Free Idaho Well Driller Licensing Examination Practice Questions

Sample Practice Questions

Try these 10 sample questions from the Idaho Well Driller Licensing Examination practice bank. Each includes the answer and explanation. Continue with the interactive practice above to review the full question set.

1. 1An Idaho landowner plans to construct a 60-foot domestic well personally using a powered rotary rig. Which credential rule applies?

   1. A. The owner may proceed without a credential because the well is on the owner’s property
   2. B. The work must be done by a licensed driller or a permitted operator under licensed-driller supervision
   3. C. The owner needs only an operator’s permit because the well is domestic
   4. D. The owner may proceed after filing a drilling permit, regardless of licensure

   Answer: B

   Explanation: IDAPA 37.03.10.020.01 states: "A well shall only be drilled by a licensed driller, or an operator working under the supervision of a licensed driller"; the owner exception applies only without power-driven mechanical equipment. A powered rotary rig does not qualify for that exception.

   Reference: 370310 — IDAPA 37.03.10.020.01

2. 2Which equipment falls within Idaho’s definition of a well rig or drill rig?

   1. A. A power-driven percussion, rotary, boring, digging, jetting, or augering rig
   2. B. A pump hoist
   3. C. A trenching machine
   4. D. A hand-operated soil auger

   Answer: A

   Explanation: A well rig is "Any power driven percussion, rotary, boring, digging, jetting, auguring, or any other power-driven mechanical equipment used in the drilling of a well." The other equipment is not being used to drill a well.

   Reference: 370309 — IDAPA 37.03.09.010.68

3. 3A formation yields water to a well in quantities sufficient to make production feasible for beneficial use. What does Idaho’s rule call that formation?

   1. A. Aquifer
   2. B. Aquitard
   3. C. Aquiclude
   4. D. Aquifuge

   Answer: A

   Explanation: An aquifer is "Any geologic formation(s) that will yield water to a well in sufficient quantities to make the production of water from the formation feasible for beneficial use." The described formation meets that definition.

   Reference: 370309 — IDAPA 37.03.09.010.03

4. 4During construction through unstable material, what is the intended function of temporary casing?

   1. A. Support the borehole until permanent casing and the annular seal are installed
   2. B. Remain as the final production casing after well completion
   3. C. Carry grout permanently as an additional casing string
   4. D. Serve as the well screen within the production zone

   Answer: A

   Explanation: Temporary casing is steel pipe used "to support the borehole within unstable or unconsolidated formations during construction of a well" and removed around permanent-casing and seal installation. Its function is temporary borehole support.

   Reference: 370309 — IDAPA 37.03.09.010.52

5. 5A contractor plans to increase the diameter of an existing well casing. How is that work classified?

   1. A. A well modification requiring prior drilling authorization
   2. B. Routine pump maintenance not affecting well construction
   3. C. Well development that may proceed under the original permit
   4. D. Decontamination requiring only a completion report

   Answer: A

   Explanation: The definition of modify includes "increase or decrease the diameter of the casing or the well bore," and drilling permits are required before modification. The proposed diameter change is therefore a regulated modification.

   Reference: 370309 — IDAPA 37.03.09.010.33 and 045.01.a

6. 6A helper will operate drilling equipment while a licensed Idaho driller supervises the job. What authorization must the helper hold?

   1. A. A company license
   2. B. A drilling permit
   3. C. An operator’s permit
   4. D. A water-right permit

   Answer: C

   Explanation: The rule is explicit: "Any person authorized to operate drilling equipment under the supervision of a licensed driller shall possess an operator’s permit." The permit attaches to the equipment operator, while the other documents serve different regulatory functions.

   Reference: 370310 — IDAPA 37.03.10.020.02

7. 7A driller needs to convey grout to the bottom of an annular space before filling upward. Which tool is designed for that task?

   1. A. Tremie pipe
   2. B. Pressure-gage fitting
   3. C. Drive point
   4. D. Pitless adaptor

   Answer: A

   Explanation: A tremie pipe is "A small-diameter pipe used to convey grout, dry bentonite products, or filter pack materials into the annular space, borehole, or well from the bottom to the top." That directly matches the task.

   Reference: 370309 — IDAPA 37.03.09.010.55

8. 8Which subsurface feature naturally retards movement of water or contaminants from one zone to another?

   1. A. Confining layer
   2. B. Aquifer
   3. C. Vadose zone
   4. D. Capillary fringe

   Answer: A

   Explanation: A confining layer is a "subsurface zone of low-permeability earth material that naturally acts to restrict or retard the movement of water or contaminants from one zone to another." That function identifies the feature.

   Reference: 370309 — IDAPA 37.03.09.010.16

9. 9Which description matches pressure grouting under Idaho’s well-construction definitions?

   1. A. Pumping approved grout by positive displacement from bottom to top
   2. B. Pouring dry aggregate from land surface until the casing is surrounded
   3. C. Circulating drilling mud from top to bottom through the annulus
   4. D. Driving casing after cement has reached its initial set

   Answer: A

   Explanation: Pressure grouting is "the process of pumping and placing an approved grout mixture ... by positive displacement from bottom to top" using a listed or Director-approved method. The direction and positive-placement method identify it.

   Reference: 370309 — IDAPA 37.03.09.010.41

10. 10An existing well is shown to threaten human health and contaminate groundwater. How soon must the owner arrange the required repair or decommissioning?

    1. A. Immediately
    2. B. Within 72 hours
    3. C. Within 30 days
    4. D. Within 90 days

    Answer: A

    Explanation: The owner must have such a well "immediately repaired or decommissioned by a licensed well driller under a permit issued by the Director." The controlling deadline is therefore immediate action.

    Reference: 370309 — IDAPA 37.03.09.036.06