What is a percolation test used to determine?

A percolation test is specifically designed to evaluate the soil's ability to absorb and drain water. This test is critical in determining how quickly water can percolate through the soil, which in turn informs decisions regarding the installation of septic systems and other subsurface drainage systems. The results of a percolation test help to ensure that a system can function effectively without causing issues like contamination or water pooling, making it essential for proper land use and environmental health.

The other options, while relevant to environmental studies and land-use planning, do not pertain to the primary function of a percolation test. The quality of the water source and the presence of hazardous materials are assessed through different testing methods focused on water testing and environmental assessments, while the soil's pH level is determined through separate soil analysis techniques that evaluate chemical properties, not drainage capacity. Thus, the focus of the percolation test solely on drainage capabilities makes it a distinct and vital measurement in evaluating soil performance for water penetration.