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OSSF DR TEST PRACTICE Questions with
Detailed Verified Answers
Q: _______ and ________ soil textural classes are always
unsuitable for standard absorptive OSSF
Ans: class IA and IV
Q: List each of the major soil horizons
Ans: surface soil A, surface soil B, and parent material
Q: _____________ is a term describing the ability of water to
migrate through a soil profile under either _________ or
__________ conditions.
Ans: Hydraulic conductivity, saturated, unsaturated
Q: Interconnected pores in the soil profile allow ______ and
_______ to enter the soil at its surface and migrate downward
Ans: air, water
Q: List the four components of soil
Ans: air, water, organics, inorganics
Q: 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)?
Ans: 208.3 cubic yards
Q: 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?
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Ans: 587 gals
Q: What would be the percent slope on a lot 250 feet deep that
drops 20 feet in elevation over the depth of the lot?
Ans: 8%
Q: 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.
Ans: 6.67 cubic yards
Q: 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?
Ans: 846 gals
Q: Calculate the working liquid capacity (volume) for this septic
tank. SEE PAGE 2-39!!
Ans: 1077gals
Q: What is the surface area (area in square feet) of an
evapotranspiration system 40 feet wide and 65 feet long?
Ans: 2,600 sqft
Q: Figure the acreage for a piece of property that measures 256
feet on each of four sides.
Ans: 1.5 acres
Q: Figure the area of a lot that measures 60ft by 280ft
Ans: 16,800sqft ,0.39 acres
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Q: A disposal option that might be considered in a clay soil would
be a ________.
Ans: drip or spray irrigation
Q: The primary treatment device providing the least or poorest
treatment of domestic wastewater would be _______.
Ans: septic tank
Q: Nitrogen or nitrate removal in soil occurs by _________.
Ans: vegetation uptake
Q: The factors influencing the survival of bacteria in soil are
_______.
Ans: moisture, temperature, pH, and organic matter.
Q: Physical removal of bacteria by straining occurs when _______.
Ans: the bacteria are larger than the pore openings in the soil
Q: A solid that can be filtered out of the wastewater is a
_________.
Ans: suspended solid
Q: Which of the following describes domestic wastewater as it
leaves a home?
Ans: fresh, light in color, has dissolved oxygen
Q: Which of the following are problems caused by malfunctioning
septic tank systems?
Ans: surface water pollution, groundwater contamination, and
standing sewage in neighborhoods
OSSF DR TEST PRACTICE Questions with
Detailed Verified Answers
Q: _______ and ________ soil textural classes are always
unsuitable for standard absorptive OSSF
Ans: class IA and IV
Q: List each of the major soil horizons
Ans: surface soil A, surface soil B, and parent material
Q: _____________ is a term describing the ability of water to
migrate through a soil profile under either _________ or
__________ conditions.
Ans: Hydraulic conductivity, saturated, unsaturated
Q: Interconnected pores in the soil profile allow ______ and
_______ to enter the soil at its surface and migrate downward
Ans: air, water
Q: List the four components of soil
Ans: air, water, organics, inorganics
Q: 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)?
Ans: 208.3 cubic yards
Q: 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?
, Page | 2
Ans: 587 gals
Q: What would be the percent slope on a lot 250 feet deep that
drops 20 feet in elevation over the depth of the lot?
Ans: 8%
Q: 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.
Ans: 6.67 cubic yards
Q: 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?
Ans: 846 gals
Q: Calculate the working liquid capacity (volume) for this septic
tank. SEE PAGE 2-39!!
Ans: 1077gals
Q: What is the surface area (area in square feet) of an
evapotranspiration system 40 feet wide and 65 feet long?
Ans: 2,600 sqft
Q: Figure the acreage for a piece of property that measures 256
feet on each of four sides.
Ans: 1.5 acres
Q: Figure the area of a lot that measures 60ft by 280ft
Ans: 16,800sqft ,0.39 acres
, Page | 3
Q: A disposal option that might be considered in a clay soil would
be a ________.
Ans: drip or spray irrigation
Q: The primary treatment device providing the least or poorest
treatment of domestic wastewater would be _______.
Ans: septic tank
Q: Nitrogen or nitrate removal in soil occurs by _________.
Ans: vegetation uptake
Q: The factors influencing the survival of bacteria in soil are
_______.
Ans: moisture, temperature, pH, and organic matter.
Q: Physical removal of bacteria by straining occurs when _______.
Ans: the bacteria are larger than the pore openings in the soil
Q: A solid that can be filtered out of the wastewater is a
_________.
Ans: suspended solid
Q: Which of the following describes domestic wastewater as it
leaves a home?
Ans: fresh, light in color, has dissolved oxygen
Q: Which of the following are problems caused by malfunctioning
septic tank systems?
Ans: surface water pollution, groundwater contamination, and
standing sewage in neighborhoods
