OSSF DR TEST PRACTICE Exam fully solved & updated 2025-2026(latest
version verified for accuracy) (Questions + Answers) Solved 100% Correc
1. _______ and ________ soil textural classes are always class IA and IV
unsuitable for standard absorptive OSSF
2. List each of the major soil horizons surface soil A, surface soil
B, and parent material
3. _____________ is a term describing the ability of water to Hydraulic conductivity,
migrate through a soil profile under either _________ or saturated, unsaturated
__________ conditions.
4. Interconnected pores in the soil profile allow ______ air, water
and _______ to enter the soil at its surface and migrate
downward
5. List the four components of soil air, water, organics, inor-
ganics
6. A drainfield is 50 feet by 90 feet and must be covered 208.3 cubic yards
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)?
7. What would be the volume of a 5-foot-diameter pump 587 gals
tank that is 5 feet tall with the inlet 1 foot below the
rim?
8. What would be the percent slope on a lot 250 feet 8%
deep that drops 20 feet in elevation over the depth of
the lot?
9. How many cubic yards of gravel would be needed to 6.67 cubic yards
fill a ditch 3 feet deep, 10 feet wide, and 12 feet long
with 18 inches of gravel? 1 cubic yard = 27 cubic feet.
, OSSF DR TEST PRACTICE Exam fully solved & updated 2025-2026(latest
version verified for accuracy) (Questions + Answers) Solved 100% Correc
10. A septic tank is 6 feet in diameter and is 8 feet deep. 846 gals
How many gallons will it hold if the overflow line is
located half way up from the bottom?
11. Calculate the working liquid capacity (volume) for this 1077gals
septic tank. SEE PAGE 2-39!!
12. What is the surface area (area in square feet) of an 2,600 sqft
evapotranspiration system 40 feet wide and 65 feet
long?
13. Figure the acreage for a piece of property that mea- 1.5 acres
sures 256 feet on each of four sides.
14. Figure the area of a lot that measures 60ft by 280ft 16,800sqft ,0.39 acres
15. A disposal option that might be considered in a clay drip or spray irrigation
soil would be a ________.
16. The primary treatment device providing the least or septic tank
poorest treatment of domestic wastewater would be
_______.
17. Nitrogen or nitrate removal in soil occurs by _________. vegetation uptake
18. The factors influencing the survival of bacteria in soil moisture, temperature,
are _______. pH, and organic matter.
19. Physical removal of bacteria by straining occurs when the bacteria are larger
_______. than the pore openings in
the soil
20. suspended solid
, OSSF DR TEST PRACTICE Exam fully solved & updated 2025-2026(latest
version verified for accuracy) (Questions + Answers) Solved 100% Correc
A solid that can be filtered out of the wastewater is a
_________.
21. Which of the following describes domestic waste- fresh, light in color, has
water as it leaves a home? dissolved oxygen
22. Which of the following are problems caused by mal- surface water pollution,
functioning septic tank systems? groundwater contamina-
tion, and standing sewage
in neighborhoods
23. An inorganic chemical that affects human health is nitrate
24. Parasites (helminths) found in untreated sewage in- hookworm, round worms,
clude ________. and tapeworms
25. Viruses are responsible for such diseases as poliomyelitis and infec-
tious hepatitis
26. A type of bacteria that indicates sewage contamina- fecal coliform
tion is ________.
27. Protozoa are very simple animal organisms that may amoeba dysentery and
cause ________. Giardiasis
28. Waterborne diseases that spread by pathogenic bac- typhoid, cholera, and
teria include _________. dysentery
29. Microorganisms in wastewater include __________. bacteria, viruses, protozoa
and helminths.
30. Microorganisms that cause disease are called pathogens
_________.
version verified for accuracy) (Questions + Answers) Solved 100% Correc
1. _______ and ________ soil textural classes are always class IA and IV
unsuitable for standard absorptive OSSF
2. List each of the major soil horizons surface soil A, surface soil
B, and parent material
3. _____________ is a term describing the ability of water to Hydraulic conductivity,
migrate through a soil profile under either _________ or saturated, unsaturated
__________ conditions.
4. Interconnected pores in the soil profile allow ______ air, water
and _______ to enter the soil at its surface and migrate
downward
5. List the four components of soil air, water, organics, inor-
ganics
6. A drainfield is 50 feet by 90 feet and must be covered 208.3 cubic yards
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)?
7. What would be the volume of a 5-foot-diameter pump 587 gals
tank that is 5 feet tall with the inlet 1 foot below the
rim?
8. What would be the percent slope on a lot 250 feet 8%
deep that drops 20 feet in elevation over the depth of
the lot?
9. How many cubic yards of gravel would be needed to 6.67 cubic yards
fill a ditch 3 feet deep, 10 feet wide, and 12 feet long
with 18 inches of gravel? 1 cubic yard = 27 cubic feet.
, OSSF DR TEST PRACTICE Exam fully solved & updated 2025-2026(latest
version verified for accuracy) (Questions + Answers) Solved 100% Correc
10. A septic tank is 6 feet in diameter and is 8 feet deep. 846 gals
How many gallons will it hold if the overflow line is
located half way up from the bottom?
11. Calculate the working liquid capacity (volume) for this 1077gals
septic tank. SEE PAGE 2-39!!
12. What is the surface area (area in square feet) of an 2,600 sqft
evapotranspiration system 40 feet wide and 65 feet
long?
13. Figure the acreage for a piece of property that mea- 1.5 acres
sures 256 feet on each of four sides.
14. Figure the area of a lot that measures 60ft by 280ft 16,800sqft ,0.39 acres
15. A disposal option that might be considered in a clay drip or spray irrigation
soil would be a ________.
16. The primary treatment device providing the least or septic tank
poorest treatment of domestic wastewater would be
_______.
17. Nitrogen or nitrate removal in soil occurs by _________. vegetation uptake
18. The factors influencing the survival of bacteria in soil moisture, temperature,
are _______. pH, and organic matter.
19. Physical removal of bacteria by straining occurs when the bacteria are larger
_______. than the pore openings in
the soil
20. suspended solid
, OSSF DR TEST PRACTICE Exam fully solved & updated 2025-2026(latest
version verified for accuracy) (Questions + Answers) Solved 100% Correc
A solid that can be filtered out of the wastewater is a
_________.
21. Which of the following describes domestic waste- fresh, light in color, has
water as it leaves a home? dissolved oxygen
22. Which of the following are problems caused by mal- surface water pollution,
functioning septic tank systems? groundwater contamina-
tion, and standing sewage
in neighborhoods
23. An inorganic chemical that affects human health is nitrate
24. Parasites (helminths) found in untreated sewage in- hookworm, round worms,
clude ________. and tapeworms
25. Viruses are responsible for such diseases as poliomyelitis and infec-
tious hepatitis
26. A type of bacteria that indicates sewage contamina- fecal coliform
tion is ________.
27. Protozoa are very simple animal organisms that may amoeba dysentery and
cause ________. Giardiasis
28. Waterborne diseases that spread by pathogenic bac- typhoid, cholera, and
teria include _________. dysentery
29. Microorganisms in wastewater include __________. bacteria, viruses, protozoa
and helminths.
30. Microorganisms that cause disease are called pathogens
_________.
