# Exam Study Guide: Water Math Question

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When faced with a licensing exam, don't struggle with test anxiety! Use the question below and others from our Exam Study Guide series to study and prepare for exam questions. Take a look at this sample water treatment licensing question along with an explanation of the correct answer.

Sample question:

Using the airline method to determine the static water level in a well, an operator pumps air into the 80-foot-long airline with a tire pump. The operator notices the pressure gauge stabilized at 10 psi. How far from ground surface is the water level in this well?

A) 57 feet
B) 23 feet
C) 103 feet
D) 10 feet

Answer: The static level is the distance from ground surface to the water table. Finding the static level can be done by different methods other than using an airline and bicycle pump. In this scenario, we know the airline is 80 feet in length and that it took 10 psi to pump all of the water out of the airline. We also know 1 psi is equal to 2.31 feet of water.

(10 psi) (2.31 ft/psi) = 23.1 feet

This means the airline is submerged 23.1 feet into the water. So now we just need to subtract 23.1 feet from the length of the airline to determine how far down the water level is from the ground surface.

80 ft – 23.1 ft = 56.9 ft

So, the correct answer is A.