- The Honest Answer: Where This Exam Gets Hard
- The Format by the Numbers
- Who Finds It Hard, and Why
- Ranking the Ten Domains by Difficulty
- Why Construct Closed Loop Well Deserves Extra Time
- Closed-Book Conditions and What They Change
- Retakes, Cost, and the Real Stakes
- A Domain-Ordered Prep Plan
- The Hurdle Before the Exam: Eligibility and Paperwork
- Frequently Asked Questions
- The exam has 75 multiple-choice questions, a 90-minute limit, and a passing score of at least 70%.
- Difficulty depends on field experience: candidates with 24+ months building loop wells find it far easier than newcomers.
- Construct Closed Loop Well covers pressure testing, tremie grouting, flow testing, and grout top-off checks.
- Failed attempts carry no mandatory waiting period, but each retake costs another $125 examination fee.
The Honest Answer: Where This Exam Gets Hard
The Certified Vertical Closed Loop Driller (CVCLD) exam is not a trivia test, and it is not an exam you can pass by memorizing vocabulary lists. It is a competency check built around what a vertical closed loop driller actually does on a job: sizing up a client's needs, planning a project, setting up a site, constructing a loop well, and wrapping everything up cleanly. Whether you find that hard depends almost entirely on how much of that work you have done with your own hands.
A driller with several years of loop-well construction behind them tends to recognize the questions as familiar problems. A candidate who has spent most of their time on conventional water wells, or who is brand new to the trade, will hit unfamiliar territory around loop-specific procedures such as pressure testing the installed loop, grouting method, and handling fluid displaced during installation.
This guide breaks down where the difficulty actually lives, so you can decide how much preparation you need. If you want the full list of content areas first, the CVCLD exam domains guide walks through all ten.
The Format by the Numbers
The National Ground Water Association (NGWA) awards the CVCLD credential, and PSI delivers the proctored computer-based exam at testing centers. The Vertical Closed Loop (VCL) examination is a single exam, independent of the CWD and CWD/PI drilling and pump examinations, so you are not stacking multiple tests to earn this credential.
| Exam Element | What NGWA Publishes |
|---|---|
| Questions | 75 multiple-choice |
| Time limit | 90 minutes |
| Passing score | At least 70% |
| Exam fee | $125 (VCL examination fee) |
| Delivery | PSI proctored, computer-based, at test centers |
| Score report | Provided before you leave the testing center |
| Retakes | No mandatory waiting period |
Do the pacing math: 75 questions in 90 minutes gives you roughly 72 seconds per question. That is comfortable for questions you know cold and tight for scenario items that require you to reason through a sequence of field steps. A 70% passing score means you can miss up to roughly 22 questions and still pass, which leaves a real margin, but it is not a license to skip an entire domain. For a precise breakdown of scoring, see the CVCLD passing score article.
Who Finds It Hard, and Why
The eligibility rules tell you a lot about the intended audience. Applicants must be at least 20 years old and must have at least 24 consecutive months of experience constructing loop wells or conventional water-supply wells. The exam is designed for working drillers, so it assumes a baseline of field fluency before you ever sit down.
Candidates who tend to find it manageable
- Drillers who have personally run loop-well installations, including grouting and pressure testing.
- Crew leads who handle site setup, utility awareness, and customer communication.
- Contractors who also manage estimating, scheduling, and close-out paperwork.
Candidates who tend to struggle
- Water-well drillers whose loop-well experience is thin and who have not seen the full installation-to-testing sequence.
- Rig operators who focus on drilling and have limited exposure to planning, business, and close-out duties.
- Anyone who has relied on an experienced foreman to make the judgment calls on grout, fluids, and testing.
Notice that the second group's struggles are not about drilling skill. They are about breadth. The exam's ten domains run from client assessment through business management and professional development, so a strong operator can still lose points on the parts of the job someone else usually handles.
Ranking the Ten Domains by Difficulty
The ten domain lines for this credential reproduce duties A through J from NGWA's DACUM Research Chart for Geothermal Contractors (June 2017), currently linked as the Geothermal Vertical Closed Loop Drilling Operations DACUM. NGWA recommends these duties for exam preparation, but they are unweighted job-task competencies, not an official percentage blueprint. That means no one can tell you reliably how many questions come from each domain, so treat the ranking below as a judgment about preparation effort, not a prediction of question counts.
| Domain | Typical Difficulty for Drillers | Why |
|---|---|---|
| 1: Assess Client Needs | Moderate | Requires thinking beyond the rig: site conditions, system requirements, client expectations. |
| 2: Develop Project Plan | Moderate to high | Planning logic and sequencing are often handled by someone else on the crew. |
| 3: Initiate Project Plan | Moderate | Paperwork, permits, and coordination rather than hands-on skill. |
| 4: Mobilize for the Site | Low to moderate | Familiar to anyone who has set up a rig on a job site. |
| 5: Construct Closed Loop Well | High | Loop-specific procedures: testing, grouting, fluid handling, subsidence checks. |
| 6: Decommission Wells | Moderate to high | Less routine work for many drillers; rules and methods must be recalled precisely. |
| 7: Demobilize the Site | Low to moderate | Practical and intuitive, but details matter. |
| 8: Close Out Project | Moderate | Documentation and handoff steps that field-focused candidates overlook. |
| 9: Manage Business Activities | Moderate to high | Business knowledge is the most common gap for employee drillers. |
| 10: Pursue Professional Development | Low to moderate | Conceptually simple, but easy to neglect when studying. |
These difficulty labels are a reasoned estimate based on the nature of each duty, not data from NGWA. Adjust them to your own background: an owner-operator may find Domain 9 trivial and Domain 5 familiar, while a new hire may find the reverse.
Why Construct Closed Loop Well Deserves Extra Time
Domain 5 is where the credential earns its name, and it is the domain where theoretical knowledge alone will not carry you. The construction duty includes steps that happen in a specific order, and a question may ask you to identify what comes next, what is missing, or what went wrong.
Domain 5: Construct Closed Loop Well
Know the full installation sequence and the reason behind each step, not just the steps themselves.
- Pressure testing of the loop both before and after installation.
- Loop flow testing to confirm the circuit is open and moving fluid as expected.
- Tremie grouting to seal the borehole from the bottom up.
- Displaced-fluid handling as grout and loop assemblies push fluid out of the borehole.
- Grout-subsidence and top-off checks after the grout settles.
Think of these as a chain. If you understand why a loop is pressure tested before it goes in the ground, you can reason about what a failed test means and what to do about it. If you only memorized that testing happens, scenario questions will feel like guesses.
Key Takeaway
For every step in Domain 5, practice answering three questions out loud: what do you do, why do you do it at that point, and what does it look like when it goes wrong? That habit converts field experience into exam-ready reasoning.
Official recommended references include the Guidelines for the Construction of Loop Wells for Vertical Closed Loop Ground Source Heat Pump Systems, the Lexicon of Groundwater and Water Well System Terms, and Groundwater & Wells (third edition). The terminology in the lexicon is worth skimming because exam questions use precise terms, and a misread word can send you to the wrong answer. For a structured approach to using these materials, the CVCLD study guide lays out a full plan.
Closed-Book Conditions and What They Change
NGWA's Exam Preparation Success Guide specifies closed-book testing, government-issued identification, and no outside materials. This matters for difficulty in a way people underestimate. In daily work, a driller might look up a spec, check a manual, or call a colleague. On exam day, none of that is available.
The practical effect is that knowledge you "sort of know" or "know where to find" does not count. You need recall that is fast and reliable, especially for procedures, sequences, and terminology. That is why a one-page review of must-know facts is more useful the week before the exam than rereading entire documents.
Retakes, Cost, and the Real Stakes
One factor that lowers the pressure: there is no mandatory waiting period for retaking a failed exam. You can regroup, study the domains where you slipped, and try again when you are ready. The trade-off is financial, since the published VCL examination fee is $125 per attempt.
Membership in NGWA is optional. The generic enrollment application mentions member discounts across the certification program, but the VCL page publishes a single $125 price, so do not assume a member-versus-nonmember split for this exam without checking the current NGWA page. The CVCLD certification cost breakdown covers the fee picture, including what is and is not confirmed about renewal costs.
The stakes extend beyond the exam fee. Certification is maintained annually: renew by December 31 with the renewal fee, seven continuing-education hours or points, and a signed affidavit addressing professional conduct and required operating licenses. The first renewal and education-reporting period is the first full calendar year after initial certification. A current renewal-fee amount was not verified for this article, so confirm it directly with NGWA. If you are weighing the long-term commitment, the ROI analysis and the salary guide put the credential in a career context.
A Domain-Ordered Prep Plan
Generic study schedules do not account for the fact that this exam's difficulty is uneven. The better approach is to order your preparation by domain, putting the highest-effort areas where you have the most time and the lowest-effort areas near the end for review. The timeline below assumes a candidate with solid drilling experience but limited business and planning exposure; adjust it to your own gaps.
Domain 5 Foundations
- Walk the full loop-well construction sequence from start to finish.
- Read the loop-well construction guidelines with attention to testing and grouting.
Domains 5 and 6
- Drill the "why" behind pressure testing, flow testing, and top-off checks.
- Review decommissioning methods and requirements.
Domains 1, 2, and 3
- Study client assessment, project planning, and plan initiation as a connected workflow.
- Practice scenario questions that require sequencing decisions.
Domains 8, 9, and 10
- Cover close-out documentation, business management, and professional development.
- Review the lexicon terminology you keep missing.
Domains 4 and 7, Then Full Review
- Quickly refresh mobilization and demobilization.
- Take timed practice sets at 75 questions in 90 minutes.
Why this order? Domain 5 gets the earliest and most repeated attention because it is the hardest and most distinctive. Domains 4 and 7 come last because, for an experienced driller, they are mostly familiar and need only a refresher. Use the CVCLD practice tests to simulate the timing and identify which domains pull your score down, then loop back to those areas.
The Hurdle Before the Exam: Eligibility and Paperwork
Many candidates focus on the exam and underestimate the application. Certification requires more than a passing score. You must submit all required application materials within 12 months of the qualifying exam, and the package includes the certification agreement, a legal-compliance affidavit, and two groundwater-industry professional references.
The references deserve planning. They must come from people outside your current company who can verify your required experience, which can take time to arrange if your professional network is concentrated in one employer. Start those conversations early rather than after you pass. The full eligibility picture, including the 24-month experience requirement and age minimum, is covered in the CVCLD requirements article, and scheduling details live in the exam dates guide.
Frequently Asked Questions
It will be considerably harder. Eligibility requires at least 24 consecutive months constructing loop wells or conventional water-supply wells, and the exam assumes field familiarity with loop-specific steps like pressure testing, tremie grouting, and top-off checks. Without that experience, build it before attempting the exam.
The exam has 75 multiple-choice questions and requires a passing score of at least 70%. That leaves room for a number of misses, but not enough to ignore a whole domain. Aim for steady competence across all ten rather than perfection in a few.
Yes. NGWA specifies no mandatory waiting period for retakes after a failed exam. Each attempt carries the published $125 VCL examination fee, so it is worth analyzing your weak domains before paying to sit again.
No verified weighting is published. The ten domains reproduce job-task duties A through J from NGWA's DACUM Research Chart for Geothermal Contractors and are unweighted competencies recommended for preparation. Study all of them rather than guessing at percentages.
No. Membership is optional. The VCL page publishes a single $125 examination fee, and no member-versus-nonmember split for this exam is confirmed, so check NGWA's current page before assuming any discount applies.
The CVCLD exam rewards drillers who understand the whole loop-well workflow, from the first client conversation to the final close-out. If you have the field time and put your preparation effort where the difficulty actually is, especially Domain 5 and the planning and business domains, the exam is a fair test of work you already do. For more background on the credential itself, explore what CVCLD certification involves and the training options available.