The Water Systems General exam is the foundation test for NGWA's Certified Pump Installer (CPI) designation: 50 closed-book questions in one hour, passed at 70 percent or better alongside a specialized water systems exam (K or L) within a single 12-month window. The tested content follows a real job from start to finish — determining customer needs, assessing the site, selecting components, preparing and installing the system, and troubleshooting what already exists. This guide walks you through the verified format, the content outline with question counts, the certification eligibility rules, and one worked example that builds supplementary well-test arithmetic.
How the exam fits the CPI credential
The Water Systems General exam is one of two exams you must pass to earn the CPI designation.
To earn the Certified Pump Installer designation, you must pass the water systems general exam and at least one specialized pump and water systems exam — Exam K or Exam L — with scores of 70 percent or better on both, all within one 12-month period.
The credential comes from NGWA's Voluntary Certification Program, which the association has run since 1970 and describes as the only national certification program for contractors and pump installers in the groundwater industry. Some state agencies have adopted these same tests inside their own licensing programs, but NGWA certification and a state license remain two separate things — holding one does not automatically give you the other.
Sources: NGWA Certification exams (National Ground Water Association) — Certification exams page; NGWA Certification for contractors — Program overview and eligibility
Format, scoring, and scheduling
Expect 50 questions in one hour, closed book, with your score printed immediately at the end.
The Water Systems General exam consists of 50 questions with a one-hour time limit, and all NGWA examinations are closed book. Scores are issued immediately after you finish, so collect your score report at the test center before leaving; NGWA cannot issue scores over the phone.
You can test year-round at more than 400 PSI test centers, and no NGWA approval is needed just to sit an exam — certification application and eligibility are handled separately with NGWA. PSI administers the online exams and handles scheduling through its test-taker website.
Sources: NGWA Certification exams (National Ground Water Association) — Certification exams page; PSI NGWA candidate information bulletin — Cover September 20, 2022; content pages 5–7 marked May 2022
What the exam covers
The content outline has six duty areas. Installation has the largest allocation at 16 questions, followed by component requirements at nine and troubleshooting at eight.
PSI's NGWA candidate information bulletin — cover dated September 2022, with content pages marked May 2022 — lists the tested duty areas and their approximate question counts. Treat those page dates as historical and confirm the current outline with NGWA or PSI before finalizing your plan.
Installation and troubleshooting together account for 24 of the 50 questions, so those areas deserve the largest share of your study time.
| Content area | Questions |
|---|---|
| Determine Customer Needs | 6 |
| Assess Job Site | 6 |
| Determine System Component Requirements | 9 |
| Prepare to Install Pump System | 5 |
| Install Pump System | 16 |
| Troubleshoot Existing Pump System | 8 |
Eligibility rules for certification
Passing the exams is only part of the credential; the application adds age, experience, references, and signed paperwork.
You are eligible to apply for certification if you are at least 20 years old and have at least 24 consecutive months of full-time pump installation experience.
The application also requires written experience references from two professional contacts who are not affiliated with your current company, a signed agreement form, and an affidavit for the current year. All application materials must reach NGWA within 12 months of the qualifying exam session, so start gathering the paperwork before your second exam rather than after it.
Sources: NGWA Certification for contractors — Program overview and eligibility; PSI NGWA candidate information bulletin — Cover September 20, 2022; content pages 5–7 marked May 2022
Studying from the pump installer task chart
NGWA's DACUM chart maps the job duties behind the exam areas; its duty letters are not exam letters.
NGWA publishes a DACUM research chart — a job-task analysis built by a panel of working pump installers — covering the same ground as the exam: assessing customer needs and job sites, selecting pump, pipe, wire, and tank components, preparing for and performing the installation, troubleshooting existing systems, and handling administrative duties such as permits, warranties, and continuing education.
The chart is a task map, not a procedure manual. Its duty letters (A through G) have nothing to do with exam letters like K, L, or N. Use it to see how the six exam content areas chain together in real work: what you learn about the customer's needs and the water source feeds component selection, which feeds the installation, which you later troubleshoot. Note that Exam N, well servicing and maintenance, is a separate specialty and is not one of the two exams required for the CPI.
Sources: DACUM Research Chart for Pump Installers (NGWA) — Duties A–G task chart; PSI NGWA candidate information bulletin — Cover September 20, 2022; content pages 5–7 marked May 2022; NGWA Certification exams (National Ground Water Association) — Certification exams page
Worked example: reading a well test
Specific capacity is pumping rate divided by drawdown, measured at the same moment in the test.
The pump installer task chart includes evaluating well test results and water-source parameters. As background for reading those results, USGS defines specific capacity as pumping rate divided by drawdown measured at the same time.
Try the original exercise before checking the answer. Keep the units and measurement time attached to the result.
Practice example
During a well test, a pump runs at 80 gpm, and at that same moment the water level has dropped 20 feet below its pre-pumping level. Calculate the well's specific capacity, state its units, and explain what that single number can and cannot tell you.
Show answer
Specific capacity = 80 gpm ÷ 20 ft = 4 gallons per minute per foot of drawdown. It tells you the yield the well produced for each foot of drawdown at that point in the test. It does not, by itself, prove the well can sustain that yield over time or by itself select a pump — you would compare readings across the test and weigh them with other well and aquifer information.
Both numbers must come from the same moment in the test: the USGS definition pairs the pumping rate with the drawdown measured at the same time, so a rate from one stage of the test paired with a water level from another would distort the result. The units carry the meaning — four gallons per minute produced for every foot of drawdown at that reading. Treat the figure as one data point in a sizing decision rather than a verdict on the well.
Sources: USGS Water-Supply Paper 2220, Basic Ground-Water Hydrology — Selected fundamentals on well construction, development, and specific capacity; DACUM Research Chart for Pump Installers (NGWA) — Duties A–G task chart
Official study materials worth your time
Start with NGWA's recommended water systems texts and the Exam Preparation Success Guide; add the online training if you want structure.
NGWA's exam page lists the materials it recommends for the water systems exams: the Professional Designations Information and Study Guide, Groundwater & Wells (third edition), Water Systems Handbook (13th edition), Basic Water Systems: A Pump and Hydraulic Training Manual, and Engineering Your Business. The Model Environmental Health and Safety Manual is listed for the general water systems exam specifically.
NGWA University offers self-paced online training courses for the general water systems exam, built by NGWA-approved subject matter experts with Oklahoma State University education specialists, including knowledge checks and study guides. NGWA's exam page points you to the Exam Preparation Success Guide for an overview of how and what to study, and notes that the Professional Designations Information and Study Guide can be purchased through the NGWA online store. Prioritize the materials matching your weakest content areas rather than working through the full list.
Sources: NGWA Certification exams (National Ground Water Association) — Certification exams page
Your next steps
Confirm the current outline, pick your specialized exam, prepare the paperwork, and schedule.
A short checklist to move from reading to testing:
- Confirm the current exam outline and scheduling details on NGWA's certification exams page and PSI's test-taker site, since the bulletin pages used here carry 2022 dates.
- Decide whether your work fits Exam K (water systems under 100 gpm) or Exam L (over 100 gpm), and plan to pass it and the general exam within the same 12-month period.
- Gather eligibility paperwork early: two references from outside your current company, the agreement form, and the current-year affidavit, all due within 12 months of your qualifying exam session.
- Schedule through PSI, which tests year-round at more than 400 centers, and remember the exam is closed book.
- Check your state's contractor licensing rules separately — some states use these NGWA exams, but state requirements are set by the state.
Sources: NGWA Certification exams (National Ground Water Association) — Certification exams page; NGWA Certification for contractors — Program overview and eligibility; PSI NGWA candidate information bulletin — Cover September 20, 2022; content pages 5–7 marked May 2022
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