DESIGNATED REPRESENTATIVE OSSF EXPECTED
QUESTIONS WITH VERIFIED ANSWERS
Question 1.
1 psi =
ANSWER
2.31 ft per waterhead
Question 2.
The first compartment in a
2 compartment septic tank must
ANSWER
contain 1/2 to 2/3 of the required volume
Question 3.
The size of any drainfield needed depends on
two factors:
ANSWER
Wastewater loading (Q), and Long-term soil acceptance rate (Ra) determined by soil class.
Question 4.
Trickling Filters
ANSWER
use larger media consisting of rock, cinder, tire chips, or plastic forms to harbor bacteria.
Effluent is sprayed over media and trickles down. maintains an aerobic environment
Question 5.
Evapotranspiration (ET)
Drainfield
ANSWER
sandy loam beds, porous media, distribution pipe, must be covered with vegetation, may be
lined or unlined
,Question 6.
Where does Adsorption occur
best?
ANSWER
In water with high hardness and neutral or slightly acidic pH. This is the most important
mechanism for removing viruses.
Question 7.
An operational
test of an aerobic system includes
ANSWER
ensuring air is entering and mixing in the aeration vessel, activating pumps and high-water
alarms to ensure operational
Question 8.
Ten Acre Rule
ANSWER
An OSSF for a single-family residence on a 10 acre lot or more with disposal lines at least 100ft
from property line are not required to apply for a permit for a new construction.
Question 9.
Maintenance Technician and Apprentice note
ANSWER
Only license that doesn't require exam, Apprentice does not require class either
Question 10.
Methemoglobinemia (Blue
Baby Syndrome)
ANSWER
A serious, sometimes fatal poisoning in infants after ingesting water with nitrate. Nitrate
impairs the oxygen-carrying capacity of blood.
,Question 11.
Risers on any
kind of tank in an OSSF must:
ANSWER
- have inside diameter equal to or larger than clean-out
- be permanently fastened with watertight connection to tank lid
- have removable watertight caps protected against unauthorized access
Question 12.
Anaerobic bacteria are found in:
ANSWER
septic tanks, waterlogged soils, decay, biological mats in drainfields that remain saturated
Question 13.
Porous media
must be between
ANSWER
.75" to 2" and resistant to chemical reaction *exception for tire chips of double-strength
geotextile fabric which can be 3"*
Question 14.
Drainfields following
secondary treatment with disinfection (Non-Standard)
ANSWER
Used in class Ia soils, fractured rock, fissured rock
Question 15.
Why is aeration important?
ANSWER
achieves maximum decomposition of organics and destruction of harmful bacteria and
viruses. Encourages aerobic microflora to grow
, Question 16.
What concentration does Nitrogen occur in domestic wastewater?
ANSWER
20 to 80 mg/L
Question 17.
Leaching Chambers (Proprietary)
ANSWER
Bottomless chambers used in subsurface drainfields that does not require gravel. Advantage is
only 60 to 75% of the absorptive area of a standard drainfield is required. *Not an alternative
for unsuitable soil*
Question 18.
The majority
of aerobic systems utilize what method of disposal
ANSWER
surface application
Question 19.
Daily
ANSWER
How often must an installer check an apprentice's work?
Question 20.
Soil materials greater than
2mm
ANSWER
Gravel
QUESTIONS WITH VERIFIED ANSWERS
Question 1.
1 psi =
ANSWER
2.31 ft per waterhead
Question 2.
The first compartment in a
2 compartment septic tank must
ANSWER
contain 1/2 to 2/3 of the required volume
Question 3.
The size of any drainfield needed depends on
two factors:
ANSWER
Wastewater loading (Q), and Long-term soil acceptance rate (Ra) determined by soil class.
Question 4.
Trickling Filters
ANSWER
use larger media consisting of rock, cinder, tire chips, or plastic forms to harbor bacteria.
Effluent is sprayed over media and trickles down. maintains an aerobic environment
Question 5.
Evapotranspiration (ET)
Drainfield
ANSWER
sandy loam beds, porous media, distribution pipe, must be covered with vegetation, may be
lined or unlined
,Question 6.
Where does Adsorption occur
best?
ANSWER
In water with high hardness and neutral or slightly acidic pH. This is the most important
mechanism for removing viruses.
Question 7.
An operational
test of an aerobic system includes
ANSWER
ensuring air is entering and mixing in the aeration vessel, activating pumps and high-water
alarms to ensure operational
Question 8.
Ten Acre Rule
ANSWER
An OSSF for a single-family residence on a 10 acre lot or more with disposal lines at least 100ft
from property line are not required to apply for a permit for a new construction.
Question 9.
Maintenance Technician and Apprentice note
ANSWER
Only license that doesn't require exam, Apprentice does not require class either
Question 10.
Methemoglobinemia (Blue
Baby Syndrome)
ANSWER
A serious, sometimes fatal poisoning in infants after ingesting water with nitrate. Nitrate
impairs the oxygen-carrying capacity of blood.
,Question 11.
Risers on any
kind of tank in an OSSF must:
ANSWER
- have inside diameter equal to or larger than clean-out
- be permanently fastened with watertight connection to tank lid
- have removable watertight caps protected against unauthorized access
Question 12.
Anaerobic bacteria are found in:
ANSWER
septic tanks, waterlogged soils, decay, biological mats in drainfields that remain saturated
Question 13.
Porous media
must be between
ANSWER
.75" to 2" and resistant to chemical reaction *exception for tire chips of double-strength
geotextile fabric which can be 3"*
Question 14.
Drainfields following
secondary treatment with disinfection (Non-Standard)
ANSWER
Used in class Ia soils, fractured rock, fissured rock
Question 15.
Why is aeration important?
ANSWER
achieves maximum decomposition of organics and destruction of harmful bacteria and
viruses. Encourages aerobic microflora to grow
, Question 16.
What concentration does Nitrogen occur in domestic wastewater?
ANSWER
20 to 80 mg/L
Question 17.
Leaching Chambers (Proprietary)
ANSWER
Bottomless chambers used in subsurface drainfields that does not require gravel. Advantage is
only 60 to 75% of the absorptive area of a standard drainfield is required. *Not an alternative
for unsuitable soil*
Question 18.
The majority
of aerobic systems utilize what method of disposal
ANSWER
surface application
Question 19.
Daily
ANSWER
How often must an installer check an apprentice's work?
Question 20.
Soil materials greater than
2mm
ANSWER
Gravel
