ME Well Driller common mistakes
ME Well Driller · Understand the traps and how to avoid them.
Treating the well casing and grout column as separate design decisions, so the candidate answers siting questions without checking whether the proposed casing depth and annular seal can actually isolate the identified contamination source.
The exam tests siting and construction together, but candidates study them as separate chapters and answer each question in isolation. They also default to a single 'standard' casing depth instead of deriving depth from the geology and the nearest pollution source described in the stem.
What to do instead
For every siting or construction item, write out three lines before choosing: (1) what contamination or aquifer-separation risk the stem describes, (2) what casing/grout element addresses it, (3) whether the stated depth or material achieves that. Practice with stems that give a shallow sand-and-gravel zone over bedrock and require you to justify casing seat depth and seal length together.
Choosing a well location by distance alone, ignoring slope, drainage, and setback direction, so the candidate picks a site that meets a numeric distance but sits downgradient or in a drainage path from the contamination source.
Distance setbacks are the easiest number to memorize, so candidates latch onto them and stop reading the rest of the stem. They also forget that the exam stem often deliberately places the 'compliant' distance in the wrong topographic position.
What to do instead
Build a one-page siting checklist: distance to source, upslope versus downslope, surface drainage direction, floodplain, and access for the drilling rig and grout equipment. Drill on stems where two candidate locations both satisfy the distance but only one is upgradient and out of the drainage way.
Answering Maine law and rule questions from general industry practice or from another state's rules instead of from the specific Maine statute and department rules, particularly on licensing, notification, and reporting deadlines.
Experienced drillers answer from habit and field custom, and the exam deliberately tests the written requirement where it differs from common practice. Candidates also study only once and do not refresh on amendments.
What to do instead
Work directly from the current Maine well drilling statute and the department's well rules, and make a table of every deadline, notification, and record-keeping duty with the exact citation beside it. Re-read the table the week before the exam and flag any item you cannot cite.
Confusing the driller's reporting obligations with the owner's, and guessing which events trigger a report, a notification, or a permit versus which are simply good practice.
The duties overlap in the field, and candidates remember that 'a report gets filed' without pinning down who files it, to whom, and within what time. Stems that describe a routine completion versus a sealing or abandonment event expose the gap.
What to do instead
Make a trigger table with columns for event, who is responsible, what document is produced, recipient, and deadline. Include new well completion, pump installation, alteration, and abandonment as separate rows, and test yourself by covering the last three columns.
Treating grout as a single material and answering placement questions without distinguishing neat cement, bentonite, and sand-cement mixes by their shrinkage, permeability, and suitability for different annulus conditions.
Candidates memorize 'grout the annulus' as a concept and never build a comparison of mix types, so any question that turns on choosing the right material or on the risk of bridging and voids becomes a guess.
What to do instead
Build a comparison chart of the common grout types across permeability, shrinkage, set time, density, and appropriate use, then practice stems that describe a dry hole versus a wet hole, a cased versus uncased annulus, and a deep versus shallow seal, and justify the material choice from the chart.
Describing abandonment as 'fill the hole with something' rather than specifying the sequence: removal or perforation of casing, placement method, seal material, and the top seal at grade, and the reason each step exists.
Abandonment is infrequent work for many drillers, so the procedure is remembered as a vague outline. The exam scores the sequence and the purpose of each step, and candidates lose points on order and on why the casing is treated before sealing.
What to do instead
Write the abandonment procedure as a numbered checklist with a one-line purpose beside each step, then practice explaining why an improperly abandoned well can act as a vertical conduit between aquifers. Rehearse the same checklist for a well with casing, one without, and one with an artesian flow.
Sizing a pump from the well's static water level alone, without accounting for drawdown, pumping level, friction loss in the drop pipe and fittings, and the required pressure at the tank.
Static level is the number printed on the well report and the easiest to grab, so candidates skip the total dynamic head calculation. They also forget that the pump must be set below the pumping level, not the static level.
What to do instead
Practice full total dynamic head worksheets: static level, drawdown to pumping level, lift to the pressure tank, friction loss from pipe size and flow, and pressure head in feet. Then verify the selected pump's curve delivers the design flow at that head and that the setting depth keeps the intake safely submerged.
Matching a water treatment device to the contaminant name without checking the water chemistry that determines whether the device will actually work, such as hardness, iron, pH, or the presence of competing ions.
Candidates memorize a one-to-one list of contaminant and treatment and stop there. Exam stems add a chemistry detail that invalidates the obvious device, and the candidate never looks for it.
What to do instead
For each common problem (iron, manganese, hardness, arsenic, nitrate, low pH, bacteria), write the treatment options plus the water-quality conditions that favor or rule out each one. Practice stems where the obvious device fails because of pH, high iron fouling, or competing ions, and state the pretreatment needed.
Answering safety items by naming the hazard instead of the control, so the candidate identifies 'confined space' or 'electrical' but does not select the specific procedure, PPE, or lockout step the stem is asking for.
Hazard recognition is easy and feels like the answer, so candidates stop reading at the hazard word. The exam is written to reward the control measure, and the plausible distractor is always the bare hazard name.
What to do instead
Practice rewriting each safety stem as 'what is the next action' and answer with a control: test the atmosphere before entry, lock and tag the disconnect, set the rig's outriggers and check for overhead lines, use the required respiratory protection. Build a hazard-to-control table for the jobsite tasks you actually perform.
Quoting a price or signing a contract without a written scope that states the estimated depth, the price-per-foot basis, what happens if depth changes, and who bears the risk of a dry or low-yield hole.
Drilling is priced on uncertain depth, and candidates answer contract questions from how they normally talk to customers rather than from what the written agreement must contain. They also overlook the reporting and record duties that attach to the job.
What to do instead
Draft a model contract outline covering scope, estimated versus actual depth, unit pricing, change-order procedure, dry-hole and low-yield provisions, payment terms, and the records you will deliver to the owner and the state. Then practice stems that describe a depth overrun or a low-yield well and identify which contract clause governs.