The soil profile changes dramatically from Edmonton's flat northeast industrial parks to the deep ravine clays along the North Saskatchewan River. In the northeast, you might hit glacial till with silt lenses where a Lefranc test gives you a quick, reliable K value at the base of a borehole. Head down toward Riverbend or the valley floor, and the geology shifts to coarse alluvial sands and gravels, or even fractured bedrock. That's where a Lugeon test becomes essential — you need to know how much water that rock mass will take under pressure before you design a deep excavation or a bridge abutment. The city's variable post-glacial geology makes site-specific permeability data non-negotiable, and our lab reports are backed by ASTM D6391 procedures and local drilling crews who know the Edmonton till.
In the Edmonton till, a single Lefranc test at the right depth is worth more than a hundred lab perm tests on disturbed samples.
Scope of work in Edmonton
Typical technical challenges in Edmonton
Edmonton sits at roughly 645 metres above sea level, and its post-glacial stratigraphy is famously unpredictable — thick lake clays, pre-glacial gravel channels, and Cretaceous bedrock all within a few city blocks. If you skip a field permeability test and rely on textbook values, two things can happen: your dewatering system is undersized and the excavation floods, or you overdesign the system and burn budget for no reason. In the river valley, where the water table often sits just a few metres down, underestimating inflow can put shoring stability at risk. For rock sockets in the Horseshoe Canyon Formation, a Lugeon test tells you whether the shale is tight or riddled with fractures that need grouting before pile installation.
Our services
We run two types of in-situ permeability tests across the Edmonton metro area, both executed from drill holes logged by our geotechnical team.
Lefranc test (soil and granular)
Constant or falling head test isolating a short section of the borehole with a packer. We measure flow rate and head difference to calculate hydraulic conductivity. Standard procedure for dewatering studies, infiltration analysis, and basement waterproofing design in Edmonton's till and sand layers.
Lugeon test (fractured rock)
A packer test run in bedrock intervals, typically 3 to 5 metres long. We apply water pressure in five stages and measure take. The Lugeon value tells you the rock mass permeability and the likelihood of needing grouting. Critical for bridge piers, deep shafts, and tower foundations socketed into Edmonton's sandstone or shale.
Questions and answers
How much does a Lefranc or Lugeon test cost in Edmonton?
When do I need a Lugeon test instead of a Lefranc?
Lefranc tests work well in soil and granular materials. When your borehole hits bedrock — sandstone, shale, or fractured claystone — you switch to the Lugeon method. The Lugeon test applies staged pressures to measure the rock mass's ability to take water, which is vital for socket friction design and estimating grout take.
Can you run the test in the same borehole as the SPT sampling?
Yes. We typically drill and sample the full depth first, then install a packer and run the Lefranc or Lugeon test in the target interval. This keeps costs down because you're not mobilizing a separate drill hole just for permeability data.
How long does a field permeability test take on site?
A single Lefranc test takes roughly 30 to 60 minutes once the hole is prepped. A Lugeon test with the full five-stage pressure cycle runs closer to 90 minutes per interval. Multiple intervals or deep bedrock setups will add rig time.
What's the typical hydraulic conductivity of Edmonton till?
It varies a lot. Intact glacial till can be as low as 1×10⁻⁷ cm/s, but sand lenses and fractured zones within the till can jump two or three orders of magnitude. That's exactly why we run the test — the range is too wide to assume. More info.