NGWA CPI case studies

NGWA CPI · Put your knowledge to work in context.

The Certified Pump Installer (CPI) credential is administered by the National Ground Water Association (NGWA), a groundwater industry association whose certification programs sit under its "Advance Your Career" section alongside contractor certification, the Geothermal Driller (CVCLD) credential, certification FAQs, and a public directory of NGWA certified professionals. The CPI is intended for the tradespeople who install, service, and troubleshoot water well pumping equipment - the people who set pumps, size and connect drop pipe and wiring, and commission the system so it delivers water reliably. The NGWA CPI case studies are 5 cases and about 3,460 words.

Short-cycling submersible: waterlogged bladder tank

An 82-year-old farmhouse is served by a 6-inch steel well 280 ft deep, static water level at 62 ft. The 1 HP, 12 gpm submersible is set at 200 ft on 1 1/4-inch poly with a torque arrestor, fed by a 12/3 plus ground drop cable.

716 words, about 4 min 2

Step-rate test on a low-yield screened well

A 6-inch PVC-cased well is 260 ft deep with screen from 140 to 240 ft; static water level sits at 34 ft. The owner wants to replace a worn 10 gpm submersible and add lawn irrigation.

696 words, about 3 min 3

Three-phase motor tripping on current unbalance

A 5 HP, 230 V, three-phase submersible is set at 240 ft in a 6-inch well. The drop cable is 240 ft of 12/3 with ground copper in the well; the run from the panel to the wellhead is 60 ft of 10/3.

686 words, about 3 min 4

Pump replacement on a nonconforming wellhead

You are called to replace a failed 3-wire, 1/2 HP submersible in a 6-inch steel-cased well at a lake cottage. The well is 120 ft deep, static water level 28 ft.

687 words, about 3 min 5

Shallow-well jet losing prime at elevation

A homeowner at about 5,200 ft elevation has a 1/2 HP shallow-well jet pump mounted on a pad beside a 2-inch driven point well roughly 30 ft deep. When the system was installed, static water level was 18 ft below the pump and the unit delivered about 8 gpm with no trouble.

675 words, about 3 min