CWD Cheat Sheet 2026

The 30 highest-yield CWD facts, distilled from real exam questions. Print it, save it as a PDF, or study it here — free, no sign-up.

1. Why is it important to use drilling mud during rotary drilling? → To cool the bit and stabilize the borehole
2. What is the PDCA cycle in CWD quality management? → Plan-Do-Check-Act: an iterative continuous improvement method
3. Which type of risk assessment uses numerical probabilities and consequence values to calculate a quantitative risk score? → Quantitative risk assessment (QRA)
4. Which communication protocol is most commonly used to transfer data between downhole data loggers and surface computers in modern monitoring wells? → SDI-12, Modbus, or wireless telemetry (cellular/satellite)
5. During drilling in a known pesticide-contaminated area, workers should wear at minimum which respiratory protection? → Half-face air-purifying respirator with organic vapor cartridges
6. What should be done before starting drilling equipment? → Check equipment, surroundings, and perform safety checks
7. Why is ground stability important at a drilling site? → To prevent ground-related hazards and equipment instability
8. Which scenario represents 'risk avoidance' on a well drilling project? → Selecting an alternate drill site to avoid drilling through a known contaminated zone
9. When a driller encounters a sudden increase in drilling rate (fast drilling) in otherwise tight formation, this MOST likely indicates: → A fault zone or fracture with open voids
10. When rehabilitating an old well, which test should be performed BEFORE chemical treatment to establish a baseline? → All of the above
11. What does confined aquifer mean? → An aquifer under pressure between impermeable layers
12. The vadose zone is best defined as: → The unsaturated zone between the land surface and the water table
13. What is the function of a drilling rig’s mud pump? → To circulate drilling fluid through the system
14. A driller is working adjacent to an active agricultural field. Which risk is MOST specific to this setting? → Pesticide and fertilizer contamination of shallow groundwater
15. Why is nitrate considered a major groundwater contaminant? → They pose health risks, especially to infants
16. What does the Environmental Protection Agency (EPA) regulate regarding groundwater? → Regulates groundwater protection and contamination prevention
17. What risk does drilling through a confining layer (aquitard) pose if not properly managed? → Hydraulic connection between aquifers of different quality
18. A step-drawdown test is used primarily to: → Evaluate well efficiency and identify non-linear head losses
19. Stream gauging data shows baseflow increases after no recent rainfall. This MOST likely indicates: → Groundwater is discharging into the stream (gaining stream)
20. Glacial outwash deposits are valued as aquifer materials primarily because they consist of: → Well-sorted sands and gravels with high permeability
21. General liability insurance for a well drilling contractor primarily protects against: → Third-party bodily injury and property damage claims
22. Which of the following is a secondary water quality standard? → Iron concentration
23. What should a CWD professional do upon discovering a colleague's unethical conduct? → Report through appropriate channels with proper documentation
24. Which surging method uses a tight-fitting piston to alternately push and pull water through the screen? → Mechanical surging with a surge block
25. GIS (Geographic Information System) mapping software is used by well drillers and hydrogeologists to: → Spatially analyze well locations, aquifer data, and regulatory setback compliance
26. What is change management in CWD technology? → A structured process for evaluating and implementing changes safely
27. What risk management technique involves transferring financial liability for a drilling project's environmental damage to a third party? → Risk transfer via insurance
28. What does benchmarking mean in CWD quality improvement? → Comparing performance against recognized standards of excellence
29. For tax purposes, a well drilling company's heavy equipment is typically depreciated using which method under US tax law? → MACRS (Modified Accelerated Cost Recovery System) with Section 179 expensing options
30. What does residual risk mean in CWD practice? → Risk remaining after all controls are implemented