The general drilling exam is the first of two computer-based exams the National Ground Water Association requires for the Certified Well Driller designation. It runs 50 questions in one hour at a PSI test center, is closed book, and costs $75 per exam. NGWA structures its exams around a job-task analysis chart for drilling contractors, so the most reliable plan is to review that chart, study the recommended drilling texts, and use your score report's section breakdown to target weak areas if you retake. After passing both required exams, certification depends on references, an affidavit, and an application submitted within 12 months.
What the general drilling exam looks like
The exam has 50 questions with a one-hour limit, taken on computer at PSI test centers year-round. It is closed book, costs $75 per exam, and your score is issued immediately.
PSI Services administers the online exams at more than 400 test centers, and you can schedule year-round at test-takers.psiexams.com/ngwa or by calling (855) 579-4642. All centers are ADA compliant, and accommodation requests go through NGWA first.
The exam is closed book, so no outside material may enter the test center. You will need a government-issued ID at check-in, and personal items are not allowed. Scores are issued immediately after completion, so collect your score report before leaving; NGWA can reissue a copy for a fee but never by phone.
Each exam costs $75 regardless of NGWA membership status. Membership still matters elsewhere: the FAQ notes that members pay discounted prices for study materials and annual recertification, and that a non-member who later applies a state-licensing exam result toward certification may owe the outstanding difference. Confirm current pricing with NGWA before you book.
Sources: Groundwater | NGWA Certification exams — Certification Exams section, ngwa.org; Groundwater | NGWA Certification FAQs — Certification FAQs, ngwa.org; NGWA Exam Preparation Success Guide (PDF) — Study resources tables, dated 5-2019
The two-exam path to the CWD designation
The CWD requires the general drilling exam plus at least one specialized drilling exam, both passed within one 12-month period with scores of 70 percent or better.
NGWA lists the drilling specialties, dated November 1, 2009, as: Exam A/B (cable tool), Exam C/D (air rotary), Exam E/F (mud rotary), Exam G (reverse circulation), Exam H (jetting and driving wells), and Exam M (augering and monitoring). Exam M is the exception to the standard length at 75 questions. Every specialty exam also costs $75.
There is no waiting period to retake a failed exam, but the clock matters: you have one year from passing your first exam to pass all the exams your designation requires. Plan both sittings rather than treating the second as an afterthought.
Practice exercise
You operate mud rotary rigs, have scheduled the general drilling exam, and want the specialized exam that matches your rig type. Which exam completes the CWD exam requirement, and what score and timing conditions apply?
Show answer
Exam E/F, mud rotary drilling. You must pass the general drilling exam and Exam E/F within one 12-month period, scoring 70 percent or better on each.
NGWA lists Exam E/F as the mud rotary specialty. Exam M is the 75-question augering and monitoring specialty, so it is a different specialization rather than the mud rotary match. The rig-type match is the stated assumption of the question; NGWA itself accepts any one specialized drilling exam. Passing both exams is not the finish line for certification either, because the application steps described later in this article must also be completed.
Sources: Groundwater | NGWA Certification exams — Certification Exams section, ngwa.org; Groundwater | NGWA Certification FAQs — Certification FAQs, ngwa.org
Official topic areas and how your study list maps to them
PSI’s September 2022 bulletin publishes a six-area outline for the General Drilling exam. Well construction carries 16 questions and well development 11; the complete allocation totals 50.
The question counts below come from the candidate bulletin. NGWA’s current exam page confirms the general exam’s 50-question, one-hour format. Check the bulletin linked through NGWA when you book for any later revision.
Use the drilling DACUM chart to unpack the duties into study topics. It is a job-task analysis, so its wider business and professional-development duties are not additional weighted domains in this exam table. Review all six tested areas and give extra attention to the subjects you find difficult.
| Content area | Questions |
|---|---|
| Mobilize for the Site | 10 |
| Construct Water Well | 16 |
| Rehabilitate Wells | 5 |
| Develop Wells | 11 |
| Decommission Wells | 3 |
| Demobilize the Site | 5 |
Sources: PSI NGWA candidate information bulletin — VISUALLY CHECKED NGWA CONTENT TABLES ; Groundwater | NGWA Certification exams — Certification Exams section, ngwa.org; DACUM Research Chart for Drilling Contractors and Operators (PDF) — Duties A through L, NGWA/OSU task chart
Recommended study texts and courses
NGWA names specific texts for the drilling exams and offers a self-paced online course for the general drilling exam. No study material guarantees an outcome, so treat the list as coverage guidance.
These resources are among the texts NGWA recommends for the general drilling exam. If you are also preparing for a specialty exam, check its assignments separately: the Employee Safety Manual also covers the augering and monitoring exam, while the Model EHS Manual also covers the general water systems exam.
NGWA University Online Training offers a self-paced course for the General Drilling and Water Systems exams, built by NGWA-approved subject matter experts with Oklahoma State University education specialists. It includes 3D models, knowledge checks, study guides, and video lectures. NGWA also publishes the Professional Designations Information and Study Guide and an Exam Preparation Success Guide covering how and what to study.
NGWA's own materials carry a clear caveat: no study material can guarantee exam outcomes. Use the list to make sure each chart duty has at least one solid reference, and buy through the NGWA bookstore if you want member pricing.
| Study resource | Assignment by NGWA |
|---|---|
| Professional Designations Information and Study Guide | All exams |
| Groundwater & Wells, third edition | All exams |
| Manual of Water Well Construction Practices, third edition | All drilling exams |
| Water Well Driller's Beginning Training Manual | All drilling exams |
| Procedures for Well Drilling Operations (CD) | All drilling exams |
| Employee Safety Manual, second edition | General drilling, and augering and monitoring exams |
| Model Environmental Health and Safety (EHS) Manual (CD) | General drilling and general water systems exams |
| Water Systems Handbook, 13th edition | All water systems exams and the general drilling exam |
Sources: Groundwater | NGWA Certification exams — Certification Exams section, ngwa.org; NGWA Exam Preparation Success Guide (PDF) — Study resources tables, dated 5-2019
A study routine built on the chart and your score report
Start with a self-assessment against the DACUM chart, study the weak areas in short blocks, and if you fail, use the score report's section breakdown to direct the retake.
NGWA's Success Guide suggests this sequence before scheduling: review the exam content outline and the DACUM chart for your field, do a self-assessment, and prioritize the areas you are least familiar with. While studying, it recommends short blocks of about one hour, taking notes, drawing equipment and processes, explaining what you learned to someone else, and consulting coworkers, supervisors, or equipment suppliers for hands-on context.
If you do not pass, the score report includes a scores-by-section breakdown below the pass/fail result, and those sections match the duties on the DACUM charts. That makes the report your retake syllabus: study the weakest sections first. Remember there is no retake waiting period, but the 12-month window from your first pass keeps running.
The hands-on suggestions above are NGWA's study recommendations, not exam requirements, and paper study cannot substitute for supervised field competence. If a topic only makes sense on a rig, arrange to see it under supervision rather than memorizing it blind.
Sources: Groundwater | NGWA Certification FAQs — Certification FAQs, ngwa.org; NGWA Exam Preparation Success Guide (PDF) — Study resources tables, dated 5-2019
After you pass: certification application and renewal
Passing both exams starts a 12-month application window. Certification requires two industry references, a signed affidavit, and annual renewal by December 31.
Once you pass the required exams with 70 percent or better, contact NGWA within 12 months of your most recently passed exam. You must submit written references from two groundwater professionals who are not affiliated with your current company, and sign an affidavit stating there is no legal action pending against you within 12 months of the qualifying exam session.
Certification renewal requirements must be fulfilled by December 31 each year, and applications received through January 31 are accepted without a late fee. NGWA membership and certification renewal are separate processes completed individually, and maintaining certification is the individual's responsibility regardless of employer.
The program certifies individuals, not companies. If a certification lapses for two or more years, you must retake the exams and follow the same procedure as a new candidate; previously passed category exams no longer count.
Sources: Groundwater | NGWA Certification FAQs — Certification FAQs, ngwa.org
Test-day and process pitfalls to avoid
Most avoidable problems are administrative: prohibited items, a missing score report, a window that quietly expires, or confusing certification with state licensing.
Leave personal items somewhere safe and bring a government-issued ID, since the test center prohibits outside material in this closed-book exam. Cramming late the night before is a habit NGWA's Success Guide warns may actually hurt your score.
Never leave the test center without your score report; a reissue costs a fee and scores are never given over the phone. Track the 12-month requirement deliberately, because passing the general exam starts a clock that only passing the second exam stops.
Finally, do not assume NGWA certification is a drilling licence. In most states licensure is a separate legal requirement, and states that use NGWA's exams for licensing follow their own legislative rules. Contact your state for licensing questions and NGWA for certification questions.
Sources: Groundwater | NGWA Certification exams — Certification Exams section, ngwa.org; Groundwater | NGWA Certification FAQs — Certification FAQs, ngwa.org; NGWA Exam Preparation Success Guide (PDF) — Study resources tables, dated 5-2019
Your next steps
Work through the checklist in order: confirm scope, self-assess, gather references, schedule both exams, and plan the application.
- Review the drilling DACUM chart and the exam content outline, then list your weakest duties
- Choose your specialized drilling exam so both exams fit inside 12 months
- Gather the recommended texts or enroll in the NGWA University general drilling course
- Schedule through PSI at test-takers.psiexams.com/ngwa or (855) 579-4642; email certification@ngwa.org for scheduling problems or accommodations
- Line up two references from groundwater professionals outside your company before your exam dates
- For practice questions and more study guides, see the linked resources on this site
Sources: Groundwater | NGWA Certification exams — Certification Exams section, ngwa.org; Groundwater | NGWA Certification FAQs — Certification FAQs, ngwa.org; NGWA Exam Preparation Success Guide (PDF) — Study resources tables, dated 5-2019; DACUM Research Chart for Drilling Contractors and Operators (PDF) — Duties A through L, NGWA/OSU task chart; PSI NGWA candidate information bulletin — VISUALLY CHECKED NGWA CONTENT TABLES
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