Bay.
Most completed wells fall near the median depth of 130 ft. Recorded depths cover 8,638 wells.
Median depth of 130 ft falls inside the reported range. Deeper completions here usually mean higher mineral content but steadier year-round pressure.
Bedrock and drift aquifers recorded by drillers in this area. Recorded for 8,553 of these 8,684 wells.
4,436 of 8,684 Crystalline Canadian Shield rock. Yields soft, slightly acidic water with minimal dissolved solids, relying on secondary fracture networks for groundwater storage.
1,561 of 8,684 Fractured sedimentary shale formation (including Odanah / Pierre members). Characterized by high total dissolved solids (TDS) and potential sulfur/iron compounds.
1,532 of 8,684 Shallow to intermediate glacial drift aquifer deposited in alluvial channels or outwash plains. Yields softer water but requires continuous sediment filtration and shallow bacterial monitoring.
483 of 8,684 Major regional bedrock aquifer formed by Ordovician/Silurian dolomite. Known for reliable, high-volume yields with elevated mineral hardness and dissolved calcium/magnesium carbonates.
432 of 8,684 Impermeable glaciolacustrine clay and silt deposits formed in ancient glacial lakes. Acts as an effective regional aquitard confining underlying aquifers.
89 of 8,684 Deep basal sandstone bedrock unit (including Winnipeg Formation). Supplies exceptionally stable yields; often exhibits moderate mineral hardness with silica-rich water.
20 of 8,684 Unclassified hydrogeological formation from legacy provincial drill records.
2,626 holes found no usable water. test holes, observation or monitoring wells, dewatering wells, decommissioned wells, dry holes, no-aquifer holes, and other non-supply wells filtered out of the headline
A published hardness range, when one exists for this place and aquifer. Not a test of your well.
Measured nearby
Measured government tests within 25 km of Thunder Bay.
USGS (2018) bands reprinted by Health Canada. A range can cross more than one band. This is not a sample.
What this is not
Health Canada has not set a maximum acceptable concentration for hardness. A wide published range can sit in more than one USGS band.
THUNDER BAY, UNORGANIZED, THUNDER BAY DISTRICT, 13.83 km away, in the wider area.
18 government lab tests, dated 2006–2025.
Hardness 78–91 mg/L as CaCO₃, median 86.8.
Worked out by wellwaterguide.ca from 18 government lab tests.
reported hardness, or calculated from measured calcium and magnesium when hardness was not reported
Provincial Groundwater Monitoring Network (PGMN): water chemistry and well locations Open Government Licence - Ontario
THUNDER BAY, UNORGANIZED, THUNDER BAY DISTRICT, 15.51 km away, in the wider area.
3 government lab tests, dated 2006–2010.
Hardness 106–109 mg/L as CaCO₃, median 107.
Worked out by wellwaterguide.ca from 3 government lab tests.
reported hardness, or calculated from measured calcium and magnesium when hardness was not reported
Provincial Groundwater Monitoring Network (PGMN): water chemistry and well locations Open Government Licence - Ontario
SHUNIAH, THUNDER BAY DISTRICT, 21.49 km away, in the wider area.
18 government lab tests, dated 2007–2025.
Hardness 29–35 mg/L as CaCO₃, median 32.
Worked out by wellwaterguide.ca from 18 government lab tests.
reported hardness, or calculated from measured calcium and magnesium when hardness was not reported
Provincial Groundwater Monitoring Network (PGMN): water chemistry and well locations Open Government Licence - Ontario
Historical permit and construction activity by decade.
56% of dated wells are over 30 years old (pre-1995). Steel casing installed before 1995 can lose integrity over time. Any older well should get a casing inspection and a certified bacterial test before reliance.
Treatment
This page does not turn a hardness range or a well depth into an equipment total, a grain capacity, or a drilling price. Read the methodology, the filtration guide, and the products catalog.
Suggested system
Test kit
estimate, confirm with a lab testA test of your own well comes before any equipment. Test for coliform bacteria.
Water testingIron and manganese filter
estimate, confirm with a lab testManganese above the aesthetic objective, consider an iron/manganese filter. A monitoring well near this place has median iron of 0.847 mg/L and median manganese of 0.217 mg/L.
Iron and manganese guideBecause water wells in Thunder Bay average 130 ft into crystalline bedrock, contractors equipped with heavy rotary rigs and proper casing seals are recommended. Contact local drillers directly or request competitive bids.
Yard: Thunder Bay, ON (25 km away)
Yard: Greater Sudbury, ON (655.1 km away)
Yard: Stratford, ON (861.1 km away)
Yard: Barrie, ON (864.8 km away)
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Quick answers about water wells in Thunder Bay.
Among 8638 producing water wells with a recorded depth, the median is 130.0 ft (39.62 m).
Explore neighbouring hydrogeological formations and compare drilling depths