Same idea as a perc test.
What I do is a soil morphology evaluation which in Missouri at least, is preferred since I can provide more information. Whereas a perc test just tells you how fast water infiltrates.
But many lay people refer to what I do as a perc test, so in that sense, yes a perc test.
What methods do you use on the morphology? Are you mostly looking at texture and structure by depth?
Texture, structure, water tables, depth to bedrock are the important things, but I also record color, rock content, consistency, shrink/swell, slope, etc.
In the end, I assign a value of how many gallons per day the soil can absorb, and that determines how big the wastewater system must be.
