TCEQ On-Site Sewage Facilities (OSSF) Practice Exam

The correct choice identifies texture and type as the critical soil characteristics for determining the feasibility of a septic system. Soil texture refers to the proportion of different sized particles, such as sand, silt, and clay, which significantly influences how water moves through the soil. For a septic system to function effectively, the soil must be able to adequately absorb and filter effluent from the septic tank.

Soil type is equally important as it encompasses the broader classification of the soil's characteristics, including its composition, drainage capabilities, and overall suitability for absorbing wastewater. Specific soil types, such as sandy soils, allow for rapid drainage, while clay soils may retain water and create a risk of system failure due to poor absorption.

Both texture and type play fundamental roles in assessing percolation rates, the potential for groundwater contamination, and ultimately, the design and placement of the septic system. Understanding these characteristics ensures that the septic system can function properly without causing environmental harm.