• 105 questions

Septic Installer Practice Test Idaho

Unofficial questions on Idaho's subsurface sewage rule and guidance manual, each answer naming its subsection.

What bond must an applicant for a basic installer's permit deliver?

Pick an answer, then press Check answer. Then you see Correct or Not quite, with the reason. Keys: A to D pick, Enter checks.

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Exam mode: 40 questions, no time limit, 28 right to pass (70%).

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Unofficial practice questions, not affiliated with the Idaho Department of Environmental Quality. Bank checked October 12, 2026.

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All 105 questions

Installer permits, bond and exam (Section 006) 18

  • A company has several employees who install systems. Who must take the exam and be licensed? DEQ, Idaho Septic Installer Online Exam FAQ
  • After passing the exam, what does a person do with the certificate to get an installer's license? DEQ, Idaho Septic Installer Online Exam Instructions
  • An installer keeps the annual license current. How often must the exam be taken again? DEQ, Idaho Septic Installer Online Exam FAQ
  • How long a course must a refresher course agenda be able to fill? Idaho TGM, section 1.5.2.1
  • How many types of installer registration permit does Idaho offer? IDAPA 58.01.03.006.01
  • How often may the Idaho installer exam be retaken after a fail? DEQ, Idaho Septic Installer Online Exam FAQ
  • How often must an installer attend a refresher course approved by the Department? IDAPA 58.01.03.006.03
  • On what date do installer permits expire each year? IDAPA 58.01.03.006.03
  • What are the questions of the Idaho installer exam derived from? DEQ, Idaho Septic Installer Online Exam FAQ
  • What bond must an applicant for a basic installer's permit deliver? IDAPA 58.01.03.006.05.b
  • What bond must an applicant for a complex installer's permit deliver? IDAPA 58.01.03.006.05.b
  • What score does Idaho's rule set for passing the installer exam? IDAPA 58.01.03.006.02
  • What time limit does the online installer exam have? DEQ, Idaho Septic Installer Online Exam FAQ
  • Where in Idaho may an installer's registration permit be used? Idaho TGM, section 1.5
  • Which of these systems needs a complex system installer's permit? IDAPA 58.01.03.006.01.b
  • Which permit is required to operate, maintain or monitor extended treatment package systems? IDAPA 58.01.03.006.01.c
  • Who may install a septic system without an installer's permit? IDAPA 58.01.03.006.08.b
  • Who must execute the installer's bond? IDAPA 58.01.03.006.05.c
Show all 105 questions (87 more)

Permits, inspections, violations (004, 005, 011, 012) 14

  • A notice of intent to revoke a permit becomes final after how many days unless a hearing is requested in writing? IDAPA 58.01.03.012.04
  • An inspection needs test holes dug. How much advance notice must the permittee give, weekends and holidays aside? IDAPA 58.01.03.011.03
  • An installation permit becomes invalid if the work is not completed and approved within what time of issuance? IDAPA 58.01.03.005.08
  • The installer wants to change the trench layout shown on the approved permit. What is required? IDAPA 58.01.03.005.10
  • Part of a system was covered before it was inspected. What can the Director require of the permittee? IDAPA 58.01.03.011.02
  • What may the Director ask a permittee for to prove the origin and quality of materials used? IDAPA 58.01.03.011.04
  • What must be reserved on the parcel along with the new drainfield? IDAPA 58.01.03.004.06
  • What must the owner of a failing system do? IDAPA 58.01.03.004.05
  • When may a newly installed system first receive wastewater? IDAPA 58.01.03.011.05
  • Which of these may not be discharged into a system unless the Director approves? IDAPA 58.01.03.004.03
  • Which repair may be done without an installation permit? IDAPA 58.01.03.005.02.b
  • Which trade has one seat on the Technical Guidance Committee? IDAPA 58.01.03.004.07
  • Who submits the installation permit application? IDAPA 58.01.03.005.03
  • Within how many days of the final inspection does the owner receive a copy of the as-built drawing? IDAPA 58.01.03.011.05

Definitions (Section 003) 12

  • A drainfield excavation is 8 feet wide. What is it called? IDAPA 58.01.03.003.02
  • A subsurface system designed for how many gallons of wastewater a day is a large soil absorption system? IDAPA 58.01.03.003.21
  • A system that receives more than how many gallons a day is a "central system"? IDAPA 58.01.03.003.08
  • After how long without flow is a system an "abandoned system"? IDAPA 58.01.03.003.01
  • For how long each year is the "normal high groundwater level" maintained or exceeded continuously? IDAPA 58.01.03.003.17.a
  • For how long each year is the "seasonal high groundwater level" maintained or exceeded continuously? IDAPA 58.01.03.003.17.b
  • Surface water that exists continuously for less than two months a year is which kind? IDAPA 58.01.03.003.38.d
  • Surface water that exists continuously for more than six months a year is which kind? IDAPA 58.01.03.003.38
  • What does a "standard system" consist of? IDAPA 58.01.03.003.36
  • What slope from the horizontal makes a hillside or roadcut a "scarp"? IDAPA 58.01.03.003.30
  • Where does the building sewer begin? IDAPA 58.01.03.003.07
  • Which of these is a basic alternative system? IDAPA 58.01.03.003.03.a

Septic tanks (Section 007) 27

  • A shop, not a dwelling, has a maximum daily flow of 800 gallons. What minimum tank capacity applies? IDAPA 58.01.03.007.08.b
  • After the piping is disconnected and the tank pumped, how is an abandoned septic tank finished? IDAPA 58.01.03.007.22.c
  • How deep below the liquid level does an outlet tee or baffle extend? IDAPA 58.01.03.007.12.d
  • How deep must the liquid in an Idaho septic tank be at a minimum? IDAPA 58.01.03.007.06
  • How far must a septic tank be from permanent or intermittent surface water? IDAPA 58.01.03.007.18
  • How large must the inspection port above each inlet and outlet be at a minimum? IDAPA 58.01.03.007.15
  • How thick must the concrete lids or covers of a septic tank be? IDAPA 58.01.03.007.04.b
  • How thick must the walls and floor of an adequately reinforced concrete septic tank be? IDAPA 58.01.03.007.04.a
  • How thick must the walls of a concrete septic tank be if they are not reinforced? IDAPA 58.01.03.007.04.a
  • How wide must an Idaho septic tank manhole be at its narrowest? IDAPA 58.01.03.007.14
  • Idaho allows septic tanks in series. How much of the total liquid capacity must the initial tank provide? IDAPA 58.01.03.007.17
  • Idaho's vented tees and baffles reach how far up from the liquid surface? IDAPA 58.01.03.007.11.c
  • In Idaho, the tank inlet comes in how many inches higher than the liquid level? IDAPA 58.01.03.007.11.a
  • May the wastewater from one building sewer be divided between two septic tanks? IDAPA 58.01.03.007.16
  • The tank manufacturer supplies written installation instructions. What must the installer do? IDAPA 58.01.03.007.19
  • The total volume of a septic tank must be at least what share of its liquid capacity? IDAPA 58.01.03.007.10
  • What is Idaho's separation between a septic tank and a dwelling foundation or property line? IDAPA 58.01.03.007.18
  • What is the minimum distance from a septic tank to a private well? IDAPA 58.01.03.007.18
  • What is the minimum distance from a septic tank to a public water well? IDAPA 58.01.03.007.18
  • What is the minimum tank capacity for a five-bedroom dwelling? IDAPA 58.01.03.007.08.a
  • What is the smallest interior horizontal dimension allowed in a septic tank or compartment? IDAPA 58.01.03.007.05
  • What vertical separation is required from the top of a septic tank to the seasonal high water level? IDAPA 58.01.03.007.18
  • What wastewater flow does the rule assign a three-bedroom single family dwelling? IDAPA 58.01.03.007.09
  • What wastewater flow does the rule give a four-bedroom single family dwelling? IDAPA 58.01.03.007.09
  • Which material is unacceptable for a new septic tank? IDAPA 58.01.03.007.01
  • Which separation distances apply to an effluent pipe? IDAPA 58.01.03.007.21
  • Who is responsible for abandoning a septic tank? IDAPA 58.01.03.007.22

Standard drainfields (Section 008) 28

  • A four-bedroom home, 300 gallons a day, sits on design soil group C. What absorption area is required? IDAPA 58.01.03.008.02.b
  • A three-bedroom home, 250 gallons a day, sits on design soil group B. What absorption area is required? IDAPA 58.01.03.008.02.b
  • Above what slope is a site not suitable for an absorption bed? IDAPA 58.01.03.008.09.b
  • At what grade are distribution laterals and trench bottoms laid? IDAPA 58.01.03.008.03
  • For how many complete drainfields must an acceptable site be large enough? IDAPA 58.01.03.008.02.c
  • How far must a drainfield be from a water distribution line that is not double-encased? IDAPA 58.01.03.008.01.d
  • How far must a drainfield be from a well? IDAPA 58.01.03.008.01.d
  • How far must a drainfield be from an irrigation canal or ditch? IDAPA 58.01.03.008.01.d
  • How far must a drainfield be from the foundation of a building with a basement? IDAPA 58.01.03.008.01.d
  • How far must a drainfield in design soil group A be from permanent surface water, other than irrigation canals and ditches? IDAPA 58.01.03.008.01.d
  • How many feet of effective soil must lie between the drainfield bottom and the normal high groundwater level in design soil group A? IDAPA 58.01.03.008.01.c
  • How much aggregate must lie under the distribution laterals? IDAPA 58.01.03.008.03
  • How much soil must cover the top of the aggregate? IDAPA 58.01.03.008.03
  • How much undisturbed earth must be left between trenches? IDAPA 58.01.03.008.03
  • In an absorption bed, how far apart at most may distribution laterals be spaced? IDAPA 58.01.03.008.09.c
  • What absorption rate is used to size a drainfield in design soil group B? IDAPA 58.01.03.008.02.b
  • What does Idaho's rule lay over drainfield aggregate as a soil barrier? IDAPA 58.01.03.008.06
  • What effective diameter must trench aggregate have? IDAPA 58.01.03.008.07
  • What effective soil depth is required above an impermeable layer, in any design soil group? IDAPA 58.01.03.008.01.c
  • What effective soil depth is required above the seasonal high groundwater level? IDAPA 58.01.03.008.01.c
  • What is the greatest depth allowed for a standard trench? IDAPA 58.01.03.008.03
  • What is the greatest width allowed for a standard trench? IDAPA 58.01.03.008.03
  • What is the longest an individual distribution lateral may be? IDAPA 58.01.03.008.03
  • What is the most total trench area a standard subsurface disposal facility may have? IDAPA 58.01.03.008.03
  • What is the steepest natural slope allowed on the site of a standard drainfield? IDAPA 58.01.03.008.01.a
  • What may not be done on a treatment area trench or the replacement area? IDAPA 58.01.03.008.08
  • When must trenches not be excavated? IDAPA 58.01.03.008.05
  • Which machines may not be driven on the bottom of a drainfield excavation? IDAPA 58.01.03.008.10

Guidance manual: building sewer and setting a tank 6

  • How far below the finished grade must a building sewer be installed at a minimum? Idaho TGM, section 3.2.2
  • How must septic tanks and dosing chambers be set in the excavation? Idaho TGM, section 3.2.3
  • In a straight run of building sewer, cleanouts are placed at intervals of up to how many feet? Idaho TGM, section 3.2.2
  • More than 6 inches of fill is needed to level the bottom of a tank excavation. To what should the fill be compacted? Idaho TGM, section 3.2.3
  • What is the least uniform slope of a building sewer toward the point of discharge? Idaho TGM, section 3.2.2
  • Who has jurisdiction over the design and installation of the building sewer? Idaho TGM, section 3.2.2

How this list was compiled: IDAPA 58.01.03, Individual/Subsurface Sewage Disposal Rules and Rules for Cleaning of Septic Tanks (https://adminrules.idaho.gov/rules/current/58/580103.pdf), and the Idaho Department of Environmental Quality's Technical Guidance Manual for Individual and Subsurface Sewage Disposal Systems, December 2025 (https://www2.deq.idaho.gov/admin/LEIA/api/document/download/14470). The department's Idaho Septic Installer Online Exam FAQ (https://www2.deq.idaho.gov/admin/LEIA/api/document/download/21525) says the exam questions are derived from those two documents and that the exam is open book; its Septic and Septage page (https://www.deq.idaho.gov/water-quality/wastewater/septic-and-septage/) links both. Read October 12, 2026. Licence: Own work. Every question, wrong choice and explanation was written for this site from the text of the rule, the manual and the department's exam sheets. Nothing comes from the installer examination, a course provider or a question pool.

How it works

This unofficial Idaho septic installer practice test asks 105 of our own questions from IDAPA 58.01.03 and the Technical Guidance Manual. Not affiliated with the Idaho Department of Environmental Quality or the public health districts.

Read the full guide

Where each answer sits

Each answer names its subsection of the rule, so practice doubles as a map of it: 003 definitions, 005 permits, 006 installers, 007 tanks, 008 drainfields. Eight questions come from the manual's pages on installer permits, building sewers and setting a tank.

Exam mode

Exam mode draws 40 questions, our number, and marks a pass at the rule's 70 percent. The real exam has no time limit, so no clock runs, and the department gives no question count.

What is left out

Complex alternative systems, such as pressure distribution and sand mounds, belong to the complex installer exam. Here they appear only where the rule says which permit they need.

  • Tank: 50 feet from a private well, 100 from a public one, 5 from a property line. Drainfield: 100 feet from any well.
  • Sizing: 250 gallons a day for three bedrooms, 50 more per bedroom, divided by 1.0, 0.5 or 0.2 for soil group A, B or C.
  • Standard trench limits: laterals 100 feet long, trenches 6 feet wide and 4 feet deep at most, 1,500 square feet in total.

Questions and answers

Is the Idaho septic installer exam open book?

Yes. The department's exam FAQ says the questions are derived from IDAPA 58.01.03 and the Technical Guidance Manual, and that the exam is an open-book test with both documents on its Septic and Septage page.

What score do you need to pass the Idaho septic installer exam?

Seventy percent or more, under IDAPA 58.01.03.006.02. The department's exam FAQ says a failed exam can be retaken, with no limit on the number of tries.

How do I get a septic installer license in Idaho?

Pass the basic or complex installer exam, then take the certificate to your area's public health district with the registration fee and a surety bond: $10,000 for a basic installer, $30,000 for a complex installer.

Do I need a license to install my own septic system in Idaho?

No, for a standard or basic alternative system on your own property (IDAPA 58.01.03.006.08). The department's exam FAQ adds that anyone hired to help must be licensed. An installation permit is still required.

How often is an Idaho septic installer license renewed?

Every year. Permits expire on the first day of January, and installers attend at least one Department-approved refresher course every three years (IDAPA 58.01.03.006.03). The exam is taken once, as long as the license is kept current.

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