SEPTIC LICENSE COMPREHENSIVE STUDY GUIDE 2026
FULL QUESTIONS AND SOLUTIONS GRADED A+
● Soil Science Basics. Answer: Understanding soil properties relevant to OSSF site
evaluation
● Soil Texture Classes. Answer: USDA classification: sand, loamy sand, sandy loam, loam,
silt loam, clay loam, and clay
● Infiltration Rate. Answer: Rate at which water enters the soil surface
● Hydraulic Conductivity. Answer: Rate at which soil transmits water under a pressure
gradient
● Saturated Zone. Answer: Soil zone in which all pores are filled with water
● Unsaturated Zone. Answer: Vadose zone above the water table where treatment occurs in
drain fields
● Aerobic Bacteria. Answer: Oxygen-requiring microorganisms responsible for efficient
decomposition of waste
● Anaerobic Bacteria. Answer: Bacteria functioning without oxygen; primary organisms in
septic tanks
● Biozone. Answer: Area of biological activity in the soil surrounding the drain field
● Nitrogen Cycle. Answer: Transformation of nitrogen compounds through the OSSF and
soil
● Ammonia. Answer: Primary form of nitrogen in septic effluent
● Nitrification. Answer: Conversion of ammonia to nitrates by aerobic bacteria in the soil
● Denitrification. Answer: Conversion of nitrates to nitrogen gas under anaerobic conditions
● Phosphorus Removal. Answer: Adsorption of phosphorus by soil particles limiting
phosphorus movement
FULL QUESTIONS AND SOLUTIONS GRADED A+
● Soil Science Basics. Answer: Understanding soil properties relevant to OSSF site
evaluation
● Soil Texture Classes. Answer: USDA classification: sand, loamy sand, sandy loam, loam,
silt loam, clay loam, and clay
● Infiltration Rate. Answer: Rate at which water enters the soil surface
● Hydraulic Conductivity. Answer: Rate at which soil transmits water under a pressure
gradient
● Saturated Zone. Answer: Soil zone in which all pores are filled with water
● Unsaturated Zone. Answer: Vadose zone above the water table where treatment occurs in
drain fields
● Aerobic Bacteria. Answer: Oxygen-requiring microorganisms responsible for efficient
decomposition of waste
● Anaerobic Bacteria. Answer: Bacteria functioning without oxygen; primary organisms in
septic tanks
● Biozone. Answer: Area of biological activity in the soil surrounding the drain field
● Nitrogen Cycle. Answer: Transformation of nitrogen compounds through the OSSF and
soil
● Ammonia. Answer: Primary form of nitrogen in septic effluent
● Nitrification. Answer: Conversion of ammonia to nitrates by aerobic bacteria in the soil
● Denitrification. Answer: Conversion of nitrates to nitrogen gas under anaerobic conditions
● Phosphorus Removal. Answer: Adsorption of phosphorus by soil particles limiting
phosphorus movement
