CWD CWD Well Maintenance & Rehabilitation

Question 1

What is the primary purpose of well redevelopment after installation?

Accepted Answer

Remove drilling fluid and fine particles to restore natural permeability

Answer

Increase the water table elevation

Answer

Test for bacterial contamination

Answer

Measure aquifer transmissivity

Question 2

Which surging method uses a tight-fitting piston to alternately push and pull water through the screen?

Accepted Answer

Mechanical surging with a surge block

Answer

Overpumping

Answer

Air surging

Answer

Jetting

Question 3

A well experiencing gradual decline in yield over several years most likely indicates:

Accepted Answer

Biofouling or mineral encrustation of the screen

Answer

Aquifer depletion

Answer

Pump wear only

Answer

Seasonal water table fluctuation

Question 4

What chemical is commonly used to treat iron bacteria fouling in a domestic water well?

Accepted Answer

Sodium hypochlorite (chlorine bleach)

Answer

Hydrochloric acid

Answer

Potassium permanganate

Answer

Hydrogen peroxide only

Question 5

The specific capacity of a well is defined as:

Accepted Answer

Pumping rate divided by drawdown

Answer

Total gallons pumped per day

Answer

Drawdown divided by pumping rate

Answer

Static water level minus pumping water level

Question 6

When rehabilitating an old well, which test should be performed BEFORE chemical treatment to establish a baseline?

Accepted Answer

All of the above

Answer

Video camera inspection

Answer

Pumping test to measure current specific capacity

Answer

pH test of the water