OSSF DR TEST PRACTICE EXAMS
WITH QUALIFIED QUESTIONS AND
ANSWERS
_______ and ________ soil textural classes are always unsuitable for standard absorptive OSSF -
ANSWER-class IA and IV
List each of the major soil horizons - 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. - ANSWER-Hydraulic conductivity, saturated, unsaturated
Interconnected pores in the soil profile allow ______ and _______ to enter the soil at its surface and
migrate downward - ANSWER-air, water
List the four components of soil - 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)? -
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? - 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? - 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. - 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? - ANSWER-846 gals
Calculate the working liquid capacity (volume) for this septic tank. SEE PAGE 2-39!! - ANSWER-1077gals
What is the surface area (area in square feet) of an evapotranspiration system 40 feet wide and 65 feet
long? - ANSWER-2,600 sqft
Figure the acreage for a piece of property that measures 256 feet on each of four sides. - ANSWER-1.5
acres
Figure the area of a lot that measures 60ft by 280ft - ANSWER-16,800sqft ,0.39 acres
A disposal option that might be considered in a clay soil would be a ________. - ANSWER-drip or spray
irrigation
The primary treatment device providing the least or poorest treatment of domestic wastewater would
be _______. - ANSWER-septic tank
Nitrogen or nitrate removal in soil occurs by _________. - ANSWER-vegetation uptake
The factors influencing the survival of bacteria in soil are _______. - ANSWER-moisture, temperature,
pH, and organic matter.
Physical removal of bacteria by straining occurs when _______. - ANSWER-the bacteria are larger than
the pore openings in the soil
, A solid that can be filtered out of the wastewater is a _________. - ANSWER-suspended solid
Which of the following describes domestic wastewater as it leaves a home? - ANSWER-fresh, light in
color, has dissolved oxygen
Which of the following are problems caused by malfunctioning septic tank systems? - ANSWER-surface
water pollution, groundwater contamination, and standing sewage in neighborhoods
An inorganic chemical that affects human health is - ANSWER-nitrate
Parasites (helminths) found in untreated sewage include ________. - ANSWER-hookworm, round
worms, and tapeworms
Viruses are responsible for such diseases as - ANSWER-poliomyelitis and infectious hepatitis
A type of bacteria that indicates sewage contamination is ________. - ANSWER-fecal coliform
Protozoa are very simple animal organisms that may cause ________. - ANSWER-amoeba dysentery and
Giardiasis
Waterborne diseases that spread by pathogenic bacteria include _________. - ANSWER-typhoid,
cholera, and dysentery
Microorganisms in wastewater include __________. - ANSWER-bacteria, viruses, protozoa and
helminths.
Microorganisms that cause disease are called _________. - ANSWER-pathogens
WITH QUALIFIED QUESTIONS AND
ANSWERS
_______ and ________ soil textural classes are always unsuitable for standard absorptive OSSF -
ANSWER-class IA and IV
List each of the major soil horizons - 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. - ANSWER-Hydraulic conductivity, saturated, unsaturated
Interconnected pores in the soil profile allow ______ and _______ to enter the soil at its surface and
migrate downward - ANSWER-air, water
List the four components of soil - 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)? -
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? - 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? - 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. - 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? - ANSWER-846 gals
Calculate the working liquid capacity (volume) for this septic tank. SEE PAGE 2-39!! - ANSWER-1077gals
What is the surface area (area in square feet) of an evapotranspiration system 40 feet wide and 65 feet
long? - ANSWER-2,600 sqft
Figure the acreage for a piece of property that measures 256 feet on each of four sides. - ANSWER-1.5
acres
Figure the area of a lot that measures 60ft by 280ft - ANSWER-16,800sqft ,0.39 acres
A disposal option that might be considered in a clay soil would be a ________. - ANSWER-drip or spray
irrigation
The primary treatment device providing the least or poorest treatment of domestic wastewater would
be _______. - ANSWER-septic tank
Nitrogen or nitrate removal in soil occurs by _________. - ANSWER-vegetation uptake
The factors influencing the survival of bacteria in soil are _______. - ANSWER-moisture, temperature,
pH, and organic matter.
Physical removal of bacteria by straining occurs when _______. - ANSWER-the bacteria are larger than
the pore openings in the soil
, A solid that can be filtered out of the wastewater is a _________. - ANSWER-suspended solid
Which of the following describes domestic wastewater as it leaves a home? - ANSWER-fresh, light in
color, has dissolved oxygen
Which of the following are problems caused by malfunctioning septic tank systems? - ANSWER-surface
water pollution, groundwater contamination, and standing sewage in neighborhoods
An inorganic chemical that affects human health is - ANSWER-nitrate
Parasites (helminths) found in untreated sewage include ________. - ANSWER-hookworm, round
worms, and tapeworms
Viruses are responsible for such diseases as - ANSWER-poliomyelitis and infectious hepatitis
A type of bacteria that indicates sewage contamination is ________. - ANSWER-fecal coliform
Protozoa are very simple animal organisms that may cause ________. - ANSWER-amoeba dysentery and
Giardiasis
Waterborne diseases that spread by pathogenic bacteria include _________. - ANSWER-typhoid,
cholera, and dysentery
Microorganisms in wastewater include __________. - ANSWER-bacteria, viruses, protozoa and
helminths.
Microorganisms that cause disease are called _________. - ANSWER-pathogens
