CVCLD Passing Score 2026: Exactly What You Need to Pass

The Number: 70% on 75 Questions

If you are preparing for the Certified Vertical Closed Loop Driller (CVCLD) credential from the National Ground Water Association (NGWA), the passing standard is refreshingly plain: NGWA's certification FAQ specifies a passing score of at least 70%. The Vertical Closed Loop (VCL) examination is the single exam that earns the designation, and it stands on its own. It is separate from the CWD and CWD/PI drilling and pump examinations, from other geothermal qualifications, and from state licensure.

The exam-specific issuer page publishes the structure you will be scored against: 75 multiple-choice questions, a 90-minute time limit, and a USD 125 examination fee. PSI provides the proctored, computer-based testing at its test centers, and you register through the PSI portal for NGWA exams.

This article covers what that threshold means for your preparation, how the testing day works, and how the passing score fits into the larger path to certification. For the broader picture of eligibility and process, see our guide to CVCLD requirements, eligibility and prerequisites.

What 70% Means in Practice

A 70% standard on a 75-question exam is a useful planning target, but treat the arithmetic carefully. Seventy percent of 75 is 52.5, so as a working rule you should aim to answer at least 53 questions correctly. That figure is simple math on the published standard, not an official cut-score statement from NGWA. NGWA publishes the percentage; it does not publish a scaled-score conversion, an itemized answer key policy, or a statement about how unscored questions might be handled. Plan around the plain reading: you need to be right on roughly seven of every ten questions.

What 70% does not tell you is how hard the exam feels. Many candidates ask whether a 70% threshold is generous or demanding. That depends almost entirely on your field experience, because the questions are written around what a working loop driller actually does on a job site. Our breakdown in How Hard Is the CVCLD Exam? digs into difficulty, and the CVCLD pass rate article explains why no verified pass-rate figure should be quoted as fact.

Exam Format and Testing Conditions

Knowing the format removes a surprising amount of anxiety. Here is what the published materials establish:

Ninety minutes for 75 questions works out to a little over a minute per question. That is workable for most prepared candidates, but it rewards decisiveness. Do not spend four minutes agonizing over a single grouting question while easier items wait. Mark it, move on, and return if time allows.

The currently linked NGWA Exam Preparation Success Guide (May 2019) specifies closed-book testing, government-issued identification, and no outside materials. Bring valid ID that matches your registration, and do not plan on a formula sheet or notes. If you want a quick pre-exam review aid built around these constraints, our CVCLD cheat sheet is designed for study, not for the testing room.

A note on fees and membership

The VCL exam page publishes a single USD 125 price. NGWA membership is optional. The generic enrollment application mentions member discounts across the broader certification program, but no VCL-specific member versus nonmember fee split is published on the exam page, so do not assume one. For the full financial picture including renewal, see CVCLD certification cost. Note that the current renewal-fee amount was not verified for this article, so confirm it directly with NGWA before budgeting.

Score Report and Retake Rules

Two policies make the CVCLD exam less stressful than many credentialing tests:

• Immediate feedback. NGWA's FAQ states you receive a score report before leaving the testing center. You will know where you stand the same day.
• No mandatory waiting period. If you do not reach 70%, there is no required cooling-off interval before you may retake the exam.

The practical effect is that a failed attempt is a setback, not a lockout. But remember that each attempt is a registration with its own cost, and the retake logistics, such as scheduling availability at a PSI center, still apply. Use a failed score report diagnostically: note which topic areas felt weakest and rebuild your plan around them before booking again. Scheduling details are covered in our CVCLD exam dates and scheduling guide.

Where the Points Come From: Ten Job-Task Areas

This is the part of the passing-score conversation that most online articles get wrong. Candidates want to know how many questions come from each domain so they can optimize their study hours. The honest answer is that no verified percentage blueprint exists in the materials available for this credential.

What does exist is NGWA's DACUM Research Chart for Geothermal Contractors (June 2017), currently linked as Geothermal Vertical Closed Loop Drilling Operations DACUM. It lays out ten duty areas, A through J, and NGWA expressly recommends it for exam preparation. These are unweighted job-task competencies. They are not a ten-domain percentage blueprint, and they do not exhaustively define exam coverage. Do not infer weights from how many subtasks sit under each duty.

The ten areas are:

1. Assess Client Needs
2. Develop Project Plan
3. Initiate Project Plan
4. Mobilize for the Site
5. Construct Closed Loop Well
6. Decommission Wells
7. Demobilize the Site
8. Close Out Project
9. Manage Business Activities
10. Pursue Professional Development

Because the weights are unknown, the safe strategy for clearing 70% is breadth with extra depth on the hands-on construction material. A candidate who is brilliant at drilling but ignores business management or project close-out is gambling on the draw. For a domain-by-domain walkthrough, read the CVCLD exam domains guide.

The Domain You Cannot Afford to Miss

While the domains are unweighted in the published materials, Construct Closed Loop Well is the core of the trade, and it is where your field knowledge should be sharpest. The published scope for this duty area includes:

Think about what each of these demands in terms of exam-style reasoning. Pressure testing before and after installation is not just a procedure to memorize; you should understand why the sequence exists, what a failed test implies, and what you do next. Tremie grouting questions tend to probe the logic of placing grout from the bottom up and why it protects the borehole and the groundwater. Displaced-fluid handling ties directly to environmental responsibility on site. Grout-subsidence and top-off checks test whether you understand that the job is not finished when the pipe is in the hole.

The same scope-awareness applies to Decommission Wells, a domain that surprises candidates who think of themselves purely as installers. Abandoning or closing a borehole properly is a core professional responsibility, and it appears as its own duty area in the DACUM chart. For official reading, NGWA recommends 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 paid contents of these references were not retrieved for this article, so confirm what each covers before purchasing. The general Exam Preparation Success Guide notes that VCL source citation is still in development, and its separate water-well and pump exam topic tables should not be treated as VCL content.

A Domain-Ordered Study Sequence

You do not need an elaborate system. What you need is an order that matches how you will be tested and where drillers typically have gaps. Here is a sequence that front-loads the technical core and leaves room for full-length timed practice. Adjust the pacing to your own schedule, and see the CVCLD study guide for a longer treatment.

The reasoning is straightforward: terminology comes first because every domain uses the same vocabulary, the construction core gets the middle of the plan while your energy is high, and the closing domains get dedicated time so they are not left to chance. The last week simulates the real conditions you will face, including the time pressure and the lack of reference materials. The main practice site at CVCLD Exam Prep offers timed question sets that fit this final stage.

After You Pass: Application Timing and Renewal

Passing the exam is necessary but not sufficient. The credential is awarded through NGWA, and several conditions sit around the score itself.

Eligibility and application deadlines

To qualify you must be age 20 or older and have at least 24 consecutive months of experience constructing loop wells or conventional water-supply wells. NGWA's FAQ states that all required application materials must be submitted within 12 months of the qualifying exam. Those materials include the certification agreement, a legal-compliance affidavit, and two groundwater-industry professional references from outside your current company who can verify the required experience. Missing that 12-month window is a costly mistake because a passing score alone does not make you certified. Our requirements guide walks through each item.

Keeping the credential

Certification is renewed annually by December 31. Renewal requires the renewal fee, seven continuing-education hours or points, and a signed affidavit addressing professional conduct and required operating licenses. You are also expected to maintain a high standard of work. The first annual renewal and education-reporting period is the first full calendar year after initial certification. This is also where the tenth domain, Pursue Professional Development, stops being theory and becomes your annual obligation.

If you are weighing whether the credential justifies the effort, our articles on whether CVCLD is worth it and the CVCLD salary guide take up that question. Earnings discussion for this field should distinguish shallow ground-source heat-pump loop drilling from deep geothermal-power drilling, and the closest occupational proxy is Earth Drillers, Except Oil and Gas, which is not CVCLD-only pay.

Frequently Asked Questions

For a plain-language introduction to the credential itself, see What Is CVCLD Certification?, and when you are ready to test your readiness against the 70% line, head to the CVCLD practice test.