Installer I Exam Questions and
Answers 100% Pass
Site Characteristics - ✔✔existing structures; slopes; wells; streams influence system
design
Soil Characteristics - ✔✔40 million bacterial cells in a single gram of soil Healthy soil is
living and breathing and packed with microbes that breakdown pathogens
vertical separation - ✔✔dept of soil on property
restrictive layer - ✔✔bedrock, groundwater, impermeable layer, dept of water will no
longer seep into soil
Conventional Gravity System - ✔✔consists of 3 parts, Septic Tank; Drain-field; soil
benighted. requires min 3 ft of native undisturbed drain soil benighted the drain field -
clean filter every 6-12 mths
Sludge layer - ✔✔top layer in septic system
Scum layer - ✔✔bottom layer in the septic system
effluent - ✔✔clear liquid between the sludge & scum layers
Distribution box - Dbox - ✔✔equal distribution of effluent. Is attached to the lateral
drain lines, effluent flows out through small holes into the surrounding soil where
aerobic or oxygen loving bacterial & other microbes treat the wastewater by removing
pathogens
COPYRIGHT © 2025 BY BRITTIE DONALD, ALL RIGHTS RESERVED 1
, Pressurized System - ✔✔wastewater is pumped to a certain area of the property
Pressurized System distributes the wastewater, vertical separation is 2-3 ft
Alarm float - ✔✔3rd and highest float, if the pump fails, and has too much wastewater,
the wastewater rises and sounds the alarm on. some pumps use a transducer rather
than an alarm pump
redundant float - ✔✔helps to turn off the pump if the water level drops too low, or have
adequate wastewater to cover the pump
on/off float - ✔✔turns the pump on as the water level rises - the effluent is dossed
every few hours to spread out the lateral drains into the drain field, water level stops
the pump - in order for the drain field to dry out between doses
Mound system - ✔✔specially engineered sand 1' - 2'
Sand Filtered System - ✔✔box of engineered sand and gravel, then is pumped out to a
drain field
Conventional onsite wastewater treatment system - ✔✔consists of a two chamber
treatment tank and a drain-field or leach-field. The treatment tank separates the
material that will either float or sink. Typically the septic tank volume for a
conventional tank and onsite effluent disposal system (such as a drain field) is
estimated at a minimum of 1000 gallons or 1.5x average total daily wastewater flow.
Preliminary Site Check - ✔✔check to see if your lot appears to be large enough for a
conventional septic tank and drainage system
Lot size - ✔✔lot must be at least 3/4 of an acre.
setbacks - ✔✔layout of typical system on your plat map and see if your system meets
the required setbacks
COPYRIGHT © 2025 BY BRITTIE DONALD, ALL RIGHTS RESERVED 2
Answers 100% Pass
Site Characteristics - ✔✔existing structures; slopes; wells; streams influence system
design
Soil Characteristics - ✔✔40 million bacterial cells in a single gram of soil Healthy soil is
living and breathing and packed with microbes that breakdown pathogens
vertical separation - ✔✔dept of soil on property
restrictive layer - ✔✔bedrock, groundwater, impermeable layer, dept of water will no
longer seep into soil
Conventional Gravity System - ✔✔consists of 3 parts, Septic Tank; Drain-field; soil
benighted. requires min 3 ft of native undisturbed drain soil benighted the drain field -
clean filter every 6-12 mths
Sludge layer - ✔✔top layer in septic system
Scum layer - ✔✔bottom layer in the septic system
effluent - ✔✔clear liquid between the sludge & scum layers
Distribution box - Dbox - ✔✔equal distribution of effluent. Is attached to the lateral
drain lines, effluent flows out through small holes into the surrounding soil where
aerobic or oxygen loving bacterial & other microbes treat the wastewater by removing
pathogens
COPYRIGHT © 2025 BY BRITTIE DONALD, ALL RIGHTS RESERVED 1
, Pressurized System - ✔✔wastewater is pumped to a certain area of the property
Pressurized System distributes the wastewater, vertical separation is 2-3 ft
Alarm float - ✔✔3rd and highest float, if the pump fails, and has too much wastewater,
the wastewater rises and sounds the alarm on. some pumps use a transducer rather
than an alarm pump
redundant float - ✔✔helps to turn off the pump if the water level drops too low, or have
adequate wastewater to cover the pump
on/off float - ✔✔turns the pump on as the water level rises - the effluent is dossed
every few hours to spread out the lateral drains into the drain field, water level stops
the pump - in order for the drain field to dry out between doses
Mound system - ✔✔specially engineered sand 1' - 2'
Sand Filtered System - ✔✔box of engineered sand and gravel, then is pumped out to a
drain field
Conventional onsite wastewater treatment system - ✔✔consists of a two chamber
treatment tank and a drain-field or leach-field. The treatment tank separates the
material that will either float or sink. Typically the septic tank volume for a
conventional tank and onsite effluent disposal system (such as a drain field) is
estimated at a minimum of 1000 gallons or 1.5x average total daily wastewater flow.
Preliminary Site Check - ✔✔check to see if your lot appears to be large enough for a
conventional septic tank and drainage system
Lot size - ✔✔lot must be at least 3/4 of an acre.
setbacks - ✔✔layout of typical system on your plat map and see if your system meets
the required setbacks
COPYRIGHT © 2025 BY BRITTIE DONALD, ALL RIGHTS RESERVED 2
