Jar soil test for leachfield design

[JohnnyB_]

I am assessing soil for a leachfield design and am curious if anyone has a good method to classify the soil without doing a percolation test. I am in the process of doing the soil jar test (see attached) but curious if there is a standardized methodology I can use. Thanks in advance.

 

[GeoEnvGuy]

Classifying the soil typically means performing a grain size analysis and Atterberg limits to determine its USCS classification. Ontario building code has a supplemental standard SB-6 to assign a percolation time to soil classification. Looking at the picture attached it looks like clay clods which were not broken up at the bottom of the jar, if there is a large portion of fine grained silt/clay in your leachfield area this will require more size or importing permeable backfill.

 

[JohnnyB_]

Thank you for the reply. The regulation I have to follow in CO gives LTAR values for soil classified in the USDA classification system, which seems to be a more broad spectrum and less detailed than the USCS classification system. I can classify the soil with sieves under the USCS but I can't find the supplemental standard SB-6 that you mentioned. Is there any chance that you could send me the url to the standard or upload it here?

 

[GeoEnvGuy]

Hi JohnnyB, you may want to reach out to others in your jurisdiction to see how they go about fulfilling the local requirements for permitting. As for the ontario supplemental standard 6 you can find it by searching for " ontario building code 2012 volume 2 pdf ".

 

[JohnnyB_]

Thanks!