OR Well Driller common mistakes
OR Well Driller · Understand the traps and how to avoid them.
Treating a domestic-use exemption as a blanket exemption from well construction standards, so the candidate answers that a small household well needs no casing, seal, or approved completion because it is not a 'public' well.
Candidates memorize that domestic and small-volume uses are often exempt from water-right permitting and then over-extend that exemption to construction and sanitary standards, which typically still apply regardless of use volume or permit status.
What to do instead
Separate the two questions explicitly in study notes: permitting/water-rights exemptions versus construction/ sanitary requirements. For every practice item, ask 'is this question about a water right or about the physical well?' and apply the construction standard unless the item states a specific statutory construction exemption.
Placing the annular seal only at the top of the casing or using too short a seal, and answering that a shallow surface seal is sufficient where the item describes multiple water-bearing zones or an artesian condition.
Candidates picture the visible wellhead and forget that the seal's purpose is to isolate the annulus over the full interval of casing that must be protected, especially across confining layers and flowing conditions.
What to do instead
Drill the function first: the seal prevents surface and shallow groundwater from moving down the annulus and prevents cross-connection between zones. Then practice determining seal depth from the described geology (depth to first confining layer, artesian head, casing depth) rather than from a memorized number of feet.
Confusing the well's total depth with the screened or open interval, and computing yield, drawdown, or specific capacity using total depth instead of the actual producing interval.
Items often give total depth, static water level, and pumping water level together; candidates grab the largest number and use it as the saturated thickness, which is a different quantity.
What to do instead
Before calculating, write the three depths on scratch paper and label them: total depth, static water level, pumping water level. Saturated thickness equals water level to total depth (or to the base of the screen), and drawdown equals pumping level minus static level. Practice with items that deliberately supply a distractor depth.
Answering that a completed well requires no further action once the driller leaves the site, omitting the required completion report, log submittal, or registration within the stated deadline.
Candidates focus on the physical drilling sequence and treat paperwork as separate from the job, so they miss items that hinge on who files what, with which agency, and by when.
What to do instead
Build a one-page reporting matrix: report type, who must sign, which agency receives it, deadline, and what triggers the obligation (new well, deepening, redevelopment, abandonment, pump installation). Review it before each practice set so filing deadlines become automatic.
Describing well abandonment as simply filling the hole with drill cuttings or leaving the casing in place, rather than following the required sealing procedure with the specified material and verification.
Abandonment is taught briefly and candidates treat it as cleanup rather than a regulated closure with its own standards, so they default to the cheapest physical action.
What to do instead
Study abandonment as its own topic: what must be removed, what must be filled, with what material, and what documentation or inspection is required. Compare it against construction sealing so the two procedures are distinct in memory rather than merged.
Assuming a water right is automatically lost by non-use after any short gap, or conversely assuming it can never be lost, instead of applying the specific forfeiture, abandonment, and due-diligence rules described in the item.
Candidates hold a vague idea that 'use it or lose it' applies uniformly, without distinguishing forfeiture by statute from abandonment by intent, or the effect of approved extensions and recognized exceptions.
What to do instead
Learn the concepts as separate boxes: forfeiture (statutory non-use period, often with extensions or excuses), abandonment (intent plus act), and relinquishment. For each practice item, identify which doctrine the facts point to and which statutory period or exception applies before choosing an answer.
Treating a groundwater right as transferable to any other use or place of use without regard to injury to other water-right holders or the need for approval, and answering that a change in point of diversion is a routine driller decision.
Candidates conflate the driller's physical ability to relocate a well with the legal authority to change a water right, so they skip the approval and no-injury analysis.
What to do instead
Memorize the change-approval sequence: application, notice, protest opportunity, injury analysis, and agency decision. Practice items that ask 'who must approve' and 'what must be shown' separately from items that ask 'can the driller physically do it'.
Applying confined-aquifer equations to an unconfined aquifer, or using the wrong form of the pumping-test analysis, so the computed transmissivity or permeability is off by a factor tied to saturated thickness.
The equations look similar and candidates select by memorized formula shape rather than by first identifying the aquifer condition and the assumptions each solution requires.
What to do instead
Start every hydraulics item by classifying the aquifer (confined versus unconfined, steady versus transient) and listing the assumptions. Then choose the matching solution. Work a small set of problems in each of the four combinations and compare the resulting units and magnitudes.
Interpreting a pumping test's drawdown at a single observation point as the aquifer's yield, ignoring boundary effects, leakage, well efficiency, and the difference between formation loss and well loss.
Candidates reduce well hydraulics to 'more drawdown means less water' and do not separate losses inside the well from the aquifer's actual response, so they misjudge specific capacity and safe yield.
What to do instead
Practice decomposing drawdown into aquifer loss and well loss, and identify signatures of boundaries (recharge or barrier), leakage, and partial penetration in the time-drawdown curve. For each item, name which effect the data suggest before computing anything.
Answering disinfection and water-quality items from general household practice (for example, a household bleach dose or a short contact time) rather than the specified concentration, contact time, and sampling sequence for a new or repaired well.
Candidates rely on everyday experience with chlorination and do not recall that well disinfection has prescribed strength, contact time, and a required bacteriological sample before the well is placed in service.
What to do instead
Memorize the disinfection protocol as a checklist: calculate volume from well diameter and water column, add the specified chlorine concentration, maintain the required contact time, flush, then collect the required sample and confirm results before use. Practice the volume calculation, since items frequently test it.