What does a soil percolation test measure?

A soil percolation test measures the rate at which water seeps through the soil from a saturated test hole. This test is essential for determining the soil's drainage capabilities and its ability to absorb wastewater, which is crucial for designing septic systems or evaluating suitability for certain types of vegetation and land use. The results help assess whether the soil can adequately process effluent and support wastewater disposal without causing surface runoff or contamination of groundwater.

The other options do not align with the objective of a percolation test. For instance, measuring the rate of soil erosion involves evaluating the loss of soil due to water or wind, which is not the focus of a percolation test. Similarly, the pH level of soil relates to its acidity or alkalinity, and moisture content pertains to how much water is present in the soil, neither of which is measured directly by a percolation test. Thus, option B accurately describes the specific purpose and function of the soil percolation test.