Classifying Soil Types: Good vs Bad?

Good vs Bad Soils?

After reading this article you will be suitability qualified to wow your family, neighbours and friends at your next big garden party when the conversation inevitably turns to the pristine condition of the host’s garden and lawn and they repsond with it’s just ‘good soil’!

Contrary to your next-door neighbours, soils are not good or bad like a Marvel character but an unconsolidated matrix of minerals, organic matter, gases, liquids and organisms which contribute to the overall condition of SOIL!

How to Classify Soil Types

Within the mineral element soils are classified as cohesive particles which are typically less than 0.063mm in size and include clays and silt, and granular particles which are greater than 0.063mm and are classified up to boulders which are classified as 630mm and above. As Plato once said ‘no two soils are born exactly alike’ and every site contains a unique balance which ultimately dictates a soils suitability for a proposed development.

Determining the Suitability of Soils

At Omnia we understand the complexity of soils and our engineers use a range of industry approved techniques to classify soils including, crumbling, moulding, sniffing (via PID) and agitating them to provide a detailed log for our clients. Alongside this we carry out in-situ testing such as Standard Penetration Test (SPT’S), California Bearing Rations (CBR’s) and Hand Shear Vane Testing (HSV) plus carry out soil laboratory testing including particle size distribution, plasticity testing and shear testing. The end results is a report which doesn’t tell you if your soils is good or bad, but provides you with detailed information on the soils onsite to assist with foundation design and ultimately determine if the soils are suitable for the proposed end use.

Dealing with Contaminated Soil

At this point you are clearly the true soil expert at the party and your audience is eating out the palm of your hand. Now you can finish of your Shakespearean recounting of the above with a final few words on contamination. ‘Did you know that soils contain a legacy of human development and its impact on the world’. Remember PCB’s, DDT and asbestos…they are just a couple of examples of contaminants which persist within our soils. To your stunned audience ‘FEAR NOT, Omnia are on hand to carry out laboratory testing of your soils to determine the potential risks posed to future site users! We can put your mind at ease with our technical expertise! We have never found a site that has soils which cannot be treated, removed or covered, and we pride ourselves in taking on your challenge!


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Speak to an Expert

Dr Adrian King

Principal Geo-Environmental Consultant