The steel casing drops first, driven past the loose topsoil into the weathered granite that sits under half of Roseville. Then the flush water clears the borehole and we lower the packer assembly until it seats right above the test interval. For a Lefranc test in a shallow monitoring well off Pleasant Grove Boulevard, we might use a simple falling-head setup with a graduated burette. A Lugeon test at depth for a water tunnel alignment requires the high-pressure pump, the pressure transducer at the collar, and a steady nerve to hold five pressure steps without blowing the packer through a fractured zone. MASW surveys often guide us to the right depth before we mobilize the permeability rig, especially where the decomposed granite transitions unpredictably into hard, jointed rock. The whole setup runs off a portable water tank because Roseville's summer heat means you can't count on a reliable hydrant flow at every lot.
A single Lugeon value without a proper packer seal is worse than no test at all. We pressure-test every setup.
Our approach and scope
Local ground factors
Roseville sits on the boundary between the Sacramento Valley alluvium and the Sierra Nevada foothills metamorphic belt. That means a single site can have clean river cobbles at 8 feet, tight clay at 15 feet, and fractured meta-andesite at 30 feet. If you skip the field permeability test and rely on grain-size correlations alone, you risk either undersizing your retention basin and flooding the adjacent property, or overestimating the grout take in a fractured rock curtain and blowing your construction budget. The IBC requires stormwater infiltration rates based on in-situ testing for any basin larger than a bioswale, and Roseville's Public Works plan checkers are strict about it. A dry hole during an August test can also mislead you: the water table under the city drops seasonally by 15 to 20 feet, so a Lefranc test in the unsaturated zone needs to be run as a falling-head test, not a constant-head test.
Applicable standards
ASTM D2434: Standard Test Method for Permeability of Granular Soils (Constant Head), ASTM D5092: Standard Practice for Design and Installation of Groundwater Monitoring Wells, IBC Section 1803.5.5: In-situ hydraulic conductivity for stormwater infiltration, ASCE 7-22: Geotechnical investigation requirements for seismic design
Complementary services
Lefranc (Falling/Rising Head) Test
Best for shallow soils, monitoring wells, and infiltration basins. We use a 2-inch PVC standpipe with a slotted screen and a graduated burette for precise head measurements in the decomposed granite and alluvial soils common across Roseville.
Lugeon Packer Test in Rock
Five pressure steps run at a set depth interval in fractured metavolcanic or granitic rock. We use a single or double pneumatic packer and digital pressure recording to calculate Lugeon values for grout curtain design and tunnel pre-excavation.
Variable Head Permeability in Boreholes
For deeper alluvial sequences near Dry Creek, we run constant-head or falling-head tests inside a cased borehole, isolating the test zone with a packer to avoid leakage around the casing annulus.
Infiltration Basin Verification Testing
Multiple tests at varying depths, logged to meet Roseville Public Works submittal requirements. We provide the K-values and a summary letter signed by the project geologist within five business days.
Typical parameters
Quick answers
What does a field permeability test cost in Roseville?
A single Lefranc or Lugeon test typically runs between US$620 and US$1,190 depending on depth, access, and whether you need a single packer or double packer setup. Mobilization is usually included for projects within the Roseville city limits. If you need multiple tests at the same site or we are already on location with the drill rig for SPT sampling, the per-test cost drops noticeably.
Which test do I need for a stormwater basin, Lefranc or Lugeon?
For the typical retention basin in Roseville's decomposed granite and alluvium, a Lefranc falling-head test is the right choice. Lugeon tests are for fractured rock at depth, such as dam foundations or deep tunnel alignments. If your basin excavation hits hard rock within the first 10 feet, we will switch to a packer test in the borehole to get a reliable K-value for the rock mass.
How long does a permeability test take, and when do I get results?
A single test interval takes about 60 to 90 minutes to set up the packer, saturate the test zone, and run the pressure or head steps. On a typical day in Roseville, we complete two to three test intervals. You get the calculated K-values and Lugeon numbers in a summary email within three business days, with the full signed report following within the week.