Where should percolation tests be performed in relation to soil evaluation?

Percolation tests are crucial for assessing how well water drains through soil, which directly impacts the suitability of the land for various uses, such as septic systems. Conducting these tests in soil identified as most restrictive is essential because this layer has the least permeability and can significantly affect the overall drainage characteristics of the site.

If percolation tests are performed in a layer that allows for better drainage, the results may not accurately reflect the performance of the more restrictive layers that could hinder drainage. For effective soil evaluation, it's necessary to understand how the most restrictive soil layer will interact with water movement and drainage systems. By focusing on this layer, the evaluation provides a clearer picture of potential issues related to water saturation, which is critical for making informed decisions regarding land use and waste management.