OSSF Designated Representative (DR)
Practice Examination 2026/2027 Latest
Update|| On-Site Sewage Facility (OSSF)
Certification Preparation Guide
QUESTION 1
Individuals working as a ______ or in any capacity for an OSSF
______ cannot work as an Installer, Designer for a fee, or private
Site Evaluator within the jurisdiction of the permitting authority.
Correct Answer: Designated representative (DR), permitting
authority
QUESTION 2
____ and _____ soil textural classes are always unsuitable for
standard absorptive OSSF
Correct Answer: class IA and IV
QUESTION 3
List each of the major soil horizons
Correct Answer: surface soil A, surface soil B, and parent
material
1 page
,QUESTION 4
________ is a term describing the ability of water to migrate
through a soil profile under either ______ or ______ conditions.
Correct Answer: Hydraulic conductivity, saturated, unsaturated
QUESTION 5
Interconnected pores in the soil profile allow ____ and _____ to
enter the soil at its surface and migrate downward
Correct Answer: air, water
QUESTION 6
List the four components of soil
Correct Answer: air, water, organics, inorganics
QUESTION 7
A drainfield is 50 feet by 90 feet and must be covered with an
average of 15 inches of sand loam. How many cubic yards of
sandy loam soil must be purchased (find the volume of a
rectangular object)?
Correct Answer: 208.3 cubic yards
QUESTION 8
What would be the volume of a 5-foot-diameter pump tank that is
5 feet tall with the inlet 1 foot below the rim?
Correct Answer: 587 gals
2 page
,QUESTION 9
What would be the percent slope on a lot 250 feet deep that
drops 20 feet in elevation over the depth of the lot?
Correct Answer: 8%
QUESTION 10
How many cubic yards of gravel would be needed to fill a ditch 3
feet deep, 10 feet wide, and 12 feet long with 18 inches of gravel?
1 cubic yard = 27 cubic feet.
Correct Answer: 6.67 cubic yards
QUESTION 11
A septic tank is 6 feet in diameter and is 8 feet deep. How many
gallons will it hold if the overflow line is located half way up
from the bottom?
Correct Answer: 846 gals
QUESTION 12
Calculate the working liquid capacity (volume) for this septic
tank. SEE PAGE 2-39!!
Correct Answer: 1077 gals
3 page
, QUESTION 13
What is the surface area (area in square feet) of an
evapotranspiration system 40 feet wide and 65 feet long?
Correct Answer: 2,600 sqft
QUESTION 14
Figure the acreage for a piece of property that measures 256 feet
on each of four sides.
Correct Answer: 1.5 acres
QUESTION 15
Figure the area of a lot that measures 60ft by 280ft
Correct Answer: 16,800 sqft, 0.39 acres
QUESTION 16
A disposal option that might be considered in a clay soil would be
a ______.
Correct Answer: drip or spray irrigation
QUESTION 17
The primary treatment device providing the least or poorest
treatment of domestic wastewater would be ______.
Correct Answer: septic tank
4 page
Practice Examination 2026/2027 Latest
Update|| On-Site Sewage Facility (OSSF)
Certification Preparation Guide
QUESTION 1
Individuals working as a ______ or in any capacity for an OSSF
______ cannot work as an Installer, Designer for a fee, or private
Site Evaluator within the jurisdiction of the permitting authority.
Correct Answer: Designated representative (DR), permitting
authority
QUESTION 2
____ and _____ soil textural classes are always unsuitable for
standard absorptive OSSF
Correct Answer: class IA and IV
QUESTION 3
List each of the major soil horizons
Correct Answer: surface soil A, surface soil B, and parent
material
1 page
,QUESTION 4
________ is a term describing the ability of water to migrate
through a soil profile under either ______ or ______ conditions.
Correct Answer: Hydraulic conductivity, saturated, unsaturated
QUESTION 5
Interconnected pores in the soil profile allow ____ and _____ to
enter the soil at its surface and migrate downward
Correct Answer: air, water
QUESTION 6
List the four components of soil
Correct Answer: air, water, organics, inorganics
QUESTION 7
A drainfield is 50 feet by 90 feet and must be covered with an
average of 15 inches of sand loam. How many cubic yards of
sandy loam soil must be purchased (find the volume of a
rectangular object)?
Correct Answer: 208.3 cubic yards
QUESTION 8
What would be the volume of a 5-foot-diameter pump tank that is
5 feet tall with the inlet 1 foot below the rim?
Correct Answer: 587 gals
2 page
,QUESTION 9
What would be the percent slope on a lot 250 feet deep that
drops 20 feet in elevation over the depth of the lot?
Correct Answer: 8%
QUESTION 10
How many cubic yards of gravel would be needed to fill a ditch 3
feet deep, 10 feet wide, and 12 feet long with 18 inches of gravel?
1 cubic yard = 27 cubic feet.
Correct Answer: 6.67 cubic yards
QUESTION 11
A septic tank is 6 feet in diameter and is 8 feet deep. How many
gallons will it hold if the overflow line is located half way up
from the bottom?
Correct Answer: 846 gals
QUESTION 12
Calculate the working liquid capacity (volume) for this septic
tank. SEE PAGE 2-39!!
Correct Answer: 1077 gals
3 page
, QUESTION 13
What is the surface area (area in square feet) of an
evapotranspiration system 40 feet wide and 65 feet long?
Correct Answer: 2,600 sqft
QUESTION 14
Figure the acreage for a piece of property that measures 256 feet
on each of four sides.
Correct Answer: 1.5 acres
QUESTION 15
Figure the area of a lot that measures 60ft by 280ft
Correct Answer: 16,800 sqft, 0.39 acres
QUESTION 16
A disposal option that might be considered in a clay soil would be
a ______.
Correct Answer: drip or spray irrigation
QUESTION 17
The primary treatment device providing the least or poorest
treatment of domestic wastewater would be ______.
Correct Answer: septic tank
4 page
