What Is A CWD?

What CWD Means in Groundwater

In the water well industry, CWD stands for Certified Well Driller. It is a contractor-level credential offered through the National Ground Water Association (NGWA), the trade organization that serves drillers, pump installers, and groundwater professionals. The designation signals that a driller has met a documented standard of field experience and has passed written examinations covering both general drilling practice and a specific drilling method.

This article is about that credential only. Other credentials share the same three letters, and they have nothing to do with wells, rigs, or groundwater. If you arrived here looking for the well drilling credential, you are in the right place. For related definitions, see our explainers on what CWD stands for and CWD meaning, and our overview of CWD certification.

The Two-Exam Pathway

The structure of the CWD is what sets it apart from single-exam credentials. To earn it, you must pass:

1. General Drilling, the foundation exam covering the full lifecycle of a water well project.
2. At least one drilling-method specialty exam, which tests the technique you actually use in the field.

Both must be passed within the same 12-month period, and each requires a score of at least 70%. That 70% is the required examination score. It is not a pass rate, and no current aggregate pass rate has been verified, so be cautious with any site that quotes one. Our CWD pass rate and CWD passing score articles explain how to interpret these figures.

The 12-month window creates a real planning problem. If you pass General Drilling and then let the clock run out before passing a specialty, you may have to retake an exam. Schedule the two sessions with that window in mind, rather than treating them as unrelated events.

Who Qualifies to Sit for It

NGWA does not hand the credential to anyone who can pass a test. The eligibility requirements combine age, experience, and attestations:

• You must be 20 years of age or older.
• You need 24 consecutive months of full-time drilling or pump-installation experience.
• You must supply two written professional references from people who are not affiliated with your current employer.
• You must provide the required agreement and a current-year affidavit.
• Application materials must arrive within 12 months of the qualifying examination session.

The unaffiliated-reference rule trips up candidates who assume their boss or company owner can vouch for them. Line up references early, such as a supplier, an inspector, a consulting hydrogeologist, or a driller from another firm who has seen your work. For the full checklist, read CWD requirements.

Inside the General Drilling Exam

The General Drilling exam contains 50 multiple-choice questions to be completed in 60 minutes. Its content outline is organized into six formal objectives that follow a well project from start to finish. The published item allocations are counts of questions, not percentage weights, so treat them as a guide to emphasis rather than a precise formula.

These six headings are the formal objectives for General Drilling only. They are not a complete blueprint for the additional specialty exam you must also pass. Our complete guide to all six CWD content areas goes deeper on each one.

An NGWA-authored General Drilling study guide maps preparation references to these same six headings. It is a useful supplement, but it does not supply complete specialty coverage. We summarize how to use it in our CWD study guide.

Choosing a Drilling-Method Specialty

The specialty exam is where the credential becomes personal to your trade. Most drilling specialty examinations normally have 50 questions. The notable exception is Exam M, Augering and monitoring, which has 75 questions. That difference matters for pacing and stamina, so confirm the format of the specific exam you choose before you schedule it.

How should you choose? A few practical considerations:

• Match your daily work. Pick the method you operate most often. Questions reward hands-on familiarity.
• Check the current exam list. Specialty offerings and formats are published by NGWA, so verify them on the official certification exams page rather than relying on memory or forum posts.
• Consider your career direction. If you plan to expand into a different method, that may influence which specialty you pursue first, though you must pass at least one.

Exam Day Mechanics

The exams are closed-book and computer-based, administered by PSI Services at proctored testing centers. A few rules to know in advance:

• A nonprinting, nonprogrammable calculator without an alphabetical keypad is permitted.
• Scratch paper is supplied and is collected at the end.
• No reference materials are allowed in the testing room.

Because the format is multiple choice, expect scenario-driven questions that ask you to pick the best action or the correct specification. Wording like "most appropriate" or "first step" is common in field-based exams, so train yourself to compare answers against real procedure rather than hunting for a familiar phrase. For timing details, see CWD exam dates, and for a realistic sense of difficulty, read how hard the CWD exam is.

Fees and What They Do Not Cover

The published examination fee is $75 per examination, the same for members and nonmembers. Since the CWD requires two exams, a first-attempt path costs at least $150 in exam fees.

That figure is a floor, not a full budget. The candidate bulletin separately warns of an additional certification-application fee for nonmembers, without stating the amount. It also does not account for study materials, travel to a testing center, time away from the rig, or any retakes. Renewal fees are a separate category entirely (covered below). Our CWD certification cost breakdown lays out how to build a realistic budget.

Voluntary Certification Versus State Licensing

This is the single most misunderstood point about the credential. The NGWA certification is voluntary. It is not a government license. Many states and provinces have their own licensing or registration rules for well drillers, and those rules determine whether you may legally drill in that jurisdiction.

The CWD does not replace a required license, and a license does not automatically give you the CWD. They are separate things:

• State licensing is a legal permission to operate, governed by the state or local authority.
• CWD is a professional credential that demonstrates tested knowledge and verified experience.

Renewal of the CWD even requires compliance with licensing requirements, which shows how the two interact. Check your own jurisdiction's rules first, then decide how the credential fits your career. Some regulators or employers may recognize it in certain ways, but confirm that locally rather than assuming.

Who Values the Credential

Because the CWD is voluntary, its value shows up in how employers, clients, and peers read it. The credential tends to matter most in settings where proof of competence helps win work or build trust:

• Water well drilling contractors, where it can differentiate a crew lead or owner-operator.
• Companies bidding on commercial or municipal work, where documented qualifications strengthen proposals.
• Firms that pair drilling with pump installation or monitoring well work, especially if your specialty matches their method.
• Environmental and geotechnical drilling operations, particularly relevant for augering and monitoring specialties.

We do not quote salary figures here because none were verified for this credential, and inventing numbers would mislead you. For a qualitative look at earnings and career impact, see the CWD salary guide, the analysis of whether the certification is worth it, and our roundup of CWD jobs.

Keeping the Credential Active

Earning the CWD is not the end of the process. Renewal is annual and requires:

• Seven continuing education points (CEPs)
• An affidavit
• Applicable fees
• Compliance with licensing requirements

The stated renewal due date is December 31. The currently linked 2027 renewal form lists $50 for members and $150 for nonmembers. These are renewal fees, not examination fees, so do not confuse them with the $75 exam cost.

Sequencing Your Preparation

Rather than a generic schedule, build your plan around the structure of the exams. Here is one way to order the work, tied to the published item allocations and the two-exam requirement:

The logic is simple: weight your early effort toward the domain with the most items, then sweep the smaller ones, and give the specialty its own dedicated time. You can find a condensed list of must-know facts in our CWD cheat sheet, and the CWD training page covers additional preparation options. When you are ready to test yourself with original, category-mapped questions and explanations, try the CWD practice test.

Frequently Asked Questions