OSSF DR PREPARATION TEST 2026
QUESTIONS AND CORRECT ANSWERS
GRADED A+
● Who regulates OSSF systems in Texas? Answer: Texas Commission
on Environmental Quality (TCEQ)
● What type of systems can Installer I install? Answer: Conventional
(standard) systems only
● Can Installer I install aerobic systems? Answer: No
● Who is responsible for obtaining the OSSF permit? Answer: Property
owner
● When must an OSSF permit be issued? Answer: Before excavation
begins
● Who performs the site evaluation? Answer: Designated Representative
(DR) or Professional
● Can an Installer I perform a site evaluation? Answer: No
, ● What is a limiting condition? Answer: Water table, bedrock, or
restrictive soil layer
● What is the minimum vertical separation for a conventional system?
Answer: 24 inches
● From where is vertical separation measured? Answer: Bottom of
trench to limiting condition
● If separation is 22 inches, does it pass or fail? Answer: Fail
● What is the minimum septic tank size for a single-family residence?
Answer: 1,000 gallons
● What must septic tanks be? Answer: Watertight
● What is the primary purpose of a septic tank? Answer: Separate solids
from liquids
● What do septic tank baffles prevent? Answer: Solids from exiting the
tank
● What must access openings be? Answer: Accessible to grade
QUESTIONS AND CORRECT ANSWERS
GRADED A+
● Who regulates OSSF systems in Texas? Answer: Texas Commission
on Environmental Quality (TCEQ)
● What type of systems can Installer I install? Answer: Conventional
(standard) systems only
● Can Installer I install aerobic systems? Answer: No
● Who is responsible for obtaining the OSSF permit? Answer: Property
owner
● When must an OSSF permit be issued? Answer: Before excavation
begins
● Who performs the site evaluation? Answer: Designated Representative
(DR) or Professional
● Can an Installer I perform a site evaluation? Answer: No
, ● What is a limiting condition? Answer: Water table, bedrock, or
restrictive soil layer
● What is the minimum vertical separation for a conventional system?
Answer: 24 inches
● From where is vertical separation measured? Answer: Bottom of
trench to limiting condition
● If separation is 22 inches, does it pass or fail? Answer: Fail
● What is the minimum septic tank size for a single-family residence?
Answer: 1,000 gallons
● What must septic tanks be? Answer: Watertight
● What is the primary purpose of a septic tank? Answer: Separate solids
from liquids
● What do septic tank baffles prevent? Answer: Solids from exiting the
tank
● What must access openings be? Answer: Accessible to grade
