NGWA Exam H is a closed-book, 50-question exam with one hour allowed and a 70 percent minimum passing score, published as a single Jetting and Driving Wells domain. It counts as a specialized drilling exam toward the Certified Well Driller designation when paired with the general drilling exam, with both passed at 70 percent or better within one 12-month period. Build your study around the sourced definitions of jetted and driven wells, the objective of well development, and the published task charts, and use the official study texts for formation-level detail this guide cannot verify for you.
What the exam looks like on test day
Exam H is a closed-book test of 50 questions with one hour allowed and a 70 percent minimum passing score, and the official content table lists it as a single domain.
PSI’s September 2022 candidate bulletin lists Exam H as 50 questions in one hour, with a 70 percent passing score and closed-book conditions. Its outline contains one 50-item domain, Jetting and Driving Wells, with no finer allocation in that table.
Exam H has been one of the drilling exam categories since November 1, 2009, alongside cable tool, air rotary, mud rotary, reverse circulation, and augering and monitoring. The ordinary drilling and pump exams share the same 50-question, one-hour format; Exam M, augering and monitoring, is the exception at 75 questions.
Scores are issued immediately after you finish, so collect your score report at the test center before leaving. NGWA can reissue a lost report for a fee, but exam scores are never given over the phone.
Official sources used: Groundwater | NGWA Certification exams; PSI NGWA candidate information bulletin — Content tables, pages 5-7
How Exam H fits the Certified Well Driller route
Passing Exam H alone does not certify you. The Certified Well Driller designation requires the general drilling exam plus at least one specialized drilling exam, both passed within one 12-month period at 70 percent or better.
Exam H is one of the specialized drilling exams you can pair with the general drilling exam for the CWD designation. Both required exams must be passed within a single 12-month period with scores of 70 percent or better on each. Certification eligibility is a separate check that runs alongside your exam results.
The program is NGWA's voluntary national certification, running since 1970 and governed by a certification committee under the NGWA Board. It is not a license: NGWA notes that many state agencies use the same exams as part of their own licensing requirements, so current state rules control what you may legally do in your work area. Keep the two systems separate in your planning.
Once you qualify, application materials must be received within 12 months of your qualifying exam session, so treat that deadline as part of the certification plan, not an afterthought.
- Be at least 20 years old.
- Have at least 24 consecutive months of full-time drilling or pump installation experience.
- Pass the general drilling exam and one specialized drilling exam within one 12-month period, each at 70 percent or better.
- Provide written experience references from two professional contacts not affiliated with your current company.
- Submit an agreement form and an affidavit for the current year.
Official sources used: Groundwater | NGWA Certification exams; Groundwater | NGWA Certification for contractors
The two construction methods at the heart of the exam
A driven well is made by driving casing fitted with a screened drive point into the ground; a jetted well is made by excavating a hole with a high-pressure jet of water. These two definitions are the foundation of the single 50-item domain.
USGS defines a driven well by its casing and screened drive point being driven into the ground. A jetted well is excavated by a high-pressure water jet. Compare what advances the hole: driven casing in the first description and the water jet in the second.
Use the NGWA-recommended construction texts to study equipment and formation suitability in depth. These brief definitions explain the methods; they do not specify suitable depths or operating settings.
Try the original description-matching exercise below before reading its answer.
Practice exercise
Two neighboring shallow wells were built in different ways. Well 1 was installed by hammering a string of casing, fitted with a screened drive point, down into the ground. Well 2 was made by washing a hole open with a high-pressure stream of water while the loosened material was carried away. Name the construction method used for each well, and name the phase that must follow construction so the finished well can produce sediment-free water.
Show answer
Well 1 is a driven well, and Well 2 is a jetted well. The phase that follows construction is well development.
The USGS reference defines a driven well as casing driven with a screened drive point, which matches Well 1, and a jetted well as a hole excavated by a high-pressure jet of water, which matches Well 2. The same reference describes well development as the phase after construction whose objective is to remove clay, silt, and fine-grained sand from beside the screen or open hole so the well produces sediment-free water. Recognizing the mechanism from a described job, and knowing what development is for, are the two definitional skills this exercise secures.
Official sources used: PSI NGWA candidate information bulletin — Content tables, pages 5-7; USGS Water-Supply Paper 2220, Basic Ground-Water Hydrology — Pages 52-53, 58
Well development and reading a yield test
Development removes clay, silt, and fine sand from beside the screen so the well yields sediment-free water, and specific capacity gives you a simple way to describe a test result: pumping rate divided by drawdown, both read at the same time.
The development objective concerns the area beside the screen or open hole, where fine material can remain after construction. Knowing that purpose helps distinguish development from excavating the hole.
Specific capacity is pumping rate divided by drawdown measured at the same elapsed time. Match the two readings before dividing. The resulting ratio alone does not establish long-term yield or select a pump.
Practice exercise
During a pumping test on a newly developed well, the pump discharges 12 gallons per minute, and the drawdown measured at that same elapsed moment in the test is 4 feet. Calculate the specific capacity, and state what this single number can and cannot tell you.
Show answer
Specific capacity is 12 gpm divided by 4 ft, which is 3 gallons per minute per foot of drawdown. It describes this test moment only; it does not by itself prove sustainable yield or justify a pump choice.
The definition requires dividing the pumping rate by the drawdown observed at the same time in the test, and the prompt supplies that assumption explicitly. The arithmetic is 12 ÷ 4 = 3 gpm per foot. Because the definition is tied to one instant, the result is a snapshot of well performance, not a guarantee about long-term yield or the correct pump for the installation.
Official sources used: USGS Water-Supply Paper 2220, Basic Ground-Water Hydrology — Pages 52-53, 58
Official study materials and the task charts
NGWA names specific recommended texts for the drilling exams, offers an exam preparation success guide, and publishes DACUM job-task charts that the organization says are helpful for contractor certification study.
For the drilling exams, NGWA recommends the Professional Designations Information and Study Guide and Groundwater & Wells, third edition, for all exams, plus the Manual of Water Well Construction Practices, third edition, and the Water Well Driller's Beginning Training Manual for all drilling exams. NGWA also publishes an Exam Preparation Success Guide describing how and what to study. Use these references to study construction topics beyond the short explanations here.
NGWA University's online training courses prepare candidates for the General Drilling and Water Systems exams specifically, so they support the other exam in your CWD pair even though the course list does not name Exam H. Calling NGWA customer service is the listed route for questions about other recommended study materials.
The DACUM research charts for drilling contractors and operators were created by water well system professionals and analyze major duties and related tasks for the trade; NGWA describes them as helpful to professionals studying for contractor certification. Use them as a map of what working drillers do, from assessing client needs and obtaining permits to constructing, developing, and decommissioning wells, not as a construction procedure manual. The chart's duty letters are task-analysis labels and do not correspond to exam letters.
Official sources used: Groundwater | NGWA Certification exams; DACUM Research Chart for Drilling Contractors and Operators
Scheduling, fees, and scores
Each exam costs 75 dollars regardless of NGWA membership, and you schedule through PSI, which administers the online exams at more than 400 test centers year-round.
PSI Services administers the exams, and scheduling is done through PSI's website or by phone at (855) 579-4642. The test centers are open to candidates year-round, and the program does not require special computer skills. No NGWA approval is needed before you sit an exam; eligibility review for certification is a separate process.
All testing centers are ADA compliant. If you need special accommodations, contact NGWA by phone at (800) 551-7379, or (614) 898-7791 from outside the United States, or email certification@ngwa.org; NGWA records your information, sends approval to PSI, and PSI contacts you to complete registration.
Your score prints immediately after completion, so collect the report before leaving the test center. Replacement reports are available from NGWA for a fee, ordered by phone, and never issued over the phone.
Official sources used: Groundwater | NGWA Certification exams; PSI NGWA candidate information bulletin — Content tables, pages 5-7
A focused way to prepare
Study the domain as one connected subject: lock in the two method definitions, the development objective, and specific capacity, then use the recommended texts and task charts to fill in formation and field detail.
A practical sequence, offered as study advice rather than an official requirement: start by writing out, from memory, what makes a well driven versus jetted and what development is supposed to accomplish. Then work through the recommended drilling texts for the formation-level behavior the definitions do not cover. The DACUM chart gives you a checklist of professional duties so you can spot areas you have not touched, such as client assessment, permits, or decommissioning.
Because the exam is one 50-item domain, breadth matters: give the whole domain your time instead of over-investing in one subtopic. When you can explain each mechanism, the purpose of development, and a specific-capacity calculation without notes, use the free practice questions to check yourself, then schedule through PSI. Both required exams must land inside your 12-month window, so book the general drilling exam with enough room to complete the pair.
- Write the driven-well and jetted-well definitions and the development objective from memory.
- Study formation-level suitability in the NGWA-recommended drilling texts, where that detail is published.
- Use the DACUM drilling chart to confirm you have covered each professional duty area.
- Practice the specific-capacity calculation until the same-time rule is automatic.
- Schedule both required exams within one 12-month period through PSI.
Official sources used: Groundwater | NGWA Certification exams; PSI NGWA candidate information bulletin — Content tables, pages 5-7; DACUM Research Chart for Drilling Contractors and Operators; USGS Water-Supply Paper 2220, Basic Ground-Water Hydrology — Pages 52-53, 58
Official sources used
Exam facts verified against the PSI bulletin and NGWA pages: