Complex Installer Exam Questions and
Answers
When the native soils are A-1 or coarser, the filter sand shall envelop the drain rock such that at least 3
feet of filter sand is between it and the native soils. - Answer-True
Acceptable Operation and Maintenance Entities for extended treatment package systems include all of
the following except ___. - Answer-Two or more homeowners
An individual or subsurface disposal system or component that has not been previously used in Idaho or
otherwise requires field review prior to approval as an alternative system, is called ___. - Answer-
Experimental System
The minimum residual head used for calculating flow and pump sizes on pressure distribution systems is
___. - Answer-2.5 feet
Drainfields that are failing due to ___ are NOT candidates for drainfield remediation components. -
Answer-A single-family dwelling with gravity drainfields and system inspection is recommended to verify
that the drainfield is not malfunctioning due to excessive hydraulic loading (e.g., leaking toilets, faucets,
or high-occupancy rates), or soil structural changes due to use of an ion exchange water softener.
When installing a sand mound, the maximum slope of natural ground is ___% for A soils, and ___% for
C-2 soils. - Answer-
, For sand mounds, the mound should be ___. - Answer-As long and narrow as practical
The minimum separation distance from a septic tank to temporary surface water is ___, and the
minimum separation distance from a septic tank to intermittent surface water is ___. - Answer-25 feet/
50 feet
If drainfield remediation components are used on a failed system and there is sewage on the ground,
how many days does the remediation system have to mitigate the public health threat? - Answer-The
DRC is expected to abate the public health threat of sewage on the ground and all other indications of
biomat failure within 30 days of installation.
Failure to comply with the rules is grounds for revocation of the installers registration permit. - Answer-
Grounds for Revocation. Failure to comply with these rules shall be grounds for revocation of the permit
or the certification, or both.
Drip laterals in a non-continuous flush drip distribution system should be flushed ___. - Answer-Drip
distribution zones should be flushed every 2 weeks.
Large soil absorption systems that receive more than 5,000 gallons per day must be greater than ___
from building foundations and ___ for property lines regardless of soil type. - Answer-75 feet / 75 feet
The minimum depth of natural soil required between the bottom of a sand mound with 12 inches of
filter sand below the aggregate and groundwater is 2 feet for ___. - Answer-C soils
Which of the following are not drip distribution system design criteria? - Answer-Time dosing is optional
as is the frequency of back flushing the filter
Two cell infiltrative systems may not be placed within ___ of the owners' property line, and within ___
from a neighboring dwelling. - Answer-Cells may not be placed within 100 feet of the owner's property
line and may not be placed within 300 feet from a neighboring dwelling.
Answers
When the native soils are A-1 or coarser, the filter sand shall envelop the drain rock such that at least 3
feet of filter sand is between it and the native soils. - Answer-True
Acceptable Operation and Maintenance Entities for extended treatment package systems include all of
the following except ___. - Answer-Two or more homeowners
An individual or subsurface disposal system or component that has not been previously used in Idaho or
otherwise requires field review prior to approval as an alternative system, is called ___. - Answer-
Experimental System
The minimum residual head used for calculating flow and pump sizes on pressure distribution systems is
___. - Answer-2.5 feet
Drainfields that are failing due to ___ are NOT candidates for drainfield remediation components. -
Answer-A single-family dwelling with gravity drainfields and system inspection is recommended to verify
that the drainfield is not malfunctioning due to excessive hydraulic loading (e.g., leaking toilets, faucets,
or high-occupancy rates), or soil structural changes due to use of an ion exchange water softener.
When installing a sand mound, the maximum slope of natural ground is ___% for A soils, and ___% for
C-2 soils. - Answer-
, For sand mounds, the mound should be ___. - Answer-As long and narrow as practical
The minimum separation distance from a septic tank to temporary surface water is ___, and the
minimum separation distance from a septic tank to intermittent surface water is ___. - Answer-25 feet/
50 feet
If drainfield remediation components are used on a failed system and there is sewage on the ground,
how many days does the remediation system have to mitigate the public health threat? - Answer-The
DRC is expected to abate the public health threat of sewage on the ground and all other indications of
biomat failure within 30 days of installation.
Failure to comply with the rules is grounds for revocation of the installers registration permit. - Answer-
Grounds for Revocation. Failure to comply with these rules shall be grounds for revocation of the permit
or the certification, or both.
Drip laterals in a non-continuous flush drip distribution system should be flushed ___. - Answer-Drip
distribution zones should be flushed every 2 weeks.
Large soil absorption systems that receive more than 5,000 gallons per day must be greater than ___
from building foundations and ___ for property lines regardless of soil type. - Answer-75 feet / 75 feet
The minimum depth of natural soil required between the bottom of a sand mound with 12 inches of
filter sand below the aggregate and groundwater is 2 feet for ___. - Answer-C soils
Which of the following are not drip distribution system design criteria? - Answer-Time dosing is optional
as is the frequency of back flushing the filter
Two cell infiltrative systems may not be placed within ___ of the owners' property line, and within ___
from a neighboring dwelling. - Answer-Cells may not be placed within 100 feet of the owner's property
line and may not be placed within 300 feet from a neighboring dwelling.
