Determining the amount of organic material in soil

[Matsuri]

What is the best method for determining the % of organic material in soil. We are screeening soils to remove roots etc to increase useable fill and need to determine the amount of organic material remaining.

 

[Ron]

For this purpose, I would use ASTM D2974...it is a loss on ignition test for organic material in peats and clays, but will work on sands and mixtures as well.

There are other, more sophisticated methods, but most testing labs can do D2974 without much difficulty and it will give you the result you need to limit the organic material in the soil.

 

[BigH]

As an addition to Ron's post, what are you "limits" for organic matter in the fill? Do you have set percentages permitted? If you find that the percent organic is 3, is that a red flag? 4? 5?

 

[YannisChasiotis]

There is also AASHTO T-194.