OSSF DR TEST PRACTICE Exam
Questions and Answers Graded A+
_______ and ________ soil textural classes are always unsuitable for standard
absorptive OSSF - Correct answer-class IA and IV
List each of the major soil horizons - Correct answer-surface soil A, surface soil B,
and parent material
_____________ is a term describing the ability of water to migrate through a soil
profile under either _________ or __________ conditions. - Correct answer-
Hydraulic conductivity, saturated, unsaturated
Interconnected pores in the soil profile allow ______ and _______ to enter the soil
at its surface and migrate downward - Correct answer-air, water
List the four components of soil - Correct answer-air, water, organics, inorganics
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
©COPYRIGHT 2025, ALL RIGHTS RESERVED 1
,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
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%
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
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
Calculate the working liquid capacity (volume) for this septic tank. SEE PAGE 2-
39!! - Correct answer-1077gals
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
Figure the acreage for a piece of property that measures 256 feet on each of four
sides. - Correct answer-1.5 acres
Figure the area of a lot that measures 60ft by 280ft - Correct answer-16,800sqft
,0.39 acres
©COPYRIGHT 2025, ALL RIGHTS RESERVED 2
, A disposal option that might be considered in a clay soil would be a ________. -
Correct answer-drip or spray irrigation
The primary treatment device providing the least or poorest treatment of domestic
wastewater would be _______. - Correct answer-septic tank
Nitrogen or nitrate removal in soil occurs by _________. - Correct answer-
vegetation uptake
The factors influencing the survival of bacteria in soil are _______. - Correct
answer-moisture, temperature, pH, and organic matter.
Physical removal of bacteria by straining occurs when _______. - Correct answer-
the bacteria are larger than the pore openings in the soil
A solid that can be filtered out of the wastewater is a _________. - Correct answer-
suspended solid
Which of the following describes domestic wastewater as it leaves a home? -
Correct answer-fresh, light in color, has dissolved oxygen
Which of the following are problems caused by malfunctioning septic tank
systems? - Correct answer-surface water pollution, groundwater contamination,
and standing sewage in neighborhoods
An inorganic chemical that affects human health is - Correct answer-nitrate
©COPYRIGHT 2025, ALL RIGHTS RESERVED 3
Questions and Answers Graded A+
_______ and ________ soil textural classes are always unsuitable for standard
absorptive OSSF - Correct answer-class IA and IV
List each of the major soil horizons - Correct answer-surface soil A, surface soil B,
and parent material
_____________ is a term describing the ability of water to migrate through a soil
profile under either _________ or __________ conditions. - Correct answer-
Hydraulic conductivity, saturated, unsaturated
Interconnected pores in the soil profile allow ______ and _______ to enter the soil
at its surface and migrate downward - Correct answer-air, water
List the four components of soil - Correct answer-air, water, organics, inorganics
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
©COPYRIGHT 2025, ALL RIGHTS RESERVED 1
,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
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%
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
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
Calculate the working liquid capacity (volume) for this septic tank. SEE PAGE 2-
39!! - Correct answer-1077gals
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
Figure the acreage for a piece of property that measures 256 feet on each of four
sides. - Correct answer-1.5 acres
Figure the area of a lot that measures 60ft by 280ft - Correct answer-16,800sqft
,0.39 acres
©COPYRIGHT 2025, ALL RIGHTS RESERVED 2
, A disposal option that might be considered in a clay soil would be a ________. -
Correct answer-drip or spray irrigation
The primary treatment device providing the least or poorest treatment of domestic
wastewater would be _______. - Correct answer-septic tank
Nitrogen or nitrate removal in soil occurs by _________. - Correct answer-
vegetation uptake
The factors influencing the survival of bacteria in soil are _______. - Correct
answer-moisture, temperature, pH, and organic matter.
Physical removal of bacteria by straining occurs when _______. - Correct answer-
the bacteria are larger than the pore openings in the soil
A solid that can be filtered out of the wastewater is a _________. - Correct answer-
suspended solid
Which of the following describes domestic wastewater as it leaves a home? -
Correct answer-fresh, light in color, has dissolved oxygen
Which of the following are problems caused by malfunctioning septic tank
systems? - Correct answer-surface water pollution, groundwater contamination,
and standing sewage in neighborhoods
An inorganic chemical that affects human health is - Correct answer-nitrate
©COPYRIGHT 2025, ALL RIGHTS RESERVED 3
