As I said in my reply above, is may have been an attempt at reducing the cycling of the sump pimp. That is an awfully small sump. I would suggest digging the sump deeper and doing away with that line that goes back to the sump. The valve is closed now, and I see no use for that line for a "normal" sump and sump pump installation.
As I said above, there should be a weep hole just above the check valve. That is not something that is normally done for a sump pump in a conditioned place, but as this is a cellar and it appears the discharge line exits the cellar rather close to the sump. You have an issue with water in the outside line freezing should that line be full of water. I'm assuming you cellar maintains enough heat to keep the sump area from hard freezing.