- CWD means Certified Well Driller, a voluntary credential from the National Ground Water Association (NGWA).
- You must pass General Drilling plus at least one drilling-method specialty within 12 months, scoring 70% or higher on each.
- General Drilling alone does not confer CWD; the specialty exam is mandatory.
- The published exam fee is $75 per examination, so two first attempts cost at least $150.
What CWD Means Here
On this site, CWD stands for Certified Well Driller, a contractor credential offered through the National Ground Water Association (NGWA). It is a professional designation for people who construct water wells, and it has nothing to do with any other credential that happens to share the same three letters. If you are searching for quick definitions, our pages on what CWD stands for and CWD meaning cover the terminology in short form.
The credential signals that a driller has met a defined experience threshold, supplied professional references, and passed closed-book examinations covering both general drilling practice and a specific drilling method. It is a credential earned by working drillers and pump installers, not by classroom students with no field background.
The Two-Exam Pathway
The single most important structural fact about this certification is that it is built from two separate examinations, not one. To earn CWD, a candidate must pass:
- General Drilling, which covers the shared body of knowledge for well construction work, and
- At least one drilling-method specialty exam, which tests a specific way of drilling or installing.
Both must be passed within the same 12-month period, and each requires a score of at least 70%. Passing General Drilling by itself does not give you the CWD designation. Many first-time candidates misread this and budget time and money for one test, only to discover the specialty requirement later.
| Component | What It Covers | Format |
|---|---|---|
| General Drilling | Six formal objective areas spanning mobilization through demobilization | 50 multiple-choice questions in 60 minutes |
| Drilling specialty exam | One drilling method of your choosing | Normally 50 questions; Exam M (Augering and monitoring) has 75 |
| Required score | Each exam individually | At least 70% on each |
| Time window | Both passed together | Within the same 12-month period |
The 70% figure is the required examination score. It is not a pass rate, and no current aggregate pass rate has been verified. For a discussion of what is and is not known about outcomes, see our breakdown of the CWD pass rate and the explanation of the CWD passing score.
Who Can Apply
Because the credential certifies experienced practitioners, eligibility goes well beyond registering for a test. Based on NGWA's published requirements, a candidate needs:
- To be age 20 or older
- 24 consecutive months of full-time drilling or pump-installation experience
- Two written professional references from people not affiliated with your current employer
- The required agreement
- A current-year affidavit
Timing matters too. Application materials must arrive within 12 months of the qualifying examination session. That means you should not sit the exams and then let the paperwork drift; the clock runs from the session date. Our CWD requirements guide walks through the eligibility pieces in more detail.
Exam Format and Fees
How testing works
PSI Services administers the examinations as closed-book, computer-based tests at proctored centers. You cannot bring reference material into the room. A nonprinting, nonprogrammable calculator without an alphabetical keypad is permitted, and the scratch paper you are supplied must be returned at the end of the session.
General Drilling is 50 multiple-choice questions in 60 minutes, which works out to a little over a minute per item. Most drilling specialty exams also run 50 questions, with the notable exception of Exam M, Augering and monitoring, at 75 questions. If you pick that specialty, plan your pacing accordingly.
What the fees look like
The published examination fee is $75 per examination, the same for members and nonmembers. Since CWD requires two exams, two first-attempt sittings cost at least $150. Treat that as a floor, not a total. The candidate bulletin also warns of an additional certification-application fee for nonmembers, without stating the amount, so confirm it with NGWA before you budget. Retakes, study materials, travel to a proctored center, and renewal costs all sit outside the exam fee. Our CWD certification cost breakdown organizes these line items, and the CWD exam dates guide covers scheduling logistics.
Key Takeaway
Do not quote "$150" as the cost of becoming a Certified Well Driller. It is only the minimum for two first-attempt exams. Add the nonmember application fee (amount unpublished in the bulletin), any retakes, and renewal.
The Six General Drilling Areas
The General Drilling exam is organized around six formal objective headings. Published item allocations are 10, 16, 5, 11, 3, and 5 questions respectively. These are item counts, not published percentage weights, and no percentages should be inferred. Note also that these six areas describe General Drilling only; they are not a complete blueprint for the specialty exam you also need. For a deeper walk-through, see the CWD exam domains guide.
Domain 1: Mobilize for the Site (10 items)
Everything that happens before the bit touches ground: getting equipment and crew to the location and making the site safe and workable.
- Site assessment, access, and utility awareness
- Equipment readiness and transport planning
- Safety setup and regulatory preparation
Domain 2: Construct Water Well (16 items)
The heart of the exam and its largest allocation. Expect the densest, most technical questions here.
- Borehole drilling and fluid management
- Casing, screen, and annular materials
- Grouting and sealing practices
Domain 3: Rehabilitate Wells (5 items)
Restoring performance in existing wells.
- Recognizing causes of declining yield
- Treatment approaches and their limits
Domain 4: Develop Wells (11 items)
Improving the connection between the well and the aquifer after construction.
- Development methods and when each applies
- Judging when development is complete
Domain 5: Decommission Wells (3 items)
Properly closing wells that are no longer in service, a small but unmissable block.
- Sealing to protect groundwater
- Documentation of the closure
Domain 6: Demobilize the Site (5 items)
Finishing the job responsibly.
- Site restoration and cleanup
- Record keeping and handoff
Because Construct Water Well carries the largest allocation at 16 items, it deserves the largest share of your study hours. But do not ignore Develop Wells at 11 items; together those two areas account for a majority of the General Drilling exam.
Choosing a Drilling Specialty
The specialty requirement is where candidates have the most freedom and, often, the most hesitation. NGWA offers drilling-method specialty examinations, and you need at least one. The logic for choosing should be practical:
- Match your daily work. The specialty exam tests a method; you will find it far easier if you perform that method regularly.
- Check the item count. Most specialties are 50 questions, but Exam M, Augering and monitoring, is 75. A longer exam changes your pacing and your fatigue management.
- Consider your market. The methods most common in your region are the ones employers and clients tend to recognize.
One caution: official materials map preparation references to the six General Drilling headings, but they do not supply complete specialty coverage. Plan to source method-specific references separately. Our CWD study guide discusses how to divide preparation time between the two exams.
NGWA Certification vs. State Licensing
A frequent point of confusion: CWD is a voluntary certification, not a government license. State licensing or registration of well drillers is a separate matter handled by each state's own authority, with its own rules, applications, and fees. Holding CWD does not substitute for a state license where one is required, and having a state license does not make you a Certified Well Driller.
| Feature | NGWA Certified Well Driller | State Licensing |
|---|---|---|
| Nature | Voluntary professional credential | Legal authorization to operate, where required |
| Issued by | National Ground Water Association | State or local authority |
| Exams | General Drilling plus a specialty, via PSI Services | Varies by jurisdiction |
| Renewal | Annual; seven CEPs, affidavit, fees | Varies by jurisdiction |
Renewal ties the two together in one respect: maintaining the NGWA credential includes compliance with licensing requirements. In other words, you are expected to stay in good standing with your state while holding CWD. For thoughts on how the credential fits into a career, read is the CWD certification worth it, and for the employment angle see CWD jobs and the CWD salary guide.
Keeping the Credential Active
Certification is not a one-time event. Renewal is annual and requires:
- Seven continuing education points (CEPs)
- A signed 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 and should never be confused with the $75 examination fee.
Accumulate your CEPs steadily through the year rather than in a December scramble. Keep certificates and records, since the affidavit is a statement you are signing.
Sequencing Your Preparation
Because the two exams must be passed within one 12-month window, sequencing matters more than technique. A reasonable approach is to start with General Drilling, since its six objective areas are published and well mapped, then layer on the specialty. Weighting your time by item allocation keeps you honest: Construct Water Well first and longest, Develop Wells next, then the smaller blocks.
Construct Water Well
- Work through drilling, casing, screen, and grouting concepts
- This single domain is 16 of 50 items
Develop Wells and Mobilize for the Site
- Develop Wells (11 items) and Mobilize (10 items) together cover 21 questions
Rehabilitate, Decommission, Demobilize
- Smaller blocks of 5, 3, and 5 items; do not skip Decommission just because it is small
Specialty exam and timed review
- Study your chosen method from method-specific references
- Practice under 60-minute conditions for General Drilling
Supplemental preparation is available too. An NGWA-authored General Drilling Exam Study Guide, distributed by the Empire State Water Well Drillers Association, maps preparation references to the same six headings. It is a useful companion, though it does not cover specialties. For a compact review, try the CWD cheat sheet, and when you are ready to test yourself, the practice test hub offers category-mapped questions. If you want to gauge the challenge first, see how hard the CWD exam is.
Sample Practice Questions
Original questions like these mirror the closed-book, multiple-choice style. Try them without notes, then read the explanations.
Question 1 (Construct Water Well)
Why is the annular space around a well casing typically sealed with grout in the upper portion of the borehole?
- A. To increase the well's pumping rate
- B. To prevent surface water and contaminants from migrating down along the casing
- C. To reduce the weight of the casing string
- D. To make future screen replacement easier
Answer: B. The seal blocks a direct pathway for surface contamination to reach the aquifer. It protects water quality rather than affecting yield or convenience.
Question 2 (Develop Wells)
What is the main purpose of well development after construction?
- A. To paint and label the wellhead
- B. To remove drilling fluid residue and fine material so water moves freely from the formation into the well
- C. To lower the static water level
- D. To satisfy the final site inspection only
Answer: B. Development repairs the damage drilling does to the zone near the borehole and improves the hydraulic connection to the aquifer.
Question 3 (Decommission Wells)
When a well is permanently taken out of service, which outcome is the primary goal of decommissioning?
- A. Preserving the pump for resale
- B. Leaving the borehole open for later inspection
- C. Sealing the well so it cannot serve as a conduit for contamination to the groundwater
- D. Reducing the property's tax assessment
Answer: C. An abandoned open well is a pathway for pollutants, so proper sealing and documentation protect groundwater.
The full set of category-mapped questions, with explanations for each domain, is available at the main CWD practice test site.
Frequently Asked Questions
No. General Drilling alone does not confer CWD. You must also pass at least one drilling-method specialty exam, with both passed within the same 12-month period at 70% or higher each.
The published fee is $75 per examination for members and nonmembers, so two first-attempt exams cost at least $150. That is not the full budget: nonmembers face an additional certification-application fee whose amount the bulletin does not state, and retakes and renewal cost extra.
You must be at least 20 years old with 24 consecutive months of full-time drilling or pump-installation experience, two written professional references unaffiliated with your current employer, the required agreement, and a current-year affidavit.
No. CWD is a voluntary NGWA certification, while licensing is a separate legal requirement set by each state. Holding one does not replace the other, and NGWA renewal includes compliance with licensing requirements.
Renewal is annual, due December 31, and requires seven continuing education points, an affidavit, and applicable fees. Sources conflict on late fees, so confirm the deadline with NGWA rather than assuming a grace period.