Which of the following statements about soil structure and pore spaces is true?

The statement regarding large pore spaces being important for absorbing sewage effluent is accurate because pore size directly influences the movement and retention of water and other liquids in the soil. Larger pore spaces allow for a greater flow of fluids, which is essential for effective drainage and absorption of sewage effluent. When sewage is introduced into the septic system, it requires adequate space within the soil to percolate and be treated effectively before it reaches the groundwater. This process of absorption is critical for preventing contamination and ensuring that the effluent is adequately treated by the natural filtering properties of the soil.

In contrast, smaller pore spaces tend to retain water more effectively and may lead to saturated conditions where water cannot move through the soil as quickly. This can create problems for sewage absorption as it hinders proper drainage, potentially resulting in system failure or groundwater contamination. While soil structure does play a role, it is not irrelevant to septic systems because the arrangement and size of soil particles significantly impact filtration and absorption capabilities. Thus, understanding the interactions between soil structure, pore spaces, and sewage absorption is vital for effective septic system design and maintenance.