NGWA CWD study guide
NGWA CWD · Work through your exam, one topic at a time.
The NGWA Voluntary Certification Program, started in 1970, is described by the National Ground Water Association as the only national certification program for contractors and pump installers in the groundwater industry. It is designed and governed by groundwater contractors and is recognized by numerous state agencies, some of which have adopted the NGWA exams for their own licensing programs. The Certified Water Well Driller (CWD) credential is aimed at individuals with at least 24 consecutive months of full-time drilling or pump installation experience who want to demonstrate professionalism and gain local, state, and national recognition. To become certified, a candidate must be at least 20 years old, pass two exams within one 12-month period with a score of 70 percent or better on each, and submit written references from two professional contacts not affiliated with the candidate’s current company, an agreement form, and an affidavit for the current year. Topics on this exam: Drilling general exam and Specialized drilling exam (one additional, chosen by candidate). The NGWA CWD study guide has 2 sections and about 760 words.
01Drilling General Exam: Sanitary Well Design, Grouting, and Completion
The general drilling exam is the part every CWD candidate takes, whatever specialty is added to it. It tests whether you can site, design, construct, develop, and test a well that keeps contamination out of the aquifer and sand out of the pump. Expect groundwater fundamentals - aquifer type, static versus pumping level, cone of depression - alongside casing and screen selection, annular sealing, disinfection, yield testing, and the state well-construction code that overrides any rule of thumb. Seal the annulus from the bottom of the casing upward with a tremie pipe; top-down pouring bridges and leaves voids.
393 words, about 2 min02Specialized Drilling Exam: Declared Method Command (Mud Rotary Example)
The specialized exam is one additional paper you choose - for example cable tool, mud rotary, or air rotary. It tests depth of command in that method: the rig and tooling, the circulating or lifting system, control of formation pressure, and the judgment calls when the hole misbehaves. The example below uses mud rotary, but the structure of the reasoning transfers to whatever specialty you declare. Mud does four jobs: cool the bit, carry cuttings, wall the hole with filter cake, and hold formation fluids back with hydrostatic pressure.
367 words, about 2 min