Exam Study Guide: Filtration Rate Math Question

Interested in Education/Training?

Get Education/Training articles, news and videos right in your inbox! Sign up now.

Education/Training + Get Alerts

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:

An operator closes the influent valve on a gravity filter and notices the water level drops eight inches in two minutes. What is the filtration rate in gpm/ft2 of surface area?

A) 0.67 gmp/ft2

B) 5.0 gmt/ft2

C)10 gpm/ft2

D) 2.5 gpm/ft2

The correct answer is D, 2.5 gpm/ft2 because 8 ÷ 12 = 0.67'; 0.67' x 1' x 1' x 7.48 gallons = 5.0 gallons; 5.0 gallons ÷ 2 minutes = 2.5 gpm; 2.5 gpm ÷ 1ft2 = 2.5 gpm/ft2.

About the author: Drew Hoelscher is the program director of drinking water operations at the Environmental Resources Training Center (ERTC) in Edwardsville, Illinois.



Discussion

Comments on this site are submitted by users and are not endorsed by nor do they reflect the views or opinions of COLE Publishing, Inc. Comments are moderated before being posted.