TOPIC: Septic system

I had a septic inspection the other day and discovered a problem but didn`t really know how to fix it? can anyone help with some suggestions? everything is working fine with the system except that after the tank it has a pump to pump the liquids to the mound and the field, but the connection comes above the ground right before it ties into the field, when the pump engages liquid sprays out of the connection just before the mound, obviously the field has a blockage. How does one determine where the blockage is with out excavating? or what is a next thing to try? we cant be sure that it isn't even frozen, it could be and I dont know if the line that is buried from the tank, and then  coming above ground is causing it? the weather here in Canada is still below freezing. I am just learning septic systems still and this is my cousins house.

How does one determine where the blockage is with out excavating?

Find a clean-out closest to the problem area and use a plumbing snake camera.