We are soon to get a new septic system. Ours is rather archaic and it’s time for a new one (I’ll spare you all the cruddy details). The guys who are putting it in, said we could save a bit of coin if we did our own percolation or “perc tests” to see how big of a drain field we’d need based on the drainage characteristics of our soils.
First, you dig four holes three feet deep, mark a point a few inches below the surface, and fill the hole with water and measure how far it has dropped in a certain time period. Repeat this until three readings are close to each other (the first few readings, the drop is large as the soil saturates.
We had a helpful recorder so we could haul water and time measurements.