Field Permeability Testing (Lefranc/Lugeon) in Pickering, Ontario

The difference in soil behavior between the Rouge River valley and the tablelands near Highway 7 is striking. In the valley you get silty clays with glacial lake deposits. Up on the tableland it shifts to sandy till with much faster drainage. This contrast means a single assumed permeability value for a Pickering project is a gamble. We apply the in-situ permeability test directly on your site to measure how water actually moves through these layers. A Lefranc test in a borehole gives us point-specific data in soil. When we hit fractured bedrock, which is common north of Taunton Road, we switch to the Lugeon method. The result is a real hydraulic conductivity number, not a textbook estimate, backed by our understanding of the Halton Till and local bedrock formations.

A Lugeon value under 3 in Pickering's Georgian Bay shale usually means tight rock suitable for cut-off walls without heavy grouting.

Our service areas

Our approach and scope

What we often see around the Duffin Heights area is perched water in the upper weathered zone, completely disconnected from the deeper aquifer. Standard lab tests on a bag sample will miss this. Field testing catches it every time. The Lefranc method works in soil at a constant or falling head, isolating a specific test section with a packer. For rock, the Lugeon test uses five pressure stages to check if fractures dilate with pressure. We cross-check the results with a grain-size analysis from the same borehole to understand why a value is what it is. For deeper investigations where SPT values are erratic, combining this data with SPT drilling and cpt testing builds a complete geotechnical model that covers strength and drainage in one go.

Field Permeability Testing (Lefranc/Lugeon) in Pickering, Ontario — Technical reference — Pickering

Local geotechnical context

We worked on a townhouse development near the Petticoat Creek floodplain where the geotechnical report assumed a blanket permeability from a single grain-size correlation. During excavation the contractor hit a sand lens that the boreholes missed. Water poured in at 200 liters per minute. The dewatering system was undersized and the excavation flooded twice. That sand lens, only 60 centimeters thick, had a permeability two orders of magnitude higher than the surrounding clay. A field permeability test at the right depth would have flagged it. The cost of the delay was ten times what the test program would have cost. In Pickering, where glacial stratigraphy changes meter by meter, skipping direct permeability measurement is the most expensive shortcut you can take.

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Regulatory framework

ASTM D6391-11: Standard Test Method for Field Measurement of Hydraulic Conductivity Using Borehole Infiltration, ASTM D4630-19: Standard Test Method for Determining Transmissivity and Storage Coefficient of Low-Permeability Rocks, Ontario Building Code (OBC) — Geotechnical requirements for foundation drainage and dewatering

Typical values

Parameter	Typical value
Test Standard for Soil	ASTM D6391 (Lefranc method)
Test Standard for Rock	ASTM D4630 (Lugeon method)
Measured Parameter	Hydraulic conductivity (k in cm/s or m/s)
Test Depth Range	Up to 30 m in soil, deeper in rock depending on rig capacity
Typical Soil k in Pickering	10⁻⁵ to 10⁻⁷ cm/s in silty till
Typical Rock Lugeon Value	1 to 15 Lugeon units in local shale and limestone
Reporting	Detailed log with pressure vs. flow graphs per test interval

Quick answers

What does a field permeability test cost in Pickering?

For a standard Lefranc or Lugeon test program in Pickering, the cost typically ranges from CA$810 to CA$1,280 per test interval, depending on depth, access conditions, and the number of stages required. A full site program with multiple boreholes and several test depths will be priced based on the specific scope of work.

When do I need a Lugeon test instead of a Lefranc test?

You need a Lugeon test when the borehole reaches bedrock. The Lefranc method works in soil. The Lugeon method uses packers and five pressure stages to test rock mass permeability and fracture behavior. In Pickering, we often run both on the same borehole: Lefranc in the overburden, Lugeon in the shale or limestone below.

How long does a single test take on site?

A single Lefranc test in moderately permeable soil can take 30 to 60 minutes to reach steady flow. A full five-stage Lugeon test in rock usually takes two to three hours per interval. We schedule the testing as part of the drilling program so the rig time is used efficiently.

Can you correlate this data with grain-size lab results?

Yes, and we recommend it. We send samples from the same test depth for grain-size analysis. Comparing the lab-derived hydraulic conductivity with the field-measured value gives a strong calibration point for the site. It also helps explain anomalies caused by soil fabric or fissures that lab tests miss.

Location and service area

We serve projects in Pickering and surrounding areas.

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