“The Lighthouse Companies is a amazing company that figures out what it takes to solve any soil issue. We are proud to have worked with them in 2016 and look forward to 2017 with them. Alan Levine is professional as well as proficient.”

Do you need testing and classification of the topsoil for your construction project?  Project specifications for commercial projects often require the topsoil be tested by an independent testing laboratory prior to import and use at a project site.  We can easily collect samples and test your topsoil for you or if you prefer you can bring the samples to us for testing.

What is included in our topsoil testing and classification?

We perform topsoil testing in general accordance with the NRCS USDA Kellogg Soil Survey Laboratory Methods Manual, Soil Survey Investigation Report No. 42, Version 5.0 Issued 2014 and ASTM D 4972 for pH.

Some of the parameters we test for and the typical allowable limits are summarized below:

Test Description Allowable Limit
Organic content 5 – 10%
Maximum particle size Less than 0.75 inches
Percent retained on ¼ inch sieve Max. 3%
pH 5.5 – 7.0
Overall composition Sand 20-35%
Silt 25-50%
Clay 10-30%
Soluble salts 600 ppm

What test are required for topsoil testing and classification?

Required independent testing for commercial properties typically includes basic soil groups:

  • moisture and saturation percentages
  • Nitrogen-Phosphorus-Potassium (N-P-K) ratio
  • pH
  • soil salinity

Secondary nutrient groups (calcium, magnesium, sodium, Sodium Absorption Ratio (SAR)) and micronutrients (zinc, manganese, iron, copper) are commonly requested as well.

Additional testing such as toxic soil elements (boron, chloride, sulfate), cation exchange and base saturation percentages, soil amendment and fertilizer recommendations with quantities for plant material being transplanted may be requested but are less common.

What sample size do I need?

Depending on your project specifications, we typically recommend that the areas sampled should not be larger than 1 acre and should contain at least 6-8 cores for each sample area.  These cores are then thoroughly mixed to create one composite sample. The process is repeated for each additional acre to be tested.  Problem areas should be sampled separately and compared with samples taken from adjacent non-problem areas. The location of the sample areas should be noted and marked on a parcel sample location map for future reference as well as project submittals.

Service areas

Our engineers are licensed to perform topsoil testing and classification in the following states: Florida, Illinois, Indiana, Iowa, Kentucky, Minnesota, Mississippi, Ohio, Texas, and Wisconsin.