Test your septic math skills — or practice for your next certification exam.


If a rectangular pump tank is 49 inches wide, 68 inches long and 62 inches deep:

1. Determine the gallons per inch.

2. If the pump runs for three minutes and the effluent levels measured from the surface change from 66 inches to 73.5 inches, determine the pumping rate.

Related: Septic Tank Deterioration All About Gas

3. If the system has a check valve and the required dose is 75 gallons, how long should the timer be set for the “on” setting in a timed dose system?

4. If the number of cycles required for the system is six times per day, how long should the “off” timer be set for?

5. If the timer was set to pump six times a day and the cycle counter read 3,442 today and 2,899 on the previous visit 120 days ago, is the system operating properly?

Related: Septic System Approval Process Not So Simple

6. The elapsed time meter reads 215.8 hours today. On the last visit 120 days ago it read 192.6 hours. What is the total time recorded in minutes? What are the total flow and the average flow for 120 days? Is this system operating properly?

Answers are posted here.

Here’s a review of Simple Septic Math and our Pointers for Onsite Arithmetic.

Related: Industry Revisits Homeowner Inspection Programs

Related Stories

Like this story? Sign up for alerts!