u/BoscoStubbs

Hi, i am new to pool ownership and maintenance. I had professionals come out to open my pool today. They showed me some basics with the sand filter and pump system, including how to waste once the pressure gauge hits 30psi. I noticed this line that runs into the ground. Is there any way i can tell whether this is a designated waste line? The pool professional couldnt tell so was unwilling to use it (understandably). Is there any other purpose this line could have?