Disposal of Communion wine
What is the proper disposal of Communion wine?
Unused wine from individual cups and the flagon can be stored in bottles and reused. I imagine your question concerns wine that remains in the chalice, the common cup.
There is no prescribed way of disposing of that wine. Some churches have a sink with a drain that bypasses the regular wastewater system and instead deposits the wine on the ground outside the church. Other churches simply dispose of the leftover wine through a regular sink and drain.
Churches will determine how they respectfully dispose of the element that was used in the sacrament.