OSSF DR TEST PRACTICE UPDATED
ACTUAL Exam Questions and CORRECT
Answers
_______ 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
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
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
Parasites (helminths) found in untreated sewage include ________. - CORRECT ANSWER -
hookworm, round worms, and tapeworms
Viruses are responsible for such diseases as - CORRECT ANSWER - poliomyelitis and
infectious hepatitis
A type of bacteria that indicates sewage contamination is ________. - CORRECT ANSWER -
fecal coliform
Protozoa are very simple animal organisms that may cause ________. - CORRECT
ANSWER - amoeba dysentery and Giardiasis
Waterborne diseases that spread by pathogenic bacteria include _________. - CORRECT
ANSWER - typhoid, cholera, and dysentery
ACTUAL Exam Questions and CORRECT
Answers
_______ 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
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
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
Parasites (helminths) found in untreated sewage include ________. - CORRECT ANSWER -
hookworm, round worms, and tapeworms
Viruses are responsible for such diseases as - CORRECT ANSWER - poliomyelitis and
infectious hepatitis
A type of bacteria that indicates sewage contamination is ________. - CORRECT ANSWER -
fecal coliform
Protozoa are very simple animal organisms that may cause ________. - CORRECT
ANSWER - amoeba dysentery and Giardiasis
Waterborne diseases that spread by pathogenic bacteria include _________. - CORRECT
ANSWER - typhoid, cholera, and dysentery
