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OSSF TEST PRACTICE EXAM 2025 BRAND
NEW ACTUAL EXAM WITH 100% VERIFIED
QUESTIONS AND CORRECT SOLUTIONS|
ACE YOUR GRADES.
1. Which of the following is a likely cause of a "rotten egg" odor
from an aerobic treatment plant? - correct answer -Mechanical
aerator failure, hydraulic overload caused by leaking toilet
2. Which of the following is a way to evaluate an aerobic
treatment plant for excessive solids and need for wasting? -
correct answer -30-minute settling test
3. Which of the following is true of standard intermittent sand
filter? - correct answer -provides secondary wastewater
treatment, has a maximum surface loading rate of 1.2
gal/day/sqft, requires at least 24 inches of filter media which
meets definite specifications (ASTM C-33)
4. When would an intermittent sand filter with disinfection system
be selected over a properly designed and installed septic tank
system? - correct answer -For a standard drainfield in class Ia
soil
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5. Trickling filters and wetlands - correct answer -are secondary
treatment processes
6. Which of the following considerations should receive the
greatest emphasis in selecting a type of OSSF disposal option?
- correct answer -soil and site conditions
7. On a West Texas site with 16 inches of Class Ia soil over
fractured rock, suitable OSSFs would include - correct answer -
lined ET or mound systems
8. What are the minimum soil requirements for leaching chambers
or gravelless pipe systems following a septic tank? - correct
answer -The same as for a standard absorptive drainfield, 2
feet of well-drained Class Ib, II, or III soil below the field bottom
9. OSSF surface application always requires - correct answer -at
least secondary treatment and disinfection
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10. Surface application is often selected over other OSSF
disposal options because of - correct answer -clay soils and/or
seasonal groundwater problems
11. What must be known to determine the size of spray area
required for an OSSF spray irrigation system? - correct answer
-Rate of irrigation (Ri) allowed in that area and (Q) in gal/day
12. Systems that routinely require a pump tank include - correct
answer -surface and drip irrigation and sand filters
13. The setback from a public water well for an aerobic plant is -
correct answer -50 feet
14. A maintenance provider for a surface application OSSF
using a proprietary aerobic plant must have an employee who
is - correct answer -a licensed maintenance provider or a
registered maintenance technician
OSSF TEST PRACTICE EXAM 2025 BRAND
NEW ACTUAL EXAM WITH 100% VERIFIED
QUESTIONS AND CORRECT SOLUTIONS|
ACE YOUR GRADES.
1. Which of the following is a likely cause of a "rotten egg" odor
from an aerobic treatment plant? - correct answer -Mechanical
aerator failure, hydraulic overload caused by leaking toilet
2. Which of the following is a way to evaluate an aerobic
treatment plant for excessive solids and need for wasting? -
correct answer -30-minute settling test
3. Which of the following is true of standard intermittent sand
filter? - correct answer -provides secondary wastewater
treatment, has a maximum surface loading rate of 1.2
gal/day/sqft, requires at least 24 inches of filter media which
meets definite specifications (ASTM C-33)
4. When would an intermittent sand filter with disinfection system
be selected over a properly designed and installed septic tank
system? - correct answer -For a standard drainfield in class Ia
soil
, Page | 2
5. Trickling filters and wetlands - correct answer -are secondary
treatment processes
6. Which of the following considerations should receive the
greatest emphasis in selecting a type of OSSF disposal option?
- correct answer -soil and site conditions
7. On a West Texas site with 16 inches of Class Ia soil over
fractured rock, suitable OSSFs would include - correct answer -
lined ET or mound systems
8. What are the minimum soil requirements for leaching chambers
or gravelless pipe systems following a septic tank? - correct
answer -The same as for a standard absorptive drainfield, 2
feet of well-drained Class Ib, II, or III soil below the field bottom
9. OSSF surface application always requires - correct answer -at
least secondary treatment and disinfection
, Page | 3
10. Surface application is often selected over other OSSF
disposal options because of - correct answer -clay soils and/or
seasonal groundwater problems
11. What must be known to determine the size of spray area
required for an OSSF spray irrigation system? - correct answer
-Rate of irrigation (Ri) allowed in that area and (Q) in gal/day
12. Systems that routinely require a pump tank include - correct
answer -surface and drip irrigation and sand filters
13. The setback from a public water well for an aerobic plant is -
correct answer -50 feet
14. A maintenance provider for a surface application OSSF
using a proprietary aerobic plant must have an employee who
is - correct answer -a licensed maintenance provider or a
registered maintenance technician
