Quality Site Assessments with Permeameter Testing of Soil

Constant Head Permeameters

Several years ago, CSSi started using permeameters and quickly discovered how useful and cost-effective they are for site assessments.

The field saturated hydraulic conductivity (Kfs) of soil is easily determined when using the permeameter. The stable rate of fall of water through the permeameter (in millimeters) when multiplied by the corresponding soil factor for the size of augered hole produces the Kfs value.

To make the translation of the data easier we calculated soil factors based on research by Mooers and Waller (1) that apply to CSSi permeameters and make the calculation of Kfs much easier.

(1) Mooers, J.D., and D.H. Waller, 1993 ON-Site Wastewater Disposal in Nova Scotia, Final Report, On-Site Wastewater Research Program Phase 2 1990-1993. Technical University of Nova Scotia.

Advantages of CSSi Permeameters:

Much faster test: In sandy loams and loams a permeameter test typically takes between 15 – 20 minutes. A properly conducted perc test in the same soil would take between 8 and 12 hours with presoaking and two draw downs. Very small amount of water needed. Usually 5 to 10 L per test is required. Controlled parameters: The size of the hole is controlled by the auger, the head of water driving the flow through the soil is constant, and the amount of water that permeates from the hole is precisely measured in milliliters. The more variables that can be controlled, the more repeatable the test should be. Variable depths: Holes can be augured and tests conducted between 30 cm – 70 cm with relative ease. Client’s perspective. The permeameter is seen as a scientific instrument that can be easily explained and takes very little time. More hydraulic conductivity determinations per site. Evaluators can easily conduct at least 6 – 7 tests per site within a couple of hours. No cheating necessary: Since the permeameter test is so quick and has the controlled permeameter noted above, no cheating is necessary and results are more consistent. Easy calculation of Kfs: The soil factors prepared by CSSi based on research make the calculation of Kfs easy.

Testing Tips

The permeameter is used to determine Kfs, the field saturated hydraulic conductivity.
Dig your test pits first to determine the design depth and depth for the permeameter tests.
It is cost-effective to conduct 2 or 3 constant head permeameter tests at one time.
We recommend a minimum of 6 – 7 permeameter tests within or just downslope of the proposed soil infiltration area.
With the huge time savings you should find that the permeameters completely pay for themselves in the first one to three jobs.
Ensure permeameters are securely supported when not in use-they can break if allowed to fall.
Use a stony auger to control hole size when augering permeameter holes in gravelly soils.
Check holes for smearing caused by the auger in finer textured soils.

Payment methods

Visa, MasterCard, E-Transfer, cheque or cash (paid before shipping) All shipping is by Greyhound freight, Purolator or UPS – You choose.

Price

4” permeameter $639 + tax charged to your credit card + shipping collect, Operating Instructions and Permeameter Log Sheets Once you have purchased a permeameter, CSSi will email you a link that will allow you to print out the permeameter sheets and the permeameter summary form (In the past we include a CD with operation instructions and the appropriate log sheets).

Augers

Stoney soil auger: we have found this auger to generally be more useful. The two tines protrude outward and tend to pull gravel into the hole. However, sometimes you need to use your hand to clean-out the bottom of the hole. Currently sold out – should be restocked soon.

Sand Gravel Screens

When logging test pits, the coarse fraction should be separated from the sand/silt/clay fraction. This enables one to do a fairly quick and accurate assessment of the coarse fraction. Screening greatly facilitates hand texturing, since small stones that interfere with casting and ribboning are not there. Coarse fraction screen: $55 + tax charged to your credit card, plus shipping collect.

For more information about our permeameter testing, please give us a call.