Frequently Asked Questions

Sampling Instructions

Follow the protocols outlined by the AOWMA to identify the different horizons in the soil. Sample each soil horizon for which you want the texture identified and send them to the lab to determine what the most limiting layers are. This information is to be used with the information collected on site to determine the loading rate.

Sample Submission Instructions:

Only about 1-2 cups of soil are required, please limit the sample sizes to that. Please ensure you have filled out the sample submission form (available on the Files & Online Submissions tab) and included that with your sample submission. Samples missing information (such as test package and signature) will be placed on hold until all appropriate information has been provided. Prismatic Testing:

Prismatic Testing

The 2015 SOP now mentions new testing for Prismatic soils. Prismatic soils used to be classified the same as blocky and granular in the SOP but are now treated differently. Make sure you know how to identify them.

What is soil texture?

Soil texture is a measure of the percent of sand, silt, and clay in the soil. It is combined with grade and structure to determine the water loading rate.

What does sieving mean?

Extra test required to determine whether Sand, Loamy Sand, or Sandy Loam should be classified as Very Fine, Fine, Medium, Coarse, or Very Coarse.

What is prismatic testing?

Prismatic soil is similar to columnar but younger and does not have rounded tops. It can cause potential failures in a septic system. In order to build with prismatic soils, the Standard of Practice from 2015 in Alberta requires four additional tests: SAR, COLE, Dispersion and EC.