CWD Certification

What Certified Well Driller Actually Means

On this site, CWD stands for Certified Well Driller, a contractor-level credential offered through the National Ground Water Association (NGWA). If you are new to the acronym, our explainers on what CWD certification is and what CWD stands for cover the basics. The short version: this is a credential for working drillers who construct, rehabilitate, develop, and decommission water wells, and it is earned by passing closed-book, computer-based exams administered by PSI Services at proctored testing centers.

What makes the credential distinctive is that it is not a single test. General Drilling alone does not confer CWD. You also need at least one drilling-method specialty exam, and both must be passed inside the same 12-month window. That structure shapes everything about how you should prepare, budget, and schedule, and it is the main reason candidates who treat it like a one-exam credential get surprised.

The Two-Exam Pathway: General Drilling Plus a Specialty

The pathway has two required components:

1. General Drilling: 50 multiple-choice questions in 60 minutes, covering the foundational knowledge shared across drilling methods.
2. At least one drilling-method specialty exam: Specialty exams normally have 50 questions. Exam M (Augering and monitoring) is the exception at 75 questions.

You need at least 70% on each exam. There is no averaging: a strong General Drilling score cannot rescue a weak specialty result, or vice versa. Both passing results must fall within the same 12-month period, which means a failed specialty attempt can put time pressure on your plan if you passed General Drilling early.

The exam format is also practical to know in advance. A nonprinting, nonprogrammable calculator without an alphabetical keypad is permitted, and the testing center supplies scratch paper that is collected afterward. Bring a compliant calculator rather than assuming you can use a phone or a scientific model with programmable memory.

Eligibility and Application Mechanics

Eligibility is experience-based, which is one reason this credential carries weight with employers. Per the NGWA requirements, you need:

• 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

Application materials must arrive within 12 months of the qualifying examination session. That is a separate clock from the exam-pairing window, so track both. Our full breakdown of CWD requirements and how to qualify walks through the paperwork, and the CWD exam dates guide covers scheduling logistics.

Inside the General Drilling Exam: Six Domains

The General Drilling content outline is organized into six formal objectives. The published item allocations are counts of questions, not percentage weights, so we report them as items. The six headings and their allocations, in order, are: Mobilize for the Site (10), Construct Water Well (16), Rehabilitate Wells (5), Develop Wells (11), Decommission Wells (3), and Demobilize the Site (5). For a deeper walkthrough of each area, read our complete guide to the six CWD content areas.

One important caution: these six domains are the formal objectives for General Drilling. They are not a complete blueprint for the specialty exam you also need. Build your specialty study plan from the specialty's own content outline in the NGWA candidate bulletin.

Choosing a Drilling-Method Specialty

Because CWD requires at least one drilling-method specialty, your choice is a real decision. A few practical considerations:

• Pick the method you actually run. Specialty exams assume hands-on familiarity. Your daily experience is your biggest study asset.
• Mind the length. Most specialty exams run 50 questions, but Exam M (Augering and monitoring) has 75, so budget more endurance and pacing for it.
• Think about your market. Consider which method your employer or region leans on, since that affects how directly the credential supports your work.
• Consider adding more later. The requirement is at least one specialty. Additional specialties are a way to broaden your credentialed scope down the road.

Exam Fees and the Real Cost Picture

The published examination fee is $75 per examination for both members and nonmembers. With two required exams on first attempts, you should plan on at least $150 in exam fees alone. That number is a floor, not a full certification budget.

Several other cost elements sit outside that figure. The candidate bulletin warns of an additional certification-application fee for nonmembers but does not state the amount, so check the current NGWA pages before you budget. Study materials, travel to a proctored center, time away from the rig, and any retakes are your own costs. Once certified, annual renewal fees apply. Our CWD certification cost breakdown helps you organize these line items, and the ROI analysis weighs them against career benefits.

Voluntary NGWA Certification vs. State Licensing

A frequent point of confusion: CWD is a voluntary professional certification, whereas well driller licensing is typically handled at the state level and is a legal requirement to operate. They are different things with different purposes.

• State licensing establishes whether you may legally drill wells in a given jurisdiction, under that jurisdiction's rules.
• NGWA certification demonstrates a nationally recognized level of knowledge and experience, tested through the exams described above.

Holding one does not automatically satisfy the other. NGWA also lists compliance with licensing requirements as part of renewal, so the two interact. If you are weighing how the credential translates to opportunities, our pages on CWD jobs and the CWD salary guide are good next stops. Because we cannot verify a single national pay figure, treat any earnings discussion as dependent on your region, employer, and experience.

Original Practice Questions With Explanations

These original questions mirror the multiple-choice style of the General Drilling exam, organized by domain. For a larger bank, use the CWD practice tests.

Mobilize for the Site

Q1. Before setting up a rig at a new site, which action is most important to complete first?

1. Mixing drilling fluid
2. Confirming the location of underground and overhead utilities
3. Ordering extra casing
4. Painting the site boundary

Answer: B. Utility conflicts create serious safety and liability risks, so they are verified before equipment is positioned. The other options are routine tasks that do not take priority over hazard verification.

Construct Water Well

Q2. What is the primary purpose of sealing the annular space in a water well?

1. To increase the well's pumping rate
2. To reduce drilling time
3. To prevent surface water and shallow contaminants from migrating down the borehole
4. To make the casing lighter

Answer: C. The annular seal protects the aquifer by blocking vertical movement of contaminants along the outside of the casing. It is a protection measure, not a yield or speed measure.

Rehabilitate Wells

Q3. A once-productive well shows gradually declining yield. Which step is the most logical first move?

1. Abandon the well immediately
2. Investigate likely causes such as screen or formation clogging before choosing a treatment
3. Double the pump size
4. Re-drill beside it

Answer: B. Diagnosing the cause comes before selecting a rehabilitation method. Jumping to a remedy without a diagnosis wastes money and can worsen conditions.

Develop Wells

Q4. During development, a well that continues to produce large amounts of sand most likely indicates:

1. Development is complete
2. Development is not yet finished or screen and filter pack issues need attention
3. The well should be pumped harder immediately
4. The water quality is excellent

Answer: B. Persistent sand production signals unfinished development or a screen and pack problem. A properly developed well should clear up and stop pumping sand.

Decommission Wells

Q5. Why must unused wells be properly decommissioned rather than simply abandoned?

1. To make the property look tidy
2. To eliminate a direct pathway for contaminants to reach groundwater
3. To save on future permit fees
4. To increase the water table

Answer: B. An unsealed well acts as a conduit between the surface and the aquifer. Proper sealing removes that pathway.

Demobilize the Site

Q6. Which task belongs to demobilization?

1. Selecting the drilling method
2. Restoring the site and completing project records
3. Ordering screens
4. Performing the initial site survey

Answer: B. Demobilization wraps up the job: cleanup, restoration, and documentation. The other choices belong to earlier phases.

Sequencing Your Preparation

Rather than a generic schedule, tie your calendar to where the points are. Construct Water Well (16 items) and Develop Wells (11 items) together account for over half of the General Drilling item allocation, so they deserve the most time. Our CWD study guide goes deeper, and the cheat sheet is useful for last-pass review.

For preparation reading, NGWA authored a General Drilling Exam Study Guide that maps references to the same six headings. It is a helpful supplement, but it does not supply complete specialty coverage, so do not rely on it for your specialty. For a realistic sense of difficulty, see how hard the CWD exam is; note that no current aggregate pass rate has been verified, and the 70% figure is the required score, not a pass rate (see what the data shows on CWD pass rates).

Renewal: Annual CEPs, Fees, and Deadline Cautions

Certification is not a one-time event. Renewal is annual and requires seven continuing education points (CEPs), an affidavit, applicable fees, and compliance with licensing requirements. The stated due date is December 31. The currently linked 2027 renewal form lists $50 for members and $150 for nonmembers. Those are renewal fees, not exam fees.

Build CEP collection into your year rather than scrambling in December. Track certificates as you earn them so the affidavit and documentation are simple to complete.

Frequently Asked Questions

Ready to test yourself against the General Drilling domains? Start with the CWD practice tests, then use the domains guide to target your weakest areas.