MI Well Driller common mistakes
MI Well Driller · Understand the traps and how to avoid them.
Treating the regulatory minimum casing depth and grout-return requirements as generic industry rules of thumb instead of looking up the Michigan-specific numbers for each well type (residential, irrigation, public, monitoring).
Candidates study national drilling material or their own field habits, then assume one casing/grout depth covers every well classification; Michigan rules vary by well type, diameter, and intended use, so recall of a single number fails on scenario items.
What to do instead
Build a one-page matrix of Michigan well classifications against required casing depth, casing material, and annular seal method, and drill yourself by writing the numbers from memory, then checking the rule text; practice with scenario stems that name the well use rather than asking for the number directly.
Sizing the annular seal (grout) volume using only the borehole volume and ignoring the oversized hole, washout zones, and the casing displacement, so the calculated sack count is short.
Candidates apply a simple cylinder formula from the hole diameter and forget that grout must fill the annular space between casing and formation, plus any enlarged or caved zones; they also skip subtracting casing wall volume or adding a calculated excess percentage.
What to do instead
Practice computing annular volume as hole volume minus casing displacement, then applying an explicit excess factor for the stated formation condition; work several numeric items end to end and sanity-check that the answer exceeds the neat annular volume, since grout jobs virtually never use less.
Confusing well development with well rehabilitation: choosing a development method (surging, jetting, bailing, airlift) as the answer for a problem that is actually about restoring a plugged or encrusted screen.
Both activities use overlapping equipment and vocabulary, so candidates pattern-match on the tool name rather than the objective; exam stems describe a symptom (declining specific capacity, iron bacteria) and expect a rehabilitation or disinfection answer, not a new-well development step.
What to do instead
Before answering, classify the stem by well life stage: new construction (development to remove drilling fluid and fines) versus in-service decline (rehabilitation, disinfection, screen repair). Memorize the objective of each method so the tool follows from the goal, not the other way around.
Selecting a pump setting depth or pump type without checking the well's static water level, drawdown, and yield, resulting in a pump that either runs dry or is set above the screen.
Candidates focus on the pump's rated capacity and head and skip the well-side constraints; they also forget that the setting must stay below the pumping water level with adequate submergence and above the top of the screen or open interval.
What to do instead
For every pump-sizing item, first extract static level, anticipated drawdown, yield, and screen interval from the stem, then test the proposed setting against all four. Practice by sketching a well log and marking the acceptable setting band before evaluating answer choices.
Interpreting a water quality lab result without accounting for sample holding time, preservation, and the difference between field and lab measurements, so a valid sample is judged contaminated or a compromised sample is accepted.
Candidates treat any detected bacteria or turbidity as proof of aquifer contamination and overlook that coliform positives can come from the sampling tap, unsterilized fittings, or exceeded holding time; conversely they accept a nitrate result from an unpreserved, day-old sample.
What to do instead
Learn the standard preservation and holding-time rules for the parameters this exam tests (bacteriological, nitrate, metals, volatile organics), and in each item ask whether the sampling procedure itself could explain the result before concluding the well is contaminated. Practice writing the resample justification.
Describing abandonment as simply filling the hole with material, without specifying the required seal interval, material, and verification for the casing, annulus, and open borehole separately.
Plugging looks like a single action, so candidates give a one-step answer and miss that Michigan rules require sealing the entire well, removing or perforating casing where specified, and using approved materials placed by approved methods; they also skip the recordkeeping and notification steps.
What to do instead
Structure abandonment answers as a checklist: what happens to the casing, what fills the annulus, what fills the borehole below and above, which material is approved, how placement is verified, and what documentation is filed. Recite the checklist until it is automatic, then apply it to each scenario.
Misreading the site geology and choosing a screen or gravel pack that is incompatible with the formation gradation, for example specifying a uniform fine sand pack against a coarse gravel aquifer or screening a fine sand with too large an opening.
Candidates memorize screen-slot rules without connecting them to sieve analysis and uniformity; they also confuse the purpose of a gravel pack (filtering formation fines) with the purpose of the screen (retaining the pack), so the slot size is picked relative to the wrong material.
What to do instead
Practice the chain explicitly: formation grain-size distribution, then gravel pack sized to the formation, then screen opening sized to retain the pack. Work numeric items where you must pick a slot from a supplied sieve table, and state which material each opening is meant to hold back.
Answering well siting items by distance alone, ignoring setback requirements from contamination sources, floodplain and drainage considerations, and the requirement to case off or seal unsuitable upper formations.
Candidates reduce siting to a single separation distance they half-remember, and overlook that the exam also tests setback from septic systems, animal lots, and surface water, plus the need to grout off unconsolidated or contaminated zones rather than simply drilling deeper.
What to do instead
Study siting as a set of independent constraints (source setbacks, topography and drainage, nearby land use, subsurface conditions requiring sealing) and check each constraint separately against the proposed location. Practice by listing every disqualifying feature in a described site before choosing.
Treating jobsite safety items as generic common sense, so answers miss the drilling-specific hazards: rotating machinery and auger entanglement, high-pressure grout and discharge lines, confined space entry into pits and vaults, and electrical hazards from overhead lines near mast raising.
Candidates skim safety content because it feels obvious, and therefore do not encode the specific controls (lockout, guarding, line restraint, clearance distances, atmospheric testing) that the exam distinguishes from general caution.
What to do instead
Study safety by hazard-control pairing: for each task (mast up/down, auger change, grouting, pit entry, pump service) write the specific control and the specific regulation-style requirement. Practice items that describe a task and ask which control applies, rather than which is generally safest.
Mixing up the roles and sequence of the state regulatory process: who must be licensed, what notification or permit precedes drilling, and which records must be submitted after completion.
Candidates learn technical construction well but treat administrative requirements as an afterthought, so they cannot order the steps or identify which party (owner, contractor, licensed driller) holds each obligation.
What to do instead
Write a timeline from pre-drilling notification through completion of the well record and submission, labeling the responsible party at each step. Test yourself by removing one step and reconstructing it, and by identifying which obligations fall on the licensed individual versus the property owner.